Garage Conversion

[matt5195]

I have got a single skin double detached garage(small alleyway between house and garage), which i want to attach to the main house and then convert into a kitchen/diner, garage currently as flat roof, i want to change this to a sloping roof.
i have been told that if i want to build internal walls (timber/insulated) then i will have to put new foundations on the inside of the garage to support the load of the internal walls.

What is the best option to go for?

1. Dig internal foundations and put timber stud wall up.
2. Putting internal foam insulation and render direct to single skin with roughcast render (at this link http://www.foamglas.co.uk/building/installation_videos/)
or
3. Putting external thermal insulation and render to outside wall (would i then have to put an internal wall in, or will insulation be adequate)

Thanks for your help, Matt

 

[^woody^]

Timber stud walls do not need foundations unless they are load bearing

 

[matt5195]

Don't believe they will be load bearing, but do have to raise the floor by 2', so it matches original house floor level, so would this be the reason?

 

[^woody^]

No, just span it with a double joist on hangers or built in