A thesis project for completion of the College of Environmental Design Masters of Architecture program at the University of Colorado at Denver
Douglas A. Kehr April 24, 1980
All animals are molded by, and are captives of their environments"
TABLE OF CONTENTS
Problem Statement City Map
Site Context Map Hi story
What is a Zoo?
Issues Addressed Summary Personal Goals Product
Spatial Requirements Service Diagram Temperature Relationships Solar Data Code Check
Concept Site Plan Floor Plan Sections Elevations Mechanical Diagram Structural Diagram Model
Psychology of Restraint Bi bliography
This thesis ties together my varied educational experiences, a Bachelor of Science degree in Biological Science and Zoology and Master of Architecture degree. It is because of my interest in Zoology that I chose for my thesis a small mammal house for the Denver Zoological Gardens.
The solution to my thesis should represent a synthesis of all my architectural learning at the University.
With the completion of this thesis my formal education at the University of Colorado at Denver comes to a close, but my learning has just begun.
Douglas A. Kehr
I would like to gratefully acknowledge the time, suggestions, and critical comments kindly given by the following:
Susan and Philip Greenberg Greenberg and Greenberg, Architects
A1an Peterson-Architects-Planners-Associates Clayton F. Freiheit
Zoo Director, Denver Zoological Gardens C. Gary Long, Jr.
Director of Architecture, University of Colorado at Denver
Corinne Kehr Wife
The Denver Zoo wants to turn the old Buffalo Range area into an exhibition complex displaying small mammals, reptiles, amphibians, as well as some fish, invertabrates, and possible a few birds.
The theme of the exhibit would be principally ecological and should attempt to show how animals depend upon their environment and each other, and how these factors interrelate.
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Man began to study animals while he was still living in caves, and will probably continue to do so as long as he exists.
Human societies could only begin to assemble anything resembling a zoo when they ceased to be nomadic and had won wealth and leisure to feed their curiosity about animals.
Some exotic wild animals were frequently exchanged as tokens of esteem between monarchs. It was common practice for early rulers to assemble a group of different animals into their private menageries, which was a status symbol and a source of amusement for royalty -these were the forerunners of today's zoological parks. The first of today's zoos is Schonbunn, opened in Vienna in 1752. This was built by the Holy Roman Emperor I for his wife Maria Theresa.
In 1827 the Zoological Society of London was established and its guidance provided the basis for the word "zoo". One of the first zoos in the United States was in New York's Central Park which opened in 1864.
The modern world has over 30 zoos that have passed their hundredth birthday. The Denver Zoo was founded in 1896 making it one of the earliest zoos west of the Mississippi.
The Denver Zoo began when a bear cub was presented to the city and was housed at City Park. Gradually other native animals were added and the Denver Zoo was born. One of the Zoo's earliest claims to fame was Bear Mountain built in 1918, and it is still in use. It is a realistic barless exnibit of concrete rock. Other improvements
were slow to materialize until 1950 when groups of concerned citizens formed the Denver Zoological Foundation and began work to improve
the zoo and help it grow with Denver. Membership in the Foundation is vital to the zoo's continued growth and development.
Denver's Zoo is now a major zoological park and draws nearly 900,000 visitors each year. Special emphasis has been placed on exhibiting the animals in their own environments. Many forms of rare and endangered wildlife are bred and raised and at the present time the collection contains over 1500 specimens representing nearly 400 species. The Zoo sees itself as giving equal importance to the visitors, employees, and of course, its animals in its design.
"The role of education is the most important aspect of the modern zoo."
What is a Zoo?
A zoo's function is four fold; recreation, education, conservation and research. From the recreational standpoint, zoological parks enable city dwellers to enjoy nature and wildlife of the world right in their hometown. The captive animals serve to show the urban dwellers nature appreciation and environmental education. Conservation is achieved through captive propagation, especially of endangered species. Many animals owe their very survival to zoo breeding programs. Zoo research is primarily aimed at studies into veterinary medicine, animal behavior and reproduction physiology. Through these studies in zoos our knowledge of the animals is greatly enriched and broadened to permit the solution of problems in the wild and captivity.
Types of Signs
The Denver Zoo is located in Denver's City Park. The site is located on the zoo's north side just west of the Hungry Elephant Restaurant and has been utilized for about 15 years as a "temporary" exhibit for the American Bison and Longhorn Cattle. This is the last expanse of land available for new zoo development within the confines of its present boundaries. The area encompasses 2h acres and will include the Animal Hospital expansion. The topography is flat with only one tree located on the southeast corner of the site.
Denver enjoys a mild, sunny, semi-arid climate without the extremely cold mornings of winter, or the hot afternoons of summer. Some animals can be left out year round, but some can be left outside only in the summer and need a place to be held during the winter. Some animals will need to be indoors year round. Average annual precipitation is a relatively low 14.5" a year. Snowfall is 59" per year. Denver's climate makes it ideal for solar energy applications.
The zoo is centrally located only ten minutes from Stapleton International Airport, major bus terminals, and downtown Denver. An RTD bus, route 23, stops at the zoo's main entrance. There are also major bus routes that surround City Park on York Street, Colorado Boulevard, and 17th Avenue. Free parking is provided at the main entrance, located on 23rd Avenue between York Street and Colorado Boulevard. There are also plenty of bike racks located just outside the main entrance.
Adequate lighting must be available for satisfactory observation of the exhibit. Daylight has the advantages of being both natural and inexpensive. However, it is not always dependable, varies seasonably, and prevents interesting lighting effects obtainable only with controlled artificial lighting. Each exhibit has its own lighting requirements which must be resolved through investigation of the animals needs and the effects desired. Installation of infra-red, ultraviolet and germicidal
lights are often of special value with certain animal species. For indoor exhibits, the use of operational skylights has several advantages where direct unhindered sunlight and ventilation are of value to the health of the animal. As has been mentioned, shade is another important planning factor and is especially important where aquatic exhibits with their attendant algal growth are concerned.
Adequate measures should be taken to prevent animal escapes, both by the animal breaking out through human error or because of vandalism. Exhibits in any way accessible to the public should always be key locked. Access doors and operating levers to dangerous animal enclosures should be clearly identified.
In general, there are three basic and sometimes conflicting needs to be considered in planning a zoo animal exhibit, namely those of the animal, the visitor, and the attendant.
The needs of the animal take precedence over those of the other two. Since different animal species have different needs, it is important to select those species whose needs can be met without conflicting with those of the visitor and the attendant. Intelligent exhibit design, however, resolves many such conflicts and thus increases the variety of animals which may be exhibited in zoos. It therefore behooves the zoo architect to seek as much technical information and help as is available on the biological needs of the animals to be exhibited.
What has been termed the "social environment" of captive animals is as yet a poorly understood phenomenon but one which may very well exert strong influences on the health and longevity of animals in captivity. Enclosure design should reflect our knowledge of species1 requirements, optimum group size, space needs, sex ratios, and facilities for exercise.
Exhibit Size: Largely determined by the size and activity of the animal. As a general rule,
with many exceptions, however, the larger the quarters, the greater will be the husbandry success of the species.
Exhibit Shape: Also determined largely by the specific kind of animal involved. In any case, acute corners are to be avoided since animals very often will panic when driven into a tight place.
Exhibit Orientation: Where large areas are involved, the greatest dimension should parallel the public viewing area so as to keep the viewing distance between the visitor and the animal to a minimum. Orientation of the exhibit to the sun, especially during the summer season, should also be evaluated for special requirements or problems. Excessive glare in the viewers' eyes should
be avoided, and the amount of sun which might be beneficial or detrimental to the particular animal involved should be considered. Excessive exposure to sun can be a serious health as well as maintenance problem. This is especially true of aquatic exhibits with their problems of algal control.
Materials: Should be selected for ease of maintenance (nonporous, long wearability, low upkeep, permanence), naturalistic appearance, nontoxicity, readily available construction items in standard sizes, shapes, and specifications, etc. Due to constant exposure to weather, cleaning abrasives and detergents, acidic animal wastes etc., the selection of exhibit construction materials used in a zoo require special investigation. Nontoxic paints should always be specified where animal contact is possible.
Eye Level: Depending on the habitat preferences of the animal in nature (ground-living, tree-living, etc.) the visitor's eye level should be considered accordingly in planning the floor and ceiling elevations of the exhibit. In this way the animal will be within maximum viewing range of the visitor. In especially large exhibits, several visitor observation areas are often included--frequently at varied levels.
Step-ups: Since zoo visitors occur in all sizes, from very young children on up, it behooves the designer to ensure adequate observation facilities for everyone. Where cage floors must be above floor level, the use of step-ups for children and short adults are helpful. Observation platforms of several "stepped-up" levels or ramped up decks are useful for highly popular exhibits where crowds cause visibility problems.
Props or Decorations: Such items as are used to impart a natural setting for the exhibit in addition
to fulfilling certain biological and psychological needs of the animals. Examples such as plants, trees, and rock work, termite nests (any one of which may be real or artificial), and even native artifacts (spears, shields, temple ruins, huts, etc) all contribute to the display value of an animal exhibit. Strategically located cage props are important in providing hiding places for animals from one another, objects on which to rub, exercise, mark, sun, etc.
Enclosures should be designed so the animal may be easily shifted from the exhibit into an adjacent holding, isolation or reserve area without having to restrain or catch the animal. Viewing apertures should be designed into such facilities so that animal movements may be observed from a safe place by the attendant and, especially where flighty animals are involved, without the animal viewing the operator. Prisms used in such installations provide a wide angle of observation. The inclusion of a sliding wall of removable bars in a shift cage expands its function to that of a "squeeze cage"; another very useful item of animal husbandry. With the built-in squeeze cage an animal may be immobilized for veterinary treatment without the need of removing it from its exhibit area.
Depending on the kind of animal exhibited, many different types may be used to contain it within its enclosure. For esthetic reasons, those barriers which are the least visible are the most desirable. Barriers which have been used are of the following types:
a. Vertical wires held under tension
d. Moats (dry or water-filled)
f. Walls (including such naturalistic features as vertical rock formations)
g. Glass (both flat and curved or "invisible"
h. Psychological (such as birds exhibited in a wel1-illuminated exhibit area and reluctant to fly into a darkened visitor area)
i. Electrical ("shock" fences as well as charged glass windows)
j. Thermal (refrigerated coils and hot water lines)
When structural barriers are used which interrupt the visibility of the exhibit, such restrictions may be reduced to a minimum by lowering the amount of light reflection from the barrier. With bars, fencing, etc., reflections can be reduced tremendously by painting the barrier flat black or other flat dark colors.
