
Loft Conversion Drawings in London | Fixed Fee
Dormer, mansard, hip-to-gable and Velux lofts — drawn, checked and approved.


A loft conversion is one of the most cost-effective ways to add a bedroom in London — but the right drawings depend on your roof type, your borough's rules and whether the work is permitted development or needs planning permission. DrawingsDirect draws every loft type and checks your permitted development eligibility before you commit to an application. Getting the route right at the drawing stage is what protects the whole build: a loft designed as permitted development but actually needing planning permission stalls on site, while one over-specified for a full application pays for consent it never needed.
Fixed fees from £1,100 · Drawings in ~7 days · Free redraws to approval.
Do I need planning permission for a loft conversion in London?
Many loft conversions are permitted development, but volume limits (40m³ for terraced homes, 50m³ for detached and semi-detached), materials and the presence of a conservation area or Article 4 direction can change that. We assess your roof and borough and recommend the fastest lawful route — often a Lawful Development Certificate rather than a full planning application. A certificate is worth having even when the work is clearly permitted: it gives your buyer's solicitor and your building-control surveyor documentary proof the loft is lawful, which matters when you sell.
Which loft conversion type suits your roof?
The best conversion depends on your roof shape and the headroom it offers.
Dormer
A box dormer adds headroom and floor area at the rear and is the most common London loft — frequently permitted development.
Mansard
A mansard rebuilds the rear (or front and rear) roof slope for maximum space, common in conservation areas but usually needing planning permission.
Hip-to-gable
Extends a hipped roof to a vertical gable, ideal for semi-detached and end-of-terrace homes.
Velux / rooflight
The simplest option — rooflights within the existing roofline, almost always permitted development.
What building regulations apply to a loft conversion?
Loft conversions must meet fire escape, structural and insulation standards — a protected stairway, adequate floor joists and beams, and often a means of escape window. A loft that adds a third storey to a two-storey house triggers stricter fire-separation rules, including fire doors to habitable rooms off the new stairway. We coordinate the structural calculations with the drawings so the build proceeds without delays.
How long does a loft conversion take to draw and approve?
We deliver a full drawing set in roughly 7 days from survey. If your loft is permitted development a Lawful Development Certificate takes about 8 weeks at most London boroughs; a full householder planning application is an 8-week statutory determination once validated. Building-regulations approval runs in parallel, so the structural and construction detail is ready for your builder to price while any planning decision is pending.
| Loft type | Best for | Usual route | Fee from |
|---|---|---|---|
| Velux / rooflight | Roofs with existing headroom | Permitted development / LDC | £1,100 |
| Dormer | Rear headroom + floor area | Permitted development / LDC | £1,300 |
| Hip-to-gable | Semi and end-of-terrace roofs | Permitted development or planning | £1,600 |
| Mansard | Maximum space, conservation areas | Full planning application | £2,200 |
Loft Conversion Drawings in your London borough
Local planning constraints, conservation areas and Article 4 notes for each council.
Complete your drawing package
Rear, side-return, wraparound, double-storey and basement extensions, drawn to approve.Planning Permission
Chartered planning drawings and application management for every London borough.Building Regulations Drawings
Full-plans construction packages with structural calculations, coordinated in-house.
Loft Conversion Drawings — frequently asked questions
How much do loft conversion drawings cost in London?+
Will my loft need a fire escape window?+
Is a dormer loft permitted development?+
Can I convert my loft if I live in a conservation area?+
Do you provide the structural calculations for the steels?+
Ready for loft conversion drawings that get approved?
Tell us your London address and project. We'll confirm feasibility and a fixed fee within one working day — with a free planning appraisal of your property's potential.