This hyper-healthy home remodel features an air-sealed envelope with a whole house ERV for continuous ventilation. We also used natural clay plasters on all walls and ceilings, and sustainable cork flooring. With 4 bedrooms, 3 bathrooms, an office, and a fully featured basement bar, as well as two basement living areas, this new space allows an older home to take on a new life.
There’s a lot of information out there now about hemp construction. Since the recent passing of the 2018 Farm Bill in congress, which legalizes the growing of industrial hemp on a federal level, the hempcrete building technique has gained media attention.
But what do you need to know if you are thinking about your new dream hemp house or hempcrete remodel?
How Hemp is Used in Construction
Many articles in the press have done a good job of explaining the use of hemp in hempcrete walls. This system involves hemp hurd being mixed with lime binder and then loosely packed into forms that are built around the wall framing. This is applicable in both new builds and remodels. There is lots of room to experiment, as well.
For example, the hemp-clay house we worked on uses the hemp portion of the wall solely as an infill which butts up to the inside of the otherwise more conventional wall. It serves as a thermal break and plaster substrate. Hemp can also be mixed into plasters, earthen floors, and used in creating blocks, with either lime or clay binders.
There are companies that make building products made with hemp that could replace plywood, batt insulation, and even wood framing members. For now, though, hempcrete (or hemp-lime, or hemp-clay) is the king of hemp building.
Benefits of Building with Hemp
There are many benefits to building with hemp and hempcrete systems.
First off, the environmental benefits. One way hemp is better than other building materials that it may replace is that its production (farming) and processing (making the hemp plant into hurd) can require less energy, water, and time inputs. In fact, due to its long root system, hemp plants can actually improve soil health by increasing organic matter in soil over time and naturally loosening dense soils.
A hemp home may use less lumber, since the wooden frame of the house can be designed with greater spacing than if the home used more conventional insulating batts that are designed for 16″ or 24″ spaces. And since hemp grows much faster than trees, it requires less water and energy inputs, and a smaller area of land to produce an equivalent amount of material.
Hemp also replaces insulation. Batt insulation like fiberglass and mineral wool are manufactured products that need a lot of energy to create and ship. If local hemp hurd is used instead, the embodied energy is much lower. Also, hemp captures carbon from the air as it grows, which is then sequestered and stored in the walls of your building for as long as it stands. This means you get to start out with a carbon neutral or even carbon negative home from the beginning!
The rise of “sick building syndrome” is well documented. As homes get more energy efficient with tighter envelopes, indoor air quality can decrease. Particularly when the materials used to build and finish them and the products we bring inside are off gassing chemicals and VOCs, this can result in poor health, lowered cognitive abilities, and potential long term disease. In addition, mold can become a problem from condensation forming within wall systems or inside of poorly ventilated homes.
Hemp can help with this is a few ways. If you follow our plaster site, you may have read about how plasters can improve indoor air quality. The lime (or clay) binder in hempcrete is the same earthen material as in a natural plaster. Also, most hemp walls are finished using plaster on the inside.
Also, hemp won’t contribute to VOC and chemical off-gassing as it is a wholly plant based material which has been dried and processed before being mixed with the lime.
Finally, hempcrete walls are highly mold resistant. The lime binder has a very high pH while wet, which prevents mold. And, once it has cured and been plastered, a hempcrete wall regulates humidity and allows water vapor to pass through it in a way that won’t lead to any points of condensation within the wall. There are also no gaps within the wall through which air can move. This eliminates another source of moisture and mold, and contributes to the longevity of your building.
Boosting Local Economies
Growing hemp is seen as a healthier, safer alternative to other economic activities, like mining and large scale industrial agriculture. Because hemp requires less inputs of pesticides and herbicides than other crops like cotton, soy, and corn, it is a good candidate for replacing or joining into a crop rotation with these plants. Also, parts of the country whose economies were dependent on coal mining or manufacturing jobs could use the recent legalization of industrial hemp to carve out a new living. In Colorado, hemp and marijuana growing is already boosting the economy.
Current Challenges of Building with Hemp in Colorado
Since industrial hemp is a new crop in the United States, we are lagging slightly behind in the manufacturing of products using hemp and in the processing of the raw plant material. The equipment, factories, and machinery required for such a task are expensive and it will take time to catch up to other countries where hemp building has been popular for decades.
For example, when we built our hemp-clay project, using a unique and lower carbon version of hempcrete where clay is used to bind the hemp together in the wall instead of lime, we used imported hemp hurd. There are drawbacks to this, like increased embodied energy. However, the current consistency and quality of processed hemp hurd available locally (if it is available at all) meant that there would be more headaches and room for errors than if we bought from a part of the world where hemp building is well established. In those countries, the processing of the plant into the final product is seamless and reliable.
