Where a proposal involves a significant change in ground levels, illustrative drawings should be submitted to show both existing and finished levels. These drawings should demonstrate how the proposed development would relate to existing site levels and any neighbouring developments.
In the case of householder development, the levels may already be evident from floor plans and elevations. However, in the case of sloping sites, it will be necessary to show how proposals relate to existing ground levels or where ground levels outside the extension would be modified.
Level drawings
These will need to indicate the following:
- a scale bar or a measured dimension
- the existing and proposed levels on the site and where levels differ from that of land immediately adjoining the site
- be plotted on a plan to scale 1:200 or 1:500, and use spot ground levels at regular intervals in a grid pattern across the site
- a fixed and identifiable datum level, usually “Above Ordnance Datum” (AOD)
- the finished floor levels of proposed buildings.
Section drawings
These will need to indicate the following:
- a scale bar or a measured dimension
- existing and proposed ground levels where significant cut and fill operations are proposed, or where slopes in excess of 1 in 20 exist (or will exist)
- “slices” (cross sections) through buildings, normally at a scale of 1:50 or 1:100
- “slices” (cross sections) through land, normally at a scale of 1:200 or 1:500
- be accompanied by a plan showing the points between which the cross sections have been taken, which should also indicate the direction of north
- existing and proposed buildings within and adjacent to the site
- finished floor and ridge levels of buildings.