Starting back at the beginning. Choosing building site and method. Earth berm??

Hey Everyone,

With my Wife's support, I have been planning our new straw bale home. She has been leaving building decisions pretty much up to me.

Well..... After a couple of YouTube videos illustrating various building methods, my Wife has taken a significant interest  in the design/build process. We are starting from scratch and it is looking like many of the things that I thought may be too "wild" for my Wife, she is embracing.

Looks like earth bermed is definitely  on the table as well as some rammed earth and straw bale.

Also, our original site that we thought we would build is not going to play. We have to move up the hill a bit. That puts our best view (important) to the NW of the house.

I am certain that if I build a house facing North I will be arrested by the "solar police"

Perhaps if I build "solar atrium" above ground on the South side and my view windows on the North side? Picture a "shed" running the length of the South wall with South facing windows and a black thermal mass opposite the windows.  The "floor" would be partially open to the room below to allow light and ventilation.

Am i nuts??

Any suggestions are welcome.

Thank you.

Stephen

Any thoughts?

It appears an earthship is right out for your situation. A wofati with modifications might be feasible. Can we have more information on your topography? I take it that the location with NW view slopes down to the NW. Is it near the top of a ridge or mound? How wooded is the area, especially to the south?

It may be possible to combine modest view windows with other solar collection arrangements. If you will be home most nights, operable shutters of some sort might allow daytime views and nighttime insulation.

I am certain that if I build a house facing North I will be arrested by the "solar police"

Only by the ignorant ones.   It would be helpful if you would go to you profile on premies and ill in your location; it avoids repeated questions from those wanting to give location appropriate answers.

NW windows would avoid summer overheating but give an evening boost for over night when the hose has been shut up to keep it cool on hot days.   Building a greenhouse into a south berm to store heat in the berm is the logical course in my mind.  Instead of digging down to put air tubes to store heat, add them to the berm as it is built.

The idea I have in mind for a SW slope is: the summer sun rises in the NE and sets in the NW,  an East entrance would allow comfortable morning  sun but summer sun would be above the overhang to prevent overheating while winter sun would shine in until the sun set in the SE.

I've lived in passive solar earth bermed houses in the high desert.

What climate are you in? And you implied you're in the northern hemisphere, right?

1) In a humid climate, in summer the thermal mass can attract condensation. It wasn't a problem in our dry climate but I've seen it in another place I've visited many times: humidity to a problematic level.

2) The earth down deep holds at about the annual average temperature. Where we are, that is something like 10C, which is lower than comfortable room temperature. So there's a conundrum with the earth berming. It's much warmer than the outdoors air temperature in winter, which is good, but it's lower than the desired room temperature. So the best is to have the rooms you want warm on the south side, and use the earth bermed northern side of the structure as a thermal buffer zone, things like corridors, storerooms (great for a pantry I can attest!), stairs, dry composting toilet room.

3) Solar gain really truly happens best on the south-facing side. East, west and north facing sides get excess unwanted sun in summer and insufficient sun in winter. Overheating in summer, especially night overheating due to west-facing windows, is seriously uncomfortable. Your situation, with the solar exposure windows above the living spaces won't work well for passive heating, but could work for an active system using a medium like air or water to move the heat to the living space. It's not dictated by "solar police" but by geometry and how the earth turns.

4) If you're in a climate with plenty of wood and you like heating with wood, then the strawbale and rammed earth construction could hold enough heat to reduce your heating season and might be part of a solution.

Best of luck! Curious to hear what climate and latitude you're in.

Thanks Everyone.

I am in Eastern Oklahoma. The climate here is on the warm side and fairly humid.  We have 40 acres that is mostly wooded. Clearing for pasture is going to stock me up with oak to burn. I am planning a mass wood heater of some sort. RMH or Russian stove to keep us warm in the winter.

My biggest comfort concern is keeping cool in the Summer. We  see a fair number of 95F-100F days. I will have a pair of small mini-splits to help out.

Our lot slopes from a high point at the NE corner down to the SW.  My southern view is up the hill. Not a big hill though. View to the NW is my silvopasture, creek , hayfield and woods.

I am thinking of something that resembles the typical Earthship except we want to cover the roof as well.

The main windows would face NW and I could build an above ground greenhouse on the South side with thermal mass and vents/skylights  to the house below.

