frequently asked questions

• Doesn’t straw burn?

  • While loose straw is quite flameable, highly compressed straw doesn’t let enough oxygen in for the flame to get a foothold and spread. It tends to smolder, then go out when the flame goes away. We haven’t yet tested our blocs with the ASTM E-84 standard, though strawbale has been tested and passed with high marks. We’ve also done anecdotal fire testing. See the picture spread at left.

• What about mold?

  • StraBlocs™ are installed when dry and generally into structures that are already weatherized from the elements. Mold spores are everywhere and will thrive in sustained relative humidity above 60% and on damp surfaces. These conditions will encourage mold growth on all organic and some inorganic materials including other materials such as wood & drywall. The key to avoiding mold growth in all homes is climate control and careful air and water detailing during construction. StraBlocs™ are not more prone to mold. In fact, StraBlocs™ are unique in that the properties of clay actually helps regulate humidity — improving air quality and reducing chances for mold.

• Straw seems like a good home for rodents…

  • Rodents will make themselves at home just about anywhere if they’re given the chance to get in. Like most conventional homes, our insulation is thoroughly sealed, covered or otherwise made inaccessible to the critters around us.

• How much carbon is stored in a StraBloc™?

  • There’s about 8lbs of carbon per StraBloc™. This is equivalent to about 30lbs of atmospheric CO2 which about the same as burning a gallon and a half of gasoline. Even small structures built with StraBlocs™ lock up ONE TON of atmospheric carbon!

• Can StraBloc™ be part of Passivhaus and other high performance assemblies?

  • Absolutely! We’ve taken a lot of care to ensure compatibility with good air detailing and maximizing. The StraBlocs™ feature 2” of continuous insulation natively. StraBlocs™ are often paired with wood fiber board to decrease both operational carbon and embodied carbon.

• How do you run electrical & plumbing?

  • We’ve designed in electrical chases into our simple StraBloc™ systems. It’s also easy to install service cavites outboard of vapor retarders per standard high performance detailing. Plumbing is best serviced in interior partition walls or coming from floor rather than wall supply and drains.

• Y’all pack by hand? That can’t scale.

  • We understand the StraBloc™ system wont be used for the average 2,000 sqft home. The StraBloc™ is intended for projects and people that earnestly want to tread lightly on the earth. We could develop ways to mass produce these blocs, but mechanization is a slippery slope. Keeping it local and human scale ensures that we’re working with an authentically sustainable product. Even solar-powered mass production requires enormous swathes of energy, transportation, and promotes a disconnect between resources and our needs. That disconnect is felt as we become more distant from the natural world and our local economy.

  • Come to a BlocParty to experience an alternative to centralized mass production:

    Picture a gathering with friends and family: you chat, listen to music, enjoy good food and drink. Multiple generations gathering to spend time working with local straw and clay, getting dirty and getting exercise. It's a neighborhood BlocParty! And there's a byproduct from all this joy -- insulation for our homes. That's the StraBloc™ vision -- pairing community bonding and ecological action to home building.

  • Another take is that there are some things in life that ought not be mass produced, but rather made with care and concern for the health of worker, home owner and the rest of the natural world. Insulation makes up less than 2-3% of a total home’s budget, but the wall system creates the envelope in which we spend the majority of our lives — the walls are the heart of the home. Consider the notion of surrounding yourself with a healthy, carbon-storing product that lives up to all your ideals — made by you and your loved ones if you want!

    • For reference, a group of six mostly volunteers at a sociable pace can make 54 blocs in 4 fun hours. That’s enough for a sauna.

    • We haven’t tested this, but we estimate that three determined folks could make enough StraBlocs™ for a 400 sqft ADU in two days.

    • We recognize the impracticailty of this system for larger builds. If you plan to build larger than 800 sqft, we recommend using full strawbales or straw panels.

  • Another take is that we could develop ways to mass produce these blocs, but mechanization is a slippery slope. Keeping it local and human scale ensures that we’re working with an authentically sustainable product. Even solar-powered mass production requires enormous swathes of energy, transportation, and promotes a disconnect between resources and our needs. That disconnect is felt as we become more distant from the natural world and our local economy.

• How much do StraBlocs™ cost?

  • Costing depends on the specific local fabricator based on material and labor costs in your region. However, a home designed specifically with StraBloc™ specifications in mind will cost the same as the average custom home if not less depending on finishes.

• Why not just use other, less expensive natural fiber insulations such as HempWool and wood fiber board.

  • We love these products and we promote their use too. Many StraBloc™ projects also utilize these products in flooring, ceiling and in hybrid wall systems.

  • The drawback with HempWool & wood fiber board is that they contain 5 - 8% petroleum products and are made centralized energy intensive factories which require trucking or shipping great distance to get to you.

  • As mentioned above, the walls are the heart of the home. Densely packed straw and clay covered with earth plaster gives a warmth and depth and coziness that’s hard to replicate with hemp and wood fiber.