UNIVERSITY OF COLORADO AT DENI/ER
/MASTER OF ARCHITECTURE
1983 fall thesis
SPRUCE STREET PLAZA
AN ARCHITECTURAL THESIS PRESENTED TO THE COLLEGE OF DESIGN AND PLANNING UNIVERSITY OF COLORADO AT DENVER IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARCHITECTURE
BARBARA YOLANDA S^ANTHO FALL SEMESTER 1983
DESCRIPTION AND LOCNTION ARCHITECTURE IN CONTEXT_
OBJECTIVES NND GONLS_____JO
03 O Ol ^
MIEl/l/ AND 1/ICINITY
OBSERNATIONS TOPOGRAPHY AND SUN PATH TRAFFIC SEYNER TREE CONER
ZONINING / CODES
ZONING DISTRICT /I/IAP______
OBJECTNES BULK REGULATIONS FLOOR AREA RNTIO USES ALLOXNED IN ZONE
LANDSCKPING DWELLING UNITS/NCRE
UNIFORNN BUILDING CODE_____.93
FLOOD PLAIN REGUATIONS____.115
SITE DENELOPHKENT. REQUIREMENTS_____
RESIDENTIAL CO/l/1N\ERCIkL STATISTICAL DAT/I STRUCTURE
COST ESTINXKEE NNALYSIS
S^UCE STREET PWZK
FORE^NRD DESIGN PROCESS PROJECT STATEPOENT DESCRIPTION AND LOCNTION ARCHITECTURE IN CONTEXT OBJECTNES NND GONLS ARCHITECTURAL INTENT
This thesis project is an attempt to apply my three years of graduate work in architecture at the University of Colorado at Denver. I intend to take a building type with which I have some familiarity, mixed-use residential/ commercial, located in Boulder, Colorado as an architectural response to what I feel is an important building type in our urban communities. The problem of redeveloping housing is critical within our cities and society today.
As a thesis study of architecture in the City of Boulder, this problem will emphasize the relationship of the proposed building to its neighborhood and the special quality of "place" that characterizes Boulder.
The selection of my thesis project and site is intended to illustrate a dilemma common to many new urban projects that intervene in established neighborhood settings--the tension between new and old; the need for simultaneous conservation and change. The project will examine a context of shared characteristics among its buildings, spaces and streets. But at the same time it is a context of many differences--diversifies of use, age and architectural style. The problem is an exercise in interpretation of the city.
My thesis is an opportunity to examine urban change, with the City of Boulder
serving as a laboratory. My study will not be limited to architectural issues--it will also focus on the urban physical environment in broad terms--economic development, housing conditions, zoning dilemmas, the debate over limits on downtown development. This is important because the city is a network of interdependent, changing forces and parts, establishing a framework for considering urban architecture, and the evolving form of the city.
The problem and opportunity of building within sensitive contexts is one of growing importance in most cities. The age of abundant supply of inexpensive, developable land has passed, now replaced by shortages of urban space, inflated land costs and the clash between forces of conservation and development. A growing economy and employment base, increased housing demand, and an extremely limited land supply have intensified these forces. The primary design tasks in the immediate decades ahead will be redevelopment of relatively small, "tight" urban sites, and the adaptive reuse of existing buildings.
Architects and others who design the urban environment will need to be more resourceful than they have in the past, likely working with less space, fewer material resources, increased public participation, and more complicated economic and legal parameters. An ability to interpret and critically respond to delicate urban settings will be increasingly important, as will an improved literacy in "reading" cities and the forces that make them work.
Architecture is a social art that provides spaces for society's needs and cultural aspirations. Its objective of making high-quality "places" that enrich the experience of both daily life and special occasion encompasses several overlapping scales of responsibility, from the community to the individual dwelling.
In the context of education, my thesis problem is a vehicle to learn the process of design. My feeling is that I am to study, learn, and develop a process of thinking, and not simply to solve a specific studio problem.
My attitude calls for an open mind to the values and views of others, a willingness to experiment and take risks without fear of "failure," an ability to be self-critical, and a persistent drive for excellence.
Among the characteristics of the process, I shall follow are:
-research, programming in parallel with design studies.
-development of multiple alternatives that illustrate different approaches to solving the problem and its parts.
-an emphasis on quick techniques of sketching and 3-D model-making to study design alternatives.
-regular (weekly) design studies, with thoughtful communications appropriate to the respective level of development in time, -carefully-executed drawings and other communications throughout the process, beginning with the earliest studies.
As a means of recording my design process, I will keep a journal or log of the entire experience from beginning to end. It will incorporate research, field studies, sketches and personal notes as the problem proceeds.
The project I have selected is an actual mixed-use residential/commercial development located in Boulder, Colorado. It involves the following project
OWNER: ARCHITECT: Spruce Street Ventures Manning Knapp Watson Architects & Planners
CONSTRUCTION MANAGER: MARKETING: Flagstaff Development Corporation Associated Brokers
DESCRIPTION AND LOCATION
The property consists of 2 and one-half lots of 18,066 square feet at 1525 Spruce Street in Boulder. The improvements will include commercial space, residential condominiums, open space, and parking.
The property is located on Spruce Street between 15th and 16th Streets, one block from the Boulder County Courthouse and the Downtown Mall.
I have made changes in the original program set forth by Manning Knapp Watson Architects and Planners, to comply with the requirements of the mixed-use redeveloping (MU-X) zone in Boulder, which provides opportunities for urban density housing with some commercial space as well. This new zoning proposal encourages a variety of uses, promotes store front first floors and attractive alley improvements, offers incentives for good design, and provides for pedestrian amenities and open space. The various details of this zoning are now being summarized and the final draft will be included in the Land Use Regulations in the fall of 1983.
JZ -TZ _C= JZ JZ JZ _d _cz
_d -C O -M -*-> 4-> 4-> 4-> 4-> 4-> 4->
4-> 4-> S~ CO LO kO CO CT> O
CO CT> CQ i i t i r i i C\J
Spruce Street Pearl Street Walnut Street Canyon
o Site Location
- Pearl Street Mai 1
-o- Downtown Boulder
* Boulder Library
11 Boulder Post Office
<0> Boulder County Court House
Within a few blocks of the site--at the Pearl Street Mai 1 You' 11 find a cosmopolitan selection of specialty shops, department stores, cinemas, galleries, design shops, and restaurants to fit every mood.
NRCHITEGTURE IN CONTEXT
My thesis project is architecture in urban context--the problem of integrating new building with established site and neighborhood settings.
Because of its density, strong neighborhood identities and high level of public interest in planning and design, is an excellent laboratory for studying the issues of relating new architecture to its place in the city.
-How one critically interprets, records and communicates the essential characteristics of an existing place (city, neighborhood, site).
-What attitudes and approaches are possible in relating to the cues of a context and how may these approaches be translated into architecture? Compatibility and conservation will be compared with views of the city as a collage of overlapping, diverse layers of architecture added over time.
-How do land and building economics affect site and architectural design: relationship to the nature of proposed use, density and quality of space.
My design will be compatible with the style, scale, proportions, color, and texture of the existing context. Considerations within the project allow for interior
and exterior privacy, security, orientation, views, identity, relationship to the community, and access to outside spaces. My research will include "state of the art" construction and alternative building and energy systems,
OBJECTIVES AND GOALS
-To design improvements consisting of approximately 25,000 sq. ft. of commercial and luxury condominium space.
