top of page

SAP calculations for extensions

Extending your home is a popular way to add more living space and increase your home's value.

Maximising natural daylight, providing views of the garden and connecting indoor and outdoor spaces generally leads to extensions having relatively large areas of glazing.

However, too much glazing can potentially mean higher heat loss in the winter, and too much solar gain in the summer months. This can make the space uncomfortable to live in.

For this reason, the Building Regulations set a limit on the maximum area of glazing that new extensions can have. This is set at 25% of the floor area.

For extensions with glazing which exceeds this, one option is to provide a set of SAP calculations for Building Control. The calculations compare the proposed extension to the Building Regulations requirements, and effectively allows the higher amounts of glazing to be "offset" by making improvements elsewhere in the design of the extension.

Here's what some of our recent clients had to say about the calculations we provided for their extensions:

"Resolution Energy worked quickly and efficiently to produce the SAP calculations, and were competitively priced."

S.Porter, Dove Cottage, Midhurst

"Claire was a pleasure to deal with. Prompt, precise, good communication and was able to provide a quick turnaround. I would 100% be using Claire again for any future projects. Thank you for all your help!"

R.Talwar, Cedarwood, Romsey

"I found Claire to be professional, efficient and easy to communicate with. She understood what I was seeking to achieve in regards the insulation of a roof structure and managed to achieve these objectives."

N.Cowan, Abbotts Ann


bottom of page