So, while we are still waiting for Colorado and the US to catch up with other areas of the globe, hemp building is coming to Colorado quickly, including in a studio project that we are starting later in 2019. Keep an eye out for updates!
This bathroom remodel took a small space and give it a luxurious new life. Traditional tadelakt lime plaster walls combine beautifully with modern features like a new tile floor, custom concrete shower pan, and upgraded fixtures.
We built out an unfinished basement using natural materials and systems that promote healthy indoor air quality and energy efficiency. Clay and lime plasters, a tadelakt shower, beetle-kill pine trim, barn door office partition, LED lighting, polished concrete floors and new fireplace and boiler round out the space.
Read about our process in the Case Study blog, over at our Learn page.
We were approached by a family that was hoping to have their currently unfinished basement built out to include a bedroom, bathroom, storage, living area, and home office/meditation space. This extra space will accommodate a family with up-and-coming teenagers.
Our clients already had a design for the new space and emptied the basement of most things, minus a piano which would be too difficult to move upstairs – so we built the basement around it! The bathroom design was tweaked a little by us and our plumber to make it easy to drain everything and provide required clearances and access for pipe clean-outs.
We also made some modifications to the office/meditation space, which ended up with a very cool and versatile corner of sliding barn doors.
Indoor Air Quality
Basements in older homes are notorious for being moldy, damp, and having stale air. Because we build healthy homes, breaking from the stereotype was necessary. This featured heavily in our materials selection and building method criteria.
This house has luckily not had any problems with bulk moisture in the basement (i.e. flooding). In order to create an air and vapor barrier inside the permeable concrete foundation walls, we used a polyiso foam board (a case of least-bad when it comes to foams). We foil taped all joints and caulked along the bottom. This barrier was completed using spray foam along the rim joist at the top of the wall to seal that area from air infiltration, both from outside and from the garage. Its very important to keep car fumes out of living spaces!
We also installed a small, two unit, balanced ERV, with one unit in the bedroom and the other in the living area, on the other side of the basement. These ceramic-core fans alternate drawing air in and pushing it out. The ceramic is a heat sink, designed to keep the air temperature inside the same and prevent energy loss.
A nearly silent, motion activated bathroom fan keeps excess moisture down. Clay plaster also plays a big role in managing humidity and keeping air quality high.
The existing wood-burning fireplace was replaced with a new gas insert. This is cleaner burning, and no more having to sweep dusty ashes.
Finally, we used a paperless drywall in all areas of the basement. This choice is mold resistant, since it’s actually the paper that provides the food for the mold spores. The only place that’s different is the shower, which we fully waterproofed using Schluter Kerdi products. Here, the longevity and mold resistance in the wet environment of a shower is valuable for a long lasting home. It will prevent unnecessary water damage and further remodeling work later on.
Insulation and Sound
Because of the possibility of moisture, we used mineral wool batts within the 2×4 framed walls to insulate the basement further. This insulation is rot-resistant, since it’s basically just rock, turned into fibers. Up in the ceiling, we used cellulose in mesh bags to insulate the top of the outside walls, between each joist, before the drywall went in.
Extra insulation batts went into the interior walls surrounding the bathroom and bedroom. This will allow the family to use the space in multiple ways without disturbing each other if someone is sleeping or showering.
As part of a healthy indoor environment, all the surfaces are treated with VOC-free finishes. Custom clay plasters cover all the walls and ceilings except the bathroom. The bathroom has a lime plaster on the walls and ceilings, and a groutless tadelakt shower, which will never have issues with mildew in grout lines.
All trim is custom milled beetle kill pine. Doors are from used building supply stores, and are all solid alder wood. All of the wood in the home is treated with a VOC-free and plant based oil finish.
The floor is the original slab of the basement, polished and tinted and then sealed. This is easy to keep clean, and will also keep air quality higher than if we’d used carpet. Area rugs can be used in places of high traffic or where you might be walking barefoot.
A Healthy, Natural Basement
This family was great to work with and be around, as we worked in their home. We’re excited to see how the space lives up to their needs. We are glad that this basement offers them some extra living space, without having to worry about the problems of unhealthy indoor air quality.
Check out finished photos of the job over at the projects page.
