House Extensions and Renovations
There are 2 options for doing an energy rating for a house extension. The first option is the deemed to satisfy method which includes a glazing calculator report. Both the existing and proposed windows and glazed doors must comply with the BCA requirements. If compliance is unachievable with your glazing as is, we will then try the second option before suggesting any changes to your glazing.
The second option for the energy rating is the two house energy rating method as per Practice Note 2014-55 Section 9. In this case we rate the existing house and then based on a volume formula we are given a star rating in which the proposed house (including the existing and new sections combined) must achieve. In this case, if we are still unable to achieve the star rating generated for the new works, we may then need to make some amendments to the existing and/or proposed section of the house to achieve compliance. Some changes may include but are not limited to upgrade in insulation and amending glazing type and sizes to either or both existing and proposed sections.