Any benefit in cavity insulation on one aspect of house only?

Folks,

Have timberframe dormer build with attached sun/living room off to one side (westerly aspect). This room/side of house takes full brunt of prevailing winds & rain coupled with which it has a vaulted ceiling and is arguably the most difficult room in the house to heat (or retain heat). Is there any merit in installing cavity insulation in the cavity of this room and the west gable of the house (that the room is built off) or is it meaningless if all cavities are not insulated.

Thanks in advance,
mmc

Do not fill the cavity of a timber frame construction!
Please read Post #2 in this thread which explains why this should remain fully ventilated.

Depending on the age of the house, which you might be good enough to state, the timber frame should be well insulated.
Your problem may be more to do with the inadequate insulation of the sunroom, which I'm guessing is fully glazed with minimal roof insulation.


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.

Thanks onq. House is only two-three year old. Sunroom has a vaulated ceiling (circa 16 ft to truss tyes). In terms of insulation it has 100ml rigid ks between studs, 200 ml rigid ks between sloping rafters, 300ml quilted insulation above between truss tyes (flat part of ceiling) so in theory it should be reasonably well insulated. It is not an orthodox sunroom (glass floor to ceiling) but has 4 windows & large french doors on north aspect. I think my real problem as pointed out in other post may be the insulation detail where the sunroom "meets" the main structure of the house along the west gable. I cannot recall exactly how this was insulated at the time but a bulkhead was framed out & slabbed inside the sunroom at this junction and has some quilted insulation within. I certainly have some heat loss at this point as I can feel wind at the opes for a couple of recessed spots along the underside of the bulhead. Considering opening this bulkhead at a high point & pumping with insulation but not sure if this would potentially cause other problems?

I'm always wary of where the quilted insulation meets the sloping ceiling.
Too easy to block the 50mm air gap even where its carried through.

Personally I think you have a design issue affecting your sunroom.
Its projecting out from the house and is mainly glass-walled.

Unless its almost 'bionic glass', this will be cold and drafty.
Glass is a 'psychologically' cold material, hard to sit by.

You may also be feeling "relatively" cold re the house.
Plus the "high" space is much harder to heat fully.

Warm air rises and the space heats from above.
So it take a while for the whole room to heat.

I'm not saying there aren't other issues.
But these are all relevant too.




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.