Glass barriers, when improperly installed, become viewing barriers themselves when they pick up so many extraneous reflections that the exhibit is actually hidden from view. Tilted installations, the use of light-deflecting drop curtains and walls behind the viewer and the use of curved "invisible" glass all serve to reduce and eliminate reflections. Glass, of one design or another, is so widely used in zoos that its proper installation to avoid reflections is of paramount consideration. Glass may also serve as a viewing barrier when opaqued with condensed moisture. Frequently properly directed ventilation can correct this problem.
Structures entered by the public in which the animals are maintained indoors, either seasonally or throughout the year. Often, outdoor cages, pens, or grottos are located adjacent to a building. In this way, the animals may be shifted indoor, or out--according to the weather, the year around. Indoor exhibition may be desired for reasons of climate control (most animals of tropical origin) or for reasons of display effect where a darkened visitor gallery is essential (especially with glass-fronted displays).
Whenever possible it is desirable to restrict an animal display to a single exhibit area (either indoor or outdoor) for reasons of economy and to avoid practical problems of exhibition. In the latter case, the problem usually resulting from dual exhibit cages (indoor and outdoor) is that when animals have access to both areas, the visitor must search both areas or miss the animal. Indoor cages can be designed so that the benefits of outdoor exhibition are brought indoors through the use of operational skylights, moveable roofs, adequate ventilation, etc. Where adequately large indoor exhibits are impractical or too expensive, an effective compromise is to locate the indoor exhibit cage adjacent to the outdoor exhibit so that the visitor can view both from the same vantage point. Because of the exceptionally large crowds which visit zoos, details of design and materials selection must be carefully considered in planning the public areas of zoo buildings. Floor type is important as zoo visitor traffic is generally of a "shuffling" nature. Since zoo patrons frequently
consume refreshments while walking, food spillage and the resulting hazards must be anticipated. Ramps (often imbedded with nonskid materials) are much preferred to steps. Adequate ventilation is mandatory and must be separated from animal areas. Some zoos include refrigerated air conditioning for visitor comfort. Traffic flow is another important factor and with careful planning should be as well-controlled and orderly as possible, preferably one-way on busy days. Clearly marked emergency exits are generally required by law.
A function directly proportional to the size of the animal collection. Size of this facility should reflect anticipated growth and its design should permit future enlargement. Prevention of rodent access to stored foods and ease of pest control should be incorporated in the design. Basic requirements for this activity are as follows.
Regrigerated Holding Facilities. Both chilled and freezer storage space is needed for food holding.
Kitchen. Diet preparation area with equipment such
as grinders, choppers, mixers, blenders, juicers, stoves, ovens, scales, knife sharpeners, utensils (knives, steels, spoons, etc.) and containers (pails, dish pans, trays, etc.). Thawing facilities for frozen foods are especially useful.
Storage. Nonrefrigerated food storage including grains, commercially prepared foods, and canned goods.
Employees' quarters with lockers, showers, restrooms and dining areas are necessary for any operation.
Types of Signs
Natural History. Common name, scientific name, habitat, geographic range and interesting natural history information. Where several species are exhibited together, these signs should be illustrated for easy identification.
Visitor Information. Signs which advise the visitor of opening times for exhibits, acknowledgment of donations, feeding times, etc.
Visitor Instruction. Signs for protection of animals such as "do not feed", and warnings of potential dangers to visitors, such as crossing guard rails, entering off-limit areas, etc.
Directional. Signs directing the visitor to exhibits buildings, service facilities, etc.
Currently the Denver Zoo has a rather extensive collection of various mammals, however, these are fragmented and scattered throughout the zoo. A single exhibition would be much more effective in a building designed solely for that function. The complex will be one or possible several low-profile buildings connected without outdoor exhibits and have indoor-outdoor relationships. Each ecological group of animals will have its own separate environment, therefore the planning of the mechanical system must be meticulous due to its envisioned complexity. Minimal heat or none at all in at least some of the public areas should be considered. Solar energy should also be considered due to the south facing site and excellent climatic conditions, especially for hot water for all of the pools. Animal exhibitions areas should have rounded corners to achieve a diorama effect. Extensive skylighting will be a necessity over the planted areas which will remain unexcavated wherever possible. No exhibition will be located opposite others to minimize reflections. Consideration should be given to light traps between exhibition sections and for entry areas. Since the building will contain venomous reptiles it will be regarded as a high security section of the zoo. Area housing venomous reptiles must be designed so that these animals are readily discovered and recaptured in case of an escape. The entire complex should be a harmonious blend of subtle architecture and landscaping. Only the entrances of the building(s) should have architectural character. The east part of the building should have something interesting so the visitors eating on the restaurant patio can have something to watch (an outdoor monkey exhibit).
I want to design a functional and exciting building that will efficiently serve both man and animals. In this "zoo within a zoo" the building and exhibits should educate man, show that he is not a separate entity, and extend the message of conservation.
The product will be a building that will house many types of animals comfortably and safely, while being energy conscious and interesting. The exhibits within will show many varieties of animals in their natural environment and will serve to educate and entertain the zoo's visitors.
The exhibits would be divided into 6 major and 4 minor sections for a total of 10 areas. Each section would be a separate exhibit theme representing a particular ecological region of the world. Each of the sections would be a series of indoor and/or outdoor exhibits containing animal species native to that particular region. Many of the indoor enclosures would have special lighting for nocturnal animals and some areas will need special viewing pools to observe fish and amphibians. Graphics and audio-visual effects would be necessary for all exhibit areas.
