Additional storeys/Extending upwards

Load bearing walls

With regard to the structural stability of the existing walls when undertaking an upwards extension, consideration will need to be given as to how the new loads will be supported. For example, if new floor joists are provided and they are to be supported by an existing wall, the wall will need to continue all the way down through the house to a foundation or alternatively the wall will need to be provided with an adequate intermediate support.

Existing openings

Some houses have through lounges on the ground floor where the existing load-bearing wall that did take a load down to the foundation has been removed, or it may have originally been built as a through lounge, with a steel/timber beam installed over the opening. This beam should be checked to make sure it is strong enough to carry any new loads from upwards extension that are added.

Existing foundations

The adequacy of the existing foundations to carry the extra load from the additional storeys will need to be checked. It may be necessary for the capability of the foundations to be increased by underpinning them. A structural engineer or your building control body will be able to advise you.