Types We Estimate
Every Loft Conversion Type
We estimate all loft conversion types — from budget Velux conversions to full mansard rebuilds. Click any type to see costs, suitability, and what's included.
Indicative Cost Range
£40,000–£75,000
Exc. VAT · 10–14 weeks
Rear Dormer
Most popular choice
A box-shaped extension to the rear roof slope, dramatically increasing usable floor space and headroom. The most popular loft conversion type in the UK — works on most house types.
Best Suited For
- Victorian & Edwardian terraces
- Semi-detached houses
- Most property types
Estimate Includes
- Rear dormer structure
- Flat or pitched dormer roof
- Windows & doors
- New staircase
- Full fit-out
May require planning permission depending on size and location.
Velux Conversion
Standard28–35 m² · Midlands / North baseline
Bedroom + en-suite, 2–3 Velux windows, new staircase
Rear Dormer
Mid-Range30–45 m² · Midlands / North baseline
Master bedroom + en-suite, full-width dormer, new staircase
L-Shaped Dormer
Mid-Range45–60 m² · Midlands / North baseline
2 bedrooms + bathroom, rear & side dormers, new staircase
Mansard (London)
Premium40–55 m² · London pricing (+35%)
2 bedrooms + bathroom, full mansard rebuild, premium finish
Unit Rate Breakdown
| Element | Unit | Standard | Mid-Range |
|---|---|---|---|
| Structural Engineer (calculations) | per project | £800–£1,500 | £1,200–£2,200 |
| Structural Steel (RSJs / beams) | per beam | £600–£1,200 | £900–£1,800 |
| Dormer Structure (timber frame) | per m² | £350–£550 | £500–£800 |
| Flat Roof (EPDM / GRP) | per m² | £80–£130 | £110–£180 |
| Velux Windows (standard) | each | £800–£1,400 | £1,200–£2,000 |
| Dormer Windows (aluminium) | each | £1,200–£2,000 | £1,800–£3,000 |
| Insulation (full loft) | per m² | £25–£45 | £40–£70 |
| Plasterboard & Skim | per m² | £30–£50 | £45–£75 |
| New Staircase | per flight | £2,500–£4,500 | £4,000–£8,000 |
| En-Suite Bathroom | per room | £4,500–£8,000 | £7,000–£14,000 |
| Electrics (loft level) | per project | £2,000–£3,500 | £3,000–£5,500 |
| Fire Door & Mains Smoke Alarms | per project | £800–£1,500 | £1,200–£2,200 |
Important: All figures are indicative and exclude VAT (20%), planning fees, building regulations fees, and party wall surveyor costs. London and South East costs are typically 20–35% higher. Always get a professional estimate before committing to a budget.
Regional Cost Multipliers
London
×1.35
35% above Midlands baseline
South East
×1.18
18% above baseline
South West
×1.05
5% above baseline
East of England
×1.10
10% above baseline
Midlands
×1.00
Baseline region
North West
×0.95
5% below baseline
Yorkshire
×0.92
8% below baseline
North East
×0.88
12% below baseline
Wales
×0.90
10% below baseline
Scotland
×0.93
7% below baseline
Need a project-specific loft conversion estimate?
Send us your drawings and we'll produce a fully itemised estimate within 24 hours.
How It Works
Drawings to Estimate in 24 Hours
A straightforward four-step process — from sending us your drawings to having a professional estimate in your inbox.
Why Choose Us
Why Developers & Homeowners Trust Us
38 Years Experience
Our estimators have been pricing loft conversions since before most online calculators existed. Real experience, real accuracy.
Regional Cost Data
We maintain live cost databases for every UK region — London, South East, Midlands, North, Scotland, Wales. Your estimate reflects your actual market.
Excel & PDF Delivery
Every estimate is delivered in both Excel (editable) and PDF format. Share with contractors, architects, or your bank with confidence.
24-Hour Turnaround
We quote within 1 hour and deliver the full estimate within 24 hours. No waiting weeks for a number you could have had tomorrow.
Fixed Fee, No Surprises
You know exactly what you're paying before we start. No hourly rates, no hidden extras — just a clear fixed fee for a professional estimate.
All Conversion Types
Velux, dormer, hip-to-gable, L-shaped, mansard, roof terrace — we estimate every loft conversion type to the same high standard.
Planning Permission & Building Regulations
Most loft conversions fall under Permitted Development and don't require planning permission — but there are exceptions. Mansard conversions, properties in conservation areas, and conversions that exceed PD limits will need full planning. All loft conversions require Building Regulations approval regardless of planning status.
Loft conversion costs in the UK range from £25,000–£45,000 for a basic Velux conversion up to £130,000+ for a full mansard in London. The most common type — a rear dormer — typically costs £40,000–£75,000 at mid-range specification in the Midlands and North. London costs are typically 35% higher.