Occupied space reflects a basic principle of architecture by serving the many aspects of human comfort and security. Beyond this overriding goal, interior spaces are usually individually arranged to facilitate a particular set of uses and are optimized accordingly. Flexibility is often an issue, as the use of the space and the people in it will change over time. In many cases, rapid technical advances change the way a space is used and the services needed. The advent of the desktop computer is a prime example. Architects frequently must anticipate future interior conditions as well as addressing current ones.
• Lighting—ambient and task lighting fixtures, as well as display, accent, and emergency light
• Acoustics—sound absorption, reflection, reverberation time control, room acoustics, noise control, and privacy
• Circulation—communication between spaces, emergency egress, security, signage
• Furniture —fixed and movable elements
• Finishes — floor and wall coverings, hardware and trim, paints and stains
• Specialties — equipment
Zoning for Function. The grouping of building spaces together to best serve their various common needs is the act of zoning. Zoning provides for intelligent marshalling of resources, ease of control, and articulation of the inherent order of the building’s character. Such groupings into separate zones are fundamental to organization of the building problem and are performed separately for different aspects of the design. Resolving the discrepancies between the various organizing forces requires work of informed inspiration.
Functional zoning is best recognized in the bubble diagrams of adjacency relationships common to conceptual design thinking. These clustering relationships may reveal the organization of a complete plan or suggest component modules that are repeated to fulfill the design. The number of potential zoning principles that should be overlaid on a plan varies from project to project according to the critical issues to be addressed. But even restricting these overlays to the most basic ones can create a complex organizing scheme. Arriving at an integrated scheme requires attention to each and the ability to synthesize the requirements of each into an overall plan.
Thermal Zoning. Thermal zoning is common parlance for the grouping of different rooms into distinct areas serviced by HVAC systems. Each distinct area is typically under the control of one thermostat. Common residential zoning strategy separates the day-use public spaces from the night-use bedroom spaces and places them on different HVAC systems. Note that this typically reflects the functional organization scheme of locating bedrooms upstairs or in a separate wing of the residence.
In order for thermal zoning to satisfy thermal loads and times of peak gain in all rooms in a zone with any degree of uniformity, the rooms must share five characteristics:
• Similar solar exposure and orientation: East-facing rooms and west-facing rooms will have vastly different schedules of thermal needs, just as rooms with large window areas will have different needs than rooms with smaller windows.
• Similar envelope exposure: Perimeter rooms with exposure to the outdoor environment through the exterior envelope will have different needs than rooms in the core of the building, which always need cooling because they have no means of heat loss.
• Similar occupancy type and density: Libraries and auditoriums should be grouped in different zones. Likewise, private offices and large classrooms should also not share a thermostat.
• Similar schedule: The weekday classrooms of a church school should not be in the same zone as the Sunday congregational assembly space. Weekend-use offices where cooling systems may be activated for the comfort of a few workers should not be zoned together with large lobby spaces.
• Shared incremental capacity: Where multiple modular HVAC systems are used, it is common engineering practice to select small package units and distribute them as needed across the different zones of the building. Retail buildings typically use rooftop units of about 8 to 10 tons cooling capacity and divide the retail floor area into zones of appropriate size.
Luminous Zoning. Luminous zoning is primarily determined by the availability of daylight and its depth of penetration into interior spaces. Typical approaches consider perimeter, interior, and core areas of a plan. Supplemental artificial lighting must be planned for each of these zones individually, to account for the amount of fill light required to reach desired illumination levels.
More recent and enlightened luminous zoning strategies reverse the typical uses of these zones — clerical areas are placed close to windows, where demanding visual tasks receive high-quality and abundant natural light. Executive offices and conference rooms in this scheme are placed to the interior of the plan, where fewer critical demands are made on illumination. Finally, core areas, elevators, stairs, and the like are positioned on east and west walls so that no windows are exposed to the worst solar orientations. Norman Foster’s Hong Kong Bank, Leo Daly’s Lockheed Building in Sunnyvale, California, and the Farmers Credit Bank Building in Spokane, Washington, are all examples of this luminous and solar zoning scheme (see case studies #25 and #9).
