Roof Window Replacement
Old, leaking or misted roof windows replaced with modern, energy-efficient units.
- Like-for-like or upgrade to latest models
- New flashing kit included with every replacement
- Fixed pricing with no hidden extras
Old Roof Windows Leak, Mist and Waste Energy
Roof windows installed 15 to 20 years ago are reaching the end of their effective lifespan. Seals perish, glazing units mist up, hinges stiffen and flashing kits deteriorate. The result is a window that leaks when it rains, mists between the panes, lets heat escape and no longer opens or closes properly. Older windows also lack the thermal performance of modern units, adding to your energy bills.
Radiant Roofing replaces old roof windows across Kent, Sussex and Surrey. We remove the existing unit, upgrade the flashing kit and install a brand-new window with modern double or triple glazing, improved thermal performance and smooth operation. Most replacements take just a few hours and make an immediate difference to comfort and energy efficiency.
How It Works
Window Assessment
We inspect the existing roof window, measure for replacement and recommend the best new unit — like-for-like or an upgrade to the latest model.
Fixed Quote
You receive a clear quote covering window supply, new flashing kit, removal, installation and tiling — no hidden charges.
Quick Replacement
We remove the old window, fit the new unit with a fresh flashing kit and refit tiles around it. Most replacements are completed in a single visit.
Guarantee
Your new roof window is backed by our workmanship guarantee plus the manufacturer warranty of up to 10 years.
Window Assessment
We inspect the existing roof window, measure for replacement and recommend the best new unit — like-for-like or an upgrade to the latest model.
Fixed Quote
You receive a clear quote covering window supply, new flashing kit, removal, installation and tiling — no hidden charges.
Quick Replacement
We remove the old window, fit the new unit with a fresh flashing kit and refit tiles around it. Most replacements are completed in a single visit.
Guarantee
Your new roof window is backed by our workmanship guarantee plus the manufacturer warranty of up to 10 years.
What Our Roof Window Replacement Includes
We replace all makes and sizes of roof window. Every replacement includes a new manufacturer-approved flashing kit — we never reuse old flashings, which is a common cause of leaks after window replacement.
What Does Roof Window Replacement Cost?
Typical price range
£600 – £2500
VAT may apply depending on the project
Factors that affect the price:
- 1Window size and type (standard, electric, triple-glazed)
- 2Roof covering type (plain tiles need more work than interlocking)
- 3Whether the opening size needs altering
- 4Internal lining and finishing requirements
A like-for-like replacement of a standard centre-pivot Velux costs £600 to £1,200. Upgrading to a larger window, electric operation or triple glazing runs £1,200 to £2,500. We provide a fixed quote after measuring your existing window.
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
Roof window replacement typically costs between £600 and £2,500. A standard like-for-like replacement runs £600 to £1,200 including new window, flashing kit and installation. Upgrading to a larger window or electric model costs £1,200 to £2,500. We always include a new flashing kit — reusing old flashings is false economy.
Yes. We can enlarge the structural opening to accommodate a bigger window. This involves cutting additional timber, reinforcing the structure and retiling a larger area. It costs more than a like-for-like swap but is straightforward for our team.
Misting between the panes means the sealed glazing unit has failed and moisture is getting between the glass. This cannot be repaired — the window needs replacing. Modern Velux windows use argon-filled sealed units that provide much better insulation and are less prone to seal failure.
We cover Kent, East Sussex, West Sussex and Surrey. Our teams regularly replace roof windows in Tunbridge Wells, Crowborough, Sevenoaks, Tonbridge, Uckfield, Haywards Heath, East Grinstead and surrounding areas.
Yes. All replacements are backed by our workmanship guarantee. The new window carries a manufacturer warranty of up to 10 years on the unit and glazing.
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
