Purchasing new hardware? Read our latest product comparisons

Affordable net zero: foam in, air conditioning out


February 18, 2013

Lifethings-designed Sosoljip net-zero house (Photo: Kyungsub Shin)

Lifethings-designed Sosoljip net-zero house (Photo: Kyungsub Shin)

Image Gallery (35 images)

By prioritizing energy minimization, and taking a pragmatic approach to materials and insulation, client Dr. Jung Soik and architect Yang Soo-in of Lifethings were able to construct a net zero energy house, or one that produces more energy than it uses, on a reasonable (if not meager) budget. Upon completion, Dr. Jung had spent US$284,000 on Sosoljip, the house which now stands at a fishing village four hours to the south of Seoul, South Korea.

According to Lifethings, Dr. Jung first became interested in self-sufficiency while studying in Milan, when a drivers strike to protest the price of oil made fresh produce hard to come by. Pondering the "vulnerability" of the support systems and supply lines that grease the wheels of society, Dr. Jung began to think about self-sufficient communities. Sosoljip, then, was a first practical step towards just such a community; and Lifethings was commissioned to design it.

"The client and the architect wanted Sosoljip to be based on common sense in its design, construction, and budget," Lifethings writes. The sensible budget was not so much borne out of necessity, but a proof of concept that sensible, net zero design needn't be prohibitively expensive.

Lifethings first priority in designing the house was energy minimization, with a particular focus on insulation – "the most important factor." To this end, the entire reinforced-concrete structure is encased in 20 cm-thick (7.9 in.) Styrofoam, a dense brand of polystyrene foam, the generic insulating properties of which make the material a popular choice for disposal coffee cups - or used to.

That insulation topped the hierarchy of properties precluded shingle or panel exterior surface finishing, since its installation would inevitably damage and perhaps compromise the performance of the insulation itself. Instead the architect turned to polyurea spray which forms a relatively tough, waterproof surface. Windows are kept to a sensible proportion of the surface area so as not to undo the good work done by the insulation.

The house is fitted with both photovoltaic and thermal solar panels, with a wood-burning stove for back-up. The house does without mechanized air conditioning. The on-site renewables lack the heft to run it, and in any case, Lifethings writes, "the client will gladly wear sweaters in the winter and sweat a little in the summer, which is only natural." The 230 sq m (2476 sq ft) Sosoljip will be shared by Dr. Jung and her parents, and includes both separate and shared living spaces for both.

Source: Lifethings, via Arch Daily

About the Author
James Holloway James lives in East London where he punctuates endless tea drinking with freelance writing and meteorological angst. Unlocking Every Extend Extra Extreme’s “Master of Extreme” achievement was the fourth proudest moment of his life. All articles by James Holloway

Great project, I'd give it four out of five stars. They will find that they need deployable shades of some sort outside the south-facing windows, to further reduce incoming radiation in the summer. Every degree matters when the building has no active A/C.

"Passive Houses" like this are the way to go.


I think the overhangs and depth of the window reveals would provide enough solar blinding without having to have actual solar blinds which would have increased the cost.

I think the build cost has been kept low thanks to the simplicity of it, even though concrete formwork is expensive.

Dan Marsh

I hope no wind-blown sparks hit that foam, say, from a sustainable tree prunings BBQ for example. Still sounds very expensive to me, a little architectural pre-design work could have made most of those concrete shapes virtually modular, therefore pre-cast slabs would save cost.

The Skud

A solar passive house with no eaves? Insulation is important sure, but shading your walls and windows blocks a massive amount of heat before it needs to be insulated against. Also, while we are trying to save energy, anyone figure how much embodied energy is in the concrete and polystyrene? Also curious about the labour component of the build price, & how that changes from South Korea to the US or Australia? Still, I think its a good addition to the ongoing dialogue about how we build our houses & how we can build them better.


I'd be interested to see this house modeled in the Passive House Planning Package (PHPP) to see how it preforms.

Also while the house does not have air-conditioning it would require some kind of ventilation system. Living in an airtight building like this without a proper ventilation strategy in place is never a good idea and is potentially dangerous to your health.

James Byrne

Styrofoam is a fantastic insulation. I used it extensively on my own passive solar house; however, the manufacturers have yet to address the issue of insects in applied foam. The foam provides ideal housing for a number of species, including ant and termites, and they are quick to chew into it and build extensive housing. Given my own experience I would recommend the owner (and architect) monitor the foam on an ongoing basis. The insects are often hard to find at first but over time will compromise the house in many ways.


