Cold roof ceiling level 0 16w m k.
Pitched roof u value requirement.
U values by building component.
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.
Ground floor underfloor heating 0 15w 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.
U value requirement windows whole window u value 1 4 w m k.
Highlighted in violet is the first time the u value requirement for a component was strengthened.
Note the distinction between the domestic and non domestic columns.
U value requirement party walls 0 0 w m k.
Of the building regulations 2007.
Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam.
The tables below show the suggested u values in england wales and scotland.
External walls cavity 0 55w m k external walls other not cavity 0 35w m k.
Ground floor no underfloor heating 0 45w m k.
The u value requirments for building elements are outlined in part l.
U value requirement roof 0 13 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.
The new maximum u values are.
External doors windows rooflights curtain walling.
U value requirement semi glazed doors 1 2 w m k.
U value requirement opaque doors 1 0 w m k.
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.
We don t count the pitched roof as part of the house as we will insulate the.
U value requirement floor 0 13 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.
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.
The actual specification required for a compliant building and necessary building fabric u value targets may vary depending on the actual overall proposed specification and the outcome of the energy.
If you have any additional enquiries then feel free to drop the celotex technical centre a line on technical celotex co uk.
