Jeff, I have seen your house picture on your web site but how big and what design are your greenhouses? Other than more thermal mass what mistakes have you made. I am planning a 16 by 20 on the ssw side of my house in an area that presently averages 5 feet below floor level so it will be more building up and filling than digging though I see stepping down in levels away from house. With zone 4 climate I plan a masonry stove under floor heat sys tem under part and the more I think about water storage would be good too. Being a remodeler I am pretty good at collecting old sliding door glass Probably 15 panels around at present, scratched by dogs but good enough for greenhouse. Still in planning stage for this year as a woodworking shop takes priority but I would like to start foundation to a least get another level pace to garden. vann zone 4 southern NH
