"The Natural Philosopher" wrote in message
...

The real point is that after whacking in loft insulation and SEALING it
against draughts in the loft...

You probably know but others might not...

It's very important to NOT to just wack some insulation between the rafters
or you risk a condensation problem and potential long term problems for the
roof structure. Lofts are generally designed to be ventilated spaces to
allow any moisture from the house to be removed.

If you want to put insulation between the rafters and seal the loft to
create a semi-warm storage space then you should consider going the whole
hog as you would for a loft conversion.....

Add batterns to the sides of the rafters to stop the insulation coming in
contact with the underside of the tiles/sarking and provide a 50mm
ventilation space. Install sufficient insulation between and below the
rafters (perhaps 150-200mm thick in total), then a correctly installed
vapour barrier to keep moisture away from the cold tiles/rafters. Add small
vents from the inside of the loft to the outside to allow any moisture in
the loft to get out. The next step would be to line with plasterboard but
that would probably make it a loft conversion in the eyes of building
control.

The alternative is to put insulation between the ceiling joists and retain
it as a cold roof. Seal gaps between the house and loft to keep moisture out
of the loft. Leave the gaps under the eaves open to ventilate the loft.
Insulate the loft hatch.

Colin









and putting weatherstrip on the windows and
doors, the very next think is to line the walls.




And possibly the floor.

There are HUGE potential gains to be had here, from not all that much
thickness of insulation. 6" of rockwool or celotex is easy to install
under a suspended floor for example. 2" of celotex on the outside walls
is not going to break the bank. And you could be looking at 70% or more
improvement in energy and bills.

Once that is done, boiler efficiency is not so important, and there is
always a moot point as to how much MORE energy the new boiler takes to
make.

Attention to electrical stuff is fairly trivial in terms of planet
saving. Far better gains can be had by switching off huge amounts of
public lighting between say 2 am and 6 a.m. However CFL bulbs are cheap
enough to pay for themselves in a few months..I use them because they
don't blow up every five minutes.

Likewise teenagers who spend 10-15 minutes in the shower are not saving
water or energy vis a vis a bath, either.