If planning consent is needed then they will be looking for a similar look and impression of the original materials and design of your existing property. When designing an extension try to match the most prominent features to ensure a sense of continuity. It's also an idea to make sure that any doors and windows match up with existing fixtures. For most people planning wont be necessary but you will need a few appointments on site with the local building authoruty at certain critical times of the build. This is to ensure such things as foundations, insulation and roofing are all up to building standard.
Will I Need Permission ?
The reason for planning applications are to seek control of the way that neighbourhoods and towns are developed focusing on the appearance of buildings. You will definitely need planning permission if:
- The extension is higher than your original roof
- The proposed extension is over 4 metres high and within 2 metres of your boundaries
- The total volume of original property is increased by more than 115 cubic metres (calculated using length x breadth x height)
- The total volume of original property is increased by more than 10%