The new Approved Documents L1A, L1B, L2A and L2B for Wales have been released, effective July 2014.
The requirements are more onerous that those for England with lower CO2 emission targets. 8% improvement for dwellings and 20% improvement for non dwellings. Importantly much lower backstop U-values for dwellings, both new build and extensions, have been introduced;
Floors 0.18 W/m2K.
Walls 0.21 W/m2K.
Roofs 0.15 W/m2K.
The documents can be viewed and downloaded here.