Steel structure Rear extension on stilts

HI Mark, You will definitely, definitely need a structural engineer. Get them to come and take a look and get quotes on drawings and calculations. Anything can be done (if you throw enough money at it) but the structural engineer will tell you what needs to be done, what size RSJs, foundation depth, etc. You will also need planning permission as that is outside the scope of permitted development.

Hi Mark, This is technically possible and could be a good solution for keeping more garden space on the ground floor. If I was to design the structure of it, I would look out for the following points: 1. Foundations: You might be able to use shallow pad foundations onto which your steel stilts come anchored with a steel base plate. 2. Lateral stability: You can either brace your platform between stilts or create a portal frame action to stabilize your first floor extension. Alternatively, you might be able to tie the extension floor slab to the existing building and rely on the existing building for lateral stability This is a straightforward job but i would definitely recommend using a structural engineer to satisfy yourself that the extension will be built safely. Best, H.