the way i did it id i bought an old portacabin off ebay and rent a bit of ground in a trading estate , i have everything i need inc place to park the vans. i have just bought another cabin for the w/c's to pick up their work in the morning drop it off at night , all eqipment is in there and somewhere for them to sit when its raining. My original cabin is now soley my office which i have now carpetted and done up. It is a perfect set up for a window cleaning business at a cheap price. The cabins are mine so i only pay to rent the land they sit on which is very reasonable.