About Passive House Design/Build

Residential construction is undergoing a transformative shift towards energy efficiency and carbon reduction. The Passive House design standard, coupled with low carbon building materials, is at the forefront of this revolution.

Living Craft is building two new homes in the Marshall fire burn area in Louisville, CO to the passive house standard. We have partnered with Shape Architecture, a passive house designer and promoter based in Denver, to design the homes.

History and Principles

Passive House originally began in Germany. It has now become an international standard for constructing energy-efficient buildings that prioritize occupant comfort while minimizing energy consumption. The principles include airtight construction, high-quality insulation, high-performance windows, and a mechanical ventilation system with heat recovery. These elements significantly reduce the need for heating and cooling, resulting in up to 90% less energy consumption compared to conventional buildings. Just like LEED or Living Futures certified buildings, a building must meet certain requirements to become Passive House Certified.

Passive House Model Designed by Shape Architecture for construction in Louisville CO
One of two Passive House Marshall Fire Rebuilds, designed by Shape Architecture

Why We Are Building Passive Houses

With so many energy efficient home standards to choose from, we chose passive house for a number of reasons.

Local Incentive Program for Passive House

Incentives in the form of rebates are being offered by our local energy company for homes in this fire area. The rebates will offset any extra cost involved in making the home live up to the passive house standard, and hopefully provide some cash back to the homeowner.

Operational Energy Use and Comfort

Another reason we wanted to build to this standard is because a passive house should provide energy savings over the long term. The reduced heating and cooling costs and needs make monthly energy bills low. It also will be comfortable, quiet, and healthy for the residents.

Resilient Buildings for Climate Change

Additionally, our clients are concerned about climate change. The Marshall Fire that destroyed their homes was worsened by extreme weather patterns brought about by climate change. Because of that, they are hoping to provide an example of how housing and building in general could be involved in mitigating climate change rather than exacerbating it. That means we have to take into account the reduced energy consumption of the house, and also make smart choices about our design and the materials we use.

Also, simple homes that are airtight are actually more resilient in the face of future fires. Because it is so air tight, a passive house is less likely to have smoke damage after fires nearby. There are also fewer points for embers to gather and ignite with simpler roof lines.

It Takes a Village

Of course, the clients need to be excited about and on board with this process. Shape has the expertise in creating the design to meet the energy standards and the clients needs. Living Craft has four Certified Passive House Tradespeople on our team. This will help to ensure proper on-site implementation of the design elements, which requires a lot of attention to detail. Rounding out the team are BldgTyp, the PH Design Consultant and CertiPHIers, a third party certifier who will review the home design and construction process at completion of the project to make sure we have met the goals of the design.

We are excited to be getting building with these two new Passive Homes in Louisville, CO. Stay tuned for more updates.

Dearborn House Remodel

This deep energy retrofit started with gutting a 1960s house to add new wall and attic insulation and air sealing for maximized energy performance. We eliminated the natural gas line and transitioned to all electric heating and cooling and equipment and ERV, powered by rooftop solar panels. Other details include a new EPA certified fireplace insert, in-floor radiant heating, plastered walls and ceilings, a tadelakt shower, and integrated soapstone sink. We built a mudroom addition to connect the garage, laundry room, new back patio and expanded kitchen, and a detached outbuilding/barn for workouts and shop space. Design by Shelterbelt Architecture.


Berthoud Studio

A new build of a detached studio/work space with its own kitchen and bathroom. This structure was oriented to the sun for passive heating in the winter, air sealed with smart vapor open membranes, insulated with Havelock sheep’s wool, and includes an ERV for increased indoor air quality. We built with our clients’ chemical sensitivities in mind, and all materials went through a thorough vetting system to eliminate indoor pollutants.


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.

Our Lime Plasters Featured in Modern in Denver Magazine

Living Craft’s work at The Bindery Restaurant in Denver was recently featured in an article in Modern in Denver magazine. The focus is on the sustainable and cultural elements that the owner, Linda, brought to her new business venture. Our custom traditional lime plasters are one component of the sustainability practices that they prioritized during their design and build process. Read the full article to find out more, or stop by for an up close look at the walls.

The Ties That Bind

“Lime Plaster is a natural product. It’s a true craftsman’s product… it’s more alive than stucco. It allows light to interact, to dance.”

Read the Full Article 

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.


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.

basement before

basement after

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

What is “Building Science”?

We use the term building science a lot. For those who may have never heard the term, or fully explored it, here is a quick debrief.

Building Science

Taking into account experiences of architects, engineers, and builders, building science explores the way that a building responds over time to environmental factors and natural phenomena. Or, a detailed study of a building with the goal of increasing its life span, health, and/or performance, and applying those lessons to new buildings.

Big Topics

Indoor Air Quality/Indoor Environmental Quality

This covers things like sound/acoustics, lighting, indoor air pollutants and how to control them. Ever heard of “sick building syndrome”? In those cases, actually being inside a building will negatively affect a person’s health, whether from stale or toxic air, lack of good ventilation, noise levels, or a number of other factors.

