Considered Durabase, but decided on traditional concrete foundations. Conservatory just completed. Tho the Durabase has a guarantee, I was concerned that the steel section would rust inside out. My property has solid floors and I did not want to step onto a suspended floor. Finally, price wise. I found a builder who would dig out by hand and lay concrete founds and base for a similar price. I did have good access to the site, they did not have to come through the house.