The Design Stage:   Design advice on layout, finish and specification.
Full site survey to obtain all measurements and site pictures.
Referral to a trusted builder - if required - regarding any build issues.

The Planning Application:   Drafting of your plans in Autocad -
the industry standard software.  Drawings converted to PDF's.
Floorplans - existing & proposed, Elevations, Roof Plan, Location & Site Plan.

Processing the Application:  Completion of the Application Form & Design & Access Statement.  Paperwork and plans sent electronically to the planning dpt.  Liaison with the planning department on your behalf with any queries.

The Build Stage:  Drafting additional plan detail required by your builder and the Building Control Officer.  E.g. Electrical & Plumbing Detail, Wall Construction Detail, Window Schedule.

Prices:
Stage 1 and 2:  Single extension to property possibly with some internal alterations: £850.
More complicated works involving multiple extensions / conversion work will be quoted for after an initial consultation - for which there is no charge.
Stage 3:  £150 for all applications.
Stage 4:  Single extension to property possibly with some internal alterations: £500.
More complicated projects would be quoted for individually.