Town planning and operating costs of residential areas (ASTA II)

This research ASTA II, which deals with operating costs of residential areas, is one part of a comprehensive Finnish research series concerning the impact of town planning on the economy of residential areas. The first phase, ASTA I examined building costs of residential areas. In this research, ASTA II operating costs include annual energy and maintenance costs and transportation costs in residential areas. The main emphasis is on energy consumption and costs caused by it. Microclimate and its impact on the heat consumption of buildings has been given a strong emphasis in the rescarch. Models, used in the calculations, were developed for the research and numerical data (real quantities) were collected from 24 residential areas chosen for study areas in different parts of Finland. The annual operating costs of the 24 study areas amount to appr. FIM 4,100 per inhabitant. Of the costs the buildings share account for a half, transportation costs being over a third. The most significant factor in respect of variation in costs was found to be external traffic (outside research areas). This depended on the location of the area (location of work places, distance from the urban centre etc.) In comparison with the building costs, operating costs do not depend on density variables. This is because heating costs of buildings decrease while their maintenance costs rise along with the increase of building density. On the average, energy costs account for 45 % of all the operating costs. Heating of buildings accounts for almost half while the share of external traffic alone is nearly a quarter. The variation of heating costs of buildings depends mainly on the share of district heating in the areas. Heat consumption of residential buildings does not, generally speaking, depend on the building type chosen. However, considering the building type itself, the size of the building has an impact on heat consumption. Microclimate alone causes a maximal variation of 11 % of annual heat consumption of individual buildings inside one area. However, the average heat consumption of the areas studied varies only 5 % due to differences in their microclimate. Microclimate factors having been under studying were: solar access, local temperature variation and wind conditions. The most important microclimatic factor turned out to be solar access. Almost as important a factor was local temperature variation. Resulting from the used climate data wind conditions have least affect on heat consumption. In coastal regions, on hills and in open landscape, however, the impact of winds can have quite a great significance. There are town planning solutions which, by raising the quality of a residential area, simultaneously lower its operating costs. Some solutions can raise the quality without significant changes in costs. In some cases it is possible to cut down costs without lowering quality. Solutions which raise the quality while increasing costs should be considered bearing in mind the long duration of the built environment.