Pitched Roof U Value Requirement

Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation.

Pitched roof u value requirement.

Pitched roof with insulation between ceiling joists or between rafters determine the thickness of the insulation layer required to achieve a u value of 0 21 w m2k if insulation is between the joists and 0 26 w m2k if insulation is between the rafters. U value requirements the u value of a building element i e walls floors or roofs is a measure of the thermal efficiency or heat loss through that element the lower the u value the better the thermeal efficiency of the element. If you have any additional enquiries then feel free to drop the celotex technical centre a line on technical celotex co uk. The new maximum u values are.

U value requirement semi glazed doors 1 2 w m k. Typically the u value requirement of a pitched roof is 0 18 w m2k which you could achieve with your 150mm between the rafters and another 12mm fixed under the rafters. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam. The u value requirments for building elements are outlined in part l.

U value requirement external walls 0 18 w m k. U value requirement opaque doors 1 0 w m k. The tables below show the suggested u values in england wales and scotland. U value requirement party walls 0 0 w m k.

Element u value w m2k walls 0 30 floors 0 22 flat roof or roof with integral insulation 0 20 pitched roof insulation at ceiling level 0 16 pitched roof insulation at between rafters 0 20 windows roof windows and roof lights 1 80 doors with more than 50 of the internal surface area glazed 2 20 other doors 3 00. U value requirement roof 0 13 w m k. U value requirement floor 0 13 w m k. Of the building regulations 2007.

The below drawing shows the u value requirements set out for new properties in the building regulations for each element walls floors and roofs. U value requirement windows whole window u value 1 4 w m k.