Loft Conversions in South West & West London
Unlock your home's full potential with a beautifully crafted loft conversion
A whole new floor from the roof you already own — bedroom, en-suite, and not an inch of garden lost. We build from the top down, so you keep living downstairs while the value goes up.
Inside the Loft
Scroll, and the loft is built in front of you: the steels, the new floor, the dormer, the stair. Then the family comes up.
What It Adds
The cheapest square metres you can add are the ones already under your roof.
*Illustrative guide figures while launch pricing is finalised — your exact numbers follow the free survey.
What We Do
A loft conversion is one of the most cost-effective ways to add valuable living space to your London property — without extending your footprint. OKPW specialises in dormer, hip-to-gable, mansard, and Velux rooflight conversions, transforming underused attic space into stunning bedrooms, home offices, or en-suite master suites. We handle the full process from initial survey through to building regulations sign-off, working sensitively with party wall agreements and conservation area requirements across every London borough.
Key Benefits
- An extra bedroom, office or en-suite without losing garden space
- Often the most cost-effective way to add value to a London home
- We build top-down, so your home stays liveable throughout
- Party wall, structural calculations and building control all handled
What's Included
- Structural engineering calculations
- Party wall surveyor coordination
- Building regulations application
- Structural steelwork (RSJs)
- Staircase design & installation
- High-performance insulation
- Electrical wiring & lighting
- Plumbing & heating extensions
- Plastering & skimming
- En-suite bathroom (if specified)
- Full decoration & flooring
- Building control sign-off
Our Process
- 01
Survey
Detailed measured survey of your existing roof structure, assessing feasibility, head height, and structural requirements.
- 02
Design & Planning
Architectural drawings, structural calculations, planning applications (where required), party wall notices, and building regulations submission.
- 03
Strip & Steel
Careful removal of existing roof tiles and timbers, installation of structural steelwork (RSJs), and temporary weatherproofing.
- 04
Build Out
New dormer or roof structure constructed, roofing completed, windows fitted, and the space made watertight.
- 05
First Fix
Staircase installation, electrical wiring, plumbing, heating, and insulation fitted to exceed building regulations standards.
- 06
Second Fix & Finish
Plastering, skirting, doors, bathroom fit-out, decoration, and final building control inspection for completion certificate.
Why Choose OKPW
All Conversion Types
Dormer, hip-to-gable, mansard, L-shaped, and Velux — we match the right solution to your property.
Minimal Disruption
We build from the top down, keeping your home liveable throughout most of the conversion.
8–12 Week Builds
Efficient project management means your new space is ready faster than you'd expect.
Before you start
Which loft type suits my home?
It depends on your roof and budget — dormer, hip-to-gable, mansard or Velux. We survey your roof and recommend the option that gives the most usable space.
Do I need planning permission?
Dormer and Velux conversions often fall under Permitted Development; mansards usually need planning. We confirm at survey and handle any application.
How long does it take?
Most loft conversions take 8–12 weeks on site.
How much does a loft conversion cost?
Our guide prices for a dormer run from £45,000 for a bedroom to £160,000 for a full loft with a bathroom, plus VAT. A mansard is £85,000 to £260,000. The cost calculator shows the price for your own house.
Does a loft conversion add value?
Usually. An extra bedroom and bathroom is one of the most sought-after changes to a London home. How much it adds depends on your street and the house, so we do not promise a figure.
Can I convert a loft with a low roof?
Sometimes. As a rule of thumb you want about 2.2 m of height from the floor to the ridge. Lower roofs can sometimes work by lowering the ceiling below or raising the roof. We measure on the survey and tell you honestly.
Make Your Home Worth More
A free, no-obligation survey by the people who do the work — covering Central, South and West London and Surrey, out to Guildford and Dorking.
