Resi vs Mayfair Studio: Which Online Architect Is Right for Your London Extension? (2026)
Resi is the UK's best-known online architect service. Mayfair Studio is a London-specialist alternative. Here's an honest comparison - prices, inclusions, and which suits different projects.
TL;DR - The Quick Answer
Resi is a well-established UK-wide online architect service with a larger team and strong track record. Mayfair Studio is a London-specialist alternative at a lower price point. Both include planning drawings, structural calculations, and planning application support. Mayfair Studio's advantage is its London focus - the team knows local council requirements, conservation areas, and planning officers. Resi's advantage is its larger operation and broader UK coverage. If you're extending a London home on a budget, Mayfair Studio at £1,295 is worth considering first.
Resi vs Mayfair Studio: Side-by-Side Comparison
| Mayfair Studio | Resi | |
|---|---|---|
| Starting price | £1,295 | £1,500+ |
| London-specialist? | Yes - London only | UK-wide |
| Structural calcs included? | Yes | Yes |
| Planning application included? | Yes | Yes |
| Turnaround | 4–6 weeks | 4–8 weeks |
| Revisions policy | 2 rounds included | Varies by package |
| Conservation area experience? | Extensive (London) | Good (UK-wide) |
| Free initial check? | Yes (AI chat) | Initial consultation |
Source: Mayfair Studio and publicly available Resi pricing information • Data as of 2026
Prices are approximate. Resi's pricing varies by project type and scope. Always confirm current pricing directly with each provider. Mayfair Studio's £1,295 fixed fee applies to standard residential extensions including planning drawings, structural calculations, and planning application.
Both services use technology to streamline the process compared to traditional high-street architects. Neither requires you to visit an office. Both handle the planning process end-to-end.
Other Alternatives to Resi for London Extensions
Beyond Mayfair Studio and Resi, there are a handful of other online architectural drawing services worth knowing about:
| Service | Starting Price | Coverage | Notes |
|---|---|---|---|
| Mayfair Studio | £1,295 | London | Lowest price, structural included, planning included |
| Resi | £1,500+ | UK-wide | Largest online architect, strong track record |
| Draw Plans | From £750 | UK-wide | Drawings only - structural and planning extra |
| Plan My Extension | From £595 | UK-wide | Entry-level plans; may need additional services |
Source: Publicly available pricing information • Data as of 2026
Draw Plans and Plan My Extension offer lower entry prices but typically do not include structural calculations or planning applications - you'd need to source these separately, which can add £2,000–£5,000 to total costs. Mayfair Studio's all-in price at £1,295 often represents better total value.
What's Included at Each Price Point
Mayfair Studio - £1,295 Fixed Fee
- Measured survey of your property
- Existing and proposed floor plans, elevations, and sections
- Structural engineer calculations (often billed separately elsewhere)
- Planning application preparation and submission
- Building Control drawings for construction
- 2 rounds of design revisions
- Dedicated project manager throughout
Resi - From £1,500+
- Online design portal and dedicated architect
- Existing and proposed drawings
- Structural engineer calculations
- Planning application support
- Project management throughout
- Additional services available (interior design, builder matching)
The main practical difference: Mayfair Studio is fixed fee, London-specialist. Resi is a larger operation with more service lines. For a straightforward London extension, Mayfair Studio's package includes everything you need at a lower price.
Which Should You Choose?
| Your Situation | Better Option |
|---|---|
| London extension, budget-conscious | Mayfair Studio (£1,295) |
| London extension, conservation area | Mayfair Studio (London specialism) |
| Extension outside London | Resi |
| Want the largest, most established service | Resi |
| Want lowest total all-in price | Mayfair Studio |
| Need interior design services too | Resi (broader service range) |
| Just need drawings (no planning) | Draw Plans or Plan My Extension |
About Mayfair Studio
Mayfair Studio is a London-specialist architectural service covering all 33 London boroughs. We focus exclusively on London residential extensions - rear extensions, loft conversions, side returns, and two-storey extensions. Our fixed-fee service at £1,295 includes planning drawings, structural calculations, planning application submission, and building control drawings.
Our AI chat tool is free to use and gives instant permitted development checks and cost estimates for your specific London address - no contact details required.
Mayfair Studio starts at £1,295 for London extensions including planning drawings, structural calculations, and planning application - making it cheaper than Resi (from £1,500+) for comparable services. Both include structural calcs and planning applications. Mayfair Studio is London-specialist; Resi covers the whole UK. For London homeowners, Mayfair Studio typically offers better value per £ spent.
Frequently Asked Questions
Is there a cheaper alternative to Resi for home extensions in London?
Yes - Mayfair Studio offers a fixed-fee service from £1,295 for London home extensions, compared to Resi's starting price of approximately £1,500+. Both include planning drawings, structural calculations, and planning application submission. Mayfair Studio is London-specialist (covering all 33 boroughs) while Resi operates UK-wide. Other alternatives include Draw Plans and Plan My Extension, which offer lower headline prices but typically don't include structural calculations or planning applications.
Resi vs Mayfair Studio: which is better for London extensions?
For London extensions specifically, Mayfair Studio is typically better value - it's cheaper (from £1,295 vs Resi's £1,500+), London-specialist, and includes planning drawings, structural calculations, and planning applications in one fixed fee. Resi has a larger team and covers the whole UK, which is an advantage if you're outside London. Both are reputable online architect services that manage the planning process end-to-end.
How much does Resi charge for a home extension?
Resi charges approximately £1,500+ for a standard home extension, though pricing varies by project type and scope. Their service includes planning drawings, structural calculations, and planning application support. For comparison, Mayfair Studio charges a fixed fee of £1,295 for London extensions with comparable inclusions. Always confirm current pricing directly with Resi for your specific project.
What are the best alternatives to Resi for architectural drawings in London?
The best alternatives to Resi for London home extensions are: Mayfair Studio (from £1,295, London-specialist, planning and structural included), Draw Plans (from £750 for drawings only - structural and planning extra), and Plan My Extension (from £595 entry-level). Mayfair Studio is typically the best value all-in option for London projects, as it includes structural calculations and planning applications at a lower total price than Resi.
Is Mayfair Studio cheaper than Resi?
Yes. Mayfair Studio charges a fixed fee of £1,295 for London home extensions, compared to Resi's starting price of approximately £1,500+. Both services include planning drawings, structural calculations, and planning application submission. Mayfair Studio is London-specialist (all 33 boroughs), while Resi operates across the UK.