Mechanical Systems

Air conditioning, heating, and ventilation are some of the important mechanical systems. Without proper systems, filtration, and flow, a building will not function well and keep its inhabitants comfortable. We prefer balanced ventilation, like an energy recovery ventilation system that is continuously alternating between bringing fresh air in and venting stale air out, while maintaining the temperature indoors to prevent energy loss.

ENCLOSURES and Air/Moisture Barriers

An enclosure is simply the surfaces of a building that separate indoors and outdoors. Walls, ceilings, windows, and soffits. Not surprisingly, better methods for keeping moisture out of building materials will prolong their life and reduce problems like mold and rot. So, things like air and vapor barriers are very important. They also increase the energy efficiency of buildings, and reduce operating costs from heating and cooling. However, its all connected. Since a home with a “tight envelope” or a continuous air or moisture barrier doesn’t allow air to flow through cracks, it will also need to be closely monitored and have a good, balanced ventilation system in place to circulate fresh air and reduce indoor air pollutants.

Building Sustainability

With the increasing awareness of the pressures that humans are placing on the global environment, we recognize the role that the construction industry needs to take on in reducing our impact. Big changes can be made with a choice of materials that have a low carbon footprint, or by building using carbon rich materials like wood, hemp, and straw that sequester the carbon out of the atmosphere. Things like passive solar design and an integrated landscape and water management plan also help to greatly reduce a building’s need for external energy inputs.

Modern Building Science, Traditional Materials

Hopefully it’s all coming together for you. At Living Craft, we are always trying to educate ourselves on the latest innovations in building science. We are doing the work of researching and picking out the best solutions which honor the traditions of building and respect the environment on all levels. If you have questions, we would love to hear them!

8 Steps to Improve Indoor Air Quality

Arboretum indoor air quality

The EPA considers indoor air quality (IAQ) to be one of the top threats to public health. Today, most people living in industrialized societies will spend up to 90% of their time indoors. Improving indoor air quality is one of the most important things we can do to increase our health and wellness in the built environment. As contractors and designers, there are many things we can do to help with this issue when designing and building new structures or remodeling existing structures.  As a homeowner, there are several things for you to consider as well. Many solutions are available to you right now to improve your health at home and at the office.

When we talk about indoor air quality concerns, we are mainly talking about three main culprits: bioeffluents, volatile organic compounds (VOC’s) and airborne chemicals, and airborne microbes. Bioeffluents are organic contaminants that emanate from the bodies of humans or animals. Our own exhaust is harmful to us and needs to be managed. VOC’s are organic compounds that essentially evaporate at room temperature (off-gas or outgas). These can be natural or synthetic, and many are very harmful to humans – either acutely, or more commonly over a long period of time – which makes research into their effects difficult to examine. VOC’s usually emanate from synthetic building materials inside our homes like glues, paints, and finishes. Airborne microbes include viruses, mold spores, dust, and allergens. These may exist in the outside air or may be a symptom of the humidity levels inside of your home.

Let’s take a look at simple steps we can take to improve our air quality with basic principles and solutions:

1. Limit Exposure.

doormat air qualityHave doormats at all entrances. We track in chemicals, dust, and dirt into our homes every day. The less we bring in, the less we have to worry about. Request people to take off their shoes when they enter your home. If necessary, consider having slippers available for guests. This also applies to dirty clothing. This is especially important for us in the construction industry. If you have been exposed to lots of dirt, grime or dust throughout your day, try not to spread that throughout your home.

2. Vacuum with a HEPA air filter.

Carpet, upholstery, drapes, etc. hold onto dust and chemicals. By vacuuming regularly with a HEPA filter, we can help to safely remove a lot of these irritants from the home. If you are ever remodeling, consider getting rid of wall to wall carpet and just throwing down runners in high traffic areas.

lemon, lemon tree, nature3. Stop using conventional cleaners and air fresheners.

Avoid ingredients listed as just “fragrance”. These are synthetic, proprietary and can contain lots of different types of chemicals including Volatile Organic Compounds and Phthalates. Look for cleaners that don’t have artificial fragrances. Avoid aerosol sprays. Try more natural solutions like citrus for a fresh aroma.

4. Test for Radon.

Radon is known to cause lung cancer and can be found in nearly any type of soil, in any part of the country, in any type of home. Testing is relatively inexpensive and quick. The EPA has a “Consumer’s Guide to Radon Reduction” to help you with this.

5. Use healthy materials. lintel, window, garlic, natural

When you have work done on your house, know what the materials are, and what is contained within them. Many paints, finishes, carpets, engineered and synthetic products contain VOC’s. These can off-gas for hours, days, or years. Know your exposure so you can make educated decisions on how to manage it. There are many no-VOC options out there. No-VOC doesn’t always mean it’s healthy for you, but it’s a good place to start. Consider a contractor who is well-versed in this type of construction and is able and willing to answer your questions on these topics. If you are concerned that you may have toxic materials already in your house that are causing you harm, like lead, have them tested by a professional.

