Building in the round

[Chuck Morrison]

Building a house that is anywhere close to round is a challenge. The world as we know it builds in rectangles. Virtually all building materials are produced on the assumption that we are building structures that have flat walls and roofs joined at right angles. This being the case, we have to adjust our way of thinking to build a structure that bucks the normal mindset. Yurts are a great example of a thinking differently about constructing housing. Look up "building a yurt" on google to see what I mean.

In building a more "conventional" round structure I came up with some techniques that helped me pull it off. One that was very important is shown below:
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This is a tripod made of 2" x 6" x 16' lumber supporting a makeshift crane. The crane is a 2x6 boxed beam, 22 feet long and supported at the walls by two wheelbarrow wheels There is a pivot on the tripod so that the beam can rotate around the outside wall. A block and tackle and a "come along" are then utilized to lift the 6' x 12" x 16' and 4" x 12" x 14' beams. Using this contraption I was able to lift the beams into place by myself. Below is a closer view of the wall end.
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I built the crane and tripod with lumber that I had laying around too long that was too warped to use in building. In retrospect, for safety's sake I should have used 2x8 or larger for the beam. It did bend more than I was comfortable with when lifting the largest beams.

I opted to use a post and beam style for the ceiling rather than the often seen spider web style of round building floor. I did this because I like doing wood joinery and exposed beam ceilings and also because it gives a uniform support pattern to the subfloor plywood.

[Rob Beckers]

So where is this project at now Chuck?
Are those pictures the current state of the project, or did you built this some time ago and it's now complete? If you have any more about your house I'd be interested to hear (and see) what became of it.

-Rob-

[Chuck Morrison]

The round house is still being built, The bulk of the shingles were finished this week. There's about a square left to do on pieces that aren't even built yet. The most visually interesting part of this house is the roof, which opens to the south. A few pictures follow showing it's present state.

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This is the view from the East. The cap on the very top covers the upper roof vents. These vent the roof, but not the second floor. The brick ties are visible on the PerformWall surface and you can envision the finished wall color by referencing the bundles of bricks.

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And this is the view from the South. The upper floor south wall has not been sheathed yet and will include a skirt that will overhang the first floor windows by a couple feet. I expect the upper floor outside finish will be a white or tan clapboard.

So where is this project at now Chuck?
Are those pictures the current state of the project, or did you built this some time ago and it's now complete? If you have any more about your house I'd be interested to hear (and see) what became of it.

-Rob-

[Kareem Shihab]

Wow,
Thats sure gonna be a work of art when its done. What stratigies other than south facing windows walls, and concrete base will be utilized in this house to regulate temperature i.e draw and trap warm air in winter, and aid in keeping cool air in the winter.
What about recycled materials used in the construction, did you use any? is it har to find sources of recycables.?
I have a ton of questions about sustainable building.....

[Chuck Morrison]

Insulation is key to keeping the house warm in the winter and cool in the summer. The amount of south facing glass is fine on a sunny winter day, but the nights call for insulating the windows. It has been a hard winter so far and the next week is looking to be brutally cold. There isn't enough insulation in the ceiling yet to keep the heat in.

The house is only marginally passive. Heat storage is a gravel bed under the floor, which is to be heated with active solar hot water and recirculated hot air from ceiling level. Backup heat is to be propane. There is a wood stove being used temporarily to burn scrap wood and keep the interior from getting too cold. It may become permanent.

The exterior walls are a recycled styrofoam/cement form. Windows, doors, some wood and foam insulation was purchased at auction or used, even if they weren't used I figure they are in the recycled category. Wood for the rafters and ceiling joists were cut from (standing dead) beetle killed pine trees at a local saw mill.

Here there are lots of recyle options, but you have to look for them and keep an open mind when designing and building.

[Mark Parsons]

Greetings Chuck,

Great photos.

What sorts of reasons biased you towards a round structure? As you stated it certainly makes construction more challenging. Are there other benefits?

I enjoyed your makeshift crane. I had to do a similar type of thing for posts and beams on my cottage porch. I used 2 rope block and tackles to lift the 6x6 beams tight to the trusses to fasten prior to dowelling in the posts. This way I could position and fasten myself.

