Foundations essentially exist to hold up the structure above them. If there is no foundation, your conservatory could suffer from cracks or subsidence, which could cause considerable damage.
The foundations of an exempt conservatory won't need to be inspected by a building control surveyor and you could choose to use a designed pre-fabricated base or build one in situ.
Even if they don't need be approved (if your conservatory is exempt from the requirements of the building regulations) you don’t want your conservatory to suffer from problems associated with structural movement or damp, so the depth of your foundations should take account of things like:
- ground conditions
- depth of the existing house foundations
- location of any drains
- load of the structure
Your conservatory installer, designer or builder will be able to advise on the correct foundations for the job, and if building regulations approval is needed (find out if that might be the case here) then your local authority building control team will be able to help.