Building on the seafront and thermal mass

[gasmanuk]

Hi we are currently looking into building a rear two storey extension on the rear of our 1900 detached west facing seafront property. As you can imagine we are exposed somewhat to the elements but the extension is on the rear so it wont bear the brunt of the weather but will still be exposed. My question is if anyone could give me suggestions as to best ways to insulate and building methods which would not allow air (wind) leakage. Also the upstairs is only going to have stud walls and therefore is low in thermal mass is there anything I can place in the void to help with this.

The roof would be slate and the external walls block, internal celcon maybe??

 

[legs-akimbo]

Any new type rigid insulation that meets current regs would surfice, by this I mean not to skimp by using rockwool type or polystyrene type in batts form but rather Kingspan foilbacked, better again than Kingspan would be to build with a 100mm cavity and go for full blown in insulation in polypearl or rockwool. Unbelievably warm and surpasses U value regs.

 

[Static]

Why not do the upper floor walls in brick/block?

 

[gasmanuk]

thanks static i would prefer this but downstairs is large open plan and I don't want to get into putting large span steels in to support internals walls for the reason of creating thermal mass. In realation to leg's point i trust you mean in the cavity of the external wall? do you think kingspan is better than rockwool because it doesn't let air through?

so any advice about filling stud walls would be great i did think about double boarding?

 

[Static]

How big is the extension? and what are you using for flooring structure?

 

[gasmanuk]

30 m2 upstairs and the same down stairs both will have wooden floors