CLIMATE SENSITIVE URBAN PLANNING AND DESIGN

CLIMATE SENSITIVE URBAN PLANNING AND DESIGN

771 CLIMATE SENSITIVE URBAN PLANNING AND DESIGN Vladimir Matus, Architect and Urban Planner 63 Metcalfe St., Toronto, Ontario, Canada, M4X 1R9 ABST...

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771

CLIMATE SENSITIVE URBAN PLANNING AND DESIGN

Vladimir Matus, Architect and Urban Planner 63 Metcalfe St., Toronto, Ontario, Canada, M4X 1R9

ABSTRACT The central energy distribution grid makes buildings environmentally independent. Soft path D h i l o s o p h y suggests a shift from central grid dependence to local environment dependence. Since the natural environment is in a constant state of flux, the interplay between a building and its natural surroundings must inevitably be local specific. Thus, harnessing energy from the immediate surroundings to sustain thermal equilibrium requires local specific solutions. Consequently, these solutions are not easily transferable. Applicability of ideas constitutes a major hindrance to a wider acceptance of energy and conscious planning. This paper examines a soft path urban planning approach which encompasses and builds on local uniqueness.

RESUMEN La red de distribucion central de energias hace que los edificios son independientes del medio ambiente. Pero la filosofia de seguir caminos mas adaptables requiere que cambiemos; en vez de depender de redes de distribucion centrales, debemos depender del medio ambiente local. Puesto que el medio ambiente natural esta en flujo continuo, la accion reciproca entre un edificio y su circumambiente debe ser inevitablemente determinada Dor la situacion especifica local. Por consiguiente la tarea de extraer energia del circumabiente inmediato para mantener el equilibrio termico requiere soluciones especlficas locales. Por lo tanto, e*stas soluciones no se pueden facilmente transferir. El problema de aplicar ciertas ideas en otras circunstancias pone un obstaculo a la aceptacion general del planeamiento consciente de la suministracion de energfas. En esta memoria examinaremos la posibilidad de acostar los aspectos de planeamiento urbano por un camino ma's adaptable, considerando las caracterfsticas locales singulares al proyectar construcciones.

772 KEYWORDS Ecochart; slope descriptive synthesis; cellular planning technique; central energy distribution grid; environmental dependence/independence; road alignment; space heating modes; passive solar; local uniqueness.

ECOCHART The proposed climate sensitive planning and design is derived from two sets of analyses: First, the dynamic pattern of local environmental forces; secondly, local topography. The process must begin with the gathering and organization of local environmental data, particularly those related to the sun. However, the dynamic, three dimensional complexities of the weather system escape human comprehension unless presented in a sufficiently simplified form. Thus, collected data is tabulated in a format called an Ecochart, Fig. 1, which would offer meaningful instructions to a professional and thus assist in determining an optimal design and planning strategy.

MONTHS

M

N

M

AIR TEMPERATURE HOURS OF SUNSHINE SOLAR RADIATION

COOLING D. DAYS PRECIPITATION RELATIVE HUMIDITY SOIL TEMPERATURE

4

WIND SOLAR ANGLES

z Fig. 1.

Even a superficial glance at a much simplified form of an Ecochart as shown in Fig. 1, reveals that any man-made or natural object located in the given area must inevitably suffer two major "strokes" every year. These are the extremes of summer and winter. Both are far beyond the boundaries of the human comfort zone. As a result, there is an obvious need for cooling in

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the summer and for heating in the winter. A closer study of local climatic data would reveal that although summer extremes are associated with some degree of discomfort, coping with winter extremes becomes a matter of survival for both the occupants and the buildings. This would determine the direction of our soft path planning strategy. Maintaining thermal equilibrium within the human comfort zone in buildings throughout the time of vigorous oscillation of environmental forces can be achieved in two ways. First, by means of energy input. Energy is delivered via an energy distribution grid from a remote energy generating factory into the building where it is used to mitigate environmental extremes. Secondly, by means of the siting and physical design of the building. In this case, the equilibrium is maintained solely by the capacity of the building to respond to outside change by harnessing "good" environmental forces and rejecting "bad" ones. A number of recent experiments confirmed that it is possible to construct a zero heating bill house at 43° latitude at a competitive price. However, it requires considerable assistance from the sun. Consequently, some areas in the Ecochart region would be more preferable than others.

