A shed is best but you can’t go past a home made 1000 dollar tent
Once you have your 2 hulls built you need something to put them under to continue construction, for me this posed something of a problem as whilst there was enough room to build a boat the section to build on was sloping and far from ideal.
My solution was to build a steel platform concreted into the ground for the port hull to sit on and weld up a number of frames using scrap steel that i begged and borrowed from around the place, prior to this i had never welded by the end I could i was a pro. I put each leg into a 20 litre container of cement to keep it weighted down and cross braced everything, I wrapped the poles with scrap carpet and purchased the thickest solar plastic I could find and pulled it over the top, all up it cost me around 1000, 600 for the plastic, 200 for the concrete and i ended up having to buy around $200 of steel plus some cable ties. This was a fair saving on a 50000 shed.