-To provide amenities such as pedestrian plaza space, landscaping, covered parking, southern exposure, energy conservation features, views, comfort, and luxury.
-To make a transition to the residential neighborhood.
-To create an identifiable character which becomes a quality development for the area.
-The commercial aspect will allow for a transition to the Downtown Boulder Mai 1.
-The residential condominiums will be compatible with the surrounding Whittier Neighborhood.
-Parking will be placed underground to minimize the impact of the auto.
-Residential units will be the more prominant feature of the site.
-To encourage small scale commercial development on the site without negatively impacting neighborhood.
It is my intent, as was stated in the program set forth by Manning Knapp Watson Architects & Planners, to utilize materials and style which will be harmonious with the "Old Boulder" character of the neighborhood to achieve harmony in form.
The ultimate in urban development in the heart of Boulder, I intend to design a statement of the present and a landmark of the future.
The concept for the landscaping at 1525 Spruce is to continue the existing patterns in the neighborhood, to intensively landscape the streetscape along Spruce Street, and provide a public plaza. The existing street trees will be preserved and additional trees will be planted with sod being planted beneath to match the other yards along Spruce and to continue the corridor. A variety of deciduous shrubs and ground covers will be planted along the sides. The front area will also be planted with several large deciduous trees to provide shading to the plaza and soften the building to the street. The plaza will have a more urban character with either pavers or exposed aggregate as a surface material and potted plants and benches to create usable outdoor spaces.
RECREATION Â£ CULTURE AAEDICAL / PROFESSION FACILITIES COAAKAUNITY FACILITIES LINING CONDITIONS SUMMARY AND TABLES
GEOLOGY AMD SOILS REGIONS! CLI/MME Yl/1 ICRO CLINYKrE
The miners came in 1858 searching for a mecca of gold and silver...and they found it. Boulder's mining past remains a vibrant memory of the people and lifestyle that created one of the county's premier small cities. The City of Boulder was organized and platted in 1859 and founded in 1861.
Boulder lies at the base of the Flatiron Mountains, on the front range of the Rocky Mountains, 30 miles northwest of Denver. This attractive city has long been one of Colorado's major centers of economic, social and educational activity. Boulder is a leader in scientific and cultural research because
Steamboat Springs Fort Collins Greeley Longmont
Grand Junction ''0/"'s
Delta Monaco Skyline SotithPark
Montrose / Southwest Pla/a ^ Colorado Springs
c Durango Ignacio / * Pueblo
the University of Colorado is situated at its center. The University government research agencies and private industry have contributed greatly to making Boulder an important city to the State of Colorado.
Boulder is nestled against Colorado's towering front range. Its year 'round sun makes it a haven for skiers, climbers, hikers, joggers, lovers of meadows and panoramic views. The city's unique Greenbelt system serves as both a buffer to preserve its picturesque setting and as an extensive park system for outdoor enthusi asts.
Boulder residents have always displayed a concern for the quality of their environment in maintaining its surrounding natural beauty and scale of the city. The greenbelt system was approved by the voters to preserve 30 percent (30%) of the Boulder Valley as open space for future generations, and to offer a wide variety of recreational activities. Open space is a major issue in the City of Boulder, including all new developments in the area.
In 1971, with the support of the voters, the City of Boulder passed a zoning ordinance restricting the height for all new structures to 35 feet, with 55 feet as an absolute maximum by variance only. The 55 foot limit was based on the maximum height most mature trees reach when grown in the Boulder area. In 1976, a slow-growth' plan was adopted to control the number of mulPresidential dwellings built to 450 units/year. It was supported by the residents in hopes to limit and direct the growth of the city and to prevent a 'boomtown' effect or sudden influx of large numbers of people to the area which would drastically change the character of the city.
Considered the technical and scientific center of Colorado, businesses and organizations such as IBM, Storage Technology, Ball Brothers, Beech Aircraft, the National Center for Atmospheric Research, the U.S. Commerce Department National Bureau of Standards and the University of Colorado have added much to the flavor and diversity of the area.
Boulder is cosmopolitan yet casual. Local theatre groups including the University of Colorado sponsored Shakespeare Festival, the Boulder Philharmonic, The Colorado Music Festival, Boulder Arts Center and other artist's groups have created a hub of cultural activity. People of all ages enjoy Boulder's extraordinary variety of year 'round entertainment including numerous fine restaurants.
Boulder is a model urban city that enjoys a rich diversity of people, activities, and city scape comparable to the best neighborhood of North America.
Small shops focusing on Pearl Street, only one block from the site offer almost any needed item or service within walking distance. From almost anywhere in the City of Boulder, the neighborhodo has a sweeping view of the surrounding mountains, which help define and strengthen its identity. Boulder's healthy mixture of housing and commerce give it a constant stream of vitality and street life.
The City of Boulder and Boulder County are located in the Denver-Boulder Labor Market Area, which also includes the counties of Adams, Arapahoe, Clear Creek, Denver, Douglas, Gilpin and Jefferson. Like other Colorado communities, the areas's widely diversified economy has contributed to an unemployment level which has been consistently below the national level within recent years. Typically, Colorado does not have a union tradition, although Boulder has labor unions representing communications workers, construction workers and government employees.
The transportation network in Colorado provides support to an expanding economy and access to regional, national and international markets. Boulder is served by a sophisticated highway system including U.S. 36, a 25-mile turnpike linking the city to Denver, as well as Interstate 25, and Colorado Highways 7, 72,
93, 119 and 398. The city's rail transportation is provided by Burlington Northern Railroad and Union Pacific Railroad. Other local transportation systems
include 4 motor freight carriers, 20 car rental agencies, taxi service, a city bus transit system and nationwide bus service via Trialways Bus Systems. Charter bus service is also available.
Boulder Municipal Airport provides both charter and navigational service for the Boulder area. Major air transportation is provided by Stapleton International Airport, in Denver. Stapleton now ranks as the nation's sixth busiest commercial airport and is served by 10 international carriers, 7 national carriers and 6 commuter carriers. Approximately 22.6 million passengers traveled through the airport in 1981.
There is also a major bikeway system throughout the City of Boulder with several designated on and off-street bike routes.
The public school system in Boulder is Boulder Valley School District Re-2, which includes 21 elementary schools, 9 junior high schools, 1 junior/senior high school and 5 senior high schools, with a total enrollment of 20,520 in 1981. In addition, there is a parochial school for grades 1-9, 11 private schools, a special educational center and a school for the handicapped.
Higher educational opportunities are available in Boulder through several institutions, including the Boulder Valley Vocational-Technical Center, which serves over 1,000 secondary and post-secondary students per day in the 1981-1982 school year. The main campus of the University of Colorado is also located in Boulder. CU had a total student enrollment of over 20,000 students in 1981.
The university has a total of 16 schools and colleges offering more than 140 fields of study for undergraduates and 100 fields for graduate students at its 3 campuses (in Boulder, Colorado Springs and Denver). The Boulder campus alone has 10 schools and colleges, offering undergraduates the choice of 100 fields of study and 129 fields of study to graduate students.
