Landscaping Levels and DPC
150 mm
External ground levels, including landscaping finishes such as turf, must be maintained at a minimum of 150mm below the damp proof course (DPC) level
Every figure for this topic is on one page: Cavity trays and DPC: where are they needed and how high?
Read the full answerExternal ground levels, including landscaping finishes such as turf, must be maintained at a minimum of 150mm below the damp proof course (DPC) level. This critical clearance prevents damp penetration into the building fabric and maintains the effectiveness of the DPC.
Basis in regulation
How to check it on site
Check that all finished landscaping levels are at least 150mm below the DPC.
Common failure
Ground levels are built up too high, bridging the DPC and creating a pathway for damp to enter the building.
Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.