Replacing a conservatory help.

[Superhoop]

We currently have a 4.2m x 4.2m conservatory that was built in 2007 which isn t in the greatest shape, and, like all conservatories is too cold in the winter (unless the underfloor heating is on all the time) and then too hot in summer..

House is L shaped, and it sits in the L.. we d like to pull it down and replace it with a flat roof extension of the same size, with bi-fold doors the full width of the extension on to the garden, and with a skylight..

Reading online, I think we only need building regulations approval but not planning permission.. does that sound right?

I assume we ll need to get a structural engineer to put together an application and that this will need structural calculations for the foundations, U values etc.. and I assume that will mean inspecting the current foundations to see if they ll need to be redone for the new construction or if they re already adequate.. again, is my understanding correct?

If I get someone in to do the foundations and build the walls needed, can I then build the flat roof myself (with the help of a mate who is a carpenter) and then have it inspected for sign off? Or would it just be better to bite the bullet and have a builder also build the roof?

What else have I missed? What else do I need to think about?

Thank you in advance from a complete novice when it comes to have an extension built..

Edited by Superhoop on Monday 23 March 21:20

[smokey mow]

If you are looking to match the same 4.2m dimension as the original conservatory then no it will not be permitted development and you would need to apply for prior approval.