[FarmerDreams]

We are building an earth-sheltered home concrete walls x3 buried with conventional front wall. R-49 insulation front wall and a standing-seal steel roof (for water collection) which is at ground level in back and most of way to front. This includes the normal soffit & facia needed for air circulation into the rafters etc so it does not rot. Question is with air circulating from the front wall through ceiling and out through soffit and spinners on top of roof do we need HVAC? We are going with a steel roof for 2 things: cost savings over concrete dome roof and water collection. In a well-insulated (i.e. earth) sheltered home including the roof no HVAC is needed, and will this work the same for us? R-49 insulation front wall and ceiling. Any comments welcome. We are doing a Rocket Mass heater at 1st opportunity, house situated SE (so we can see pond) with 4 foot overhang in front and double pane, non-low-e windows to allow heat in in winter.

 

[FarmerDreams]

We will have a dehumidifier, and the soffits/facia will allow air circulation from under the eaves and then out through the front of the house, which will have 13 windows & 2 doors, with some ventilation through the structure itself (or we can open windows at times) per the contractor.
We will also have a Rocket Mass Heater for the worst days, but I understand that often just cooking meals, running light bulbs, TV's & computers (2 always on when home) helps with heat too. We will have the propane cooking stove venting directly outside to prevent toxic fumes, & ventilation in the bathroom, & for the dryer, (although in winter I will route it through a bucket with water in the bottom to capture heat & humidity. My searches, though, for images of an earth-sheltered home with a steel roof only turns up ONE with a view from the back only, and it is flush to the ground from that view like ours is. It will be a peach to keep the leaves off as the nearest trees will be 80 feet away, and the 4-12 slope will allow wind to clear most of them. I am still reading everyone's comments and it is interesting to say the least.

 

[FarmerDreams]

what is SIPS??

 

[FarmerDreams]

We will have natural circulation with soffits/facia and air passing through front wall or the reverse, fans in kitchen bath etc & a rocket mass heater ASAP. We will no doubt make some small changes as time passes like a 45 degree angle greenhouse along the front of house with doors at each end to keep certain foods herbs etc available as we are planning to be self sufficient as much as possible, and with 5.25 acres 98% open that will not be a problem. I asked my contractor if SIPS will be used on the wall and will meet with him soon and ask about the roof then.