By Stuart Jeffrey Hart
Community Rebuilds is a nonprofit organization that builds straw bale homes for low-income families in Moab, Utah. The homes are built by volunteers who exchange their time for an education in natural building and sustainability. Our student intern volunteers commit to the entire 4 month build, participating in the foundation pour all the way to ‘key in the door.’ Our program is committed to replacing dilapidated, energy wasteful trailers, for highly efficient homes that use a fraction of the energy to heat and cool.
Community Rebuilds was been awarded this year’s “Innovative Path to Zero Waste Award” by the Utah Recycling Alliance. Here is how we achieved it.
To reduce the waste we produce on the build site, we follow the ‘Reduce, Re-use, Recycle’ principle.
Reduce – Our design choices help us reduce the amount of building materials that we use. When ordering roofing metal for example, we use Google Sketch-up, a computer-modeling program, to lay out the exact cuts needed. It shows us where the off-cut from one piece can be used elsewhere. This allows us to order the precise lengths of metal needed, meaning less materials are ordered and we produce the minimum waste possible. All lumber is ordered at lengths specific to the building needs. We order lumber lengths as close to the actual length needed to reduce the amount of material left. The conventional approach is to order only 16 ft lengths, then cut everything from those. The remaining pieces are often too short to be used and are discarded as waste.
A major design choice is for our houses to incorporate natural materials that are compostable. We choose to build the walls of our homes with straw bales, an agricultural industry waste product that would otherwise be burned. Extra bales and waste straw are composted. The homes we build have earthen floors and the walls and ceilings are plastered with earthen plaster. We use a combination of locally sourced sand, clay and straw for all of these applications. Plaster mix that is dropped during plastering or left over at the end is either re-hydrated and used again, or simply spread in the garden to become the soil.
Reuse – We incorporate used and repurposed building materials into our homes to reduce the cost of the homes and to reduce the amount of new building materials required. We construct non-load bearing interior walls with pallet wood salvaged from the local waste stream and earthen plasters. In addition, we reuse functional lumber, tiles, doors, windows, interior lighting and plumbing fixtures, sinks and toilets.
During construction we reuse our waste as much as possible and we try to incorporate other people’s waste material when possible. When sheeting the internal walls of our homes, we use drywall off-cuts from other build sites. Conventional construction crews will not use drywall scraps. Scraps will usually be the end of a 12′ x 4′ drywall sheet. We flip all the 4′ pieces horizontally and use them to span our 2′ on-centre framing. In our homes we piece together a total of 960 sq ft of ‘waste’ drywall. We mesh tape the extra seams and clay slip the gaps, and then our earthen plaster hides all. By collecting the salvageable scraps and using them in our homes we reduce the amount of waste destined for the landfill and save purchasing new materials.
When we are building with other conventional materials excess material and remnants are incorporated in the home as much possible. We use rigid foam insulation sheets to insulate our foundation and underneath the floor. Scrap from this process is saved and inserted into the roof cavity before we blow in cellulose. Some burnable wood scraps are collected together and used by the volunteers in their wood burning cob oven and communal fire pit. The rest is donated to a local family who use it to heat their house throughout the winter. We donated four cubic yards of burnable wood scraps from our most recent build.
We choose to use as little wood that contains glues as possible. This means that more of the wood scraps are burnable. It also reduces the amount of potentially harmful chemicals in our homes. To replace OSB sheeting on the roof, we use rough sawn 1×10 wood for the same price. We have replaced LVL beams with rough sawn 4×12’s. Both of these come from the Colorado Rockies where pine beetles have devastated huge areas of pine trees leaving them standing dead.
Recycle- We challenge ourselves to limiting our waste production to one domestic garbage bin (0.5 cubic yards) weekly. Our waste consists mainly of non-recyclable packaging and cumulates to an average of 8 cubic yards per build. By comparison, we estimate that local private contractors will dump approximately 30 cubic yards of waste during a similar sized build. To accomplish our low waste goals, we begin each new home build by creating pallet-recycling bins on our construction sites. Metal, plastic, cardboard and wood scraps are stored in them. When we need a small piece of lathe to patch a crack, some wood for blocking or cardboard to protect our floor a quick check of the recycling bins can save cutting a new piece. Once the build is over anything that hasn’t been used is recycled. At the end of our previous build we recycled one cubic yard of scrap metal and one cubic yard of cardboard.
Our goal is to create a quality affordable product with minimal waste and environmental impact. In doing so, we educate the next generation of builders how to move towards zero waste. Our students learn how the current building methods are wasteful and inefficient and how, using just a small amount of planning, we can change the home construction paradigm for the better. We are building homes in a smarter, more sustainable way. Our homes’ energy performance, thoughtful construction methods and quality stand as an example for our volunteers, the community and the construction industry as a whole.
Jeffrey was an apprentice and natural building instructor with Community Rebuilds from 2012 – 2013. He is now heading home to his native England to build small, affordable, straw bale homes using the Community Rebuilds volunteer/educate model. He can be found at www.jeffreythenaturalbuilder.com.