Even this is not an complete list, but if you start with your ‘end objective’ in mind then you should be alright and if you make sure you use an installer who is certified & has a good track record (always ask for references from satisfied recent clients who live in your area) they will be capable of dealing with planning permission & building regulations.
Conservatory size is important for planning permission
It seems to be the case that the majority of conservatories in England & Wales do not automatically require planning permission in order to be built, and so luckily that is one cost that most homeowners will not need to consider when looking at conservatory price via a cost guide at present.
However, it is important to have a rough idea of how big you can make your conservatory before you start to infringe on the limits and fall into the category that does need planning permission – just a few inches and an inspector who is particularly ‘on the case’ could mean expense at the least & disaster at the most (Sir Cliff Richard had a big problem with his £30,000 conservatory!)
You can find a lot of information about orangeries at orangerycosts.co.uk, but always check with your local authority to see what they are allowing as ‘permitted developments’ in your area, and also confirm with your installer that they can handle all the aspects of design, planning & implementation if required.