Our mission is to make affordable, ecological housing accessible to everyone.

= while fostering collaborative and regenerative practices =

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The OBI system is open source, collaborative and distributed.
Our focus is on low cost and rapidly-built structures that are modular, ecological, and energy efficient.

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AT THE HEART OF THE PROJECT IS A LIBRARY OF BUILDING MODULES—walls, windows, doors, roof, utility and functional modules, etc.—that can be combined to create a variety of structures: studios, homes, multi-family houses, greenhouses, barns, workshops, schools, offices, etc.

Our approach focuses on state of the art and ecological housing. This means that the system pays special attention to water-catchment, passive heating and cooling, photovoltaics, thermal mass, insulation, off-grid sanitation, and hydronic heat.

Designs and build instructions are contributed by designers around the world and are reviewed by experienced builders. A shared pool of designs means that each one of us does not have to reinvent the wheel. A greater number of designers means faster development. And the larger the number of contributions, the greater the diversity of approaches and solutions we can choose from.

All modules and procedures are OPEN SOURCE—forever and with no exceptions. This means that everyone is free to use, modify and redistribute them. Our OSHWA-compatible license also ensures that you are free to profit from these designs—by using them, for example, in design and/or build contractor work.

The library is made available online in standard CAD formats compatible with open source software applications such as FreeCAD and Blender. The library can be directly imported into Sweet Home 3D—an open source interior design application. Once imported into the application, modules can be simply dragged and dropped to create a building design.

The modules on the library are designed specifically to be easily and quickly built by non-professional builders. A 4×8 ft insulated wall module, for example, takes a team of two people 1 hour to build.

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In the 18th and 19th century, rural communities came together to build barns for each of their members. In our modern version of barn-raising, builds typically take place in 6-day workshops, during which participants collaborate to build a structure.

The modularity of the system enables extremely rapid builds, as modules are first built concurrently by teams and then quickly assembled on site to form the building.

Throughout several experiments, we learned that it is possible for a group of 35 people to build and install 20 wall modules in 1 day and 6 roof modules in another day. This means that it is possible to build the shell of a 24 x 16 ft structure in 2 days, Building a house may be a labor of love, but it doesn’t have to take a lifetime.

During workshops, participants acquire skills and hands-on experience with the system in order to organize their own builds. The barn-raising approach not only enables rapid builds, but also provides organizers with a stream of revenue that helps offset the cost of materials.

To further encourage adoption, replication and entrepreneurship, all workshop/build organization materials—from workflow and budget to publicity plan and logistics—are also open source. And for those who wish to build a business on top of this system, we are developing a training program geared specifically to entrepreneur-builders.

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A MODULAR SYSTEM FACILITATES INCREMENTAL BUILDING. Rather than tackling a large project in one go, our approach enables us to start with a small structure—a microhouse, for example—and then keep adding to it throughout subsequent builds.

We’ve been experimenting with and developing this method since 2013. Our first prototype was designed by Chris Reinhart and built on October 2013. It was initially a MICROHOUSE, a 12 foot by 12 foot structure with a small kitchen, a bathroom and a loft. Its walls are made from compressed earth blocks pressed with Open Source Ecology’s CEB Press. The basic structure was built during a 5-day workshop and the interiors finished over the course of 3 months. This was our home for a few months, while we worked on subsequent additions, and eventually became the kitchen.

In April 2014, we added a BEDROOM, another 12 ft by 12 ft CEB module, also with a loft. Chris Reinhart designed and led the build workshop for this addition. The soil we removed to grade the site and build the foundation was then used to make the earth blocks for the walls. We literally built a house from the dirt beneath our feet.

A few weeks later, in May, we added the MUD ROOM, as a connecting space between the first two modules. A PORCH was then built on the south side of the house—and later moved to the north side to make space for a greenhouse. The porch’s roof is made of clear plastic sheets, to allow light and heat in the winter, and is lined with shade cloth in the summer.

In late September of 2014, we added our largest CEB module to date: a 51 ft by 15 ft space that includes a LIVING ROOM, an office, a (more spacious) bathroom, and an utility room. This module was designed online by a team of volunteers led by Marcin Jakubowski and Jonathan Kocurek and its basic structure (walls and roof) was built during a 5-day workshop. The interior was finished by Marcin and Catarina, with the help of friends.

This latest module reflected several learnings from the previous builds. We learned that the traditional firewood stove we were using doesn’t quite work: the air was either too hot or too cold, and almost always smoky. We learned that, due to the CEBs high thermal mass, it is possible to avoid using an A/C in the summer as long as we are able to cool the house at night and reduce the heat coming through the windows during the day. And we learned that we’re constantly making changes, improving and experimenting – therefore we needed a hackable house.

To address the matter of heating in the winter we focused on sunlight and a more comfortable form of firewood heating. Plenty of large windows on all rooms, as well as windows on every exterior door, provide sunlight and heat in the autumn and winter. The clear roof of the porch further contributes to passive solar heating on the south side, as it’s usually a few degrees warmer than outside temperature. Since our midwestern winters are sunny but very cold, passive solar was not enough. For this reason, our main form of heating is a hydronic wood stove connected to a DIY heated floor. The cost of materials for Marcin’s open source, DIY control panel is a fraction of the commercially available ones. The heated wood floor provides an extremely comfortable, even form of heating. Its energy source – wood – is entirely local and renewable: it comes from our forest.

In order to keep the house cooler in the summer, we placed the windows and doors symmetrically so cross drafts cool the house at night, lined the porch roof with shade cloth, and installed thermal curtains on every window. With this approach, combined with the high thermal mass of CEBs, we don’t need to run the A/C unless the outside temperature is above 95 F.

The make the house hackable, we focused on keeping all systems accessible. Rather than pouring concrete over the hydronic heated floor water lines, we buried them in sand. If there is a leak in the system, we can lift the floorboards to repair it. The electric lines are not embedded in the walls, they run along the ceiling edge, inside an easily accessible channel. And the water lines run along the edge of the rooms, in a channel under the floor. If there is a leak or if we wish to add another valve, we can simply lift the boards to make the necessary repairs or changes.

Lastly, in the Fall of 2015 we added an 832 sq. ft AQUAPONIC GREENHOUSE to the south side of the building with the goal of enabling year-round food production and providing passive heating to the house. It features two 32 x 3 ft heated fish ponds, a chicken coop connected to an outside run, a rabbit pen, 48 6-ft tall aquaponic towers, 216-ft of aquaponic troughs, 2 compost beds, and a potting and seedling area.

In this latest workshop, which took place on November 2015, 35 participants built and installed 100 ft of wall modules on the first day, and then 52 ft of roof modules on the second day. We then spent the remaining 4 days finishing the structure, building two 1500 gallon heated fish ponds, 1 chicken coop, and 85 grow towers. By the end of the workshop, there were tilapia in the ponds, lettuce in the beds, and fresh eggs in the chicken coop.

Together, these structures form a 2300 sq ft living and working space—located at Factor e Farm in Missouri, USA, Overall, between the public design sessions and the workshops, around 100 people worked on this building.