We couldn’t be more pleased with our experience with this dynamic team of professionals. We hired them to build out our unfinished 1000 sq. ft. basement. Ben put together a comprehensive estimate, finding competitive bids for the electrical, heating, plumbing, and drywall portions, plus concrete floor stain & polish. We were pleasantly surprised to find that incorporating natural building practices didn’t mean the cost was any more than a conventional approach. The scope of their work included framing, insulation, plastering gorgeous natural clay & lime walls, building an incredible tadelakt shower, putting in a ventilation system, installing multiple materials, and staying on top of all the subcontractors. They gave us great recommendations for locations to find materials. Over the course of several months, we were witness to their positive energy and obvious pride in their craft. Having had countless bad experiences with home improvement projects, we are thrilled to have found these honest, reliable, gifted artisans.
We updated and opened up this bar area in a basement in Golden, CO. Natural stone wall tile and wood plank floor tile, combined with dark wood and granite countertops, give a modern and classy feel to the new space.
Living Craft Design has been working on a straw bale addition to our friends’ home in Boulder. This family is already well-versed in the benefits of natural building, so their addition incorporates passive solar heating with large, south-facing windows and a concrete slab floor to hold all that sun-generated heat. The addition has the high insulation value (R-value) that is a great feature of straw bales as a building material. Additionally, the family chose to renovate the original rooms of their home and filled the walls and ceilings with densely-packed blown cellulose as part of that process. This home will be comfortable year-round and have low energy bills as well as a reduced need for running heating and cooling systems.
A Straw-Cell Design
We jumped into the project starting with straw bale installation. This house has what’s called a straw-cell wall, with an entire wall system behind the bales, complete with wood studs, recycled denim insulation, and exterior wood siding. The bales then are stacked on the inside of this wall, meaning that labor is reduced because you don’t have to cut or trim as many bales to fit within and around the walls’ wood frames. You also only need to apply plaster to the interior side of the bales.
A great thing about the insulation materials used in this home is that they are all carbon-based, and will now be locked away in the walls of this home for a very long time. This is actually a form of carbon sequestration, one technique to keep atmospheric carbon down and help mitigate climate change. This is in direct contrast to insulation materials like foam, fiberglass, and mineral wool, which consume a lot of energy to create. This means that the manufacture of those materials produces a lot of greenhouse gas emissions, upping their carbon footprint.
Healthy, Natural Plasters
Our next step was to start the plasters. A base coat of local red clay was applied to cover the bales first. At a fun summertime work party hosted by the family, we added a leveling coat which will provide the base and shape for the finish plasters. We introduced some folks to the techniques and tools for mixing and applying natural clay plasters and played in the mud with good friends. We also started to build out the windowsills into their final shape using a lime and clay mixture with lots of straw for strength.
The final wall finish was customized to get the exact color and texture that our clients wanted, and this last, thin layer of clay-based plaster went on like a dream. Thanks to additions like wheat paste, it dries into a hard and durable finish that will last for years, and also be easily reparable in case of accidental damages.
During the wall finish process, we were preparing for and creating the tadelakt windowsills that will become perfect benches for sitting on and reading in the natural light. This Moroccan finish plaster is created from lime, which is why the base coat for the sills incorporated lime with the clay. This results in a tight bond between the materials. The smooth layers of lime were applied, soaped, and burnished using stones to create a shiny finish. The sills were then waxed as the final step to create a long-lasting surface that can withstand some use.
The End Result: A Beyond Green Building
We’re departing this project with lots of hope for the future which will unfold in this family’s happy, healthy, non-toxic, and environmentally friendly home. Not only will it be a beautiful space to raise a family, but also a good model for other front range homeowners looking to sustainably add some space and renew their original home.
We tackled a big project earlier this year with the complete remodel of a bathroom in Denver. The bathroom had been updated back in the 1990s, and it definitely looked a little dated. More problematic, there were moisture issues which resulted in peeling wallpaper, water stains in the foyer below, and the potential for greater damage. The homeowner needed an update, not only in the style of the bathroom, but also with its functionality!
We worked with our client’s needs and desires, and came up with a modern new layout and design that incorporates lime plasters, including Moroccan tadelakt for use in the shower and custom built sink basin. Also new are the coordinating wooden cabinets, trim, and door, and large format tiles on the walls and floor, plus pebble tile in the shower basin.
For improved building performance, we installed a new motion-detector equipped ventilation fan to move moisture to the outside of the home, fully waterproofed the shower walls and floors, and added blown cellulose and improved air sealing in the attic. An energy audit, performed both before and after upgrades, confirmed that the home will now have lower heating and cooing costs. These performance upgrades also allowed the homeowner to claim a rebate with their energy company.
Check out some of our before and after shots to see the differences!