Suggested "major" exhibition areas are:
1) Southwestern U.S. Desert
2) Florida Everglades
4) East African Savanna
5) West African Forest
6) Malaysian Jungle
The "minor" exhibition areas are:
1) Colorado Rocky Mountains
2) Eurasian Temperate Forest
3) Australian Outback
4) Northern Tundra or Taiga
Southwestern U.S. Desert 1800 Square Feet
The purpose of this section would be to show a diversity of creatures that have become adapted to survive in the inhospitable world of desert; thermo-regulation would be an important aspect of the exhibits. It could be divided into 2 sections; the desert by day and the desert at night. Both sections would be useful to explain to zoo visitors how animals deal with temperature extremes and water scarcity in the desert.
Possible inhabitants of the desert exhibit could include:
Desert pupfish Spadefoot toads Desert tortoises Roadrunners Cactus wrens Kangaroo rats Jack rabbits Cacomisties Coatis Margays Scorpions Tarantulas Peccaries
Lizards (various) Rattlesnakes King snakes Trap-door spiders Gila monsters Coral snakes Bull snakes Elf owls Quai 1 Kit foxes Badgers Skunks
Florida Everglades 2,000 Square Feet (Walk-through exhibit)
This section would be principally devoted to reptiles of the
southwestern U.S. notably the American alligator. The zoo would hope
to recreate a typical section of a southern swamp and possible route
visitors through the exhibit on an elevated bridge. The alligator
exhibit area should be large enough to encourage the animals to breed.
In addition to the alligators, this section could also exhibit:
Water snakes Bullfrogs
Rat snakes Congo eels
Water moccasins Aquatic turtles (various)
Tree frogs Anolis
Amazonia 2,000 Square Feet
The Amazon region is one of the world's richest wildlife areas, chiefly composed of tripical rain forest. Its zoological diversity insures exciting exhibition possibilities. The zoo proposes to recreate a large section of Amazon Riverbank with underwater viewing for zoo visitors. Spaces above and behind the water, as well as between major aquatic exhibits, would be adapted for a variety of small mammals, reptiles, and some birds, amphibians and insects. Properly executed, this section of the building could become one of the outstanding zoo exhibits in the country!
Possible inhabitants of Amazonia could include:
Small monkeys (Squirrel, Saki, Owl)
Anteaters (Tamandua, Silky)
Boas (common, tree)
Anacondas Tortoises Vine snakes Caecilians Poison frogs Lungfish Arowana Arapaima Piranha
Hercules beetles Brazilian killer bees
Opossums (Murine, Wooly, Water)
Amazon dolphins (India)
Aquatic turtles (Matamata)
Pit vipers (Fer-de-lance)
Coral snakes Horned frogs Tree frogs
Tropical fish (Angels, Discuss)
Electric eels Giant Cockroaches Leaf-cutter ants Large millipedes
East African Savanna 1,800 Square Feet
East Africa supports an enormous variety of wildlife on its grassy savannas. A panoramic exhibit featuring the small mammals, some birds, the reptiles and several fishes of East Africa would be a major feature of the building. One segment could concentrate on the life in and around a termite hill, another could present animals which associate in Baobab trees. Predator-prey exhibits could readily be featured here.
Potential inhabitants of the East African Savanna could include:
Galagoes (Senegal, Greater)
Electric catfish Dung beetles
Mongooses (banded, dwarf)
Oxpeckers Jacanas Crakes Kingfi shers Hornbi11s Lovebirds Walking catfish Mouth-brooders Elephant fishes
West African 1,800 Square Feet
The tropical rain forest of West Africa are home to many interesting, yet secretive animals. This section would follow the East African exhibit to demonstrate adaptation diversity among animals of the same continent. Much of this section would be nocturnal displays and at least the crocodile pool should have underwater viewing.
Some possible exhibits are:
Giant pouched rats
Carpet vipers Rhineroceros vipers Dwarf crocodiles
Talapoins Colobus monkeys Squirrels
Night adders Tree vipers Gaboon vipers Hinge-back tortoises
Malaysian Jungle 1,800 Square Feet
This area of the exhibit complex will be another rain forest section focusing on the small mammals, reptiles, amphibians, and fishes of Southeastern Asia. Here again, there is an enormous wildlife diversity from which to draw exhibition material which will provide meaningful educational experiences for the zoo visitor.
Species for consideration include:
Tree shrews Lorises (2 species)
Flying "lemurs" Fruit bats
Tri-colored squirrels Giant flying squirrels
Bush-tail porcupines Hog badgers
Ferret badgers Binturongs
Palm civets Clawless otters
Fishing cats Golden cats
Clouded leopards Leopard cats
Linsangs Mouse deer
Flying snakes Rock pythons
Blood pythons Reticulated pythons
Tree vipers Russel's vipers
Cobras King cobras
Geckoes Flying "dragons"
Tree frogs Horned frogs
Mudskippers Archer fish
Land hermit crabs Coconut crabs
This concludes an analysis of the "major" exhibition area
complex, we shall now examine the so-called "minor" sections.
