With all the existing Building Regulations being updated to properly reflect a need and demand for improved Building standards, there is a greatly increased requirement for U-value targets of floor, wall and roof construction to be met. Why meet the requirements when it is very simple to exceed the current expectations and to set the future expectations of energy conscious homes? Let me explain how.
A standard cavity wall is the most likely construction method to be shown on a planned extension to an existing home; external render on 100mm block, 100mm cavity, with 60mm insulation, with 100mm block, internal dry-lining with insulation backed plasterboard. This will give you an overall wall thickness of about 385mm and a U-value of 0.24W/m2K, 0.03W/m2K inside the minimum requirement of 0.27W/m2K.
That’s fine, the structure meets the requirements of the Building regulations, there is no issue.
Now if I offered you this structure, 385mm thick and returning 0.24W/m2K you would be happy. Yes?
What if I offered you a structure that gives you the same structural capacity of the blockwork, 18.6% space saving and a massive 42.9% improvement on the block work structure insulation values? This structure will return a U-value of 0.15W/m2K and is only 315mm thick. How happy would you be now?
In general terms, my structure is 48% better insulated, saving you money €€. It looks the same, it acts the same as a traditional wall. The price difference for this massive saving (50% less energy, remember) is so minimal you should be calling me for more information and a design specification . . .