cheap shed

try freecycle first  chelle. then look at a shiplap shed or solid panelled one . if your good at building you can build one your self from pallets as seen on the poultry pages . i dont like the feather edge boards as they tend to be really draughty ..and yes you need a window to allow light a simple one 1ft squareish  wil do .the bigger the glass the more heat you lose , most diy stores sell decent 6x4 sheds at reasonable prices .£130 ish