Colorado Rocky Mountains 1,200 Square Feet
This area would focus principally upon native species of mammals, reptiles, amphibians and fish. The exhibit could represent a trout stream in the mountains with an associated beaver pond and a nearby
Talus slope. Properly executed, its potential as a zoo exhibit is exciting! Independent research conducted at the Denver Zoo in 1972-1973 indicated that the Colorado pika, if given suitable conditions,
can not only be kept but bred i
ral part of this section of the
In addition, the following
Beavers Chipmunks Rock squirrels Red fox Martens Owl s Grouse Trout
captivity. Pikas should be an mteg-building.
species could also be included:
Yellow-bellied marmots Golden-mantled ground squirrel Porcupines Striped skunk Weasels Jays Frogs
Eurasian Temperate Forest 1,200 Square Feet
Several interesting exhibit possibilities present themselves when considering the temperate forested regions of the continent of Eurasia. The animals listed could, for the most part, be kept in outdoor enclosures with minimal shelters:
Wolverines Red pandas Hedgehogs Pallas' cats Owl s Jays
Australian Outback 1,200 Square Feet
The continent of Australia is home to some of the most unique wildlife in the world. This section would be a panoramic exhibit
featuring the inhabitants of the semi-arid, scrub regions (outback) of Australia. Several of the exhibits would be nocturnal.
Possible inhabitants include:
Bruch-tail phalangers Native cats Kookaburras Parakeets Cockatoos
Blue-tongued skinks Bearded dragons Monitors
Amethystein pythons Brown snakes Black snakes
Wombats Sugar gliders Wallabies Frogmouths Lorikeets Brush turkeys Stump-tailed skinks Frilled lizards Carpet pythons Taipans Death adders Tiger snakes
Northern Tundra or Taiga 600 Square Feet
This section would be quite small in size and totally outdoors.
The zoo envisions a moated enclosure for displaying Arctic foxes with an associated aviary (fronted with harp wire) for Snowy owls.
Such a large, complex exhibition building requires highly specialized and extensive facilities to properly care for the exhibits. These should include:
1) a diet kitchen with short-term food storage 2,500 square feet
2) 2-3 holding rooms for small mammals and reptiles -600 square feet
3) a high security holding room for venomous reptiles -200 square feet
4) holding tanks for fishes, aquatic reptiles and amphibians 200 square feet
5) A keeper's locker roon, lavoratory, shower and lounge -2,000 square feet
6) an office for a curator or supervisory keeper 250 square feet
7) a live food room 500 square feet
8) several mop closets 150 square feet
9) dry storage rooms 500 square feet
10) storage areas for exhibit props 1,500 square feet
11) winter storage 2,000 square feet
12) Service 6,000 square feet
The following should be included to serve the visiting publ
1) Restrooms 200 square feet
2) benches indoor and outdoor
3) drinking fountains
4) waste containers
The approximate building area equals 31,400 square feet.
Winter Design Temperature 2F Winter Degree Days 6200
Sun angles for Denver, Colorado at 40 N. Latitude.
June 21 (Solstice)
5 am 7 pm 4
6 am 6 pm 15
7 am 5 pm 26
8 am 4 pm 37
9 am 3 pm 49
10am 2 pm 60
11am 1 pm 69
March 21 (Equinox)
7 am 5 pm 11
8 am 4 pm 23
9 am 3 pm 33
10am 2 pm 42
11am 1 pm 48
December 21 (Solstice)
8 pm 4 pm 6
9 am 3 pm 14
10am 2 pm 21
11 am 1 pm 25
Building Code Check
Project Animal House Location Denver Zoo Applicable Zoning Ordinance Denver Applicable Building Code Denver
Floor Area Ratio.Building Sq. Ft. Limits 7800 x 33 1/3% = 10,400 Separation 4 sides x 100% = 20,800
Building Height 2 stories or 50 feet Setback 20 feet all sides
Fire Zone Designation 3 Occupancy Class B-3 Construction Type V(5)
Exterior Wall Fire Ratings 1 hour Exterior Wall opening 10 feet setback Floors Fire Rating 1 hour Roof Fire Rating 1 hour Partitions Fire Rating 1 hour Structural Frame Fire Rating 1 hour
Maximum Floor Area Unsprinklered/
Maximum Height Unsprinklered/
Number Exits Required 2
Number Stairs Required 2
Doors Width Required 3 feet
Stairs Width Required 36 inches
Corridor Width Required 44 inches
Stairway Landing Required 36 inches
Travel Distance/Dead End Required 20 feet maximum
Door Swing Swing in direction of exit travel
Stair and Balcony Rail Required 30-34 inches above nose of tread
Ramp Requirements 1:12 first floor grade
1 landing at least 5 feet wide 32" handrail
Riser/Tread Limits not to exceed 7% inches, run at least 10 inches
Vertical Opening Limits and Fire Ratings 1 hour
Exit Lighting lit at all times, 1 foot candle at floor level
Ceiling Heights minimum 7 feet over 50% floor
Light and Ventilation Requirements all portions provided with natural or artificial lights.
Skylight must be tempered or laminated glass
Toilet Room Fixture Requirements Women 3 water closets
Men 2 water closets
2 urinals 1 lav
1 drinking fountain
Zoning Code Check
Zoning Classification 0-1
.17-3(1) Zone Lot for Structures. A separate ground area, herein called the Zone lot, shall be designated, provided and continuously maintained for each structure containing a Use or Uses by Right. Each Zone Lot shall have at least one front line. Upon application to and approval by the Department of Zoning Administration, the boundaries and area of a Designated Zone Lot may be amended if full compliance with all requirements of this ordinance can be maintained.
