Driveways, paths and drainage

The short answer

Hard surfaces around a house need to deal with rainwater rather than direct it at the walls. In Scotland, new or replacement driveways generally have to be permeable or drain to a permeable area. Raising path and driveway levels above the original damp line is one of the most common causes of avoidable damp in older houses.

What the work involves

Excavation and sub-base preparation, permeable paving or a drainage strategy, gullies and channel drains, and setting finished levels at least 150mm below internal floor level where the construction allows.

Rules and consents in Scotland

Planning rules in Scotland require new hard surfaces at the front of a house to be permeable or to drain to a permeable area; otherwise permission may be required. Connecting surface water to the foul sewer is not permitted. Dropped kerbs need council approval.

What commonly goes wrong

Laying a new driveway on top of the old one, raising the level so it bridges the damp-proof course or buries airbricks.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• Cost is driven by area, excavation depth and sub-base rather than the surface material alone.
• Permeable block paving costs more than tarmac but usually avoids a planning issue.
• Drainage channels and soakaways are an additional but often necessary cost.
• A dropped kerb involves a council application and a separate contractor cost.

What to do, in order

1. 1Check the existing ground level against airbricks and the damp line.
2. 2Confirm permeable surfacing or a drainage route before design.
3. 3Apply for a dropped kerb if the access is new.
4. 4Excavate rather than build up over the existing surface.
5. 5Set falls away from the building.
6. 6Keep gullies and channels clear once complete.

Local detail for the Lothians

• Edinburgh front gardens converted to parking need a dropped kerb application to the City of Edinburgh Council and must meet permeable surfacing rules.
• Conservation areas across Edinburgh restrict the removal of front boundary walls and railings for parking.
• Garden-level flats commonly have airbricks buried by successive layers of paving added over the years.
• Clay soils in parts of the Lothians drain slowly, making soakaway design more important.

When you need a professional

A driveway or groundworks contractor, and the council's roads team for a dropped kerb. A surveyor helps where ground levels are already causing damp.

Common questions

Do I need planning permission for a driveway?

Not usually if the surface is permeable or drains to a permeable area, but a non-permeable surface at the front of a house can require it.

Why has my new driveway caused damp?

Most often because the finished level was raised above the original damp line or buried the airbricks.

Related pages

• Damp problems

  Telling penetrating damp, condensation and rising damp apart before spending money.

• Ventilation and airbricks

  Extract fans, trickle vents, airbricks and underfloor ventilation.

• Garden walls and boundaries

  Boundary walls, fences, trees and shared responsibility between neighbours.