Per Dwelling Type and Energy Sub-type may suit terraces or flats with the same orientation (rather than detached homes).

At first glance all the dwellings of a particular type may look the same. But “energy sub-types” are often needed for slight variations in:

• energy, e.g. mid-terrace and end terrace units.
• exposure/sheltering
• orientation
• shading

This method is likely to be cheaper than Per Dwelling, but could still be fairly labour intensive for a diverse project where there are many dwelling types.