Basement and cellar conversions in Romford

Covering Romford

We work in Romford (RM1) and the places around it, including Hornchurch, Dagenham and Becontree.

Homes in London

London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.

What do you get with a basement conversion?

Everything below ground depends on keeping water out. We design the waterproofing system (usually a cavity drain membrane with a pump, or tanking) to the relevant British Standard guidance, then add insulation, ventilation, light and an escape route. New basements involve underpinning and a party wall process and are designed with a structural engineer.

Damp and structural survey
Underpinning or lowering the floor where needed
Finished floors, walls and ceilings

What will a basement conversion cost?

What basement and cellar conversions typically cost. These are guide ranges; the written quote for your house replaces them.

Basement and cellar conversions	Guide price incl. VAT
Existing cellar conversion	£1,900 to £3,000 per m²
New basement excavation	£4,200 to £6,600 per m²

What approvals does a basement conversion need in England?

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.

Converting an existing cellar with no external changes usually does not need planning permission in England. Digging a new basement or adding a lightwell often does, and many councils have basement policies.

What can affect a basement conversion?

New basements nearly always involve the Party Wall Act in England and Wales.
A pump for the drainage system needs a battery back-up.

What are the steps?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Basement and cellar conversions: common questions

Does a cellar conversion need planning permission?

Usually not if nothing changes outside. New basements and lightwells often do.

Will my neighbours be affected?

New basements usually need party wall agreements. We handle the notices and surveyors.

Who deals with the council for a project in Romford?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Also covering

Learn more about basement and cellar conversions, or see every project we cover in Romford.