Another area that I have to address is roof design. I will be needing an engineer for that. Perhaps an arched/dome roof using reinforced concrete. Monolithic Domes in Texas has some interesting offerings.

Thanks again

Stephen

With good and competent design you would not need  any mini splits.
Can I suggest you consider the following;
- determines wants and needs.
- determine room sizes needed.
- create a map / aerial photo of site with contours, at 1 ft intervals.
- Arrange to speak to somebody with better skills and consider paying for help.

Did I say something wrong???

I spent a lot of time on that post and am not sure why it was deleted...................

Not sure where my brain was when I posted the description.....

The high point on my property is near the SE corner. It generally slopes to the NW.

Here is an aerial:

The red "X" near the SW corner is the new building site.

The purple box is silvo-pasture. The large yellow box is hayfield and the small yellow box is to be cleared for my solar and greenhouses.

Draft house plan:

Random ideas regarding construction:

I can buy all sorts of rock from a quarry down the road. One product is waste from cut stones,  generally about the size of 1-3 common bricks, for $7 a ton. I am considering  12" thick, slip formed, rock/concrete exterior walls.

I have a significant amount of foam block "geofill" to use as part of my infill/berm.

I need help with the roof design. I have been reading & studying and have accepted that I am going to have to hire an engineer. I don't have any permitting or inspections to deal with. I can build whatever I want and if it falls on my head, it is my own fault...... That said.... I don't want it to fall on my head.... Can anyone recommend an engineer that would be a good fit for this project?

Steve,

When you plan building a masonry heater it's good to position it in the center of the house and build around it. You could add the oven, smoker on the side of the kitchen space.
It's also good to position it on the bathroom wall so the bathroom would stay warm in winter.

Your kitchen/living room is very large and it will be more difficult to span such a roof. Of course you can mill your own heavy beams from oaks you have, but you would need massive and straight trees to accomplish it.
Are you planning to have all walls masonry? If yes - it will give you an option of easier roof construction. You could partially separate the kitchen and living room with a wall with a large arch opening and this wall would create a support for shorter beams of your roof.

In my opinion this sun room will be a space that nobody will want to use. People love to be in the kitchen where something is happening. It's a lot of space to build (like half of my house): foundation, walls, roof, finish.
I would position the kitchen/living room across entire house width from south to north - so you have the choice to be in warmer or the cooler part of the house. Bathrooms needs warmth and evaporation of moisture so the south. Bedrooms to the north - it's good to have them colder any time of the year..
Is the northern wall bermed?

If you have access to stones 1 to 3 time larger than a brick and very cheap I would really consider it. One ton of ugly, machine made bricks costs at least $300. Using stone you could lay it on mortar with wall thickness of at least 24" - as long if you are not in seismic zone. If you are, you would have to build thicker walls or reinforce them and not forget about solid bond beam. Or you could use the slip forming like you mentioned. In this case you will have no insulation unless you build 3 wythe wall. It will use a lot of concrete.

I need help with the roof design. I have been reading & studying and have accepted that I am going to have to hire an engineer. I don't have any permitting or inspections to deal with. I can build whatever I want and if it falls on my head, it is my own fault...... That said.... I don't want it to fall on my head.... Can anyone recommend an engineer that would be a good fit for this project?

I did some Google search and it seems like there is a dominance of very expensive and aggressive  company. but with persistence I found a third world offer that might be helpful.  webpage
I have a friend in the congregation that did architectural drafting;  so familiar with requirements; he was able to draw up plans for me at just the drafting expense.  Review by the county engineer only found one minor change necessary.
Have you been fallowing this thread Hobbit-Home-Progress#1863982    He had to meet stringent requirements.   So that may give you some ideas.

Thank you for the good info!

I have considered something similar in regards to the Great Room span. I have a couple of huge oak trees (30"+) that have to come out and a 6"x18"x27' bridge beam. I see rustic oak post & beam or maybe the steel beam made rustic/rusty.

With rock, gravel and sand 3 miles away @ $7-$12 a ton, there will likely be a fair bit of masonry projects around here.



The fireplace is as much for ambiance as for  heat & we want it far from my bedroom. There was method to my madness in picking that location


Yes, I am following that build. Very cool!!

Thanks for the replies.

