The easiest way of getting a u value calculation is by using our free online u value calculator.
Roof u value wales.
Roof 0 15 well i say taken care actually the document states that even these values should only be considered as a starting point towards compliance.
U value of a flat roof to comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k.
It is proposed to use mineral wool insulation between and over the joists with a thermal conductivity of 0 04 w m k.
What is a u value.
Ridge board this forms the apex of the roof and is where the rafters are fixed to both sides.
These can be supported with a detailed report.
Welcome to the welsh technical guidance page for part l of the building regulations.
For more information see our articles and how to videos below.
Each element enables the roof to span across the building and support the tiles covering on top as well as being able to transfer the loads weight created by any wind and snow down to the walls.
The new notional building parameters are published in the document as they are in england however unlike england the tighter mandatory limiting fabric values will limit the variations.
It can also be referred to as an overall heat transfer co efficient and measures how well parts of a building transfer heat.
Gov wales uses cookies which are essential for the site to work.
A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.
Check out our guide on what performance is required for the uk insulation building regulations.
The tables below show the suggested u values in england wales and scotland.
There are two additional compliance guides for building.
Note the distinction between the domestic and non domestic columns.
By continuing to use this site you agree to our use of cookies.
Where more than 25 per cent of a ceiling below a cold loft space or flat roof is being replaced then building regulations would normally apply.
Non essential cookies are also used to tailor and improve services.
Determine the thickness of the insulation layer above the joists required to achieve a u value of 0 20 w m2k for the roof construction shown below.
They cover new dwellings document l1a work to existing dwellings l1b new buildings other than dwellings l2a and works to existing buildings other than dwellings l2b.
This section contains the approved documents l1a and l1b for download below.
This means that the higher the u value the worse the thermal performance of the building envelope.
Listed below are the typical elements of a pitched roof.
The required u value will depend on the location of the project england scotland or wales type of building domestic or non domestic and the application floor wall or roof.