Acoustical Zoning for Noise Control and Privacy. Noise is unwanted sound. The discomfort it causes is of concern to designers of buildings. Privacy is a complementary concern, related to matters such as confidential conversation. Both of these issues require planning for sound separation between the sound source and the listener. Neglecting acoustical issues in the early stages of design may dictate very-high-performance walls and door separation (Transmission Loss, TL, or Sound Transmission Class, STC) between occupancies, as well as increased levels of background masking sound (Noise Criteria, NC, or Room Criteria, RC) in the final solution (see Stein and Reynolds, 2000).
In terms of basic acoustical zoning, spaces can be classified as noisy, quiet, silent, or buffer areas, depending on the noise level generated by activities they house. Rooms for mechanical equipment, copy machines, toilets, and so forth, are noisy. Conference rooms, study carrels, and sleeping rooms are examples of silent spaces. Good acoustical arrangement isolates noisy areas and separates them from silent rooms with buffer spaces such as storage rooms and closets.
Using just these four fundamental principles of functional, thermal, luminous, and acoustical zoning, it is easy to imagine the complexities encountered when all four are being considered simultaneously. Any multiuse building program will have areas with distinct thermal, luminous, and acoustic needs. Even a residence will require different thermal zones based on schedule, different luminous zones based on activity, and different acoustical zones based on noise and privacy. Consider how an overlay of these zoning considerations would affect the interior systems of a hotel, office, or school.
Circulation, Egress, and Life Safety. There are many systems of flow within building interiors. Air circulation, electrical power, daylight penetration and diffusion, paperwork and supplies, and so forth. The most important flow in a building, however, is the circulation of the occupants. Individuals and groups of people need easy access to each other, to the facilities of the building, and to its exitways. In the case of fire or other emergency these circulation flows become highly critical matters of life or death. Even in normal operation the flow rates and resulting density of people requiring open routes can be very high. Lunchtime at the Lloyd’s of London building, for example, leads to increased usage of the escalators, elevators, and toilet room arrangements of the office building as 8000 people leave the market floor and surrounding offices, only to storm back in at the end of their break (see case study #24). Other buildings, such as airports and classroom buildings, have similar critical issues related to circulation.
Life safety codes dictate organizational design responses to circulation in all public buildings. The minimum number of exits and minimum width of corridors, as well as the maximum distances to exits, are just some of the basic form regulating design considerations. The construction assembly fire rating and the corresponding fire rating of doors and mechanical penetrations are also specified by code.
Aside from the convenience and safety factors, horizontal and vertical circulation strategies are also connective elements of space planning. To use the example of Lloyd’s of London again, the market trading floor, or The Room, as it is called, is the focus of the building, much like the trading floor of the New York Stock Exchange. Richard Rogers and his team enhanced the level of face-to-face communication among the traders by folding five floor levels of The Room back onto themselves around an open atrium and connecting the vertically layered floors with open escalators. This greatly reduces the walking distance from the most remote desks as compared with the situation that would have been produced by a larger floor plate and fewer stories. It also reduces the distance to exitways and the required width of the circulation paths. Rogers then used the site area preserved by the smaller floor plate for towers containing the elevators, toilet rooms, and stairs and located them in six residual corners of the site. Norman Foster used a similar strategy at the much larger Hong Kong and Shanghai Bank (see case study #25) to organize the 43-floor bank into seven distinct vertical villages with interconnecting escalators but only one elevator stop per village.
Site Systems
Systems integration at the site level deals with issues of context: environmental, social, urban, cultural, and whatever special conditions are presented by the exact situation of the building project and its neighboring surroundings. Site systems are the first level of interface between the building solution and the site context.
• Topography—building set on, above, or into differing grade levels; retaining walls and modifications to natural grade
• Surrounding structures — shade, wind, and view determined by immediate surroundings
• Footprint—orientation, elongation, and massing of the building
• Perimeter—defining the boundaries of the site with fences, gates, walls, hedges, and/or landscaping
• Landscape—vegetation, bodies of water, and other natural features
• Paving—parking, access, driveways, pedestrian paths, terraces, patios
• Storm water—rainwater drainage, detention ponds, swales, gutters and downspouts, area drains, curbs, and gutters
• Utilities—service connections, transformers, meters, waste disposal
• Site lighting—general illumination, facade lighting, lighting for pathways, security, signage
• Appurtenances — gazebos, porte-cocheres, arbors, fences
Microclimates and Environmental Site Design
From the environmental perspective, the site forms microclimatic conditions by modifying the regional climate. Then the relationship of a building to its site begins as a series of formal responses: thermal, aerodynamic, solar, luminous, and so on. For example, a building on the north side of a hill is in a very different microclimate than a building on the south side of the same hill; a building surrounded by asphalt is in a very different condition than one surrounded by trees. To a large degree, these microclimatic modifications can be controlled by careful design and deployment of the site systems. This means that the site can be treated as an outer layer beyond the envelope and act to interpret environmental conditions favorably.
