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1、 PA R TI I I CONCEPTUALDESIGN Dennis Couture, A.S.L.A., R.L.A. Introduction Conceptual Design represents the initial effort of describing alternative plans that satisfy the development program ob- jectives in light of the site characteristics identifi ed in the site analysis. It requires full recogn
2、ition of the client pro- gram components, initial site assessment, site context, and planning and regulatory controls. Sketches, functional diagrams, or concept plans are nor- mally completed to illustrate a framework for the given de- velopment program. They generally represent diagrams of the pote
3、ntial distribution of land uses and major circulation requirements. The effort seeks to meld all pertinent com- prehensive or master planning information with site-specifi c considerations to illustrate how the site might best be de- veloped. For large-scale development, this initial cut at the desi
4、gn effort is often accomplished in what are termed blob or bubble diagrams. The intent is focused less on sophisticated graphic technique and more on fostering di- alogue, a preliminary review and assessment, and confi r- mationofdesigndirectionamongthedesignteam participants. Concept plans refl ect
5、ing land use distribution and associated circulation are reviewed in the context of their preliminary implications on infrastructure require- ments as well as economic, functional and political feasi- bility. This phase, similar to the more subjective assessment included in the initial feasibility a
6、nd site analysis steps, moves from the review of general intent to actual physical diagramming of use arrangements. This level of conceptu- alization is generally completed prior to the investment of resources and time resolving more detailed levels of design. STEP 3: CONCEPTUAL DESIGN There are gen
7、erally multiple solutions for the design of any one site. It is common for alternative concept plans to be developed as part of this initial conceptual design phase. The ensuing discussion with the development team may prompt a dialogue as to the pros and cons of the various solutions and identify p
8、roblems the designer alone may not have anticipated. The end products associated with the con- cept design phase may be a series of sketches or diagrams highlighting the distribution of land uses and preliminary infrastructure requirements. The diagrams themselves may be annotated to underscore the
9、advantages or disadvantages associated with the depicted solution and memorialized for future reference. AsdemonstratedinFigureIII.1, conceptual level sketches generally include preliminary delineation of such considerations as: ?Points of site access together with an initial align- ment of major ve
10、hicular circulation routes. The principal road network should be developed in the context of any public comprehensive or master plan- ning policies or recommendations. ?A distribution of major land use elements by type. The delineation should refl ect the approximate area re- quirement for each use
11、to begin to gauge the massing or relative area requirements necessary to accommo- date individual program components. ?Delineation of areas mandated or desirable as open space based the previously completed site analysis, such as fl oodplain, protection areas, wetlands, mature woodland, and streams
12、and stream valleys. ?Preliminary determination of the need and location of major public facilities such as schools, parks, fi re 190 FI G U R EI I I . 1Conceptual design. CONCEPTUALDESIGN191 stations, and libraries, as identifi ed in public planning documents While normally not a formal public submi
13、ssion docu- ment, conceptual sketch plans do provide information suit- able for early discussions with appropriate public offi cials. They provide suffi cient information to obtain an informal assessment by appropriate public agents/offi cials as to the development plans compliance with public compr
14、ehensive and land use policies and the local political climate. 193 CH A P T E R1 2 DEVELOPMENTPATTERNS ANDPRINCIPLES Dennis Couture, A.S.L.A, R.L.A INTRODUCTION This chapter presents an overview of some of the more prevalent land use types and development patterns that comprise our contemporary bui
15、lt environment. It offers a general discussion regarding development intensities and design patterns, including some of the more widespread infl uences on development activity. Such infl uences range from aesthetic and prevalent community attitudes regarding land development project design to the mo
16、re formative fac- tors associated with environmental, political, and economic considerations that guide site design and engineering ac- tivity. Perhaps the most overriding consideration for any land development endeavor should be the project at hand in the context of the larger community. Community
17、in this sense is more than the physical characteristics of a given projects surrounds. It embraces the extant sociocultural, political, and economic paradigms that model the dynamics in any given jurisdiction, resulting in the land development types and patterns that are built. As local context offe
18、rs a guide to project design opportunities, so do more universal con- structs that have evolved in response to the real and per- ceived shortfalls of contemporary development trends. Sensitivity to the urban-suburban-rural distinction in de- velopment types is simplistic. Development considerations
19、that are mindful of the community-making and place- making opportunities and design principles associated with traditional design, such as traditional neighborhood design (TND), neotraditional, and new urbanism, afford a renewed perspective on both the dynamics of community and the opportunities for
20、 meaningful site and project design. Sim- ilarly, constructs associated with the advocacy of smart growth and green infrastructure offer meaningful insight into responsible land development activity. These latter con- siderations are appropriate across the spectrum of urban- rural development activi
21、ties. An extensive overview of the basic tenets associated with these more recent ideological approaches to land develop- ment is beyond the purview of this chapter. Contemporary literature and professional journals abound with informa- tion on both theory and practical application. Familiarity with
22、 this information is particularly relevant for land design agents given that these approaches are perhaps more inter- twined in the livability and marketing side of land devel- opment and site design than might be evident from in-place land use regulatory controls, statutes, and zoning codes. This c
23、hapter provides an overview of prevalent contem- porary land use types. Residential and select nonresidential building considerations are presented in isolation of each other. Although this format may be considered anathema to proponents urging greater integration of potentially com- patible or supp
24、ortive land uses, extensive discussion of such endeavors, even in the context of current mixed use and planned developments, is not the objective here. Rather, identifying some of the base considerations associated with select land use types may provide a cursory foundation for better appreciating a
25、nd identifying what may be unique to each use and how they may be best integrated. A variety of factors determine the type and confi guration of a given land use, including the expectations of landown- ers, users, and consumers; the availability of land; the cost of construction; the natural attribu
26、tes of the site; and the character of the surrounding community. These are modi- fi ed to a great degree by local regulations, which are based largely on more encompassing issues of health, safety and 194 CO N C E P T U A LDE S I G N welfare, local considerations relative to the nature of local comm
27、erce, prevalent community attitudes, and past com- munity practice. An examination of the zoning ordinance in all but the smallest communities reveals great variety in the categories of permitted land uses. Typically, this includes residential, commercial (sometimes broken down into retail and offi
28、ce uses), and industrial uses. Depending on the size, location, and maturity of the community, a jurisdictions zoning doc- ument may establish other land use categories to refl ect its unique economic base, such as manufacturing, agriculture, maritime, mining, forestry, and institutional uses, to ci
29、te a few. Furthermore, the zoning ordinance, as discussed else- where in this book, normally identifi es a series of de- velopment standards, commonly expressed as minimum requirements focusing on such elements as lot size, building height, yard requirements, open space, and impervious cover. That a
30、rchitectural styles vary in different geographic regions in the country is no surprise. Regional variation in history, culture, and heritage affects development patterns in density and confi guration as well. Different names are often used to describe similar types of land use. Most local regulation
31、s are extremely specifi c concerning permitted density, height, bulk, and setback requirements for most land uses. To attempt to assemble and reproduce this wide range of specifi cations would be neither produc- tive nor useful. The discussion of land uses, development intensities, and the design pr
32、inciples in this chapter is in- tended as a primer. If there is a common denominator throughout contem- porary development, it may be its heavy reliance on the automobile as the principal means of transportation. The suburban development pattern is characterized by a strong dependence on the car for
33、 both work- and leisure-based trips. Historically, the separate clustering of residential and employment areas at density levels low enough to make public transportation infeasible have reinforced this. The single-occupant automobile continues to be the most prev- alent form of transportation in the
34、 suburbs. This phenom- enon places a unique set of requirements on resulting land use types and development patterns. Attention to a com- mon need for both vehicular circulation and on-site parking is necessary. Streets and roads provide the common linkage between and within land uses and the princi
35、pal framework of the resulting development patterns. Similarly, parking re- quirements for the automobile are a major design element in the sizing and organization of individual land uses. DEVELOPMENT TYPES Ideally, a community seeks to guide its growth in a manner consistent with its heritage, comm
36、on goals, and economic interests. Local land use activity is guided by comprehen- sive or master planning, representing a compendium of pol- icies, usually subjected to arduous public participation, focusing on topics such as population and economic growth, housing, transportation, community facilit
37、ies, and land use. While a comprehensive plan may contain a mapped graphic representation of what the community might look like at some point in the future, the local zoning ordinance and zoning map are the tools that provide the day-to-day implementation effecting land use decisions rel- ative to t
38、he overall comprehensive plan policy objectives. A clear understanding of the distinction between these doc- uments is imperative to understanding the extant land use patterns associated with development activity in any given community. Decision-makers in land development and de- sign must be sensit
39、ive to the rationale for the type and use intensities identifi ed in the comprehensive plan. They must also be fully apprised of the design standards and criteria governing the size, form, and character of proposed devel- opment, as identifi ed in the local zoning ordinance and similar regulations.
40、It may be useful for the novice to consider a local com- munity as a single large planned community. The compre- hensive plan and its associated policy statements represent the collective public vision to guide community growth. Various ordinances and regulations provide the means to implement that
41、vision. Together they provide the two im- portant elements that establish the foundation for land de- velopment patterns in a community. Historically, zoning ordinances have relied on the delin- eation of distinct geographic zones or districts that accom- modated the development of one land use type
42、. These districts generally included residential, commercial (nor- mally inclusive of offi ce and retail uses), and industrial cat- egories. Subcategories of each use may stipulate gradations in density within a land use, prompting alternative devel- opment patterns or building programs. While much
43、land activity is rooted in a single zone/single use development pattern, more fl exible development patterns and land use combinations are fostered by development controls that perpetuate planned, planned unit, and mixed use devel- opments. The objective of these latter categories move be- yond sing
44、ular use and attempt to foster a framework for greater variety in permitted land uses and arrangements. Prior to discussion of individual development types, it will be valuable to outline briefl y some of the more encom- passing planning terms. Conventional Subdivision The historic basis for much su
45、burban land use is the con- ventional subdivision, created by the division of larger land tracts into smaller land units. Such subdivision generally requires new streets for accessing the newly created smaller land units or lots. The subdivided acreage provides individ- ual lots for houses and lots
46、or parcels for nonresidential uses. While subdivisions have become varied in pattern, lot size, street alignment, open space network, and in some cases a mix in permitted land uses, conventional develop- ment continues to be predicated on the simple subdivision of land. It has been the mainstay of s
47、uburban residential 12 ? DEVELOPMENTPATTERNS ANDPRINCIPLES195 FI G U R E1 2 . 1Conventional subdivision.FI G U R E1 2 . 2Cluster subdivision. development and accommodation of proximate retail, em- ployment, and public facilities. The larger tract acreage is divided in a manner that pro- vides for co
48、mplete transfer of land ownership to subsequent users. Streets are normally incorporated into public own- ership, and community open space, if provided, may be deeded to an appropriate public or semipublic entity. Single or multiple builders may on a lot-by-lot basis, initiate con- struction. Figure
49、 12.1 below represents a typical conven- tional subdivision. Cluster Subdivision Cluster development relies on subdividing larger properties into smaller lots or parcels, but differs from conventional subdivision in that it typically results in a land plan with a greater percentage of the overall acreage set aside in com- mon, community, or conservation open space. To achieve this open space, local regulations generally allow a reason- able reduction in individual lot size and associated setbacks, provided there is no increase in the overall number of lots that would otherwise be pe