.17-3(2) Location of Structures. All structures shall be set in a distance of not less than twenty feet from each front, rear and side line of the Zone Lot, provided, however, that no setback shall be required for electrical substations, gas regulator stations and utility pumping stations except from such lines of the Zone Lot as abut public right-of-way. The space resulting from the foregoing setbacks shall be open and unobstructed; provided, however =
.17-3(2) (a) Fences or walls not exceeding 72 inches in height may be erected on any part of the Zone Lot. The height of such walls or fences shall be determined by measurement from the ground level at the lowest grade level within three feet of either side of such walls or fences. Fences or walls permitted hereunder shall not be included in computing compliance with Outside Area of Window Exposure:
.17-3(2' 'b) Any structure or part thereof which is below the grade of any setback space may project any distance into such setback space.
.17-3(2) (c) Canopies may project any distance into the front
My overall design concept is that form and function should be subtle and unobtrusive merging with the landscape to create an edifice that is appropriate for zoo architecture.
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DOUGLAS A. KEIIH MASTERS THESIS
DOUCLAS A. KSHD
PSYCHOLOGY OF RESTRAIN"
Psychology of Restraint
It is no longer necessary or acceptable to have small and gloomy cages for animals existing in barely endurable misery. The common management practices in animal husbandry, which had usually been based on intuitive methods, have now been placed on a firm scientific basis. Nonetheless there are sentimental extremists who regard even the best zoological gardens as the worst kind of prison and plead for the liberty of the animal. Their emotions ignore the fact that zoo animals can be healthier and better fed than in the wild; that zoo animals live a longer average life; that their illnesses are treated scientifically and that old animals, which could not compete in the wild, are cared for and protected.
Until recently very little was known of the life that animals lived in their natural state, and consequently the problems of life in captivity were impossible to solve. Although generalizations cannot be made for animals' requirements it is important to realize that there can be no such thing as freedom in the wild. 'Free as a bird' is a misleading expression. Like all other animals they are prisoners in space and time, confined not only by their geographical distribution but also by their relationship with other animals. These restraints have been defined as 'territory', 'dominance', and 'fleeing distance'.
Apart from such obvious physical boundaries as mountains and oceans, effective limitations are also imposed by such factors as temperature, humidity and vegetation. There are elements which can be effectively determined and reproduced in the designated environ-
ment, but they must be designed so that the animal can accept this artificial habitat as its territory.
In the simplest sense an animal's territory is a physical area from which it attempts to exclude all others apart from certain selected individuals. It is clear, therefore, that this territory must have very specialized attractions for each species. To re-create these conditions cannot be a simple achievement, and the biology of a zoology to psychology, from ethology to pathology, that no one person could satisfy all these functions. The architect must recognize himself, and be recognized, as a member of an integral team of specialists if the artificial environment is to be created with success.
The concept of territory is effectively linked with the phenomenon of dominance. Within its territory any animal can display aggression and defend its space with more confidence against any other, irrespective of its position of relative rank within the order. Thus the success of a cichlid fish in defending its territory is inversely related to its distance from the center of the territory.
For the animal to be able to accept its territory it has to be able to establish its boundaries. A typical demarcation of this area is by scent. At definite places within the territory such animals as hippopotamuses, lemurs and red pandas deposit secretions which they constantly renew. Alligators determine their territorial areas by using their bellowing roar in addition to their scent glands, but the animals most commonly associated with acoustical means of demarcation are birds and monkeys, especially the gibbons whose inter-group
howling sessions define their territories and thus prevent physical battles.
The most important part of the territorial area is the animal's home, which is the place of maximum concealment, and within their established territories many animals follow definite tracks and have designated places for carrying out specific activities at definite times.
These territories are interwoven amongst a variety of species.
In any one place at any given time there may be animals living underground, in water, amongst trees and in the air. Some will be diurnal, other nocturnal or crespuscular. There will be predators and their prey, mature animals, babies and ailing specimens, all producing a shifting balance of nature.
To reproduce such a composite pattern within a zoological garden is clearly impossible. At this moment we can only hope to achieve success within the requirements of a particular species, though certain symbiotic relationships can sometimes be maintained, as at Zurich, for example, where rhinoceroses are exhibited with cattle egrets.
On other occasions zoos may mix species together because of lack of space with no pre-planning, or simply for showmanship.
In general the mixing of various species is a difficult and dangerous proposition. To maintain a mixed exhibit successfully requires skill, time, good management and a sympathetic environment. When all these factors are available, the results can be dramatic, and are perhaps best displayed by the achievements at Borasparken in Sweden where elephants, zebras, antelopes, rhinoceroses, ostriches
and crowned cranes all live together in one large enclosure. The paddock is 23,000 square meters in area and the rocky undulating terrain enables the animals to develop their own territories and live fairly independently of each other. At night, when there is no supervision, each animal goes to its own stable.
To develop a composite exhibit of different animals in an urban zoo is understandable but much more difficult. In the design of the enclosure for grassland animals at Frankfurt Zoo the physical shape and dimensions, in the reduced area of 3000 square meters, was most cri tical.
The area was landscaped by earth moving so that the different species and rival individuals could more easily avoid contact with each other. The mounds created also relieve the flatness of the gardens, and dense shrubbery, protected by inconspicuous fencing, adds further interest to the paddock. Gazelles, blesboks, ostriches and bustards all share this one enclosure, and a small isolated hill has been provided as a look-out post for the herd leader of the blesboks.
To assist in the formation of territories and to reduce the risk of fighting, a number of dispersed feeding places are used. The fighting instinct, in fact, is the major problem in mixing different species together, and it is most important, in considering which animals may fight, to recognize the combat rituals of each species.
