In my younger days I was fortunate enough to have spent two years in West Africa in the Peace Corps. The Republic of Guinea is comprised of several different ethnic and geological regions. While I was stationed in the southern forest zone, I had the opportunity to visit the north-central area known as the Futa Jallon region, home of the Pular people, a branch of the Fulani.

The traditional Pular roundhouse has a design feature I have not seen come up in natural construction discussions, one specific design feature that I think stacks functions in an elegant way.

The basic design of the house consists of two concentric circular earthen walls with a thatched pole roof. The outer circle is about head height while the inner circle is raised significantly higher to support the roof poles at the desired pitch while also defining the central living space.

Most communal functions occur within the central area while doorways through the inner wall provide access to spaces divided by radial walls extending between the inner wall and outer wall. These spaces afford a greater degree of privacy and are used for bedrooms or storage areas. On one side a doorway extends through both walls for egress with radiating walls defining a passageway or vestibule.

The high inner wall allows heat to rise and cooler air to stratify below, a benefit in Guinea's warm climate. Windows are not traditionally a part of the design but the roof is attached in such a way as to leave a gap at the top of the walls to allow ventilation and the entry of diffused light. Ventilation also occurs around loose fitting doors or curtains hung in doorways. Warm air rises and exits through the thatched roof.

The roof is constructed so that it overhangs the structure almost to the ground, protecting the walls from erosion during the rainy season which can see over three meters of rainfall, while also providing a protected area for more storage and shelter for small livestock.

What are some ways this basic design might be adapted for a temperate climate? What are some pros and cons you can see with this design?

John, that sounds really interesting. I am trying to envision what they look like. Would you have any pictures or drawings of one?

There are some pretty good exterior photos here. You can even hear Pular being spoken as a bonus!

I'll keep looking for something interior. For now you'll have to imagine the two concentric walls.

Skip to 2:00 and 3:35



Another exterior in the background.



Here at 0:45 and 1:47

Much better! It looks like there might even be variations from person to person, home to home ?  Seems like this might work anywhere that it is hot and rainy.
I owned a Tipi for years and there are similarities. Opening at ground level, inside liner or wall, creates a draft that cools the room. Cone shape. Neat

Miles Flansburg wrote:Much better! It looks like there might even be variations from person to person, home to home ?

Certainly. There are features common in certain villages more than others, depending on the builders' experience, training and preferences.

These houses require more labor and materials than just a simple, typical African roundhouse, so people with limited resources tend to live in houses with the simpler design. If you notice from the videos I posted, having this kind of traditional house seems to be a status symbol so they must be relatively quite a bit more expensive to build and maintain. Wealthier people also tend to build homes influenced by Western homes, with rectangular floor plans, multiple attached rooms, porches, and corrugated sheet metal roofs.

Seems like this might work anywhere that it is hot and rainy.  

I agree. I was wondering what, if any, adaptations would need to be made for a more temperate climate, with a cold winter as well as a hot summer. Perhaps a way to close off the high ceiling in the central area would be helpful during the cold season. A range of ceiling joists could be installed at about eight or nine feet high, with woven mats or some other lightweight ceiling material laid across them to hold heated air closer to the living space. Insulation could be placed over the top for more heat retention. Then, as the warm season approaches, these mats could be rolled up or removed to take advantage of the high ceiling's ability to allow heat to rise and escape the structure.

I owned a Tipi for years and there are similarities. Opening at ground level, inside liner or wall, creates a draft that cools the room. Cone shape. Neat

This design would be almost like a tipi within a tipi, wouldn't it? A Hypertipi!

That reminds me of a video I once saw where there was a covered, tent-like structure surrounding a bed raised up off the ground, all within a yurt or a larger tent. Apparently it was quite warm in the bed just from body heat alone, even when the outside temperature was extremely cold.

Tipi's have what is called an Ozan, similar idea to what you describe.


Here is a video of a full Ozan. There are different sizes. You can see that it forms a smaller room inside the larger Tipi, when combined with the "liner". The larger Tipi cover is then brought back together forming a large cone. The air flow comes up from the ground level between the liner and the cover, and out through the adjustible smokehole in the top. I am not sure how firepit smoke would escape from the living area under this type of Ozan ?




So I think yout inside roof idea would work.

What type of heater were you thinking of having for the colder times? Have you seen the rocket mass heater in Pauls tipi at his lab in Montana?


HERE

I think the concept was to heat the people rather than the whole space? So it might work in your roundhouse too without an inside roof? I am wondering if your roof would be built like the thatched roofs in europe in that it would be water tight but not airtight. So you wouldn't need an interior roof ?