Since the 6th April 2006 all new applications for domestic planning permission have been subject to the mandatory building regulations detailed in Document L Part 1

New builds have to achieve an average U Value of 2.2W/m2K
Replacements have to achieve an average U Value of 2.0W/m2K
Extensions have to achieve an average U Value of 1.8W/m2K

All of Clearwood UK’s windows exceed the minimum standards set out in Document L for new builds, replacements and extensions.

Fire Regulations for Windows

Under the July 2000 Building Regulations approved document “B” (Fire Safety), there is a requirement that windows in habitable rooms in one or two storey domestic dwellings, flats and maisonettes that have an upper floor level which is no greater than 4.5m, must be capable of providing an escape route in the case of fire.

Windows that meet this requirement must have an unobstructed opening area of at least 0.33m2 and have a minimum opening dimension of 450mm in either width or height, with the remaining dimension big enough to achieve the total area of 0.33m2.

The bottom opening area of the window must be between 800mm and 1100mm from the room’s finished floor level.

For your guidance Clearwood UK has supplied a list of the most common window configurations that meet the Doc -“B” regs for fire escape for each product range.

However we strongly recommend that you should check and confirm that these window configurations and sizes comply with the Doc -“B” regs for the intended project with your architect or building control officer prior to placing your order.