Materials

To ensure that the extensions can be viewed as an integral part of the original dwelling, the materials used should harmonise with the existing materials. If your extension requires planning permission, it is likely that a condition will be imposed to the effect that matching materials should be used. Roof tiles, facing bricks and other materials should usually be the same size, colour and design as the existing ones.

Material Matching
If an exact match cannot be achieved, for example due to the effects of weathering , it is better to design the extension in such a way that the front wall is set back so that there is a slight visual break between any different materials used.



Figure 4 Extension set back to provide visual break

Design Detailing
Look at any detailing around the doors, windows and at the eaves and reflect this in the new design. Older houses in particular often have interesting arches and other special features which add character. However, unnecessary details should be avoided. Georgian columns, bow windows and other architectural features which are not in keeping with the design of the original dwelling and the area could look out of place.



Figure 5 Unnecessary detailing

Windows
To ensure that the extension is fully integrated with the original building, the windows of the extension should be aligned to the existing fenestration, both vertically and more importantly horizontally. Window design is also important, a mixture of timber and metal framed windows could appear incongruous.