TC Simple Home Heating Model

This simple model for heat loss from a house gives you an idea of what proportion of heat loss is through the different elements (walls, windows, roof etc.) and how much you might save if you added insulation or draught proofing. Enter the details of your house below and press 'Run Model' to see what it says about your own house.

Example house heat loss now: 3.3 W/C/m² Help

walls-1		windows-1		door-1		door-2		roof		ground floor		bridging		ventilation
	18%		18%		2%		2%		6%		11%		7%		37%

With changes: 2.3 W/C/m², saves 31%

walls-1		windows-1		door-1		door-2		roof		ground floor		bridging		ventilation
	4%		26%		3%		3%		3%		16%		10%		37%

House Details

First select the general shape of your house:

square	3-2	2-1	L-shape	extended

type:	terraced	semi detached	detached
floors: (excluding converted roof space)	2	1
windows:	few windows	average windows	lots windows
age (for thermal bridging Help):	Pre-2003	2003-2006	Post-2006

Now select the construction features for your house: Help

	What it is now	With changes you are considering
walls-1	Unfilled cavity Filled cavity Solid brick as built Solid brick with insulation Stone PassivHaus	Unfilled cavity Filled cavity Solid brick as built Solid brick with insulation Stone PassivHaus
walls-2	Unfilled cavity Filled cavity Solid brick as built Solid brick with insulation Stone PassivHaus	Unfilled cavity Filled cavity Solid brick as built Solid brick with insulation Stone PassivHaus
proportion of walls type1:type2	100:0 75:25 50:50
windows-1	Single glazed Secondary double glazed Double glazed pre 2002 Double glazed recent Triple glazed PassivHaus	Single glazed Secondary double glazed Double glazed pre 2002 Double glazed recent Triple glazed PassivHaus
windows-2	Single glazed Secondary double glazed Double glazed pre 2002 Double glazed recent Triple glazed PassivHaus	Single glazed Secondary double glazed Double glazed pre 2002 Double glazed recent Triple glazed PassivHaus
proportion of windows type1:type2	100:0 75:25 50:50
door-1	Solid wood Half single glazed Half double glazed	Solid wood Half single glazed Half double glazed
door-2	Solid wood Half single glazed Half double glazed	Solid wood Half single glazed Half double glazed
roof	no insulation 50mm 100mm 150mm 300mm PassivHaus	no insulation 50mm 100mm 150mm 300mm PassivHaus
ground floor	Solid, no insulation Solid, 50mm insulation Solid, 100mm insulation Suspended, no insulation Suspended, insulated	Solid, no insulation Solid, 50mm insulation Solid, 100mm insulation Suspended, no insulation Suspended, insulated
ventilation	Very draughty Fairly draughty Cosy Very cosy Air-tight with MVHR	Very draughty Fairly draughty Cosy Very cosy Air-tight with MVHR

Now rerun the model:     Run Model

Calculation details

For details of how the calculations have been done see Help.

Details for terraced house 4.9m by 9.9m tfa=97.6

Example house heat loss now

part	type	uvalue/ach	area/volume	heat loss w/c
walls-1	Solid brick as built	2.1	27.0	56.7
walls-2	Solid brick as built	2.1	0.0	0.0
windows-1	Double glazed pre 2002	3.1	18.7	57.9
windows-2	Double glazed pre 2002	3.1	0.0	0.0
door-1	Solid wood	3.0	1.9	5.6
door-2	Solid wood	3.0	1.9	5.6
roof	100mm	0.4	48.8	19.5
floor	Suspended, no insulation	0.7	48.8	34.2
thermal bridging	Pre-2003	0.1	147.0	22.1
ventilation	Fairly draughty	1.5	244.0	120.8

Total loss 322.3 W/C

With changes

part	type	uvalue/ach	area/volume	heat loss w/c
walls-1	Solid brick with insulation	0.3	27.0	8.1
walls-2	Solid brick as built	2.1	0.0	0.0
windows-1	Double glazed pre 2002	3.1	18.7	57.9
windows-2	Double glazed pre 2002	3.1	0.0	0.0
door-1	Solid wood	3.0	1.9	5.6
door-2	Solid wood	3.0	1.9	5.6
roof	300mm	0.1	48.8	6.3
floor	Suspended, no insulation	0.7	48.8	34.2
thermal bridging	Pre-2003	0.1	147.0	22.1
ventilation	Cosy	1.0	244.0	80.5

Total loss 220.2 W/C