How much will your project cost?
A realistic cost range for your extension, loft conversion or new build in London and Surrey — built from 20 years of project data. Two minutes, no callbacks.
What type of home do you have?
This helps us understand your project context and constraints.
What are you planning?
Select all that apply — you can pick more than one.
What kind of extension?
Don't know? Pick the closest — we'll refine on the visit.
How much space do you want to add?
An approximation is fine — we will refine this on site.
What kind of loft conversion?
How much extra space do you want?
What's your planned floor area?
Do you already have drawings or plans?
If not, we will include architectural design in your quote.
Do you know if planning permission is needed?
Is your property listed or in a conservation area?
This affects design constraints and material costs.
Will a party wall agreement be needed?
Usually required for semi-detached or terraced homes.
Will you need to remove internal walls?
For an open-plan layout — adds steel beam costs.
What style of garden doors?
Roof windows or skylights?
Here is your estimated cost.
Based on London & Surrey market rates and 20 years of DPS project data. Final fixed price confirmed at your free site visit.
Inclusive of materials, labour and design. Excluding VAT.
Get a precise, no-obligation quote.
A project manager will arrange a free site visit and email you a fixed-price quote — usually within one working day.
Want to see what this might look like?
Browse 320+ completed builds across South West London and Surrey — filter by service to find inspiration close to your scope.
See completed projectsGet your free, detailed quote.
A project manager will be in touch within one working day. No spam, ever.
Thank you. We will be in touch within one working day.
A DPS project manager will email or call you to arrange a free site visit and confirm a fixed-price quote tailored to your project.