Wild sheep and ibexes, for example, fight with similar ritual, rearing high on their hind legs and banging their horns together. Because they have corresponding means of attack and defence serious injury is usually avoided. But should the ibex fight a chamois the results
are likely to be much more dangerous. In accordance with its combat ritual the ibex rears on its hind legs, ready to do battle. The chamois, on the other hand, adopting its own characteristic ritual, keeps all four feet on the ground and can thrust its horns into the ibex's exposed body. Fighting is also induced between different species if the preliminary displays of threat are similar to each. Many animals have to perform a series of threatening behavior patterns before they can reach a state of readiness for fighting, so if one of the animals should adopt a posture or issue a noise which is not recognized by the other, then it does not consider the challenge, cannot respond, and fighting is avoided.
There is also, amongst species which closely resemble each other the subtle relationship of biological rank, whereby subordinate species always have to give precedence to superiors. Horned animals will not even allow socially inferior animals to lie down in their presence, and they are, in particular, 'fighting' animals. However, their instinct to fight, as with any other instinct, must not be completely subdued. A large enclosure should be provided in which a number of males can be kept, so that the fighting instinct can be satisfied amongst the constantly changing contestants.
To control the number and frequency of fights to within acceptable limits the enclosure has to be carefully designed. Acutely angled corners must be avoided, and trees, rocks and bushes provided to create separate smaller areas in which vanquished animals can retreat from sight of the opponents. It is also desirable that stables for the individual animals be located at a distance from each
other so that inferior species can retreat to their place of maximum security.
The character of the territories required by different species can also be used to advantage in that the various animals, unlike man, will not fight for space they cannot use and do not require.
Thus grassland animals can be exhibited in an enclosure also containing mountain animals if their differing types of physical territory are provided. Each species then has its own area of refuge, while the landscape can also be effectively enhanced.
Within the animal's own social group fighting is used to determine its position of rank, which is also governed by sex and certain psychological characteristics. Therefore it is undesirable to keep a social animal, such as a monkey, confined to its own company, as it is to have a large number of monkeys with no regard given to sex ratio or the other features involved with social order. The aggravating effects of confined space can often be seen all too clearly in violent form, but the misery caused to the lowest individual may not be so obvious.
The various sexual activities in animal sociology produce other criteria which need to be satisfied if the animal is to carry out its normal activities in its designed environment. Pair bonding is often established with characteristic ceremony and certain external factors are usually indispensable to these ceremonial performances.
With certain terns, for example, the male has to symbolically feed a fish to the female at one particular phase of its complicated ceremony. Booby birds, as we have seen, must have a number of pebbles with which
to perform the making of an imaginary nest, while chimpanzees cannot copulate without having witnessed the actions at some previous time.
The mistaken belief that the restriction of space upon an animal was the chief factor controlling its life in captivity has meant that far too little attention has been given to other much more fundamental requirements. It is the qua!itv of the space, rather than the quantity, which is of paramount importance. The physical boundaries for any individual are affected by what is within that area, in terms of other animals and inanimate objects, and the layout of its space.
Previously it was sufficient to show what an animal was. A lion could be taken from the unknown darkness of the African continent, and presented, on a concrete pad, in European cities. This was enough for that age. Now that we know what members of the animal kingdon look like it is time to progress. Zoos now have to cater for a more discerning public who no longer ask 'what animal is that?' but 'what does that animal do?'
To create an environment in which the animal can carry out its normal activities, and to then explain why it acts that way satisfies the requirements of the animal and the curiousity of the public.
One should design first for the well-being of the animal; all other factors, from conservation and education to maintaining the gate money, can thus be more easily resolved.
In its natural state an animal spends almost all its time involved with food. Either it is looking for something to eat, or it is trying to avoid being eaten. The moment it enters captivity this need for activity is removed. It no longer has any major occupation and unless it is to become senile or psychotic it must have a substitute
activity to keep it mentally alert and physically active.
Although it is proven that animals live longer in captivity, the duration of their existence has to be related to the quality of that existence. Can any animal, in cramped and solitary confinement, have a full and vigorous life as well as a long life? If any zoo inmates which established longevity records were in a state of misery, or even apathy, it would be better never to mention that their natural span of years was ever extended.
There is no method of measuring the quality of an animal's existence, though an assessment of well-being can be made, based on the experienced institution of a knowledgeable and sympathetic observer. For too long it has been supposed that breeding success is the sole criterion for proving satisfactory conditions, but it is dangerous to set such quantitative standards. Animals, and humans, will breed in the most appalling circumstances and indeed the stress of those conditions may prove to have a bearing on the need to procreate the species.
The activity of an animal is dependent upon both internal and external motivations. External causes are primarily the need for food and escaping from enemies, but internal necessity can also incur considerable amounts of activity. Monkeys apply their curiosity in destroying things, and parrots expend much energy in screeching. The cessation of any natural activities, such as digging or climbing, the resulting stylized patterns of behavior suggest that something is lacking in its environment.
The external causes for movement are often severely reduced in captive conditions, and lack of activity can produce serious metabolic disturbances. To train animals to carry out activities by performing
tricks is begging the question, for while it is often necessary to establish routines for catching animals for diagnostic purposes it is undesirable to extend these training routines on a circus-trick basis. The object must be to keep wild animals, in conditions as natural as possible. Animals giving highly artistic performances are as far removed from the natural state as those which have to sit in unhealthy and cramped cages.