According to the Sales & Marketing Management Magazine "1982 Survey of Buying Power," the median household effective buying income for the City of Boulder was $22,877, and for Boulder County, it was $24,193. The distribution of effective buying income of households in Boulder is represented in the table below.
Income Under $10,000 $10,000- $14,999 $15,000- $24,999 $25,000- $49,999 Over $50,000
Boulder City Fami1ies 21.9% 10.5% 22.1% 37.3% 8.2%
Boulder County Families 19.2% 9.8% 23.0% 40.3% 7.7%
Source: Sales & Marketing Management Magaz ine, 1982 Survey of Buying Power
Public Service Company of Colorado supplies both the natural gas and the electric power for the City of Boulder. Water is supplied by the Boulder Water Department. Its source is mountain reservoirs and glaciers. Average daily consumption is 14 million gallons. There are 2 water treatment plants in Boulder, one with a capacity of 50 million gallons per day and the other with a 9 million gallon per day capacity. The sewage treatment plant in Boulder has an average daily capacity of 15.6 million gallons. Mountain Bell Telephone Company furnishes phone service for the city, and Western Union provides telegraph service.
RECREATION Â£ CULTURE
Execllent year-round recreational facilities can be found in and around Boulder. There are 34 municipal parks in the city; a national park and 2 national forests are nearby. In addition, there are 4,200 acres of mountain parks in the Boulder area. Boating, fishing and hunting are available at Arapahoe National Forest, Boulder Reservoir and Mesa Reservoir. Boulder is also within easy reach of
downhill and cross-country ski areas and snowmobiling at such places as Berthoud Pass, Hidden Valley, Lake Eldora, Loveland and Winter Park.
Boulder's cultural activities include art galleries, community and university sponsored concerts, drama productions and a lecture series provided by the University of Colorado. Boulder also offers 2 outdoor and 2 indoor swimming pools, 42 tennis courts, 4 golf courses, bowling facilities, an ice skating, and roller skating rink. The annual Coors Bicycle Classic is held in Boulder and now enjoys national acclaim.
/I/IEDIGIL / PROFESSIONAL FNCILITIES
Boulder is served by Boulder Community Hospital, with a 172-bed capacity; Boulder Memorial Hospital, with 87 beds; and the University of Colorado Student Health Center, with 22 beds. Other medical facilities include 6 nursing homes, a city and county public health department, 24-hour ambulance service, 2 mental health clinics and 18 pharmacies. There are 162 physicians in Boulder; other medical and dental personnel are well established in the city.
Boulder has a sophisticated professional community. For example, there are 88 accountants (CPAs) in the city, as well as 96 architects and about 75 engineering firms, more than 300 lawyers, 165 real estate firms and 20 stock brokerage firms have established practices in the city.
Civic, fraternal, professional and social organizations are readily available in the Boulder area. All major religious denominations are represented in the city's churches and synagogues. Hotel and motel accommodations are abundant; more than 1,500 rooms are available to area visitors. Meeting and banquet facilities for 100 people are available at several places in the city. A number of excellent restaurants serve the Boulder area as well. The city has 5 local radio stations, television programs are transmitted from Denver stations. The local paper is the Boulder Daily Camera, with a circulation of approximately 28,300.
Boulder, like most of Colorado, enjoys the mild, sunny, semi-arid climate that prevails over much of the central Rocky Mountain Region. Extremely warm or cold weather is usually of short duration. The good climate results largely from Boulder's location on the eastern slope of the Rocky Mountains, in the belt of the prevailing westerlies.
Average Daily Maximum Temperature Minimum Total Precipitation Inches Per Month
January 43.5F 16.2F 0.61
February 46.2 19.4 0.67
March 50.1 23.8 1.21
April 61.0 33.9 1.93
May 70.3 43.6 2.64
June 80.1 51.9 1.93
July 87.4 58.6 1.78
August 85.8 57.4 1.29
September 77.7 47.8 1.13
October 66.8 37.2 1.13
November 53.3 25.4 0.76
December 46.2 18.9 0.43
15.51 Total Inches
Source: U.S. Department of Commerce, NOAA Environmental Data & Information Service: Comparative Climatic Data for the United States through
1980--a 30-Year Average.
SUN\N\ARY AND TABLES
Denver-Boulder SMSA Boulder County Boulder
^Projections--Denver and Evaluation, City
1 ,620,902 189,685 76,855 Regional Council of Boulder.
1 ,701 ,300 201,200 79,535
Governments & Divi
1 ,742,700 202,600 80,359
ion of Research
City of Boulder Rest of Boulder County
0-29 46,983 59,896
30-34 7,237 12,182
35-44 7,774 15,933
45-Over 4,689 24,957
Source: Division of Research & Evaluation, City of Boulder
Whi te 94.4% American Indian 0.5%
Spanish 5.4% Asi an 1.2%
Black 0.9% Other 8.4%
Source: Colorado Department of Health
Annual average temperature Average monthly temperature
Average annual precipitation Prevailing winds Average number of days
74.1FJuly 18.4 Inches
Pt. Sunny--184 Cloudy-- 24
Source: Department of Atmospheric Science--Colorado State University
UTILITIES AND SERVICES:
ELECTRICITY AND NATURAL GAS:
Public Service Company P.0. Box 551 Boulder, CO 80306
TREATED WATER SUPPLY:
Average daily consumption
City of Boulder
10.000. 000 g.p.d. winter
55.000. 000 g.p.d. summer
Type of treatment Ave. daily capacity Peak capacity
Fire department Personnel Vehi cles Stations
Police department Personnel
Golf Courses Campgrounds Tennis Courts Ski i ng Fishi ng Boati ng
11,000,000 g.p.d. 15,600,000 g.p.d.
65 full-time 7 6
54 patrol 20 detectives 28
56 Theater 10
11 Dinner Theaters 1
1 Restaurants 170
23 Motel Rooms 1,000
1 Meeting Facilities 20
8 Libraries 2
2 Swimming Pools 4
Hospi tals Clinics Doctors Denti sts
TRANSPORTATION: Major Highways
KBOL 1490 KADE1190
2 with 259 total beds 20 245 113
U.S. Highway 36
State Highways 7, 72, 93, 119, 398
35 minute drive
Service by all major airlines
4,100 foot hard surface runway
Lighted altitude 5,288 feet
Services: fuel, repair, wash
Navigation: unicorn beam
*Charter service available
Station Locati on Affiliation
KWGN-2 Denver None
KOA-4 Denver NBC
KYCU-5 Cheyenne CBS
KMGH-7 Denver CBS
KBTV-9 Denver ABC
cable service is available TELEPHONE:
Mountain Bell 1805 33rd Street Boulder, CO 80301
Telegraph Western Union
1705 14th St. Boulder, CO 80306
EDUCATION: Schools Enrollment
Elementary 21 9,467
Middle School 2 1,166
Jr. High 7 4,289
Sr. High 5 5,269
Private & Parochial 16
University 1 22,176
Trade School 1 554
$135,064,486 265,592,020 415,814,996 822,953,341 928,306,356 1 ,024,633,000
Source: Colorado Department of Revenue
MAJOR EMPLOYERS BOULDER VALLEY:
Storage Technology 8000
University of Colorado 3700
Boulder Valley Schools 2400
Ball Corporation 1500
Rockwell International 1500
County of Boulder 1000
National Oceanic &
Atmospheric Admin. 940
Neodata Services 800
City of Boulder 769
Longmont Turkey Processors 750
National Center for
Atmospheric Research 700
Boulder Community Hospital 376
Boulder Memorial Hospital 286
Syntex Chemical 270
Boulder Daily Camera 255
Techneti cs 250
First National Bank 233
Boise Homes 210
JC Penney Company 180
Colorado Electro-Optics 175
Hilton Harvest House 175
Celestial Seasonings 165
King Soopers Grocers 160
Micro Motion 150
Watts-Hardy Dairy 140
Safeway Stores 135
MAJOR EMPLOYERS--BOULDER VALLEY (Continued)
Valleylab 640 IntraWest Bank 135
Flatiron Paving Company 500 Coors Paper Packaging 130
National Bureau of United Bank 114
Standards 500 Dieterich Standard Corp. 110
AMF Head Division 470 Mesa Vista Sanatorium no
Mountain Bell 465 Boulder County Mental
Public Service Company Health Center 100
of Colorado 400 Leanin'Tree Publishing
Beach Aircraft Company 100
GEOLOGY YND SOILS
The geological make-up of the low-lying areas at the base of the foothills is comprised of quartenary deposits of loose or poorly cemented stream gravel and sand, slope wash, and terrace gravels overlaying Pierre shale. The area is not located over any known faults or areas subject to subsidence or expansive clay.
