Hi,
Could anybody help on the below. Any help would be much appreciated.
Thanks
Muffet,
First, your stuff appears "above" your post, not below - had me looking for a while there.
Second, in post #5 above Docarch advised you to get a preliminary BER report done. I agree with him. The assessor will advise you fully in relation to the theoretical rating you *should* achieve. Whether you achieve it or not is down to the quality of the design/details and the workmanship of yoru contractor(s).
Third, I think your ceiling spec will freeze out your attic and all the services therein and lead to problems down the line.
You're posting about a 1.5 storey house and you don't have a spec for the sloped roof that addresses interstitial condensation?
I'd suggest that you allow your insulation to follow the line of the (presumable pitched) roof, keeping water tanks and services warm.
I mean, you're having 300mm mineral fibre in two 150mm layers above 42.4mm extratherm - in certain conditions, the top of it will just get wet!
Your archtiect needs to get advice on this before going to site and decides on whether he is going to include the 50mm air cavity and detail to suit.
Finally and for the record you don't post like you have actually appointed an architect or been advised by one, certainly not one who's up to speed on all of this.
Insulation of the envelope and sun path orientation is only part of the issues here in achieving a good rating on a house and arguably it can all be undone by other things.
- What about in-use airtightness, as opposed to costructional airtightness and use of air-lock approaches?
- Why the predeliction with cavity construction when externally insulated masonry can work better?
- Why the lack of consideration for using a mechanical ventilation and heat reclamation system?
I think you need to take a more global advice briefing on this and stop focussing on the insulation to the exclusion of all else.
ONQ.
[broken link removed]
All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand