Roof Window & Skylight Installation in Kent: 2026 Costs
Roof windows transform loft spaces and add natural light to upper floors. Velux is the dominant brand but several alternatives exist. This guide covers 2026 installation costs and what to specify.
Typical Installation Costs (2026)
- Velux GGL standard centre-pivot window (small, 550x780mm): £900-£1,500 fitted
- Velux GGL medium (780x980mm): £1,100-£1,800 fitted
- Velux GPL top-hung larger window (1140x1180mm): £1,400-£2,400 fitted
- Velux Cabrio balcony-style window: £4,500-£8,500 fitted
- Velux integra electric/solar opening: add £300-£600 to base price
- Multiple windows in one visit: typically 10-20% saving per window
Costs include the window, all flashing, internal trim, scaffolding access, waste removal, and VAT.
What's Included in a Quality Installation
- Velux (or equivalent) window with manufacturer warranty
- Correct flashing kit for your tile profile
- Insulated underlining
- Internal trim and finishing
- Building Regulations notification where required
- All access (scaffolding, tower)
- Waste removal
Planning Considerations
Most roof window installations are permitted development without planning permission, provided:
- Window does not project more than 150 mm above the roof slope
- Window is not on the principal elevation facing a highway
- You are not in a conservation area or on a listed building
In conservation areas and on listed buildings, planning permission and/or Listed Building Consent is usually required. Conservation area properties facing a public street typically require approval before fitting any visible roof window.
What to Specify
- Brand: Velux is the standard. Fakro and Roto are credible alternatives often 20-30% cheaper.
- Glazing: double-glazed standard. Triple-glazed worth the small premium for thermal performance.
- Pivot type: centre-pivot for standard, top-hung for better view and easier window cleaning.
- Opening method: manual (cheapest), electric, or solar (best for high windows).
- Blinds: fitted at install if planned (much easier than retrofit).
Common Issues With Cheap Installations
- Wrong flashing kit (causes leaks)
- Insufficient insulation around the window
- No underlining (causes condensation)
- Internal trim not properly sealed
- Building Regs notification skipped
A proper installation lasts 30+ years; a cheap one starts leaking within 5.
Get a Roof Window Quote in Kent
We are Velux-certified installers across Canterbury, Margate, Faversham, and Folkestone. All installations include Building Regs notification and full warranty. Call 07562690714 or request a quote.
Frequently Asked Questions
How much does a Velux window installation cost in Kent?
Standard centre-pivot Velux installation costs £900-£1,500 fitted in Kent in 2026. Medium size £1,100-£1,800. Larger top-hung £1,400-£2,400. Multiple windows in one visit typically save 10-20% per window.
Do I need planning permission for a Velux window in Kent?
Most installations are permitted development without planning permission, provided the window doesn't project more than 150mm above the roof and isn't on the principal elevation. Conservation areas and listed buildings usually require permission.
Which is better: Velux or Fakro?
Velux has the broadest range, longest UK trading history, and best parts/repair availability. Fakro is a credible alternative typically 20-30% cheaper. For premium specification or long-term ownership, Velux remains the safer choice.
Should I get a triple-glazed roof window?
Worth the small premium for thermal performance, typically £100-£250 more than double-glazed. Particularly useful on south-facing windows or in well-insulated lofts where energy efficiency matters.
How long does roof window installation take?
Single window installation typically takes one full working day. Multiple windows in the same job can be installed in 1-2 days. Internal finishing (trim, plasterboard, decorating) often follows separately.
Will a roof window leak over time?
A properly installed Velux with the correct flashing kit and underlining should last 30+ years without leaks. Most leaks come from cheap installations using wrong flashing kits, missing underlining, or improper sealing. Always confirm flashing kit matches your tile profile.
Need Professional Roofing Services?
StoneRidge Roofing provides expert roofing services across Canterbury and Kent