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.

Pitched roof u value requirement.

U value requirement floor 0 13 w m k. U value requirement external walls 0 18 w m k. U values by building component. The u value requirments for building elements are outlined in part l.

U value requirement semi glazed doors 1 2 w m k. 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. Ground floor no underfloor heating 0 45w m k. U value requirement opaque doors 1 0 w m k.

External walls cavity 0 55w m k external walls other not cavity 0 35w 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. We don t count the pitched roof as part of the house as we will insulate the. Note the distinction between the domestic and non domestic columns.

U value requirement party walls 0 0 w m k. The below drawing shows the u value requirements set out for new properties in the building regulations for each element walls floors and roofs. Of the building regulations 2007. 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.

External doors windows rooflights curtain walling. 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. Pitched roof sloping ceilings. U value requirement windows whole window u value 1 4 w m k.

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. Cold roof ceiling level 0 16w m k. The new maximum u values are. U value requirement roof 0 13 w m k.

The tables below show the suggested u values in england wales and scotland. Ground floor underfloor heating 0 15w m k. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam.