I made the shed with as 'green' materials and traditional methods I could. It is has a local green oak frame with mortise and tenoned joints, Lime mortar rendering and local Douglas fir cladding. Roof is secondhand pantiles. inside it has modern foil type insulation with Douglas fir panelling. There is also a Franco belge woodstove. plan to put in a bat loft but yet to do that. All made in my garden, took about 18 months though!
Making timber frames is easier than you think and they look great, especially with lime mortar. You don't need to be a great carpenter either, oak is very forgiving, that's its charm. They look old as soon as you put them up too!