The soils appear to consist of predominantly sandy clays, with some gravel present. The major obstacle presented in local soils studies is the ground water table; it varies from 8 feet to 12 feet (8'-12') below the surface, restricting any below grade construction beyond one level, except at larger expense. See sub-surface investigation, Site Data Section for details on site specifics.
The climate of this region is considered semi-arid with many characteristics of a temperate region, only dryer, due to its location in the 'rain shadow' of the Rocky Mountains and Pacific Maritime air masses. The weather is controlled by several sources; the Continental Polar air from the north coupled with 'rain shadow' effect result in very dry, cold winters; the Continental Tropical air from the southwest produces dry, hot summers; and periodically the Maritime Tropical air masses (originating in the gulf) produce wet springs when we generally receive the greatest amount of snowfall and precipitation for the year. These various sources create a wide variety of weather conditions throughout the year with rapid changes in weather a common occurrence. The region's closeness to the mountain ranges produces adiabatic and 'rain shadow' effects (diural changes in air masses--the air warms on the mountaintop during the day drawing cool air from the valley to the mountain-top (upslope wind), then as the mountaintop air cools in the evening, the cool air mass is drawn back down into the valley (down-slope wind) adding to the variety of weather conditions in the area. The prevailing winds are from the southwest in the summer. The cold winter winds originate from the northwest. The warmest temperatures occur in July followed by a dry overheated period (July, August, September). The coolest temperatures occur in January followed by a dry, underheated period (December, January, February). The humidity in this region fluctuates more diurally than seasonally. During the summer
months, the relative humidity is, on the average, 70% at sunrise and 35% at mid-day. During the winter months the relative humidity is 65% at sunrise and 44% at mid-day. This is closely related to the daily movement of air masses in this area.
Boulder's elevation, 5,420, is slightly higher than the Denver area and eastern plain, producing somewhat cooler temperatures. Its close proximity to the base of the foothills increases the amount of snowfall in the area where weather moving upslope produces greater amounts of precipitation. There is another peculiar phenomena particular to Boulder and its proximity to the foothills and narrow canyons located along the front range--the chinook wind. Frequently from late fall to early spring, strong westerly winds make their way through the narrow canyon undergoing a 'funnelling effect' producing gusts from 70 to 130 miles per hour. A warming effect is also usually experienced after the chinook winds have passed through the area.
The Spruce Street Plaza site is located in the valley just at the base of particularly steep foothills (30% slope). Because of this location, the sun sets earlier in the evening causing the temperature to drop sooner than in the plains to the east. There is no significant vegetation on or near the site to modify the climate drastically.
The following data summarizes significant climatic factors and information specific to this area.
NMINTER dec 21
I JAN FEB MAR APR MAY JUN JUL AUG i SEP OCT j NOV HD
ANNUAL MEAN MAX. 87.9 ANNUAL MEAN MIN. 21.4
1 L L l-j ill xn rr.a.
10 in. 6 in.
SW MPH 8.9 9.2 9.9 10.3 9.5 9.0 8.5 8.2 8.1 8.1 8.5 1.8JL.J
HEATING 992 826 809 482 236 88 6 0 139 367 690 905
COOLING 0 0 0 0 29 154 282 234 109 26 0 0
ANNUAL 18.39 in.
ANNUAL 84.9 in.
BASE NMP VICINiry N\AP SHE PLAN ANALYSIS
NEIGHBORHOOD DESCRIPTION PROPERTY DESCRIPTION
SEE ANNLYSIS ^NPS
URBAN CONTEXT RESIDENTIAL /CONNKERCIAL NEIGHBORHOOD
MIEN/ AND t/ICINITY OBSERNATIONS
TOPOGRAPHY AND TREE CONER
R.74W R.73W R.72WLarimerR.71WCountyR.70W R.69W
/ B A L b" 7 A l B o 1 ) B is a r'B! j
( \ C D D ' ^C D ' \ D 5 C D y T-3N Lorqhont
>i 4-> i Z5 s3 V, A 1 B A A I B A A B A A B A / " B f
O o -a c Â£ 1 / t D U c 1 D c 1 'D w c \ D c j D - T.2N C ^
f A yt B 9C A V B Â£ A | B 1 A B A r B 1 i T IN
r i ^>C D 1 c H C )ulde D^ L 1 N jfayejtte
\ L B K B A | B A A 1 B 9 A B cb A 1* b
r \ C 0 C D ' H D * 4 D t>c D ^ } c IS 5 ; ^Brjoomfi
^ Gi 1 51 n County Jefferson County
MAP REFERS TO PROPERTY DIVISION
AND ZONING AROUND IMMEDIATE SITE (SEE ZONING SECTION) |_|p_Â£ HIGH DENSITY RESIDENTIAL /l/IR-E MEDIUM DENSITY RESIDENTIAL RB-X REGIONAL CENTER OF BOULDER VALLEY
Lot 1, Spruce Subdivision Boulder County, Boulder, Colorado.
The parcel number is 1463-303-13-012, and the Reception Number is 518936.
Prior to the recent subdivision of the property, the property was legally known as Lots 9, 10 and part of 11, Block 123, Boulder, Colorado.
The owner of the subject property, according to the Boulder County Tax Asses office, is Spruce Street Ventures, a Colorado General Partnership.
The subject property has recently been resubdivided to include into one parcel Lots 9, 10 and part of 11 in Block 123. The Boulder County tax assessment office has not yet issued a tax assessment on Lot 1 as a single parcel.
The Spruce Street Plaza property is located in the central part of the City of Boulder approximately one and one-half blocks northeast of the County Court House and Downtown Mall. (See Introduction, Description and Location).
It is located in a transitional zone between the commercial areas of downtown Boulder to the west and south and the residential areas to the north and east. The neighborhood itself reflects this zone of change. It consists of a mix of single family residential, two-four unit apartments, light commercial and other use properties.
