Extentsion

W17yne

Hi all

Right I am looking to extend on to my garage! Builder has made a suggestion in passing!

I have a single story garage and I'm looking to put a room above, to avoid taking the garage Down to rebuild he has suggested to underpin the foundation of the garage from either side, dig down a meter and a meter wide and mass fill with concrete, both sides, do I need to get the building expect or to check once we have dug down or can we just dig a meter Down then the total length of the garage to strengthen what is there?

111KAB

May be more economical to take the garage down and start again from the sound of things ie to underpin may prove more expensive than providing 'simple' footings and building a 2 storey extension. There is a good chance you will require both planning permission and building control so this is where your building 'expert' will come in.

phill99

You will need to submit a building regulation application for the extension and this will include any new foundations.

Mikeef

You could build piers in the corners and mid point of the garage wall to support steels so you can build the new cavity wall above. You will probably need new foundations under each pier and this may be more cost effective than underpinning. Not sure on the cost difference in what your builder advised.