Talk me through process of planning/building an extension

[Plateofcrumbs]

I am the start of process of planning an extension to our house and am not completely clear in my head what needs to happen and when - would really appreciate some experienced people talking me through it in simple terms (and I can ask my dumb questions here without making myself look stupid I front of architects and builders with whom I want to maintain a pretence of competence!)

The extension is a simple single-storey kitchen extension within size accepted under permitted development.

An architect has drawn up basic plans and submitted them to council. Now what happens?

If it is within the current permitted development rules the neighbours are notified, comments invited but it doesn't need to go to formal planning unless there are objections. You still have to meet buildings regulations criteria though.

Thanks! I think I have just about got my head round the planning process but I'm just less clear how things now progress with our architect and (yet to be appointed) builder. We don't plan on the architect being involved in project managing.

So depending on what kind of extension it is: do you need a structural engineer? If not, then can your builder work with your existing drawings or do they need more detailed construction drawings?

Yes, good point we are knocking out walls and a fireplace which will need supporting, so likely that will require a structural engineer.

The plans submitted to council are only very basic outlines - to me they don't seem to have nearly enough detail for a builder to work from but I know other people who have done extensions without any plans at all. I don't know how advisable or realistic that is though?

I would get proper construction drawings done by your architect, then show them to your builder before saying goodbye to your architect. If you do this without drawings, then your builder is left to work out things without much guidance and more likely to get it wrong. It will cost more, but more peace of mind, especially since you aren't getting a project manager.

I guess it varies from person to person but we got architect plans sufficient for planning and now he's starting the plans for the builder and structural engineer (which are a lot more detailed, drop on the drain pipes, the substructure of the foundations etc).

If planning permission is not required then I don't think the process would include notification of neighbours or invitation for comments - at least ours didn't. We just received a letter from council outlining process, points at which inspection would be required and points at which we had to pay - beginning and end I think for inspections and approval.

The architects can continue to manage things with the council or your builder may take over that side. You just need to use the architects plans to start getting quotes. If the drawings as they are are not sufficient for the builder they will let you know.

Architect will advise if structural engineer is required and may recommend one, or your builder may recommend one. We didn't see whatever structural engineer was required to submit to council.

sorry to jump on someone else's thread but I am in the similar position.
Can you approach builders for quotes without the building regs plans (we've just got the planning application plans) or do we have to wait for those before ringing around?