It is much more difficult, but much more satisfying, to create conditions in which the animals have facilities for play. They can, and do, provide their own entertainment and it is interesting that one of their most popular games is 'king of the castle' which is universally played, with exactly the same rules, by human children. The playing of games is the most natural and biologically suitable manner for animals to compensate the loss of activity stimulus caused by captivity.
Unfortunately the training of wild animals is regarded as such a normal and desirable activity that it is even applied, without hesitation, to such intelligent animals as dolphins who are extremely playful and resourceful on their own account.
Animals which have their natural instincts suppressed often have to invent less desirable means of activity. Monkeys, from boredom, smear their faeces over walls of their barren cages, and find they had nothing to play with but their own bodies. The animals movements become stereotyped and tension has to be relieved in mechanical actions.
Many zoos seem to be satisfied with keeping only one individual of a species, and in these circumstances the animal's need for occupation can become displayed in distorted or morbid manners. Solitary animals
may practice masturbation or attempt copulation with inanimate objects. On the other hand, if it has nothing else in its cage except a mate, a captive animal may display abnormal behavior by becoming super-sexual.
If we consider the basic premise that it is necessary to design a habitat in which the animal can carry out its normal activities, we thereby encourage the animal to keep itself active. This helps to keep the animal fit and also incidentally has a greater interest and impact for the public.
In creating the designed environment it is necessary to define a space for the animal, and whether this is done with iron bars or invisible moats makes little difference to the animal. It is still in confinement. But to encourage a sense of involvement between people and animals the separation between them should be as natural as possible.
The living space provided for the animal is often a cube, perhaps for reasons of economy or maybe even because of the architect's preconceptions on designing for human beings. The cube, however, is not biologically suitable space. The design should develop from its fitness for purpose without preconceived ideas of shape.
Because there are severe restrictions on space, materials have to be chosen and detailed very carefully. Those that may be suitable in a human context often fail to survive the activities of other less inhibited species. While it is desirable to try to reproduce the natural environment, and to use natural materials, most of the construction should use easily cleaned, impervious materials to reduce the dangers of parasitological and bacteriological infection.
In its general planning the zoo, as a representation of nature, should offer part of the challenge and excitement of wildlife. To
create the illusion of space in what is often a small area, and to provide the refreshing element of exploration, the attractiveness of the exhibit can be considered in relation to certain guidelines.
The viewing distance, for example, should vary with the size and activity of the animal and the character of its environment. Zoo design is often pure theatre, and light can be dramatically used to fall on the exhibit. Reflections on glass are also avoided in this way, and by having dark floors with darkened walls behind the viewers. Any mesh or bars, if they have to be used, are less noticeable if they have a dark, matte finish, and exhibit backgrounds are most effective when they complement the color of the animals.
Because, day in, day out, the zoo director sees so much that is familiar in his environment, his sense of awareness and faculty of discrimination can become blunted. It is important, however, that he continues to strive to seek fresh approaches to encourage the sense of participation and involvement between his public and his animals by exhibits which are consistently attractive and as natural looking as possible. If the construction of the artificial habitats satisfies all the requirements of a photographer it is invariable, in visual terms, a success, for the greatest contribution of the camera is in helping us to see. 'The mission of the camera', Lewis Numford has said, 'is to clarify the object...to see as they are, as if for the first time, a boat-load of immigrants, a tree in a park, a woman's breast, a cloud hovering over a black mountain...' or, perhaps for the last time, such extreme rarities as the Sumatran Rhinoceros at Copenhagen, the monkey-eating eagle at Frankfurt, or the ruffed lemur at London.
The significance of any physical barriers applies not only to the
animal's relationship with man, but also to any other adjacent individuals. Male animals will often attack the barriers between them, especially during the rutting season, or a single male may attempt to reach a female with young. But the animal will not always regard these barriers as limitations, for they also exclude undesirable elements. A male polar bear, trying to reach and attack a cub, certainly has an opposite reaction to that of the young animal toward the barrier.
Each animal is characterized by a specific escape reaction and a specific flight distance. The presence of an enemy within this distance causes violent disturbance, and all too often it is man who has proven himself to be the enemy. The animal must therefore be able to establish its specific flight distance, and if there is not sufficient room to escape, tension is created and the animal has to attack, or rather defend. In a confined area a frustrated animal may even lead to self-mutilation.
In theory, therefore, the flight distance should be designed for as a minimum distance between the animal and its enemy. In practice this is impossible to achieve. Studies of wild animals which regard man as an enemy suggest, for example, that the flight distance of a giraffe is 150 yards, and deer up to 600 yards. Flamingoes may tolerate man's presence up to 400 yards, and small fiddler crabs have a flight distance of no less than 10 yards. Since the area in captivity cannot fit the flight distance, the animal's fear of man has to be reduced so that its flight distance can fit the area. Once the animal has confidence and respect for man its flight distance, can, in fact, become a negative quantity.
The need to keep wild animals in captivity can only be justified, in the final analysis, in terms of conservation. And although it is
only too easy to find examples of cruelty, ugliness and bad management within zoos, these cannot be used to deny the existence of zoological gardens. They are potentially one of the greatest cultural assets that civilized man can maintain, and there are many thousands of animals living in modern zoos which have a full and happy existence. The role of the architect is to ensure that the designed environment is of a standard that will complement the other advantages that a captive animal can enjoy, such as nutrition, safety and medical treatment, so that the animal has physiological and psychological development.
This has been an excerpt from David Hancock's book "Animals and Architecture" (Praeger Publishers, Inc., New York, N.Y., 1971).
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