Choosing Materials for Your ADU

Recognize interdependence. The elements of human design are entwined with and depend upon the natural world, with broad and diverse implications at every scale. Expand design considerations and recognize distant effects.

Cradle to Cradle: Remaking the Way We Make Things, William McDonough, Michael Braungart

Why ADU materials matter

So, you’ve made the decision to go smaller. It may not be this very moment, but soon there will come a time for you to decide what kinds of building materials to use in your ADU. 

Forgive us for stating the obvious, but here it goes: ADU’s require a lot less material volume than your average house. The downside is that whatever materials go into your ADU, you’re going to be up close and personal with them over a long period of time. And with less airflow, you’ll be breathing in the fumes of whatever materials are in your space (think insulation, paints, varnishes, and the like)– which is why it’s all the more important to select non-toxic products for your ADU.

The upshot of needing less volume is that, depending on where you live, you may find it’s easier to source components from local retailers that are sustainable, less toxic, age well, and have better functionality for your needs. (That said, it’s important to get your materials right the first time, because there’s not much room to maneuver should you need to remodel after the fact.)

Many conventional building components have a high carbon cost of production and transportation, and many are even toxic. “Green” alternatives exist for virtually every building material, from the concrete in the foundation to the panels on the exterior, the insulation between the walls, the varnish on the floors, down to interior accents like trim or tile in the bathroom. 

Small spaces, special considerations

In general, materials can be expensive. Using less of them, by default, will save you money. 

Variety – There’s a lot to choose from out there. Keep in mind that each material has its own advantages and disadvantages, and you’ll have to do more research on your own once you finish this post (we’ll start you off with more resources down below). 

Durability – Think about the floors in a high-traffic area. There’s a good chance that you’ll notice some natural wear and tear; faded paint, scuffs, chips, and worn-out polish. In small spaces, your movements are less spread out and more concentrated in a smaller surface area over time, which makes it all the more important to invest in durable materials that will last. 

Sustainability – This goes beyond just the carbon footprint of any given material, and down to the air that you breathe. In smaller spaces, your body is physically much, much closer to the materials you choose to put in your home. Since the volume of air is smaller, the impact of potentially toxic materials is greater (especially when it comes to insulation). 

Talk to your building team – Generally, your building/contractor team will have their own preferences when it comes to building materials and their preferred sources for their wares. If you’re curious to learn more about the components going into your home, reach out to a Sustainable Homes Professional in your area.

Shopping for materials

The idea of local sustainability is not limited to materials, but it begins with them. Using local materials opens the doors to profitable local enterprise. It also avoids the problem of bioinvasion, when transfer of materials from one region to another inadvertently introduces invasive nonnative species to fragile ecosystems.

Cradle to Cradle: Remaking the Way We Make Things, William McDonough, Michael Braungart

Your local sustainable construction supply store might look as daunting as the one above (and it might just have a showroom to make it easy). If you have a list of materials you’re interested in and questions you have about them, finding what you need in that industrial aisle will be a whole lot less overwhelming. 

Since you’re dealing in small spaces, keep an eye out for materials in unlikely places – like your local reuse building supply store, or even the side of the road! Our designer Erin found a slab of granite for a shower ledge literally on the side of the road by her local granite store. 

The most sustainable thing you can do is find materials and reuse them- you don’t need to shop online, get things shipped cross-country, or get specially fabricated components (unless that’s what you’re going for). 

For PDX- based eco building supplies visit: 

• Small Planet Supply 
• 475 High Performance Building Supply 
• The Building Center 
• Habitat for Humanity the Restore

Conclusion

By paying attention to your material options early in the game you’ll save money, create a more comfortable, energy-efficient home, and showcase your taste for the textures and aesthetics you’ve always dreamed about.

The happy side effect of building small is that no matter what materials you use, less square footage means less overall cost and less carbon footprint. And that’s something to feel good about. 

Resources

• US Department of Energy – Insulation 
• NACHI- Fiberglass insulation: History, hazards, and alternatives 
• FSC Certification 
• Living-future.org Red-List