Layered house?

To me a house has two functions: Providing a warm area for humans, and keeping them and their belongings dry.

That are two functions, and they maybe they could be separated:
A outer shell, that keeps the rain outside and has some minimal insulation, keeping the inner area from freezing, possible using the ground as a temperature buffer.
The inner shell would be some sort of insulating material (straw, hay, wool, ...) plastered with cob.

This would allow to have a solid outer shell that keeps wind and rain outside, but allow the inner part to be changed over time without damage to the outer part.
There would probably be a gap between them, that allows to check the condition of both layers, as well as providing a lot of air flow.


Does this make sense?

Sounds a lot like a pole barn with an apartment inside,a travel trailer in a warehouse,or a cabin in a hoop house.
I like it.
I've even thought of taking an urban shell, knocking out the interior walls and building a hyper insulated tiny house in the middle, rainwater tanks and battery banks on the second floor.

Decoupling the various functions of the building envelope seems lime a way to increase design options.

The apartment in a barn analogy is great!

This idea is – to some extend – a result of the problems I see at the building I am living in right now.

1. The outside walls are not easy to reach. The triple extension ladder barely reaches high enough. Checking the state of the wall and repairing or painting it is a challenge.
2. Checking for water leaks is not possible without dismantling either the inner or the outer wall.
3. All windows have to open and do so towards the inside, in order to be cleanable (due to 1.)
4. The brick wall is load bearing, adding windows is not really possible.

Nr. 2 is solved by the approach itself (and keeping some walkable space between the inside and outside).
For problem nr. 1, I could imagine a terraced wall, so no part is higher than, say 2.4m (8').
This then allow to use simple glass panes, which should be easier / cheaper to acquire. (solving nr. 3)
Nr. 4 could be solved by placing the wooden beams inbetween the inner and the outer wall.

There is a person on this forum that built basically a large greenhouse around her trailer house.

Sebastian, sounds like you live in my neighborhood! Another benefit of disconnecting the outer and inner walls is heat transfer is reduced. In zero energy homes they do this double-stud thing to disconnect the outer and inner walls as much as possible.

I have seen designs in Northern Europe that basically build a greenhouse around an existing structure, often a cabin or house of sentimental value, usually heritage structures. I know that there's at least one interest building a project village using this concept. I know it's not exactly what you're talking about, Sebastian, but it has a number of similarities.

-CK

Todd Parr wrote:There is a person on this forum that built basically a large greenhouse around her trailer house.

A (sufficiently insulated) trailer house would probably work too, for those willing to sacrifice room heights of 3m (10ft). For a new construction, I would expect a wooden frame + staw bales to be farly easy to build.

Chris Kott wrote:I have seen designs in Northern Europe that basically build a greenhouse around an existing structure, often a cabin or house of sentimental value, usually heritage structures. I know that there's at least one interest building a project village using this concept. I know it's not exactly what you're talking about, Sebastian, but it has a number of similarities.

Good point. I have indeed seen videos of such constructions (and have to revisit them).

What is the differerence?
- A trailer or an old house is a complete thing itself (for the lack of a better term), where the two layers I have in mind, are nothing without the other. (The outer one would make for a bright shed.)
- The supporting structure can be in the intermediate space: Protected from the weather, but not invading the inner layer.
-

Amit Enventres wrote:Sebastian, sounds like you live in my neighborhood! Another benefit of disconnecting the outer and inner walls is heat transfer is reduced. In zero energy homes they do this double-stud thing to disconnect the outer and inner walls as much as possible.

Hm.. so far there "zero-energy" homes are not convincing to me. Far too complicated (and expensive).
What does your neighborhood look like?

Our neighborhood is old track homes from the 40s wood interior bones on all, and for looks they varied the exteriors from brick to wood to stone. Ours is brick. Real brick, not fiscade. It's 2-stories + a finished attic and basement. Luckily our windows are in the right places, but I can't imagine trying to make a new one. There's about 3" insulation in many of the walls, but they "forgot" the basement, attic, chimney, sealed-up window, and crawl space in the room addition. So that makes it like a wind tunnel in winter. Each wall seems to be made of something different, which makes drilling into them an adventure. Yes, I share your skepticism on the zero energy house as"the answer". I'm hoping to see a significant improvement just completing the insulation. Unfortunately, as you point out, traditional houses are not designed to make this easy, which is annoying. The expense for insulation is mostly the labor of dealing with the traditional house, so I will be doing it myself since we have a limited budget.

Your description sounds a lot like a few "homes" I've been in that had a massive system of hidden passages.

