3. Heat Loss - inside and outside partitions.

The illustration at right shows a simplified plan view of conductive heatloss.
XXNotice that heat loss is greater from rooms A, B,G & H because these are corner rooms with two outside walls. By contrast, rooms E,D & F have only one outside wall, so in this situation they are easier rooms to heat.
XXThe other thing to notice is that for the purposes of illustration the front hall and corridor (C.) is unheated, leading to some leakage of heat from all rooms into this area. This shows that the temperatures in adjacent rooms must be taken into account when conductive heat losses are being calculated.

There are two other points to bear in mind;-

• The true position in a house is of course three-dimensional. Therefore heat loss must be calculated for the floor and ceiling as well as for partitions. Upper floors in particular tend to benefit from the effect of heat seeping upwards from the rooms below, but the heat gained this way can usually only be guessed at.
• An outside wall is still an outside wall for the purpose of heat loss calculations even where there is a garage or outhouse attached to it. Unless of course the garage or outhouse is being heated.