Inhabitat » POLE HOUSES

September 28, 2005

POLE HOUSES

by Sarah Rich

With the unpleasant prediction of more devastating weather patterns over the next twenty years (and beyond), safety and resilience are becoming top priorities for builders in disaster-prone areas. A company based in Hawai’i has taken a traditional building style that traces its roots back to indigenous Polynesian, Japanese and African cultures, and applied 21st century principles to create sustainable prefab dwellings that hold up to earthquakes, hurricanes and high water. Tim Cornell began building his Pole Houses in 1988 and now offers five basic plans as well as customized plans for buyers with specific needs.

Pole Houses use large diameter wood poles to create a skeleton frame that bears the entire load of the home, making both interior and exterior walls moveable without disrupting the structural integrity (making it semi-modular). The poles are bolted to concrete footings and carry the floor girders, roofing rafters and everything in between.

Pole Houses lean towards sustainability in much the same way other “sustainable” prefab homes do. They are intrinsically more eco-friendly because they do not require invasive site-preparation, they are quick to assemble and can be built by local builders using local, renewable materials. The more directly environmental features, such as photovoltaics, wind power, tankless water heating, gray water and composting toilets are all optional, letting you be as green as you want to be.

Most exciting to me is the upcoming product from Pole Houses, called the Solar Powered P-Pod. From what I can tell, this is an entirely off-grid modular home with a wide variety of layouts and the option to design your home online using a Flash modeling system. The image at the top right is a computer-generated model of the P-Pod. I’m looking forward to seeing some real-life models and finding out just what this little solar pod home can do.

Link: www.polehouses.com

8 Responses to “POLE HOUSES”

homer Says:

September 29th, 2005 at 3:39 pm

they make perfect sense in hot climates, but i question whether they are intrinsicly more ecofriendly. at least in a northern climate, a pole house lacks the thermal mass necessary for effective passive solar heating. also, the entire underside of the home adds to it’s surface area which is exposed to wind. these things require more energy for the life of the home when compared to one built on a slab. they probably make perfect sense in hot climates.

prefab homes are obviously more sustainable than a typical trailer and the average development house, but i don’t think you could say they are more sustainable than a site-built home which was built with sustainability and the health of the immediate surroundings in mind.

Sarah Says:

September 29th, 2005 at 4:15 pm

You bring up good points, Homer. I tried unsuccessfully to reach Tim Cornell a few times to talk in detail about both the Pole Houses and P-Pods, and I still hope to have a chance to do that. At this point, all of my information comes from the website. If I get to talk to him, I will certainly ask about the issues you bring up and let you know what he has to say.

Thanks for writing

Sarah

Tim Says:

September 29th, 2005 at 10:33 pm

Homer, your comments are good.

In arid, warm, or tropical climates, thermal massing is not a major concern, as you state. Promoting proper air circulation underneath, over and through the home is essential in mitigating the damaging effects of heat, humidity, mold and mildew. A properly designed and vented pole house will not require an HVAC system for cooling comfortably. Insect infestations (especially the voracious Formosan termites) are easily controllable with a pole house.

Conversely, conventional stick-built slab on grade houses in warm or tropical regions are not inherently eco-friendly, nor energy efficient. A slab on grade house will usually require expensive energy consuming HVAC systems (which are prone to support molds and mildew in warm, humid and tropical climates). Sitework disturbances are also expensive and the natural surface water run-off patterns are interrupted with slab on grade construction. Termites and other damaging insects can have a field day with a slab on grade house. A pole house sits gently on the land requiring virtually little natural site disturbances.

As for a pole house in an extreme winter climate, we recommend the use of SIPS (or other rigid foam insert panels) for floors, walls and roofs. Passive solar systems are still viable solutions with a pole house. A pole house can also be built over an existing or new basement, utilizing the cost savings inherent in the engineered structural pole house system. The exterior non-load bearing walls of a pole house can even be placed over low concrete stem walls, creating a traditional crawl space beneath the home.

