Flat Roof Lights: Options, Costs and Installation

Flat roof lights are the standard way to bring natural light into a single-storey rear extension in London — and the range of products available in 2025, from basic domed skylights to frameless flush-fitted walk-on glass, has never been wider. Here is a guide to the main options.

What This Guide Covers

• Fixed aluminium-framed rooflight: the most popular and cost-effective option — from £800 fitted
• Walk-on rooflight: structurally glazed for roof terraces above ground floor spaces — from £1,800/m²
• Hinged access hatch rooflight: combines a roof light with loft or roof terrace access
• Dome skylights: lowest cost option but poorest thermal performance and aesthetics
• Building Regulations require minimum thermal performance (Uw below 1.6 W/m²K) for new rooflights

Introduction

London homeowners face unique challenges when it comes to glazing — from period properties with sash windows in conservation areas, to modern developments requiring structural glass installations. Getting the right advice before you commit can save you significant time and money.

At BuilderFix Glazing, we have completed thousands of glazing jobs across Greater London and Surrey — from emergency repairs in Kensington and Chelsea, to bespoke walk-on glass installations in Mayfair and Belgravia. This guide is based on real experience and the questions our customers ask us most often.

What Does This Typically Cost in London?

Costs vary depending on the type and size of work, the glass specification, frame material, and access. As a general guide, always obtain a free written quote before committing — this protects you from unexpected charges.

At BuilderFix Glazing, we provide free, no-obligation written quotes for all work. Our prices are transparent and fixed before we start — no surprises on the invoice.

What to Ask When Getting a Quote

• Is the price fixed, or could it change once work starts?
• What glass specification is included?
• Are all fixings, sealants and finishing included?
• What compliance documentation will I receive?
• What happens if there is an issue after completion?