The integration of site systems should maximize the results of these modifications. Trees established for shade also affect wind patterns and views into and out of the building. Paving is used to drain storm water from parking and surrounding areas. Solar orientation and the placement of glazing impact the availability of lighting and the issues of view and privacy. Natural bodies of water and storm water detention ponds can work as cooling towers for the HVAC system. This list can be elaborated at length, as can be seen in the next section of this chapter, but bear in mind that potential benefits depend heavily on the particulars of the building program.
Architecture as an Armature for Nature
Ultimately, site design determines a building’s place in nature. As soon as the building is completed, nature begins to reclaim it by acts of weathering, erosion, and chemical and biological change. High levels of maintenance will be required if the building and site elements are to resist nature’s reclamation. Without continuing maintenance, nature will mark the building with its weathering processes. The architect has to design according to assumptions about ongoing maintenance over the building’s lifetime to accommodate this aging. Durable materials that defy the weather are more expensive than those with shorter lives; exposed materials require more detailing than painted ones.
Mostafavi and Leatherbarrow (1993) have characterized two opposing perspectives in their book, On Weathering. They portray the maintenance of a building’s original condition as resistance to stain and the planned aging of a building into its surroundings as a graceful patina. On another level, this opposition can be seen as a more philosophical distinction between the entropy of nature and the organizational work of industrial society. Nature works toward diffuse homogeneity as wet moves to dry, hot moves to cold, high pressure moves to low, mountains erode to fill the valleys. The laws of physics move our environment toward homogenous conditions, higher states of entropy. Any potential for movement, any difference in energy levels, drives the work of nature. In nature’s pristine state, all of these motions are present. The works of an industrial society, on the other hand, are directed against natural entropic decay. In the pristine state of industry, everything is clean and gleaming. Civilization to date has been the history of this pioneering against entropy, moving instead toward organization, focus, and concentration. The pioneer mentality that generated the rise of industrial society was always aligned against the erosion of nature; stain was a symptom of failure to hold back its forces.
Accepting the inevitability of weathering embraces the opposite perspective: a graceful patina acquired as nature reclaims a built work and its setting. This attitude is more evident in Eastern civilization and in organic and naturalistic approaches to architecture. Certain aspects of it have crept into Western thinking as economic pressures make submission to entropy more practical than resistance: xeroscape and native landscapes, organic gardening, passive solar design, and the selection of natural materials, to mention a few.
Many attitudes about design are prone to regard the site as a resource for the building. The imposition of the architectural footprint on the land is given dominance over the condition of the site in terms of everything from orthogonal geometries to border plantings. The counterposition asks about the notion of buildings as systems that will gradually be reclaimed by nature anyway. It proposes that a building is, in fact, an armature for nature and so replaces industrial mechanics with natural ones wherever feasible:
• Paving blocks or stones replace concrete and asphalt paving
• Water gardens replace runoff and storm water retention ponds
• Hedgerows replace border plantings and fences
• Natural landscaping is used in favor of pesticides, fertilizers, watering, mowing and raking
• Earth-integrated buildings are designed in underground, earth-covered, or earth-bermed configurations instead of on graded sites
• Habitats for native species are incorporated in favor of exterminated lawns.
Conclusion: Integration Potentials
There are an infinite number of possible integrations between the five major building systems, between the subsystems of each, and among subsystems of different major systems. There can be no exhaustive list, and, more important, developing the correct list for each building project is a matter of careful decision making in design. It is quite possible, however, to generate a beginning list based on what has been defined here as shared mandates between the major systems. Examples of the integration potential of overlapping shared space, shared image, and shared function among the ten possible pairs of major building systems are outlined in Table 3.1.
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TABLE 3.1 Some Integration Opportunities as Shared Mandates Between the Ten Possible Pairings of Five Major Systems
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