To the north and east, the predominant use is single family residential--detached but with some two to four unit apartment houses and duplexes
interspersed. These are primarily converted single family units. From 15th Street westward and Pearl Street southward, the use is primarily heavy commercial. The Downtown Mall, which starts at 15th Street and Pearl, is just one block southwest. The Court House and other associated government buildings are located in the Mall area within a few minutes walking distance of the site. The commercial area includes retail shops, banks, office buildings, churches, movie theaters, restaurants, gasoline stations and numerous specialty retail outlets; i.e., furniture, clothing, camera, antique and other similar stores.
The immediate neighborhood consists of a variety of uses. Directly east and adjacent to the subject is the Unity Church and church school. Immediately west is a two-story brick duplex and immediately west of that is a house which has been converted to small professional offices. Directly across Spruce Street is Barker Park and the Boulder Day Nursery. To the southeast on the corner of 16th Street and Spruce is another church. A number of other churches are located throughout the neighborhood. Immediately to the north of Lot 1 is the northern half of Block 123. The property type is entirely single family residential detached as is all of Blocks 124, 145 and 146.
The immediate neighborhood is undergoing a slow transition from residential to commercial. The downtown commercial area will continue to expand as the commercial activity around the Mall continues to increase along with the Boulder population. This is a steady process that will probably continue unabated into the forseeable future. More than likely, the neighborhood will eventually be all commercial activity.
The streets surrounding Spruce Street Plaza are all macadam paved, two lane, neighborhood streets. Other improvements include concrete sidewalks, curbs, storm drainage systems and street lights. All utilities are available to the site, including public water, sewer, electricity, natural gas and telephone.
The most important single factor affecting the subject neighborhood and the subject property is its close proximity to the commercial hub of the City of Boulder.
The site is zoned HR-E which is a classification pertaining to "High Density Residential" (See Zoning and Codes). These are areas which are primarily used for or permit multi-unit residential development at apartment densities. This zoning district permits office usage by special review. The zoning I propose to use on the site is MU-X (See Zoning and Codes Section for further details).
The site is an irregularly shaped parcel of land containing 18,066 square feet.
It fronts on Spruce Street for a distance fo 150.57 feet. Its rear property line abuts an alley-way for a distance of 100.33 feet. The site slopes gently downward toward Spruce Street, with no significant topographical features. The property was recently replatted from Lots 9, 10 and part of 11, Block 123 to Lot 1 in the Spruce Subdivision.
Primary access is afforded from Spruce Street with secondary access being from the alley. For soil survey see sub-surface investigation in this section. The soil is assumed to be adequate for residential building purposes. A concrete sidewalk bordering Spruce Street runs along the southern property line.
All utilities are available to the site including public water, sewer, gas, electricity and telephone. There are no factors known which would restrict the development of the site to its fullest legal density.
The site was improved with a one story structure formerly used as Myron's Health Center but now not existant. The structure was, at one time, a single family detached residence. Additions were added to the front to increase usable floor space for commercial use. The building was estimated to be some forty years old and in fair condition. The improvement was removed as part of the site development plan to make way for a new building.
Based on the HR-E zoning with its associated restrictions and permitted uses, the site could be used for the construction of residential units either as apartments or condominiums. The zoning requires that there be a lot area of 1,600 square feet per dwelling unit. The size of the site of 18,066 square feet would allow the construction of eleven dwelling units, if the site were to be developed to its maximum density.
Currently, however, the site has been granted a Planned Unit Development (P.U.D.) approval by the City of Boulder to be developed to a higher density than the zoning would normally permit. The P.U.D. approval, which is not revocable by the City, will permit commercial or office space on the site as well. The structure must conform to the zoning restrictions within the HR-E zone with regard to set-back lines, parking and height limitations. This type of development is allowed, due to the proximity of the property to the Downtown Mall and the mixed use character of the immediate neighborhood.
SITE /IN/ILYSIS NXAPS
TOTAL AREA 18066 sq, ft.
20. 21. 22.
Law Offices 2 story Residential 2 story Unity Church 3 story Barker Park playground Residential 2 story Garage
Mini Computer Systems-1st Mini Computer Systems-1st Residential 1 story Mind-Body Transformation 1 story
Church Playground 1 st. Pillar of Fire Church
Residential - 2 story
Residential - 2 story
Residential - garage 1 st
Residential - 2 story
Residential - 2 story
Residenti al - 2 story
Residential - 3 story
Residential - garage 1
Residential - 2 story
Residential - 2 story
Residential - 2 story
Residential - 1 story
New Development Town-
houses - 2 story
Residential - 1 story
Residential - 1 story
Colorado Landmark Realtors 2 story First United Methodist Church 3 story Second Place Shop
RESIDENTIAL / CON\N\ERCML
( :---------:------------: n
, X-y- 4-> 1 ^ O) f s_ 1 u D a i | ! X... Co ii u
J Lh j CO 1 -C 4-> LO i r G3 mmr- i cp U-i ODl U T- CO) x: 4-> CO 1 f a ~ii Lh
j i ' \_L J L
"... .7T Spruce Street TV x~- ^1 r TX
no a u R p = i i d
The buildings in the neighborhood are in good to excellent condition. The residents take pride in their homes and take special care to see that their property is maintained.
There is close proximity to parks, recreation, shopping, eating facilities and excellent access to public transportation.
I/IENNS / MICINITY
^11nmim^ rf |*
The vicinity of the site is a mixed use neighborhood, residential, commercial encompassing the site and heavier commercial existing only 2 blocks away on the Boulder Mall. Cars and pedestrians exist around the site throughout the day and early evening. The site is located on a moderately busy street near a busy intersection, but basically hidden from major arteries. The pedestrian perspective and approach is very important.
A layer of diverse views exist from the site, created by natural topography of Boulder.
-Good overall visibility -Strong sense to community -Strong relationship to Boulder Mall, Street, and Park
-Strong sense of entry to site -Natural ventilation and sun important
-Accessibility is important for both public and private -Identity of site is important -Good potential for light and southern exposure -Neighborhood identity is important
-Minimize impact to neighboring buildings and residential community -Views are spectacular from site
TOPOGRAPHY AND TREE COXIER
- -v n
The site slopes gently downward toward Spruce Street, the site contains one tree located near sidewalk, a sense of enclosure is experienced with the nearby mountains and Flatirons. Around the back exists predominantly medium to large sized Ash March and a few Austrian Pine.
O O O O o G
For the purpose of my thesis work I will use the following data prepared for:
Spruce Partnership 5741 Arapahoe Avenue Boulder, Colorado 80301
SUBSURFACE INVESTIGATION PROPOSED C0ND0MINIUM/0FFICE BUILDING
1525 Spruce Street Boulder, Colorado Project 82407 February 15, 1983
CHARLES C. BOWMAN ASSOCIATES INC., CONSULTING GEOTHENICAL ENGINEERS
6595 Odell Place, Suite I Boulder, Colorado 80301
Telephone: Boulder 303/530-1975 Longmont 303/651-3870
The subsurface investigation is complete for the proposed condominium/office building to be constructed at 1525 Spruce Street in Boulder, Colorado. Two test borings were drilled in or adjacent to the proposed building envolope. The results of the test borings, our geotechnical recommendations, the Boring Logs and a diagram showing the location of the test borings are included in this report.
