Topography is an important factor in site analysis. If a site is flat, topography will not affect the location and layout of the building. But on a sloping site topography is a significant factor. The slope of a site or slope of an adjacent site will affect the access of sun & views.
Topography refers to the slope and level of the land, whether the land is flat and plain, or in sloping. Topography is a measurement of elevation and slope is the percentage change in that elevation over a certain distance. Topography is measured by to connecting points of same elevation. These points are known as the topographic contours. Slope is measured by the distance between one point to another point and this distance is divided by the lateral distance between them.
From a design point of view, a sloping site will be more challenging. If a site is sloping, the exact slope can be interpreted from a detailed Contour map. The contour locations and spacing of contours will play a big role in the setting of the building. It is always better to design buildings along with the contours, integrating it into the design to reduce the unnecessary cutting and filling of soil. i.e. you should not plan across the contour or should not cut the contours.
Soil is a mixture of mineral particles, organic matter, water and air. Soil affects the human activities from agriculture to engineering and construction of roads, building & sewage disposal system. Generally Soils vary from place to place. Their property also varies according to the type of soil whether Sandy soil, clayey soil, laterite etc, all have different properties, which affect the design of the building.
Soil type, Ground conditions and stability is essential to determine whether the site is suitable for a particular type of building where best place can be located for a building. Urban planner authorities used soil map to identify areas for suitable development for homes, industry, agriculture and recreation. For example if soil map is showing poor quality of soil for crops than one cannot develop that area for agriculture. Also Type and size of foundation will be required to decide with respect to its soil bearing capacity. Therefore this is very important from a structural point of view while designing buildings.
Thus both topography and soil are very important parameters as far as safety of the house is concerned.