[Chuck Morrison]

Hi Mark,

I have tons of reasons for a round building. Probably the strongest one is that I wanted to build a round building. That's the reason I ultimately built one, but the other ones are:

A circle is the most efficient way to enclose a given area. Most interior space for least exterior wall. This directly ties into heating and cooling issues by starting with a reduced radiating/absorbing surface.

I've been bothered by the common assumption that a long south facing wall is the optimal solar orientation. In point of fact, it is only optimal for a few hours either way of solar noon. If it's cloudy near noon, you've lost your heat for the day. A round house gives the opportunity to have meaningful solar gain from early morning to late afternoon/early evening.

A round house/roof structure is considerably stronger than an equivalently sized square or rectangular building. This is important in earthquake and high wind areas. Where this house is located we have high winds regularly, often accompanied by snow. Interestingly, the wind accelerates around the building which keeps the snow from accumulating for about 10 feet (3 meters) from the walls, except the down wind side, where it tends to accumulate in one closely defined area where a vortex is created. Pretty fun.

There are lots of less empirical reasons including the spiritual, earth mother kind of ideas. I don't put a whole lot of importance to "new age" concepts. I put a bit more on the fact that many indigenous cultures use round structures. I'm sure there are lots of reasons they had, and I'm sure they didn't have to fight with a building industry fixated on right angles. I also don't like corners.

Thanks for letting me throw these ideas out there.

Chuck

Greetings Chuck,

Great photos.

What sorts of reasons biased you towards a round structure? As you stated it certainly makes construction more challenging. Are there other benefits?

[Mark Parsons]

Interestingly, the wind accelerates around the building which keeps the snow from accumulating for about 10 feet (3 meters) from the walls, except the down wind side, where it tends to accumulate in one closely defined area where a vortex is created

Hi Chuck,

Think there may be a way to harvest some of the energy in this wind acceleration effect? Perhaps small Savonius VAWT's attached to the building exterior placed between doors and windows so not to block any view? Extract the energy to help drive the house to zero (non-renewable) energy.

Regards,
Mark

[Chuck Morrison]

Hi Mark,
I'm not sure how much savonius vawts would help. I can see how they would hinder though. Any slowing of the air in a blizzard will result in drifting of snow. Thus the now clear wind area would become clogged with snow drifts.

VAWTs are not known for being particularly efficient and while they may help out a bit, at the cost of more piles of snow to move, It seems a few properly placed PV panels would do as much or more without the snow issue.

Chuck

[John Allen]

>I've been bothered by the common assumption that a long south facing wall is the optimal solar orientation.

Me too. I am planning a remodel with two walls of passive absorbion. One facing SE and one SW. Each wall may get less than a single south wall but I'm sure the pair will outdo a single. I do plan on some kind of nightime rolldown blankets over the windows.

I also plan to cover the flatish roof with active solar thermal collectors. I think the latitude plus 15 "rule of thumb" is just that. I get a lot more sun in the summer, so the challenge is to do something useful with it. Store or convert, that is the question.

ja

[Chuck Morrison]

Hi John,
You hit the nail on the head. A rule of thumb is just that indeed. IMHO each installation has a purpose and makes use of the resources based on the requirements. I've been to San Jose several times and (assuming that's where your installation is) the climate is amazingly mild (by my standards) in all seasons. It's your call as to how you use it, but I wonder if you can really utilize that much heat in the summer.

In my case, there's a LOT of sun in the summer. This year there is very little of it in the winter, go figure, normally it's very sunny here in the winter time. My house design assumes more sun in the winter (than we're getting this year) and strives to take advantage of it. I've utilized a Zomeworks tracker to get more PV from short winter days, but it doesn't help much when it's cloudy.

Anyway, My take on it is you grab heat when (or before) you need it. I intend to soak a lot of heat into the house mass in mid fall and will place hot water collectors accordingly.

>I've been bothered by the common assumption that a long south facing wall is the optimal solar orientation.

Me too. I am planning a remodel with two walls of passive absorbion. One facing SE and one SW. Each wall may get less than a single south wall but I'm sure the pair will outdo a single. I do plan on some kind of nightime rolldown blankets over the windows.

