When considering the glazed area of a property the whole dwellings (including extensions) windows, glazed doors, and rooflights should be considered (but not conservatories). Typical - Applies if the surface area of the glazing in the dwelling is essentially as would be expected of a typical property of that age, size and character. A tollerance of +/- 10% should be accepted. More than typical - Applies if there is significantly more surface area of glazing than would would be expected (15 - 30% more), parhaps because there is a large sun room or numerous patio doors have been added. Less than typical - Applies if there is significantly less glazing than would be expected. This is rare as home owners tend not to reduce glazed areas, however a property may have an unusually small glazed area by design. Much more than typical and Much less than typical - Applies to dwellings with a very unusual amount of glazing: such as a glass walled penthouse flat or a 'Huff Haus'. Due to this option allowing measurements of each window to be accounted, it can also be used if a dwelling has a mixture of glazing types e.g. single, double and triple. The Lifespan SAP Team