It is our understanding that the proposed building will be a three story steel-frame structure supported by poured-in-place, reinforced concrete foundation walls. The building will be constructed over an underground parking area which will have a concrete slab-on-grade floor. Maximum cuts for the excavation are anticipated to be 7 to 8 feet beneath the ground surface existing at the time of our borings. For the purpose of this report, we will assume that ordinary light to moderate structural loads will be developed and that the fill placed adjacent to the building, other than backfill placed immediately adjacent to the foundation walls, will be limited to 3 feet or less in thickness.
The purpose of this report is to describe the subsurface conditions encountered in the borings, to summarize our analyses of data obtained, and to submit our geotechnical engineering recommendations. If the actual development plan differs from that described above, we should be notified so that our recommendations can be reviewed and revised if necessary.
SUBSURFACE INVESTIGATION PROCEDURES
The borings were accomplished with a truck mounted rotary type drilling rig using continuous flight augers to advance the holes. Representative samples were obtained using sampling barrels driven into the bottom of an auger-advanced hole by a 140 pound weight falling through a distance of 30 inches. The number of blows required to drive the sampler is an indication of the relative density of noncohesive soils in place. Samples obtained in the field were sealed and returned to the laboratory for further examination and testi ng.
Moisture content, density, consolidation-swell, and hand penetrometer tests were performed on representative portions of the sample recovered. The results of these tests are included with this report. In the hand penetrometer test, the unconfined compressive strength of a cohesive or moderately cohesive soil is estimated by measuring the sample's resistance to penetration of a small spring calibrated piston. Careful boring logs were kept in the field where the samples were visually classified in accordance with the Unified Soil Classification System. After completion of the testing program, the samples were again examined and the field classifications revised where necessary.
The proposed building site is presently being used as a parking lot. Spruce Street extends along the south side of the property, and an alley borders the north side. A one story building and a two story church are located immediately east of the proposed building site, and an existing two story apartment building is located immediately to the west.
In Test Boring 1, located near the north side of the proposed building envelope, a layer of fill was encountered at the ground surface and continued down to approximately 5 to 6 feet. The fill was predominantly a clay and contained varying percentages of silt, sand, and gravel. The fill was underlain by a
stratum of slightly clayey sand and gravel which continued to the maximum depth of the test boring, approximately 20 feet below the existing grade. In Test Boring 2, located near the south end of the proposed building envelope, a layer of asphalt was encountered at the ground surface which was underlain by a thin stratum of clayey, silty, sand, gravelly fill. The layer of fill was underlain at approximately 2 feet by a stratum of silty, slightly sandy to sandy, slightly gravelly clay which continued down to approximately 5 feet. At this level, the clay stratum was underlain by a stratum of slightly clayey sand and gravel which continued to the maximum depth of the test boring, approximately 20 feet beneath the existing grade. A more complete description of the subsurface soil conditions can be found in the attached Boring Logs.
GROUND WATER CONDITIONS
Ground water level observations were made as the borings were being advanced, immediately after completion, and one day after completion. Free water was not detected in the borings at the observation times. Test Boring 1 had been filled in at the time of our February 3, 1983 reading, and Test Boring 2 indicated a caving depth of 10J feet. The elevation of the ground water table, which was at or below the caving depth of Test Boring 2, can be expected to fluctuate throughout the year depending upon variations in precipitation, surface runoff, and application of irrigation water. Because of the relatively short time period covered by this investigation an accurate prediction of the long term water level rise cannot be given.
In our opinion, conventional spread footings, either continuous wall footings or isolated column footings, will provide adequate support for the proposed building. Footings can be designed using an allowable soil bearing pressure not to exceed 4,000 pounds per square foot based on dead load plus full live load. All soils encountered were nonexpansive or of low expansive potential, thus, no minimum dead load pressure need be observed. The footing bearing elevation throughout the building envelope should be placed below the overburden layer of fill and clay encountered in our test borings and should be placed on the naturally occurring sand and gravel stratum underlying the overburden layer of fill and clay. Another alternative would be to overexcavate down to the naturally occurring sand and gravel stratum and backfill and compact the footing trenches with a nonexpansive, structural fill up to the desired footing bearing elevation. If this alternative is chosen, the structural fill should be placed and compacted in accordance with the recommendations provided below. The naturally occurring sand and gravel stratum should first be compacted prior to placement of the footings on these soils or prior to placement of additional structural fill. Also, if the footing trenches are to be backfilled and compacted up to the desired footing bearing elevation, we recommend that the trenches be 4 feet wide in order to encompass the influence zone for the load distribution on the underlying soils. All exterior footings should be placed below frost depth to provide adequate cover for frost protection. Unless local codes specify otherwise, 30 inches of frost cover will be sufficient. The foundation walls and other structural elements should be designed by a qualified structural engineer.
If isolated areas of loose or soft soil are exposed during final footing excavation or, if as a result of construction traffic, the bearing soils become disturbed, these soil areas should be removed down to undistrubed, acceptable soils prior to placement of the footings. Footings can then be placed directly upon the acceptable soil, or the excavation can be backfilled up to the desired footing bearing elevation with nonexpansive granular fill, placed in lifts not to exceed 9 inches in loose thickness, and compacted to a minimum of 100 percent of maximum density as determined by the Standard Moisture Density Relationship, ASTM D698-70.
FLOOR SLABS AND OTHER SLABS-ON-GRADE
Floor slabs and other interior or exterior slabs-on-grade can be placed directly upon the natural, inorganic soils or newly placed and compacted fill, whichever is required at slab subgrade elevation. Prior to placement of any new fill or construction of the slabs, we recommend that all moderately organic topsoil or debris be removed from the existing ground surface. The exposed surface should be carefully examined and test rolled with the heaviest construction equipment available at the site to identify any loose or poorly compacted areas. A loaded 30-ton dump truck will be suitable for this purpose. The surface examination and test rolling should reveal any areas of unsuitable soils which remain after stripping. Any such areas which cannot be densified in place should be immediately removed down to undisturbed, satisfactory soil. Following approval of the stripped surface and the test rolling, and prior to placement of any new fill, the
surface should be scarified and wetted or dried to bring the surface soils to a moisture content at or near optimum moisture content.
All new fill placed should be nonexpansive and free of organic matter and debris. On-site soils, excepting topsoil, will provide suitable fill if the moisture content of the soil is altered so that the compaction standard can be reached. All fill should be placed in lifts not to exceed 9 inches in loose thickness, and where it is to remain in place beneath slabs, should be compacted to a minimum of 95 percent of maximum density, as determined by the previously mentioned ASTM specification.
The backfill placed immediately adjacent to the foundation walls, if not compacted, can be expected to settle with resulting damage to sidewalks, driveway aprons, and other exterior slabs-on-grade. To avoid settlement and disfigurement of the slabs in the event that the backfill is not to be compacted, we recommend that concrete slabs which must span the backfill be structurally affixed to the foundation walls. This is conventionally done by including horizontal reinforcing bars near the top of the foundation walls which subsequently tie directly into the slab. The slab should be reinforced as necessary for the span involved.
