Thinking of adding a small side extension to my house, probably a porch/ utility space for coats, boots, extra freezer and a separate loo. Due to an existing nearby structure (old stone wall) it makes sense to avoid deep foundations and do a lightweight build. If deep foundations were dug I’m concerned my extension would end up too small or too expensive. Having researched it, I can see that with conventional foundations, building too near the wall might involve expensive under pinning to secure it. On the other hand, if the foundations are dug far enough away to avoid any issues with the existing wall, my extension could be too small to be worth the expense.
This led me to think about lighter weight building structures which could get around the problem. I’ve looked at pictures and to be honest, from what’s above ground it can look no different to a conventional structure. Steel frame is one way to go but I imagine there may be other techniques too.
Has anyone used a light weight structure for a small extension like this? I’d be grateful for any advice or feedback