I build garden rooms but cant bring my vision to lightoing

I have a client who would like to build a garden room on an unusual shaped plot. It will be a garden room, gym and also need some garden storage space too...perhaps from a separate door? Please see attached pdf to show my initial thoughts on the space and what we ca build on the space, but open to other ideas.
From the front the building will have a main bifold doors, with the roof overhanging and some decking outside to shelter from the rain. The sides will need a few windows for light and thr roof wont have windows and it will be a flat roof and a max height of 2.5m, clad in slatted cladding - in fact they like the cladding on the outbuilding pictures i have attached.

Is this something you could help with and how much would you think it would be...doesn't need to be fancy at this stage, just give them an idea.

Thank you
Jon