Frequently Asked Questions

Shopping with us

Yes! We offer a FREE next day delivery service on stocked products, free 2 wday delivery service on most VELUX products, and 3 working day on other products. All you have to do is spend more than £50.

This offer applies to delivery in mainland Britain, excluding the Scottish Highlands.

Yes, we do. Find out more about the international delivery service we offer:

Yes, we do. And we'll send you a thank you gift if you choose to shop with us. Find out more about the Sterlingbuild Price Match+ Promise.
Yes, you can. We have a shop and warehouse in Folkestone, Kent, which is open 7.30am to 5.30pm Monday to Thursday, and 7.30am to 5.00pm on Fridays.

We do. The Sterlingbuild shop in Folkestone, Kent, has a number of roof windows and rooflights available to try before you buy, including a VELUX CABRIO balcony window. The shop is open 7.30am to 5.30pm Monday to Thursday, and 7.30am to 5.00pm on Fridays.

We don't provide an installation service; however, we work closely with a team of experienced installers who include ex-VELUX engineers.

Alternatively, we recommend you find a tradesperson on or TrustMark
If you've placed your order online you'll receive an automated confirmation e-mail. This will detail all the items you have ordered and the expected delivery dates. However, you will only receive this e-mail if you have provided us with a valid e-mail address.

If you have not received this e-mail, please check to ensure it has not been filtered into your junk or spam folder.
Visit Roofinglines, our sister site, for a complete range of high quality pitched and flat roofing materials, as well as DIY and roofers' tools.

Queries about the pitched roof windows

The product dimensions given on Sterlingbuild are all width x height for pitched roof windows and width x length for flat rooflights.

This refers to the external frame size, not the glazing area.
When working out the size of the hole for your pitched roof window, you need to add 40mm to the width 50mm to the height of the roof window size.
Flashings are an essential accessory to your pitched roof window. They enable your window to fit in your roof and create a weathertight seal to protect your roof and home.

Buying the right flashing is incredibly important and ordering the wrong flashing kit can put back your renovation project as you wait for the right one to be delivered. Our article will show you which VELUX, RoofLITE, FAKRO or Roto flashing you need for your window.

Yes! You don't need to lose out on quality and performance when you buy an alternative to VELUX. RoofLITE is a sister brand of VELUX and one that's very popular with our customers. Read our blog post on RoofLITE Vs VELUX.

It easy when you know how! The VELUX - and other brand - dataplate can be found on the side of the window's frame.

The dataplate gives essential information about the size and model of your roof window so you can buy the right blind, replacement glazing or replacement window.
For a roof window to be used as an emergency escape, it can be no less than 45cm in width or height, with a free space area of 0.33m, so it needs to be a top hung window. The sash must be able to stay open so both hands are free.

We highly recommend an insulation collar. They provide excellent insulation and weatherproofing properties for your loft conversion or home extension window – perfect for a more comfortable living space.

Other installation accessories that can improve your installation are underfelt collars, which ensure a weathertight fit, vapour barrier collars, that stop condensation forming in your roof space and lining frame kits, which create a mounting base for the internal lining of your roof window.

If your roof window is already installed, choose an energy saving blind. You might be surprised by the difference it makes to your room.
On Sterlingbuild, roof windows refer to windows that are installed on a pitched roof - you might call them VELUX windows; however, we sell a large range of other brand roof windows to cater for every budget.

Rooflights are what we call flat roof windows, including flat glass, roof lanterns and walk-on glass windows.

However, if you're looking for a window to add natural light and ventilation to an uninhabited space, you will need a skylight. These windows don't meet building regulations for living spaces but will add daylight to lofts, sheds and stables.
Check out our blog post for more information on the VELUX size codes old and new.
Our friends at VELUX said none of their windows need planning permission but they can't guarantee the renovation work you're planning for your home won't.

If in doubt, we will always advise you to talk to your local planning authority before you invest time and money into renovations, particularly if your property is listed or in a conservation area.

Sometimes local authorities will insist on conservation roof windows for loft conversions and home extensions for older buildings. All VELUX conservation windows have the modern benefits of style, energy efficiency and ease of use. It's the external frame that makes them suitable for conservation areas. If you're in any doubt as to whether you need conservation windows or not, contact your local planning authority.