I also plan to cover the flatish roof with active solar thermal collectors. I think the latitude plus 15 "rule of thumb" is just that. I get a lot more sun in the summer, so the challenge is to do something useful with it. Store or convert, that is the question.

ja

[John Allen]

Hi Chuck,

I'm curious how you can soak more than a couple of days worth of heat into the house mass without it getting too warm to be comfrtable. My initail calcs suggest a whole basement full of hot water to handle seasonal storage. This was done at MIT in 1929.

BTW, I LOVE your round house.

ja

[Chuck Morrison]

Hi John,

Interesting about the MIT study. My father has his Ph.D from there. When I was growing up a neighbor had an indoor swimming pool in his walk out basement. The house was always warm and moist. Smelled like chlorine too ....

I'm not really talking about getting a season's worth of heat into a storage mass. The mass I will be using (~8 inches of gravel) is nowhere near enough to handle a season, but it should help with daily temperature fluctuations. Gravel isn't going to heat up as evenly as solid concrete or water, so I figure 80 degrees F is the temp I'll shoot for initially and adjust accordingly.

I'm not planning on having huge amounts of thermal collectors (about 100 sq. ft.) and not every day is warm and cloudless in the fall. I expect it will take quite a while to heat even this smaller mass using solar in the waning days of fall. There also won't be any way of insulating the gravel from the floor or air flow (code issues, must be vented at all times), so there will be constant heat loss, during heating and non-heating times alike.

Thanks for the nice words about the house design. I'm hoping my experience with it will lead to a low cost, energy efficient design that could actually help folks out. Housing costs are WAY out of line and don't help keep energy use down much at all.

Hi Chuck,

I'm curious how you can soak more than a couple of days worth of heat into the house mass without it getting too warm to be comfortable. My initial calcs suggest a whole basement full of hot water to handle seasonal storage. This was done at MIT in 1929.

BTW, I LOVE your round house.

ja

[John Allen]

I'll be careful if I decide to use any chlorine in my water storage!!!

Thanks for the details on your storage, please be sure to let us know how it works out. I always trust one real data point more than a lot of calculations.

For example, yesterday my one 4x10 collector heated 100 gallons of water ~25 degrees. We had a lot of clouds yesterday. Here is a graph. I included the red lines so you can see the circulating pump because of inadequate sunshine. Sensor 67 is the hot outlet of the collector and sensor 03 is the PEX pipe entering the heat vault. F8 is the first 50 gallon barrel and 36 is the second one.

I totally agree about housing costs. since our youngest child is leaving home next September, we are actually thinking about a major downsizing move instead of the rather expensive ZEH remodel.

ja

[Joe Blake]

Over the last couple of years I've had a double water bed in one bedroom. It seems to be very good at moderating the temperature in the room, to the extent of during the previous week's 40+ degree Centigrade heat wave, the bedroom was consistently 4-5 degrees cooler than the living room, just the thickness of a hollow cored internal door away. Same in winter. The bedroom stays warmer.

The other thing that I have recently acquired is a "water-from-air" condenser machine which can produce over 30 litres of distilled, sterile water from the air (depending on relative humidity.)

This sparked an idea. If I purchased another mattress (or preferably two single bed mattresses) I could build like a "stage" in the office corner of my living room about 10-15 cm high, with the mattresses underneath, and my working area sitting on top. The space underneath would be insulated, and the water condensing machine would be used to slowly fill the mattress(es). Once full, these would act as "temperature" banks. Having a heat collector/ dissipater outside with insulated piping and a small (solar powered?) electric pump, water could be circulated in the desired direction. Just by opening some vents near "floor" level, the warmth in the water could released at night time to keep the house warmer.

In summer obviously you'd need some sort of overhead system to absorb the heat into the water, which would then be pumped at night time to the outside where it would cool, ready for the next day.

Further, There would be quite a reservoir of potable water which would be extremely useful in the dry areas of Australia.

Theoretically, because the water is distilled, filtered and sterilised by ultra-violet light, there should be no problem with growth of algae etc in the storage "tanks".

Have to give it a bit more thought.

Joe