In AE and VE Flood Zones, as well as the High Wind Hurricane Zones, a properly designed and engineered pole house will perform far superior to any conventional stick-built slab on grade house, or an elevated post and pier stick-built house, at a comparable per SF cost factor. We design our pole houses to meet and exceed the current IBC (International Building Codes) for high wind hurricane zone uplift loads, AE / VE flood zones, as well as seismic resistance requirements.

Thank you,
Tim Cornell
Managing Director
Polehouses.com

mike Says:

September 30th, 2005 at 10:01 pm

Pre-built and pre-manufacturing seems to be quite the fad… and it’s been going on for a long time - from the ubiquitous double wides to somewhat respectable (for pre-man) looking double wide and 2 story homes I now see rolling down the highway - in all sorts of configurations and assembly… not to mention the pre-man mod dwell fashion icons I’ve seen popping up in the press…

A few concerns - some already mentioned:

Termites - might they not have a field day with an improperly detailed pole house as well? Seems that any wood, near the ground, improperly detailed and protected, will be a target for water damage, termites, and other degenerative issues.

A cold climate version of this house would need to deal with insulation - as the exposed underbelly of any construction would be a weak link in a winter clime with wind and temperature swings. The ground, at some level, starts equalizing temperatures - so why not cozy up and take advantage?

SIPS - not really buying it that they are a sustainable source for home construction. The tie in to chemical companies (more dramatic if using a urethane based panel), offsite - highly technical manufactur of those panels, shipping of the panels, and the eventual inability to seperate components for recycling or downcycling (should we need to take apart a SIPs structure in 50 years) - are points against the system in my opinion. Efficient - yes - but you will also need to add an air changer to the mix - as most SIPs homes are of very tight construction - and indoor air quality (rember all that OSB and foam that is surrounding you?) will off gas, as well as keep moisture and interior finishes all locked up in the house. Small, solar powered fans may do the job… but its one more reliance on yet another system to add to the mix. Adding more complicated systems in to then change air, regulate temperature, adjust humidity… etc. don’t really seem to fit into a simple, direct, sustainable dwelling.

Perhaps a pole structure and a straw clay, straw bale, lightly framed wall with recycled cellulose or other bioregionally suitable enclosure system would be better…

Pre-manufacturing also takes away from the local economy - something that I feel is very important for sustainability to become “real”. I like (and work) for several timber frame outfits that manufacture and ship all over different regions of the country - and I think that shipping pre-made components can sometimes be beneficial - but in my gut it seems that a local craftsman, using local materials, hiring local labor, would better serve the long view of the client and the planet. (I say this cringing, as the complicated world we live in affords me creative work, while conflicting with ideas I feel would better serve a just, sustainable world!)

Proper engineering of any structure should help in hurricanes, earthquakes, and the like. Part of the beauty of a post and beam system (or timber frame, or steel frame) is that at some point in the future varying systems of the house can be stripped away, recycled, and possibly reused. A stick built home will probably go into the shredder - as fast growing wood, full of nails will likely be difficult to reuse. Keeping the materials simple and honest, for as long as possible into the lifecycle, affords great flexibility of design - 50, 100, or 200 years from now. Large beams can be re-used, and if not - they often can be made into smaller members - either for timber, or for flooring, furniture, framing, or other millwork.

I agree with Tim’s comment about natural venting - but I would extend that to ANY properly designed structure. There is no magic bullet - we need to study the land where we live - and build withing the logic of that landscape. Pole houses make sense in certain climes, when designed properly to meet the needs of the site, weather, occupant usage, and hopefully the future. I feel strongly that most of our housing woes could be fixed by simply paying attention to our local environment and evnironments of regions similar to our own - and adapting our construction techniques, details, and lifestyles to suit those parameters.

Nice work! And good discussion!

Bruce Sterling Says:

October 2nd, 2005 at 4:15 pm

Wow. Those are gorgeous. Those look like ideal vernacular architecture
for areas repeatedly scourged by post-Greenhouse Category Fives.

I could live in a place like that. I actually kinda want one.

Susan Says:

October 14th, 2006 at 11:19 pm

Does anyone know of any companies that are actually designing polehoses for the tropics? I really like the idea of the soundness of the structure in high wind /tropical environments but am having a difficult time actually finding people that are designing this kind of structure.