Rooflights are heavy. It’s best to pre-plan your delivery and installation.

Published: 8th October 2023

Modern contemporary rooflights are heavy. The bigger the desired frameless rooflight, the heavier it becomes. Any rooflight above 150 kgs is extremely difficult to ‘handball’ off the delivery vehicle and onto the ‘fit area’.

As rooflight sizes increase, the thicker the individual glass panes for the rooflight become. Sometimes the top pane can be up to 12mm thick and, on occasion, the bottom pane for the rooflight can be 21.5mm thick toughened laminated glass for our bespoke Blade rooflights. Weights for rooflights can go from 40 kgs per m2 up to an incredible 80 kgs per square metre and even more for ‘walk-on’ type roof windows. Also triple glazed rooflights are approximately 15-25 kgs per square metre heavier if that is your preferred rooflight glass specification.

Clients should cross reference the weight of their desired Blade rooflight with their structural engineer or architect, ideally pre-build, to make sure the weight of the rooflight for the new extension or new build home can be accommodated. Ofset are happy to conduct a pre-fit site visit to look at access and any potential issues with the large skylight installation.

At some point (normally over 150 kgs) a crane must be utilised. Ofset are more than happy to organise this and we can use either supply ‘spider cranes’ or, more commonly, a ‘mobile crane’ which can reach out as far as 30 metres. Ofset will organise the crane and specialist glass suckers for the bespoke rooflight installation. Each property and ‘lift’ will be designed, project specific, to suit your exact needs. Clients can also organise their own crane locally if that’s a more convenient solution for the rooflight ‘lift’.

When fitting frameless rooflights in London or Birmingham or other cities, we often have to ‘crane over’ terraced properties, so parking for the mobile crane must be considered. Again, by conducting a pre-fit survey we can pick up any issues we have to overcome before the large rooflights are delivered and fitted.

We normally charge just £1495+VAT for the installation procedure which includes the mobile crane, project specific glass suckers and specialist time served fitters who will be needed for the bespoke rooflight installation. Obviously, there is also the cost of the rooflight(s) on-top!

You can contact Ofset today to begin a conversation about beautiful bespoke bigger Blade rooflights by simply emailing or calling us. Our lines are open 10am-7pm Mon-Fri and from 12-5pm on Saturdays. We can normally supply a bespoke large rooflight installation quotation within 24 hours. We look forward to communicating with you soon to talk about bigger Blades!


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