Typical sequence for building an extension

Hi, I thought there might have been a sticky or old thread similar to my query but I couldn't find any. I am looking for a typical sequence of events that would occur in the building of an extension to a house. I know all cases are different, in my case, we want to build a singe storey side extension (c.35sqm) on to our semi-detached home. We of course will need planning permission to do so. My thoughts of what the sequence would be something like this:
1. Have a good idea on what I want from the extension.
2. Get and architect to do up planning drawings.
3. Get 3 quotes from builders based on architects drawings.
4. Pre-planning meeting??
5. Submit for planning permission with architects drawings and more detailed construction drawings.
6. If successful, specify all materials and finishes with chosen builder.
7. Build.

Of course the above is very simplified, and may be missing lots of detail. So for anyone in the industry or anyone who has had an extension built, please contribute to above sequence. Thank you.