Sandwich concrete panels have been around for a while, so this is nothing new. One benefit they offer is thermal mass on the inside, which helps regulate temperature. Styrofoam squeaks, and so minor shifts in the building (moreso in residential than in industrial/commercial construction) can set off sounds that make a woodpecker think there is food there. A pre-cast panel does not need paint, but it helps the aesthetics.

Bruce H. Anderson

Nice design but I would have fears about the out-gassing of all that plastic along with the possibility of a fire and the very toxic smoke it would produce. Also, what sort of UV protection did they use that could last the lifetime of the house. Another consideration would be the radon, humidity and possible mold that could accumulate in such a tight building.


Great - make a zero footprint house using one of the hated plastics on earth: styrofoam. No recycle ability (eventually house will need to be demolished). Made of styrene as possible carcinogen. 57 chemical by-products in its creation, including hydroflourocarbons, which are quite as bad as CFCs, but not great. etc.


@davemv. Correct! Or as they say in California - Bazinga!

Such a house would not last one season here in Canada. Winter/summer and freeze/thaw cycles would turn this home into a tinderbox in no time at all. Giant Carpenter Ants would have a field-day (pardon the pun!) and there is no shortage of those buggers in Alberta!

Now, perhaps if the walls were Pre-fabricated with wood exteriors (all 6 sides) prior to installation, there might be some saving there. But the roof MUST have a slope, there MUST be Eves and Soffets to allow air to circulate under the roof and above living areas to remove access heat and allow the cold to "temper" above the living area insulation.

As well, the foundation, while still concrete, can be slightly "over-sized" to allow for thicker "foam" built walls - again sheathed in wood or some other stiff water-repellant material. Air conditioning many not be required if a decent heat-pump were installed. A Geo-thermal system would be best, I think. Sure, it's OK to sweat a bit in summer and put on an extra sweater in the winter, but that is not the optimal way to live in this modern world. Too many people are inured to such decadent (medieval) ways of living.

Give me a heater and Air conditioner, and I will go to my grave in comfort!

In my area AC is not considered optional. The use of foam in roofing and insulating products has impressive results. But beyond the mundane if we were to increase the energy generating capacity of the units and build them in clusters the energy generated might justify giving the homes to owners for free. For example if we look at a conventional power plant and the power per acre that the plant produces and the expenses of building and running such plants and look at a designed suburb with each home dedicated to capturing a lot of natural energy the price of such housing might be rather trivial and income from the power produced keeps rolling in. Compare that to a system in which a home must be built for a profit, marketed, and perhaps produce some of its own power which takes away from money earned by the power company or even sell power back to the power company and weigh it against a housing project with homes given free that produce a lot more power than they use. From the public point of view when we have a hop scotch situation where many homes go off grid in a random pattern the cost of a power customer will go up and up as they become a smaller and smaller minority. You will pay for power that your neighbor does not buy. My way would eliminate some of that hop scotch effect as power providing homes would be built in larger clusters. And if a home owner fails to keep his property nice or becomes a public nuisance the power company could evict and get a new owner so a degree of social regulation is built into the idea. Jim Sadler

I wonder if they considered SIPs? I would have gone up really fast.


TOT, but where is best place to look for house design suitable for a humid sub tropical climate like say southern Brazil, coastal region? Thanks to anyone who can point me to some good resources.


re; Jim Sadler

Your way gives up freedom to gain nothing. Assuming enough local power generation/usage reduction to matter it is not the closest power plant that closes, it is the least cost effective for the utility.


The zero-energy home as conceived here and elsewhere is obscene in expense and unappealing industrial design. The unifying element of these homes is you can't find the front door.

For $284,000 you could build ten bungalows using local materials, passive solar design, and backup heating and cooling with low-cost Seer 20 rated split HVAC units.


If you put in an efficient HVAC unit it still comes with the option to wear sweaters in the winter and sweat a little in the summer. Given that the house is already pretty efficient you can save some money by not needing a high BTU system.

I installed a high efficiency system and run it off a Nest thermostat and my gas and electric bills plummeted.

Post a Comment

Login with your Gizmag account:

Related Articles
Looking for something? Search our articles