What is your plan for the cocoon (outer enclosure)? Will it have windows and will those windows also be the interior windows or will they be separated by the passage?

I can see this working out brilliantly if enough thought is put in before construction begins.
I had a set of plans I drew up for a small "castle" that had secret passages and an open under parapet that separated the outer skin from the inner living quarters walls.
Finances fell apart and that project was shelved.  

Bryant RedHawk wrote:    ...open under parapet...

Im trying to picture this...

Amit, the description of your neighborhood sounds indeed familiar!
The small differences:
- Here wood on the outside isn't seen too often, as it decays within a century (or less). With the increased temperature and wetness this will be even worse in the future.
- The original builders used yellow brick with a closed surface on the outside. The inside is red brick too. The idiots that modified the house some decades ago, messed this up however. (The red brick that was on the outside is pretty much soil now.)

Bryant RedHawk wrote: Your description sounds a lot like a few "homes" I've been in that had a massive system of hidden passages.

Indeed, i was eyeballing 6-10 people. There are many things in a building that can be shared: (sauna/bath, kitchen and heating, storage, tools, "living room" (more like two big rooms that can be connected and used for almost everything), …?)

Bryant RedHawk wrote:What is your plan for the cocoon (outer enclosure)? Will it have windows and will those windows also be the interior windows or will they be separated by the passage?

I hope to get to build on the side of a hill/mountain, so I didn't plan a normal "flat ground" house:
A glass wall on the south side, Stone or rammed earth wall on east/west and some sort of flat roof (slightly sloped so water drains to the hill). The interior rooms separated by 1-2m from the glass wall, with some sort of construction in between that allows to reach this space. (But not a often used walkway, so there are no people walking in front of your window.)

I have to make a better sketch on paper of this. (Trying it on the computer resulted in too many flat and rectangular surfaces, causing it to feel cold and modern, instead of organic and comfortable.)

Modern, high tech, fabric roofs, are like what you described. They have an outer shell that sheds moisture in whatever form, and an inner shell that contains the habitable space. (look up the Denver, Colorado airport for a massive example). The outer and inner shells are light permeable so they act like giant skylights, letting both light and heat in. The air gap in between the two acts as an excellent insulation especially when some warm air is flowed through the void. I thought of doing this for my house but could not find a supplier or manufacturer to work with me on such a small project. I did find, unfortunately ofter pursuing an alternative route, this company: teksupply building page

and they will make any custom size and shape you want, but it may cost you a bit. At this point though I could have bought three or four roofs from them for the cost of my concrete roof and all of the work I've had to do to get it perfectly sealed.

It's a very useful concept.
Long long ago when I worked on a trail crew I lived in my tent in a unheated bunkhouse. It was great.
I met a physicist who lives in an unheated house. He glued blue 4'x8' foam insulation sheets together making a big box over his bed and for his daughters bed also. They like it.
The simplest cabin-in-the-woods may have been another physicist. He took the big curved lower limbs from cedar trees. Tied them together to for a dome. Raided dumpsters at the lumber yard for plastic sheeting. Layered 7 layers over the dome. Tossed leaves and sticks all over the top. Installed a small wood stove and lived in it for 20 years.

I knew a family who moved from South Africa (I think) to the North West Coast of B.C., to the islands off the coast.   The patriarch made a simple but very large geodesic dome and covered it with clear plastic.  The family lived in a heated wall tent inside the dome.  The wall tent shared one short wall with part of the geodesic dome to enable the wood smoke to be vented.  They had a small kitchen garden and outdoor lounge area inside the dome, so if the weather was not great they could just stay inside.

This was a quick way to get a substantial buffer from the wet and cool, while giving them breathing room on constructing a more permanent home.  

Duane, fabric roofs are indeed interesting.
I have seen (and touched!) one made of fiber glass and concrete (for sealing) myself.
They do however require completely new ways of designing (which makes it interesting as well).
The material in question would be ETFE, which is UV transparent AND resistant, very strong, elastic and not easily flammable.

Jeremy, I am not too sure about plastic insulation that close to the living area. I can't see how humidity isn't going to be a problem.
The dome house wrapped in plastic is a good idea! Especially the wrapping foil used in logistics should be easy to get in suitable sizes and quantities, at little or no expense.
Admittedly, I too am a physicist.

Roberto, the tent (or yurt) in a dome sounds like a really good temporary building. I will definitely keep it in mind.


I am currently iterating over such a design, trying to find a shape that is easy to build, strong and has the intended appearance.