We supply the UK with two stunningly beautiful rooflights for both flat roofs and pitched

“Architecturally an amazing quality rooflights product” – Craig Driver, MD Hoopers Architects

design & cost now

"Architecturally an amazing quality product" - Craig Driver MD Hoopers Architects

the blade

Perfect for top end projects and can be made in almost any size imaginable. Up to 6000 x 3200 in one piece and up to ANY SIZE x 6000 in multi section design.

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the blade lite

This beautiful rooflight is the best value for money rooflight in the Uk at sizes up to 3000 x 1500 external kerb size. They looks stunning and are an unreal price!

design & cost now

comprehensive
lifetime guarantee

bespoke
& handmade

super energy
efficient

delivered throughout
mainland UK

check out what our clients think of us

the rollerblade

Click and drag to roll

We do big blade rooflights

We can design and supply your dream super large ‘one-piece’ Blade rooflights. Up to 6000×3200 super large bespoke rooflights in ‘one piece double or triple glazed floating rooflights. No joins, just a beautiful vista of floating glass. Or up to an incredible 6400×6000 in multi-sectional larger rooflights supported by super strong toughened laminated glass beams.

want to see more of our rooflights?

check us out on instagram:
@ofset_rooflights

choose our rooflights
from the ofset

We have tried to make your online journey with Ofset as simple as possible.

Most clients want the best possible contemporary rooflight at the fairest price. We are confident we tick both boxes. Try designing your forever rooflight online using our Bladebuilder costing tool.

Or just give us a call at 0845 2068343, and we will help guide you through the process with pleasure.

design & cost now

intelligent design

The look & structural integrity of our product is paramount.

huge choice

Choose from one of six standard colours or any RAL colour of your choosing.

lifetime guarantee

We back our amazing product for life. If it fails we replace it. Simple.

form & function

The Blade is not only the best-looking rooflight it is also the best built.

intelligent design

The look & structural integrity of our product is paramount.

huge choice

Choose from one of six standard colours or any RAL colour of your choosing.

lifetime guarantee

We back our amazing product for life. If it fails we replace it. Simple.

form & function

The Blade is not only the best-looking rooflight it is also the best built.

Enjoy light therapy when you install flat roof lights from ofset

rooflight u-values simplified

The U-value is the measurement of heat lost through a roof window. The lower the U-value, the better the rooflight is at keeping heat in.

There are three ways to measure the heat loss of a flat roof window as explained below – Ug, Uw and Ud. The glass Ug-value tends to be the lowest U-value and many rooflight companies only quote this figure which in our eyes is essentially cheating. Building regulations inspectors are not concerned with the rooflight glass U-values, they are more interested in ‘combined product’ U-values.

Clients should also bear in mind that triple glazed rooflights are not necessarily better than double glazed rooflights for the UK climate when you factor in ‘solar gain’ which is free heat harvested from the sun in the spring, autumn and winter.

glass centre pane u-value (ug)

Heat lost through the middle of the glass is called the Ug-Value. This measurement remains the same irrespective of the rooflight size.

combined glass and frame (uw)

The Uw value measures heat lost through both the aluminium rooflight frame and glass combined.

combined glass, frame and kerb (ud)

This is the combined ‘developed area’ heat loss measurement of the glass, frame and insulated kerb combined.

blade rooflight u-values

Double-A centre pane Ug-value is 1.0 w/m2k
Triple-K centre pane Ug-value is 0.4 w/m2k

Double-A glazing and frame combined Uw-value from 1.2 w/m2k
Triple-K glazing and frame combined Uw-value from 0.6 w/m2k

Double-A glazing, frame and kerb combined Ud-value from 1.1 w/m2k
Triple-K glazing, frame and kerb combined Ud-value from 0.4 w/m2k


All Blade rooflights fully comply with building regulations minimum heat loss requirements of 1.6 w/m2k for domestic installations and from 1.8 w/m2k for commercial installations. Double-A Blades are double glazed with argon gas and Triple-K Blades are triple glazed with Krypton gas, both with soft coat low-e coatings and warm edge spacer bars.

made in britain

learn from the experts

Deciding which glazing product is best for you can be a confusing business. Here’s a selection of articles to make things clearer and help you to make informed choices.