building a summerhouse in a garden in london

[jundaboom]

My uncle has given me a project to build him a summerhouse for visiting relatives in his garden.

He has requested one from WICKES with measurements of 18ft 4in x 13ft 5in x 9ft 3in. I know that I'm going to need a small team to complete this but I have friends in the construction business who SHOULD be helping.

I have a few questions as I don't want to accept the job if I can't complete it.

1. Do I need to get planning permission to build a summerhouse in his back garden?

2. He has given me a deadline of a month for the work to be completed, is this feesable and if so how big will the team need to be ?

3. There needs to be an additional en suite bathroom added, where can I begin to look for this, and again do I need to get anyone's permission before this is made?

4. Can I expect there to be many additional costs (i.e tools and materials) aswell as the cabin which is £2500? What else should I expect to buy?

Any help on this matter will be greatly accepted!!

Thanks guys!!