Flat Roof Windows in London

Arbor Skylights provides professional flat roof window installation across London, fitting rooflights in extensions, kitchens and flat-roofed rooms in areas including Dulwich, Peckham and Brockley. Each window sits on a fully sealed, insulated upstand, bringing daylight deep into the room while keeping the rain out.

Certified Skylight Installers

We are Velux-certified specialists

Fully Insured & Top-Rated

Not general builders, pros only

All London Boroughs Covered

We provide turnkey solutions

Flat Roof Window Installers London

Flat Roof Window Specialists in London

Flat roof windows are the best way to bring daylight into rear and side-return extensions, open-plan kitchens and flat-roofed rooms where wall windows can’t reach. Light from above falls straight into the middle of the room, making deep spaces feel open and bright.

Arbor Skylights installs flat roof windows across London, including Forest Hill, Lewisham and Greenwich. Whether you’re building a new extension or adding light to an existing flat roof, we recommend the right size, glazing and opening type for the space.

Flat roofs are less forgiving than pitched roofs, so the fitting matters. Every installation is completed with careful attention to the upstand, insulation and waterproofing, so the window performs as part of the roof rather than a weak point in it.

Certifications & Partners

Why Choose Our Flat Roof Window Installers in London

Flat roof windows combine a clean, modern look with practical performance. Working across London, including Blackheath, Dulwich and Peckham, we deliver flat roof window installations tailored to each property.

Ideal for flat roof extensions

The go-to choice for kitchen, rear and side-return extensions.

Designed to maximize daylight

Light from above reaches further into the room than light from the walls.

Suitable for any flat roof

We fit flat roof windows into felt, EPDM, GRP and single-ply roofs.

High thermal performance

Modern double and triple-glazed units and insulated upstands keep heat in.

Watertight upstands

The upstand and seal are where flat roof windows usually fail, so they get our closest attention.

Professional installation and finish

Neat internal reveals, ready to decorate, with a full clean-up.

Flat Roof Window Installer in Wandsworth

Flat Roof Window Specialists in London

We offer a full range of flat roof window installations across London, helping homeowners bring more daylight into extensions and flat-roofed spaces.

Flat Roof Window Installation

New flat roof windows for extensions and flat-roofed rooms, fitted on an insulated, sealed upstand.

Rooflights for Kitchen Extensions

Daylight over the island, worktop or dining table in deep rear and side-return extensions.

Flat-Glass Rooflights

A minimal, almost flush look for modern extensions and open-plan living.

Opening Flat Roof Windows

Manual and electric opening rooflights with rain sensors for ventilation.

Multiple Rooflight Layouts

Two or more rooflights in a row to light larger spaces evenly.

Rooflights for Garden Rooms & Offices

Bright, glare-free daylight for garden rooms, studios and home offices.

Flat Roof Window Installer in Wandsworth

Professional Flat Roof Window Installation in London

Arbor Skylights provides professional flat roof window installation across London, supplying and fitting rooflights for homes and extensions in areas including Brockley, Forest Hill and Lewisham. Designed specifically for flat roofs, these windows maximise daylight while maintaining insulation, weather protection and energy efficiency.

Flat roof windows are a popular choice for modern extensions, kitchens and open-plan spaces where extra daylight is needed. Available as fixed or opening units, with flat or domed tops, they can turn dark interiors into bright, inviting rooms.

We assess the roof build-up, joists and covering before recommending the most suitable flat roof window. Building a new extension? We coordinate with your builder or architect on sizes and timing so the upstand is right first time.

From survey to handover, we provide a professional flat roof window service across South East London, including Dulwich, Peckham, Greenwich and Blackheath.

INSTALLATION IN 4 STEPS

Here's How It Works

01/04

1. Survey

We check the roof structure, covering and drainage, and measure for the window.

02/04

2. Fixed quote

You get a written quote for the window, upstand, sealing and finishing.

03/04

3. Installation

Most flat roof windows take 1 to 2 days, depending on size and roof type.

04/04

4. Finishing

We line the internal reveal, test any opening mechanism and clean up.

Benefits of Flat Roof Windows

Flat roof windows bring daylight in from above while giving a clean, modern finish that suits contemporary layouts.

Made for flat roof spaces

Light where pitched roof windows can't be used.

Excellent daylight

Overhead light brightens rooms more effectively throughout the day.

Modern, low-profile finish

A clean look that suits extensions and open-plan living.

Ventilation options

Opening units keep kitchens and living spaces fresh.

Energy-efficient design

Modern glazing and insulated upstands support a warm, comfortable room.

Privacy with daylight

Light from the sky, not from neighbours' windows.

Flat Roof Window Options

Flat-glass rooflights sit almost flush with the roof for a minimal, modern look. They are the most popular choice for extensions.

Domed flat roof windows use a curved top that sheds water easily and suits budget-conscious projects.

Fixed rooflights maximise light at the lowest cost. Opening rooflights add ventilation, with electric and rain-sensor options.

Walk-on rooflights can be fitted where the roof is used as a terrace

Blinds for heat control and blackout, fitted at the same time.

Flat Roof Windows Across London

We install flat roof windows throughout London, with regular work in Dulwich, Peckham, Brockley, Forest Hill, Lewisham, Greenwich and Blackheath.

We also cover Islington, Camden, Hampstead and Finchley in the North; Hackney and Walthamstow in the East; Ealing, Chiswick and Kensington in the West; and Clapham, Wandsworth and Richmond in the South West. Not sure we cover your street? Send us your postcode.

About Arbor Skylights

Arbor Skylights was set up for one reason. Most homeowners who need a new skylight or a replacement Velux end up with a general builder, for whom roof windows are a small side job. That is where leaks, poor flashing and rough internal finishes come from.

We took the opposite approach. Skylights, Velux roof windows and flat roof windows are our only trade. Our installers have more than 35 years’ experience and have fitted more than 200k windows across London, from Victorian terraces with narrow staircases to modern flat-roof extensions.

The name says what we care about. An arbor is a shaded space in a garden; we open it to the sky. Every project starts with the same question: how do we bring the most daylight into this room, without ever letting the weather in?

Flat Roof Window FAQs

Yes. As long as the roof structure is sound, we cut a new opening, trim the joists and fit a flat roof window on an insulated upstand sealed into the existing covering.
Not when they are fitted correctly. Flat roof windows sit on an upstand so water runs away from the glass, and the upstand is sealed into the roof covering. Most leaks come from poor sealing, not the window itself.

Usually not. Rooflights on flat roofs normally fall under permitted development if they project no more than 150mm above the roof. Listed buildings, conservation areas and flats may need consent.

It depends on the room layout and where you want the light to fall, for example over a kitchen island or dining table. We plan the position with you at the survey.

Yes. Two or more rooflights in a row are a popular way to light larger extensions evenly.

A flat glass rooflight has a minimal, modern profile and usually better insulation. A domed rooflight has a curved top that sheds water easily and costs less. Both are fitted on an upstand.

Yes. Opening flat roof windows provide ventilation, and electric versions can close automatically when it rains.

Options include double or triple glazing, solar-control glass to reduce heat, and obscured glass for privacy.

Most flat roof windows take 1 to 2 days, including forming the opening, building the upstand, sealing and internal finishing.

Yes. They’re one of the most popular features of modern extensions, thanks to their clean look and ability to light deep rooms.

Get a Free Flat Roof Window Quote

Planning an extension or brightening an existing flat roof? Talk to us for expert advice and a free, fixed, no-obligation quote.