I think in your location under ground cooling tubes down slope with perforated pipe would be ideal.  During the summer the air is cooled and moisture condenses and drains away before it gets into the home.  An outlet near the fireplace brings in fresh air  and makes up for combustion air used.  My climate is different but I make use of the completely cement enclosed crawl space of my home to bring i cool air in summer and make up air for my wood stove and air exchange in winter.  My home came with electric central heat which I almost never use but I altered the circulation to draw air from under the house and open an inlet at the ceiling during the heating season to circulate the heat from the wood stove.  The air intake from the roof I routed as make up air for the clothes dryer.
In my area round timber material is often available from forest thinning or after logging when they are too small for sawing but large enough to use as timber as used in earth ships.

I agree with some of the layout suggestions given. If the sunroom has no particular view, why would people use that very large space? How could they use all of it even if they wanted to be there? It would be the warmest space in summer and the coolest in winter except when the sun is shining.

As you plan to have windows in at least some of the exterior walls, I would strongly consider flipping the plan so the master bedroom is on the east, to get morning sun when you wake up. Afternoon sun only makes the bedroom hotter at night when you want it cool for sleeping.

I agree with the idea of making the kitchen/great room run from one side of the house to the other. You will obviously want important view windows on the north side, and having the south solar windows open directly into the great room will give it the most warmth. You can easily curtain off some of the windows when you don't want solar gain in summer as that side is not the main view. Are you planning a concrete slab to collect solar gain?

As mentioned, a RMH or masonry heater needs to be near the center of the house to heat it evenly. Keeping bathroom etc. between heater and bedroom will allow that to stay cooler. Even if you don't have a specific plan, allotting a block of space to the heater from the start is important; that way, you can keep in mind what will be warmed the most in winter.

In the house which my interior designer mother designed, we had a 15' x 25' living/dining room with full size dining table and living furniture and fireplace similar to what you show. It was plenty spacious for a family of five. Are you planning to never grow your family, or will you allow for an addition in the future? If the latter, planning for the addition now will make it much easier and more workable in the future. Thick stone walls are pretty difficult to expand through.

An oak beam like you describe would make roofing the great room space trivial, if a major job to lift the main beam. It would make a good space divider between kitchen and living area without affecting the floor layout. Aside from that, there is not much to worry about in roof framing, unless you actually do a wofati-esque mass roof. The [url=https://www.omnicalculator.com/construction/wood-beam-span]beam calculator at omnicalculator can help give you an idea of what will work, so you can talk to a professional without looking totally ignorant. I used 25' span 4x12 (the maximum in the calculator) red oak with L/240 max deflection and 80 pounds per linear foot loading, and got acceptable deflection. The actual load at 100 psf on the roof would be around 1250 plf, but a 24" diameter oak beam would be stronger than more than eight of the 4x12s and much, much stiffer than that, so you would be in the realm of safety. Proper design calculations for the actual beam would be needed for certainty. Medieval oak beams spanning 25' and spaced about 16' apart have held heavy roofs for hundreds of years, and they are not 24"+ diameter logs.

The land seem flat enough where the slope doesn't seem like it will affect how much sunlight you get, if anything the trees will make a much bigger difference. the 1st and last 30minutes of sunlight doesn't provide much solar energy.

It seems that you are super interested in:
Insulation (The roof, floor, and walls could have 6inch of insulation R-30)
Green Roof (on top of the insulation and liner you could add 2inch of biochar (80% biochar and 20% soil/compost))
Green Wall/Earth Berm (insulation then liner and then you could add biochar
HVAC (ERV-Ventilator, Heat Pump to control humidity plus AC/heating, Radiant Floor Heating/Storage with pellet stove backup/RMH )
Electric (900sqft barn/carport with 20kw of solar panel. This could heat/cool via heat pump + thermal storage and also power your house)
Water: Well/Buried cistern
Septic: ATU??

I wonder what you want to build the foundation, walls and roof out of.

This might give you some inspirations:
https://naturalbuildingblog.com/wp-content/uploads/2012/05/Solar-Pit-House-PDF.pdf

The reason for not facing the front of the house South is because of the view. Facing South I have an uphill view of trees. Soon, it will be a view of solar panels.

The good view is looking Northwest. There I can look down on my silvopasture, hayfield and more trees.

Regarding Septic, we have not decided. Gravity systems are allowed here if your soil perc's. If not they install aerobic systems with sprinklers. I did see a lady in Vermont who ran the output of her standard flush toilet into a vermicomposting bed with very good result. That could work for us. Perhaps, send the grey water to a "filter bed" planted with the appropriate plants.