Sash Windows in Conservation Areas London
Traditional sash window specialists serving all London boroughs.
✓ No Call-Out Fee
✓ 5-Year Guarantee
✓ Same-Day Response
✓ Fully Insured
London has over 1,000 Conservation Areas — designated zones where the local council aims to preserve or enhance the architectural character of the area. If your property sits within one, any changes to the external appearance of your windows may require planning permission.
🏙️ Conservation Areas in London
Major Conservation Areas include most of Islington, large parts of Hackney, Kensington, Chelsea, Hampstead, Marylebone, Mayfair and Greenwich. Within these areas, replacing timber sash windows with uPVC or aluminium alternatives is typically not permitted.
- Replacing windows with a materially different design or material requires consent
- Draught proofing does NOT require planning permission
- Like-for-like repairs do NOT require planning permission
- Glass replacement with matching glass type generally acceptable
- New sash windows must match the original in design, material and finish
✅ Our Conservation Area Service
Hartwell Sash is experienced in working within Conservation Areas. We know what is and is not permitted, we use appropriate materials, and we can advise on window specifications if planning consent is required.
- Heritage glass available — period-appropriate rippled finish
- Slimline double glazing suitable for most Conservation Areas
- Traditional putty glazing where specified
- Matching paint colours and finishes
- Advice on planning requirements at no charge
Why London homeowners choose Hartwell Sash
Restore First
We never recommend replacement when repair will do the job. Your original windows are always our priority.
Period Specialists
Victorian, Georgian, Edwardian — we understand Conservation Areas and Listed Buildings across London.
5-Year Guarantee
Every job is covered by a 5-year workmanship guarantee. Fully insured and fully accountable.
Free survey today
We visit your property, assess every window and give you an honest quote — no call-out fee, no obligation, no pressure. Same-day response guaranteed.