A
Architectural
Drawings
Services
Pricing
Areas
Guides
Resources
About
Sign in
Free quote
Home
/
FAQ
FAQ
Planning, building regs, cost, process — most common questions.
Planning questions
Do I need planning permission for a loft conversion?
Usually no — most loft conversions qualify as Permitted Development if under 40m...
Do I need planning permission for a single-storey rear extension?
Standard PD limits: 3m deep (attached) or 4m (detached), under 4m high. Conserva...
Do I need planning permission for a side-return extension?
Side returns are PD up to half the width of the original house, single-storey, h...
How much does planning permission cost in London?
Council fee £206 (householder, 2026) + drawings from £840. Total typical: £1,500...
How long does planning permission take?
8 weeks statutory determination from validation. Plus 1-2 weeks validation. Plus...
What if my planning application is refused?
Three options: amend and re-submit (free for 12 months), appeal to Planning Insp...
What is a Lawful Development Certificate?
An LDC is formal council confirmation that your proposal qualifies as Permitted ...
Can I extend if my home is listed?
Yes, but you need Listed Building Consent alongside planning permission. Heritag...
What is Article 4?
A local council direction removing specific Permitted Development rights. Most c...
Can I extend in a conservation area?
Yes, but with restricted PD rights. Heritage Statement required. Materials must ...
Building-Regs questions
Do I need building regulations even if I have planning?
Yes. Planning and building regs are separate. PD removes the planning requiremen...
How much do building regulations cost?
Council LABC: £400-£900 plans + inspection for a typical extension. Approved Ins...
LABC vs Approved Inspector — which?
LABC is council-based, slightly cheaper, sometimes slower. Approved Inspector is...
What is Part L?
Part L of the Building Regulations covers thermal performance and energy efficie...
What is Part B?
Part B covers fire safety. Loft conversions require fire-protected escape route,...
Cost questions
How much does a loft conversion cost in London?
Drawings: from £1,225 fixed. Build: £45,000-£75,000 dormer, £65,000-£95,000 hip-...
How much does a rear extension cost in London?
Drawings: from £1,225 fixed. Build: £35,000-£60,000 single-storey, £75,000-£130,...
How much does a mansard roof cost?
Drawings: from £1,575 fixed. Build: £78,000-£110,000 single mansard, £120,000-£1...
How much does a basement extension cost?
Drawings: from £4,500. Build: £90,000-£150,000 single-storey, £220,000-£380,000 ...
What's not included in a fixed-fee drawing quote?
Council fees (£103-£206). Building regs fees (£400-£900). Structural engineer (£...
Process questions
What happens at the free site survey?
We measure the property accurately, photograph existing conditions, check Articl...
How quickly can you start?
Site survey usually within 5 working days. Drawings to you 2-3 weeks after surve...
Do I need a separate structural engineer?
Almost always yes for extensions. We coordinate with a partner structural engine...
Do I need a Party Wall agreement?
If you're building near or against a neighbour's wall, yes. Surveyors typically ...
Can you handle the whole project?
Drawings + planning + building regs: yes. Build contracting: no — we recommend y...