GROUND WATER TREATMENT
The ambient ground water table at the site, unless a source of water not presently contributing becomes available, is not expected to rise to a level
which will detrimentally affect the construction or utilization of the proposed building.
In our opinion the building should have the protection of a perimeter drainage system. A perimeter drainage system should prevent an accumulation of water adjacent to the foundation walls from building up sufficient pressure to cause seepage into below grade interior areas. The drainage system should consist of perforated plastic pipe surrounded by a 4-inch layer of free draining gravel with the invert of the pipe placed, if possible, at or below the top of the adjacent floor slab. The drainage pipes should be channeled to a suitable surface or subsurface outfall or to a sump pit. The sump pit should be equipped with a pump as necessary.
We also recommend that an underslab drainage system be constructed. Eight inches of washed concrete gravel should be placed underneath the floor slab. Perforated plastic pipes should be embedded in the gravel on no greater than 10 foot centers. The pipes should drain into the same outfall as the perimeter drainage system.
A locally high ground water condition can develop immediately adjacent to the building if surface drainage is not properly cared for. We recommend that the backfill adjacent to the foundation walls be mechanically compacted, and that the site grading plan include a grade of at least 5 percent perpendicular to the walls for the first 10 feet away from the walls to facilitate rapid runoff of surface water.
Roof downspouts or other water collection systems should be discharged well away from the backfill so that surface water does not have an opportunity to pond adjacent to the foundation walls and cause seepage into the backfill.
In addition, we recommend that the foundation walls which will be below grade be dampproofed.
Walls which are to retain soils should be designed as retaining walls to resist the lateral earth pressures. We recommend that on this site basement foundation walls and other walls which are not free to rotate be designed using a lateral earth pressure equivalent to that developed by a fluid weighing 40 pounds per cubic foot plus any appropriate surcharge. Use of this lateral earth pressure assumes that the soils retained by the walls are well drained and will not be allowed to become saturated at any time during the life of the walls.
Walls which are free to rotate or walls in excess of 8 feet in height should be designed using a lateral earth pressure which can be determined only after more information regarding the geometry and loading conditions of the walls is known. If additional information is needed regarding the lateral earth pressure to be used, we should be consulted so that we can provide appropriate data. We recommend that the walls be laterally supported, particularly during backfilling to minimize the opportunity for damage.
The borings in this subsurface investigation were spaced to obtain a reasonably accurate knowledge of the subsoils in the area to be occupied by the proposed building. Venations in the subsoils not indicated by the borings are always possible. We recommend that we be contacted when the excavations for the footings are complete so that we can examine the exposed soils to confirm that they are as indicated by the borings and are consistent with the design requirements. We also recommend that placement and compaction of any significant thickness of fill, particularly fill which is to remain in place beneath slabs or other structural members, be inspected and tested to assure compliance with the specifications.
Fill, CLAY, silty, sandy, contains gravel, dark brown, very soft to soft.
CLAY, silty, slightly sandy to sandy, with occasional small grained gravel, dark brown, stiff.
SAND AND GRAVEL, slightly clayey, reddish-brown, medium dense
Indicates that 12 blows of a 140 lb. hammer were required to drive a 2-inch inside diameter sample 12 inches.
Indicates that 22 blows of a 140 lb. hammer were required to drive a 2-inch outside diameter sampler 12 inches.
Indicates sampler driven onto cobble, and blow count is probably not representative.
Indicates caving level and number of days after drilling that the measurement was taken.
DEPTH BENEATH EXISTING GROUND SURFACE (FEET)
1. The borings were accomplished on February 3, 1983.
2. The stratification lines represent the approximate boundary between soil or rock types, and the transition may be gradual.
DEPTH BENEATH EXISTING GROUND SURFACE (FEET)
3. The Boring Logs are an integral part of the report and are not to be used separately.
LABORATORY TEST RESULTS PROJECT 82407
Bori ng Number Depth (ft) Moi sture Content (%) *Unconfined Compressive Strength at Natural Moi sture Content (psf) *Unconfi ned Compressi ve Strength at Saturated Moi sture Content (psf) Dry Density (psf) Swel 1 or consol idation
1 1 13.2 7000
1 4 21.0 NA**
1 9 3.5 NA**
1 14 3.9 NA**
1 19 13.8 NA**
2 1 23.8 7000
2 4 15.0 7500 7500 105 See attached curve
2 9 7.2 NA**
2 14 10.8 NA**
SLVELL/CONSOLIDATION TEST RESULTS
GENERAL REGULATIONS ZONING DISTRICT /GAP MU-X ZONE
OBJECTIVES BULK REGULATIONS FLOOR AREA RATIO USES ALLOWED IN ZONE
LANDSCNPING DWELLING UNITS/4CRE
UNIFORM BUILDING CODE ENERGY STANDARDS HANDICAPPED REQUIREMENTS FIRE PROTECTION FLOOD PLAIN REGULATIONS
ESTABLISHMENT OF ZONING DISTRICTS
In order to carry out the provisions of this ordinance, the City of Boulder is hereby divided into the following basic zoning districts determined by actual development conditions:
E, Established-areas where the character of development is stable and few changes are anticipated or encouraged
D, Developing--areas where most land is changing from vacant or rural use to urban use and densities.
X, Redeveloping--areas where many buildings are likely to be rehabitated or replaced and such action is to be encouraged.
The basic zoning districts are further divided into the following use districts:
R, Residential B, Business I, Industrial P, Public A, Agricultural
HR-E Location of Site Currently zoned HR-E
High Density Residential Areas which are primarily used for or permit multi-unit residential development at apartment densities.
RB-X Regional Center of the Boulder Valley Where a wide range of retail
and commercial operations are permitted, including the largest regional-scale businesses.
HR-X Areas in the process of changeing from low-density residential use to a primary use of multi-unit development at apartment densities.
TB-E Transitional Business Areas which are primarily used for both residential and complementary uses, including temporary lodging and office use.
MR-E Medium Density Residential Areas which are primarily used for or
permit multi-unit development at duplex, triplex or townhouse densities.
MR-X Areas which are in the process of changing from existing development
to a primary use of multi-unit residential units, where each unit usually has direct access at ground level.
MU-X Mixed use redeveloping zone (See details in following section).
Proposed zoning for Spruce Street Plaza.
ZONING DISTRICT MAP
The boundaries of these zoning areas and districts are hereby established as shown on maps entitled "Zoning District Map of the City of Boulder, Colorado which maps and all official amendments thereto are hereby made a part of this ordinance.
The following information summarizes the requirements of the Mixed Use-Redeveloping (MU-X) zone. The various details of the zone will be incorporated into the final draft of the 1983 revisions to the Land Use Regulations which is planned to go to the Planning Board and City Council this spring in draft form with final adoption in the fall.
During the past several years, it has become apparent that the current zoning categories along the Pearl Street Corridor and some surrounding areas do not reflect either the current uses of land or ideas for future redevelopment. New development has often required a special review or a non-conforming review, adding time and uncertainty to the development process. Neither the developer nor the neighborhood has been satisfied with the process or the result.
