Streetlife

I've seen quite a few threads on recommendations for builders for loft conversions and kitchen extensions recently, but I've got a slightly different request.

Before we moved into Battersea a couple of years back, we had the whole of our house re-developed as favour by a very upmarket builder my father knew (he built his house in Teddington from scratch). Unfortunately, he won't do mates rates again, and as we had a couple of issues with him, not sure we want use him anyway!

We are looking to do a few things all at once, i.e.

- Loft conversion
- Small rear extension with a toilet and folding doors
- Garden re-design

I'd like to find one firm that can do the lot, so i've been looking at the following based on the recommendations:

- Simply Extensions
- Hurlington Developments
- Good London Builders
- Upsher Harrison
- MyLondonExtensions

HOWEVER...I'm sure what is the best way to approach it. 

As we live in the Latchmere Conservation Area (the area of houses behind the Latchmere Leisure Centre), we are a bit more restricted than most people in Clapham as to what we are able to do with our property. The loft in particular, is going to be a real issue to get into.

I'm thinking we have two main options (based on my limited knowledge of the building trade and getting stuff like this done):

1) Appoint one of these firms to do the end to end solution
2) Find a RIBA architect, get them to do the drawings/planning application, and then,
a) Help me find the right suppliers to make it happen
b) Let me go off on my own and find people (e.g. someone for the loft, another for the extension, someone else for the garden)

Is that correct? Or is there another way of doing this?

I'm a bit nervous of the do-it-all firms, as they say they have architects as part of their staff, but these forums (in a few cases) seem to think otherwise, or it's not really their specialist area.

I'm quite conscious that as we live in the Conservation area, that planning is like to be an issue, so a great submission will be key, but I don't knew whether that lend's itself better to which option.

Any help/advice appreciated.