> Ignore the manual and simply calculate from first principles: also be
> aware that floor loss is heavily dependent on WIND as that takes the
> energy out of the edges a lot faster than you might think, and its
> especially so if there is a vented underfloor space.
Indeed - fortunately on 90% of the house, it's somewhat sheltered from the wind - so there aren't really gales blowing in the airbricks. And there aren't really that many airbricks.
> A U vale of less than one for a floor, sound pretty good to me though. > >
> Best is to turn all U values into K values and then add them all up,
> then take the reciprocal of the result.
Yeah - problem was that the table I was using had a fudge factor built in already for an assumed wood deck, and a carpet, as well as the two surface resistances, which confused me.
I realised an easy alternative. In the field next to my house is a massive stack of big bales.
If I simply purchase a beeeg pile, and mound it over my house to a depth of about 4m, then my insulation problems will be solved.
:)