Extension Roofing
Pitched and flat roofing for extensions — matched perfectly to your existing property.
- Seamless integration with existing roof
- Pitched, flat and combination roof designs
- Fixed pricing with no hidden extras
Your Extension Roof Must Match and Perform
An extension roof needs to do two things well: keep your new space dry and comfortable, and look like it belongs on the property. A poorly matched roof — wrong tile colour, clumsy junction details or inadequate flashing — undermines the entire project. Likewise, an extension with insufficient insulation or ventilation creates condensation problems and cold spots that make the room unpleasant to use.
Radiant Roofing installs extension roofs across Kent, Sussex and Surrey. Whether you are adding a single-storey kitchen extension with a flat roof, a two-storey side extension with a pitched roof that ties into the existing structure, or a wrap-around with a combination of both, we deliver a roof that matches your property and meets current Building Regulations for thermal performance and ventilation.
How It Works
Site Survey
We inspect your existing roof, note the tile type, colour and profile, and review the extension plans to confirm the roofing specification.
Fixed Quote
You receive a detailed quote covering all materials, labour, flashings and integration details — no surprises once work begins.
Roof Installation
We install your extension roof, carefully tying in with the existing structure using proper flashings, valleys and matching materials.
Guarantee
Your extension roof is backed by our workmanship guarantee plus manufacturer warranties on all covering materials.
Site Survey
We inspect your existing roof, note the tile type, colour and profile, and review the extension plans to confirm the roofing specification.
Fixed Quote
You receive a detailed quote covering all materials, labour, flashings and integration details — no surprises once work begins.
Roof Installation
We install your extension roof, carefully tying in with the existing structure using proper flashings, valleys and matching materials.
Guarantee
Your extension roof is backed by our workmanship guarantee plus manufacturer warranties on all covering materials.
What Our Extension Roofing Service Includes
We handle every aspect of extension roofing, from matching existing materials to weatherproofing the junction between old and new. All work meets current Building Regulations.
What Does Extension Roofing Cost?
Typical price range
£2000 – £12000
VAT may apply depending on the project
Factors that affect the price:
- 1Extension size and roof type (pitched, flat or combination)
- 2Material choice and whether matching existing tiles is required
- 3Complexity of junction details and leadwork
- 4Insulation and ventilation requirements
A single-storey flat roof extension is at the lower end, while a large pitched roof extension with valleys, dormers and reclaimed tiles sits higher. We provide a fixed quote after survey — no hidden extras.
What Our Customers Say
Verified Google ReviewsJane S.
Kent
They were very friendly, professional and polite and left the site immaculate at the end of the day. I would thoroughly recommend them to others. The work was carried out to a very high standard.
Peter B.
East Sussex
Excellent work, highly recommended! Very knowledgeable, by far the best roofing company we have ever used and super nice guys.
Sarah M.
Surrey
Radiant Roofing completed our roof repair quickly and professionally. Great communication throughout and a fantastic result.
Frequently Asked Questions
Extension roofing typically costs between £2,000 and £12,000. A small single-storey flat roof extension starts from around £2,000, while a large two-storey pitched extension with matching tiles, leadwork and complex junction details can reach £12,000 or more. We provide a fixed, written quote after surveying the site and reviewing your plans.
In most cases, yes. We carry an extensive knowledge of current and discontinued tile ranges across all major manufacturers. For newer properties, we can usually source an exact match. For older homes with discontinued tiles, we source the closest available alternative or use reclaimed tiles to achieve a seamless blend.
Yes. We install flat roofs (EPDM, GRP, felt), pitched roofs (tiles, slate) and combination designs. Many extensions use a flat roof for the main span with a pitched roof over a bay or entrance. We handle all configurations and ensure proper weathering at every junction.
We cover Kent, East Sussex, West Sussex and Surrey. Our teams regularly roof extensions in Tunbridge Wells, Crowborough, Sevenoaks, Tonbridge, Uckfield, Haywards Heath, East Grinstead and surrounding areas.
Yes. Extension roofs must meet current Building Regulations for structural loading, thermal insulation (Part L), ventilation (Part C and F) and fire safety. We ensure all our work meets these standards and can coordinate with your Building Control officer for inspections and sign-off.
Contact Us!
Get in touch with us!
Looking for a free quote? Just fill in the form below, and we'll take care of the rest!
Contact Information:
Mobile (24/7): 07753 165 005
Landline (Office Hours): 01892 356 967
Email: contact@radiantroofing.co.uk
Head Office:
Address:
Alpha House
Crowborough Hill
Crowborough
TN6 2EG
Opening Hours:
Monday to Friday: 7:30 am – 6:00 pm
Saturday: 7:30 am – 12:00 pm
Sunday: Closed (mobile still available)
Our Mobile and Email is available 24/7
