NORMAN — An innovative collaboration between the University of Oklahoma College of Architecture’s Sustainable Building Program and Cleveland County Habitat for Humanity celebrated a major milestone Saturday morning with the groundbreaking of Habitat’s first Compressed Earth Block house.
Compressed earth block (CEB) construction uses unbaked blocks made of compressed soil, clay, concrete and a small amount of water compressed into super dense bricks and laid similar to conventional masonry.
Over the next 4-6 months, Habitat volunteer crews will construct two houses on adjacent lots: one conventionally wood framed and the other with the compressed earth blocks. Once finished, both houses will be
monitored and compared for sustainability by National Green Building Standards.
“This project began two years ago and our multidisciplinary class has put a tremendous amount of testing and research into this,” said OU Assistant Professor of Architecture Dan Butko. “This is a great way for the students to be involved in a hands-on process of design and development while giving back to the community. They’ll continue to be very involved in the house’s construction and site management.”
According to Assistant Professor of Construction Science Lisa Holliday, the benefits of earthen construction material include a more pleasant living environment for the residents.
“Studies indicate that earthen houses are better insulated temperature wise and also acoustically,” Holliday said. “This is the first CEB house to be scientifically monitored and compared to a conventional house that we know of.”
A minor setback for CEB technology is cost.
“The cost of earth block construction is comparable to conventional methods,” Holliday said. “It would be more expensive if you had to pay for the labor to make the blocks.”
However, the convenience of acquiring building materials is a plus, as soil from nearby sites or the home site itself can be used.
“The carbon footprint of clay bricks and concrete is much higher, with the energy used to bake them in a kiln,” Butko said. “Our blocks for this project were made with soil dug out for campus construction projects, they dropped it off by the dumptruck.”
If CEB technology proves successful by NGBS standards, Habitat for Humanity affiliates around the nation could forseeably use this much greener method on their construction sites.
“The compression machine to make the blocks is portable, and the earth displaced in digging foundations could be used to make the actual material for the house,” Butko said.
The finished homes will look identical, with exterior siding and interior plaster concealing the earth blocks, and the test of time will determine CEB technology’s feasibility as a green alternative.
“We’re basically building the same house twice but swapping the guts for one of them,” Butko said.