If a site is flat, the topography may not influence the location and layout of the building, but on a sloping site, the topography is likely to be a significant design factor.

The slope of a site and/or the slope of adjacent sites may affect access to sun and views. For example, an east-facing hillside will have reduced afternoon and evening sunlight, particularly in winter, and depending on the height and steepness, a south-facing site may receive little or no sun during the winter months.

The location and layout of the building should be designed to minimise:

• the need for excavation or fill – as well as increasing costs, large-scale earthworks increase the risk of erosion by altering soil stability and water run-off patterns, increase sediment run-off during construction and significantly affect natural biodiversity by removing soils and plants
• the building’s footprint by using low-impact foundation systems such as pole frame construction to reduce the amount of site work and disruption
• the visual impact of the building form on the landscape. In some areas the local authority will impose restrictions on this, particularly around building materials and paint colours/reflectance values.

In some areas landslides may be a risk. LIM reports and/or council maps may identify this. The specific location of the house on site should consider the risk and aim to enhance building resilience. A Chartered Professional Engineer or Professional Engineering Geologist should be consulted.

Also see site analysis for information about sun paths and assessing site conditions and ground stability.

 

Updated: 29 October 2025