Flat Roof Minimum U Value

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.

Flat roof minimum u value. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Minimum r value state local al alabama 2015 alabama commercial energy code 2 r 25 3 r 25 state local ak alaska 2012 alaska building energy efficiency standard 7 r 35 8 r 35. Insulation for flat roofs pitched roofs and balconies and terraces. Walls 0 30 w m2 k.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. Insulation for walls including cavity walls solid walls and timber or steel framed walls. 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. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.

However in new builds u values are part of the overall goal for energy efficiency. Cold roof ceiling level 0 16w m k. A u value of 0 55 w m k is used for cavity insulation and 0 30 w m k for internal or external wall insulation. 0 11 4 fiberglass insulation.

Roofs 0 20 w m2 k. For a very good introductory overview article on r value see r values over at the website of. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. The below drawing shows the u value requirements set out for new properties in the building regulations for each element walls floors and roofs.

0 16 3 fiberglass insulation. The current legal limits under building regulations part l are as follows. 0 26 2 fiberglass insulation. Ground floor no underfloor heating 0 18w m k.

Flat metal roof. Get a u value calculation from our free online u value calculator or our technical department. 0 05 8 fiberglass insulation. R value of various materials.

U value of a flat roof. 0 039 12 fiberglass insulation. 0 027 wood roof. 0 90 1 fiberglass insulation.

0 48 1 fiberglass insulation. Floor 0 25 w m2 k. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. 0 071 6 fiberglass insulation.

All new projects must prove themselves to be reasonably energy efficient.