LOCAL TOPOGRAPHY Since topographical variations are of crucial importance in the "soft path" planning method at 43° latitude, the conventional contour map has to be translated into a form which offers a planner a set of concrete instructions. The first step is to develop a "Slope Descriptive Synthesis" which consists of a square matrix - the size of a square represents the degree of slope (slope gradient) - and of arrows or possibly colour coding which indicate the relationship to the sun (slope orientation description). The "SDS" portrays the land as a natural solar collector.

Fig. 2.

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In the second step, "Cells" , sub-areas with particular characterisitcs, are identified. For example, E3 represents an area with an eastern orientation and a gradient of three percent; S10 is a south oriented slope of ten percent; W5 is a western slope, five percent, etc., Fig. 2. By virtue of its own characterisitcs, every cell contains special constraints as well as offering unique opportunities for the development and use of the land. With the help of special matrices, the urban planner can derive from the cells a number of important instructions particularly related to land use and density, Fig. 3.

SLOPE GRADIENT % 2.5 5 10 20 20+

LAND USE DETACHED HOUSING SEMI-DETACHED HOUSING ATTACHED HOUSING LOW DENSITY APARTMENTS MEDIUM DENSITY APARTMENTS HIGH DENSITY APARTMENTS COMMERCIAL INDUSTRIAL CIVIC AND INSTITUTIONAL LARGE MIXED LAND USES PARKS, RECREATION, OPEN SPACE UTILITIES

X

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Fig. 3.

FOR

43

SLOPE % EAST

N

LATITUDE

STREET ALIGNMENT ANGLES

10

19-9

5

9-6

3

6-2

-

2

X

2

Fig. 4.

SLOPE ORIENTATION S W E N o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o

7 7S

SLOPE

MAX. MIN.

% ACCESS TO S U N

HEATING MODE

The recommended east-west street alignment works, in fact, only for southern slopes, flat grounds and partially for northern slopes. Due to the composite shadow distortion on eastern and western slopes, the street alignment must deviate from the cardinal east-west direction, Fig. 4 . These instructions are transferred into individual cells, Fig. 2 . Opportunities for a variety of energy conserving space heating modes are shown in Fig. 5 .

S o m

to

PASSIVE SOLAR | | SOL. TEMPERED |

|

ACTIVE SOLAR

[

CONVENTIONAL

0 0 • (

e

0 •• •

• •• • • • • • • •• •• • ••

SOL. ORIENT. s w E N s w E N

Fig.

s w E N s w E N s w E N

5.

THE CELLULAR PLANNING TECHNIQUE A synthesis of the cells' developmental options and street alignment instructions, Fig. 6, lead to a rudimentary outline of an energy efficient urban or community plan which can be optimized by the incorporation of other planning parameters such as engineering, social, economic, etc., Fig. 7.

Kig. h.

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It should be pointed out that these techniques are not intended to displace existing planning practices but rather to add a new layer of sophistication to the development and evaluation of human settlement plans.

Fig.

7.

CONCLUSIONS The uniqueness of this version of climate sensitive planning lies in its universality. Any area of the world can be described by a standard format. As a result, developmental options within a framework of local self-reliance are better understood and ratios between soft and hard technology become easier to determine. Furthermore, such a system approach is conducive to a meaningful transfer of experience between different regions, countries, and continents.

REFERENCES Planning and Development Department (September, 1982). Design Criteria For Energy Efficient Neighbourhood Planning, (Stage O n e ) . The Regional Municipality of Hamilton-Wentworth, Ontario, Canada. Planning and Development Department (October, 1983). Design Criteria For Energy Efficient Neighbourhood Planning, (Stage T w o ) . The Regional Municipality of Hamilton-Wentworth, Ontario, Canada. Planning and Development Department (July, 1980). Planning For Low Density A Solar Approach. The Regional Municipality of Hamilton-Wentworth, Ontario, Canada.