Fixed prices. No surprises.
Traditional architects charge £3,000–£8,000. We deliver the same quality for less.
| Package | Price |
|---|---|
Small extension Single-storey rear or side return, up to 20m² | £1,295 |
Medium extension Loft conversion or wrap-around, up to 40m² | £1,595 |
Large extension Two-storey or basement, up to 60m² | £1,995 |
Custom project New builds, change of use, complex projects | Quote |
All packages include unlimited revisions, council liaison, and free resubmission if refused.
Not bought the property yet?
Drawings come after you own the site. Before you buy, bid or exchange, the Site Planning Report is a pre-purchase planning appraisal on any UK property or plot: planning potential, risk, comparable approvals and indicative numbers. £395 fixed, delivered in 24 hours.
Pre-purchase site planning report - £395, 24 hoursWhat every package includes
Eight things you get with every fixed-fee package.
- Professional measured survey
- Architectural design drawings
- 3D visualisations
- Planning application (if required)
- Building regulations drawings
- Structural engineer coordination
- Planning officer liaison
- Unlimited revisions until approval
How we compare
Mayfair Studio versus a traditional high-street architect.
| Feature | Mayfair Studio | Traditional architect |
|---|---|---|
| Price | From £1,295 | £3,000–£8,000 |
| Survey included | Yes | Sometimes |
| Planning drawings | Yes | Yes |
| Building regs | Included | Extra cost |
| Structural calcs | Coordinated | Extra cost |
| Unlimited revisions | Yes | Charged per revision |
| AI planning intelligence | 3.7M properties | Manual checks |
| Turnaround | 1–2 weeks | 8–12 weeks |
For a full breakdown of what architects charge across every project type, see our guide to architect fees in London.
Frequently asked questions
Click each question to read the answer.
How much do architectural drawings cost for a home extension in London?
Mayfair Studio's fixed-fee packages start from £1,295 for a single-storey extension, including survey, planning drawings, building regulations, and unlimited revisions. Traditional architects typically charge £3,000–£8,000 for the same scope.
What's included in the fixed fee?
Every Mayfair Studio package includes a professional measured survey, architectural design drawings, 3D visualisations, planning application preparation, building regulations drawings, structural engineer coordination, and unlimited revisions until approval.
Do I need planning permission for my extension?
It depends on your property's specific constraints. Use Mayfair Studio's free planning permission check at mayfairstudio.co.uk/planning-permission-check for an instant answer. Buying a property or plot first? The £395 Site Planning Report at mayfairstudio.co.uk/site-planning-report is a pre-purchase planning appraisal delivered in 24 hours.
How long does it take to get architectural drawings?
Mayfair Studio typically delivers drawings ready for planning submission within 1–2 weeks. Traditional architects take 8–12 weeks on average.
What is your planning approval rate?
Mayfair Studio analyses planning data from 1.2 million applications across London to assess your chances before submitting. If your application is refused, we resubmit for free.
How much does a rear extension cost in London?
Based on Mayfair Studio's analysis of 1.2 million London planning applications and construction cost data, a single-storey rear extension in London costs £60,000–£135,000, depending on size and specification. Architectural fees with Mayfair Studio start from £1,295.