Building above garage conversion

kelbal

Hi,
We have a one story garage conversion on the side of our house. We're thinking about the possibility of building on top of it to make it 2 stories, and connect into the house on the 2nd floor. However, my suspicion is that when these garages were originally built with the house, the foundations weren't dug deep enough to allow the extra weight of a 2nd story in the future. I'm assuming it would have to be knocked and the whole lot built afresh.
I know its impossible to be certain without having a builder properly look at it - but would it generally be the case that the foundations in this type of add-on to the house wouldn't be strong enough for a 2nd story? Picture below.
Thanks

sky6

You could try digging down the side of the Garage to the bottom of the foundation to see how deep it is. That way you will have a better idea of what you face up to.

Strolling Bones

You may be lucky. The builder may have excavated and poured footings the same all over.
You need trial holes to confitm though.

sky6

Strolling Bones wrote: »

You may be lucky. The builder may have excavated and poured footings the same all over.
You need trial holes to confitm though.

That's exactly my thinking. You could also ask any neighbours who have built on top how they got on with checking their foundations. It's not scientific but should give you a good indicator along with a few trial holes yourself.