The proposed mixed use zone is a compromise, recognizing the interests of the property owner/developer and the neighborhood. The vision of the corridor is
as an interesting and varied shopping area which provides opportunities for urban-density housing with some office space as well. The scale of new buildings will be comparable to the traditional buildings in downtown Boulder. Understanding that Pearl Street will become an important automobile and mass transit link between the Crossroads Mall and the Downtown, the planning challenge is to create and strengthen the pedestrian element along that area. Boulder believes this can be done by developing a zone which encourages a variety of uses, promotes store-front first floors and attractive alley improvements, offers incentives for good design, and provides pedestrian amenities such as benches and trees for shade.
For the purpose of my thesis work I will encorporate these zoning requirements.
My site is located on this transition corridor. The site is zoned HR-E for high density residential. However, with the amount of commercial activity in the area and the conversion of some single family residences to commercial use, it is feasible to apply MU-X zoning to the site. Based on the size of the lot, its current zoning (P.U.D.), the property use in the neighborhood, the high demand for housing in the downtown Boulder area and other economic factors, the best use of this property is for MU-X zoning. This would take the form of apartments or condominiums, blending in some form of commercial or office use as long as it is compatible with its primary use--residential.
The agreed objectives of the zone are:
1. To provide a transition to the residential neighborhood abutting the zone without negatively impacting the neighborhood.
2. To encourage both residential and small-scale commercial development along selected arterials.
3. To create an identifiable character and engourage quality development and redevelopment for the area.
The bulk requirements of the zone are designed to allow greater building coverage of the lot. Unlike either the HR-X or HR-E zones, no front or side-yard setbacks are required. The open space required per residential unit is one-half that required in the HR-E zone and the open space definition itself will be amended to allow for the counting of balcony and roof-top space in some conditions.
The parking requirement for MU-X zone is an important factor. In many instances, the space required to meet the parking requirement will in fact determine the size and use of the building. However, an important factor in determining compatibility with the surrounding neighborhood is the provision of adequate on-site parking, assuring minimal parking impact on near-by residential streets. The parking requirement will be essentially the same as in the HR-X or HR-E zone, and the City's other commercial zones. The current code already allows parking reductions for mixed use projects that can demonstrate shared parking. This simply implies that residential parking spaces
may be used during the hours of 9 am and 5 pm by commercial tenants, thus, reducing the parking requirements for the site.
MU-X BULK REQUIREMENTS
1. Minimum usable open space per dwelling unit*
(See Usable Open Space Definition in Development Standards)
2. Minimum number of parking/residential
(See Parking Stall Requirements in Development Standards)
3. Minimum number parking/non-residential
4. No front setback required for first and second story; above second story, 20 foot setback required
5. Minimum rear yard setback
6. Height limit
7. No minimum side yard setback from a street
8. Minimum side yard setback for principal building
400 square feet
1 bedroom, 1 space
2 bedroom, 1.5 spaces
3 bedroom, 2 spaces
4 or more, 3 spaces
.75 per 300 sq. ft.
(1 to 400 sq. ft.)
15 feet 35 feet
12 feet, if any
*Usable Open Space Definition
In the Mixed-Use Zone (MU-X), in addition to the examples of open space listed in 37-302(b), the following may be counted as open space:
1. balconies and decks with a minimum usable width of 6 feet.
2. roofs, when designed to provide passive or active recreational space for the building occupants;
3. internal atriums and plazas.
FLOOR AREA RATIO
The floor area ratio is the ratio between the lot area and the gross floor area of the building (defined in the Land Use Regulations as the area included "within the outside walls of a building or portion thereof, including habitable penthouses and attic space, but not including vent shafts, courts, or uninhabitable areas below ground level or in the attic"). For example, a floor area ratio os 1:1 on a 7,000 square foot lot would allow for 7,000 square feet of building floor area. The lot area taken up by parking, setbacks, open space and driveways would allow for the construction of a 2 to 2\ story building under a 1:1 floor area ratio requirement.
Currently, the City's land use regulations apply floor area ratios only when a building is proposed to exceed 35 feet in height. Under the proposed MU-X zone, a floor area ratio is used whenever a building is proposed in the zone.
To exceed the specified floor area ratio, density bonus options could be sought by using a Planned Unit Development process.
There are two purposes for utilizing a floor area ratio restriction. In the first place, the scale of buildings in the zone is critical to assure compatibility with adjacent residential districts and to develop the desired character along the corridor. Second, the floor area ratio will allow incentives to provide for project amenities that may not otherwise be included.
The following proposed represents a compromise. Some participants on the committee wanted a floor area ratio of 1:.75; some wished 1:1.25. A 1:1 ratio
seemed to be a good middle ground which would continue to allow many projects to develop by-right (a goal of this zoning change).
MU-X FLOOR AREA RATIO BONUS
A maximum by-right floor area ratio of 1:1 is extablished for the zone regardless of building height. To exceed a 1:1 ratio to a maximum of 2:1, the following density bonuses apply:
1. Site and building design providing sunlight for each residential unit and private outdoor space for each residential unit exceeding, when totalled with other project open space, 10% of the open space requirement: a bonus not to exceed .25 (25%).
2. Site and building design providing private outdoor space for each office unit within a proposed project equal in square feet to 10 percent of the lot area for buildings under 25 feet, 20 percent above 25 feet: a bonus not to exceed .25 (25%).
3. Site and building design providing a street front facade and an alley facade at a pedestrian scale including such features as awnings and windows, well defined building entrances, and other building details: a bonus not to exceed .25 (25%).
4. Site and building design providing a streetside public open space of at least 500 square feet designed to compliment required right-of-way improvements and to function as a vest-pocket park and exceeding, when totalled with other project open space, 10% of the open space requirement for the use: a bonus not to exceed .50 (50%).
USES ALLOWED IN ZONE
The uses to be allowed in the zone have been selected for compatibility with the adjacent residential neighborhoods and in response to the Committee's desire to create a zone which truly encourages a mix of uses. Recognizing the importance of scale along the corridor, size of the use was also an important consideration.
A new category of use was developed. Called "a", it allows a number of commercial uses when residential use is a significant part of the project and the commercial use does not exceed a certain size. We believe that this category will proivde an incentive for mixed use projects while maintaining the desired scale.
A: Use allowed by right
S: Use permitted by special review only
a: Use allowed by right provided at least 50% of the floor area is for residential uses and non-residential use is less than 7,000 square feet; otherwise by special review only.
*: Use not allowed
Mixed Use District MU-X
1. a. Places for the retailing of goods, a
provided the stores are meant primarily for the convenience of the residents of the area in which it is located, not the whole community;
b. Same...and project no larger than A
2000 square feet in size.
2. Personal service outlets, including, A
but not limited to, barber and beauty
shops, shoe repair shops, self-service laundries, travel agencies and photographic studios;
3. a. Places for the retailing of goods, a
including, but not limited to, drug, book, stationery, liquor, florist, or specialty shops;
b. Same...and project no larger than A
2000 square feet in size.
4. 0ffices--including professional, finance a
insurance and other services;
5. Medical and dental clinics; a
6. a. Indoor eating and drinking establish- S
ments which may include meal service on an out-side patio not more than one-third the size of the indoor eating space;
b. Same...and no larger than 1,000 square a
feet in size.
7. Membership clubs--not conducted primarily S
8. Single-unit dwellings; A
9. Multi-unit dwellings; A
10. Boarding and rooming houses, fraternities S
and sororities and dormitories (including bed and breakfasts)