Case Study: Healthy Basement

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.

Design

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.

Finishes

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.

basement before
Before
basement after
After

Check out finished photos of the job over at the projects page.

Healthy Basement Finish

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.

DeGarmo Strawbale Residence

This beautiful contemporary southwest style home, built by Black Timber Builders, features straw bale insulated walls, interior clay plasters, and tadelakt showers, sink, and kitchen backsplash by Living Craft.

Urban Strawbale Addition

This straw bale addition features very high performing straw bale insulation with lath and slip straw above the windows. Warm interior clay wall plasters and smooth tadelakt windowsills give it a modern but cozy feel. Lime-washed tongue-and-groove beetle killed pine ceilings on the vaulted ceiling open up the space. Read the case study about our process to learn more about how it all went together.

Case Study: A Straw-Cell Addition

straw wallsLiving 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.

Low Carbon

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

Applying a base layer of clay plaster at the work party.
Applying a base layer of clay plaster at the work party.

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.

Ben talks building with some volunteers while others work on shaping the windowsills.
Ben talks building with some volunteers while others work on shaping the windowsills.
The finish plaster drying around the laundry room window.
The finish plaster drying around the laundry room window.

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 burnished and waxed tadelakt windowsills have an amazing shine and reflection, as well as feeling silky smooth.
The burnished and waxed tadelakt windowsills have an amazing shine and reflection, as well as feeling silky smooth.

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.

finished window and wall plaster

Bathroom Remodel Before and Afters

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!

Before after door
Take note: this shot is in after/before order!

Before after sink

Before After vanity

Before After Shower

before after niche