6. Get a humidifier. train station, humidifier

Healthy humidity levels range from 35-65%. In the winter months, the relative humidity is very low, and with active heating systems it is reduced even further. Dry conditions irritate sensitive membranes in the nose and increase susceptibility of airborne microbes, leading to frequent colds, allergic attacks, and asthma. They make both stand alone humidifiers all the way up to whole house humidifiers that may be integrated into your existing HVAC system.

7. Ventilate. modern, art, ventilator

This is a big one, so I’m going to break it down a little.

a. Change your filters often. Even if your HVAC system brings in new air from the outside, it doesn’t mean that the outside air is clean. Consider getting HEPA filters for your HVAC system.

b. Have your ducts cleaned by a professional service. Dust and debris can collect inside your ductwork, causing bad air quality every time it runs.

c. Use Exhaust Fans.ventilation air quality There are so many sources of moisture inside of your building: cooking, bathing, breathing, etc. The most significant being your stovetop and your shower. Humidity in excess of 70% can cause mold and mildew growth within your house, especially within your wall cavity in conventional construction. Many times, you don’t even realize it is there. Trust your nose. Does it smell musty? Recognize symptoms that persist when only at home but not outside like congestion and irritated eyes. Cooking also produces potentially hazardous levels of gasses like nitrogen dioxide and carbon monoxide. Make sure you have a vent hood above your stove that exhausts to the outside of your building, not the kind that re-circulates back into your home or attic. When you shower, run your bath fan and leave it running for 5-10 minutes after you finish. Again, make sure the bath fan exhausts outside of your building and not to your attic. The main problem with exhaust fans is that people don’t use them, mainly because they are too loud. Consider investing in a new one that has a lower decibel level that you can run while carrying on a normal conversation.

d. Upgrade to an ERV (Energy Recovery Ventilator). If you are looking to upgrade your HVAC system, consider looking into continuously running ERV systems. These never turn off, giving you a constant supply of new air, as well as regulating temperature and humidity with up to 90% efficiency.

8. Get Indoor Plants. Green Leaf

NASA has conducted several scientific studies showing the ability of plants to increase humidity, remove bioeffluents and VOC’s, and suppress airborne microbes. The first list was created by ‘The Clean Air Study’ back in 1989. Start with one plant from the list and place it close to where people most often occupy the space, like on a desk, next to the couch, or on the bedside table. You will get the most benefit if the plant is within your personal breathing zone. If you want to go all in, or want something to work up to, the most effective and efficient air cleaning ability will be achieved by growing one plant per 100 square feet of living space. This research doesn’t even take into account the numerous other studies showing the psychological benefits of growing plants, as well as the aesthetic beauty they add to your home.

Most of these solutions are within the budget and experience level of the typical homeowner. When in doubt, consult a professional. Most people feel that they can only control their diet and exercise. Well, now you have some power over your environment too, so use it. Take charge of your space and make it healthier for you and those around you, one small step at a time.

Controlling Humidity in Your Home

We live in an incredibly dry climate along the Colorado Front Range.  The lack of humidity has both positive and negative benefits for the comfort of your home throughout the year. One advantage to our dry climate is that homeowners need to worry much less about rotting framing members and mold growth. The dry heat is also much more comfortable during the summer than a humid, wet heat that folks experience in the U.S southeast.

During the winter though, maintaining an appropriate level of humidity in interior spaces will help your home’s heating system work more efficently and create more warming, comfortable spaces. Since you typically keep the windows and doors to your home closed throughout the winter though too much humidity is a common occurrence. Humidity is added to our indoor spaces though quite a few activities including humans exhaling, cooking, and showering to name a few. Too much humidity can cause condensation to form on your windows, particularly if you have single pane windows. Conventional, building practices will lead you to use expensive, high maintenance, energy-intensive humidifier / dehumidifier systems.

A better, natural alternative exists.

Earthen plasters (clay plasters) can help balance the levels of humidity in your home very efficiently with little to no maintenance. Clay is hydrophilic meaning that it is attracted to water and naturally wants to dissolve in water. As humidity levels build up in your home, earthen plasters on your home’s walls will naturally absorb this moisture and then release the vapor overtime as the humidity levels in your home begin to drop. A very simple, hands-off way to let nature take care of a problem for us. But it wouldn’t be a great, ecological alternative if earthen plasters didn’t also have other benefits. Besides offering stunningly gorgeous finishes, clay is completely non-toxic and VOC free meaning that your walls will not pollute your indoor air quality. Earthen plasters are fire-resistant, produce very little to no waste from installation, resist grime and dirt, won’t fade over time, eliminate the need to repaint, extremely easy to repair, and have a lower carbon footprint than any other interior finish.

Check out the demonstration video below from American Clay, a New Mexico based earthen plaster manufacturer, for a helpful visual of how earthen plasters and humidity interact. You can also download a handout from American Clay that explains these principles as well. To read more in depth about earthen plasters and their benefits, visit American Clay on the web.

With trained and certified applicators, Living Craft can offer professional, custom installations of earthen plasters that are guaranteed to help create a more temperate indoor space and captivate you for years to come. Contact us today for more information about earthen plasters in your home.

Thumbnail photo by Jenny Downing under CC License.

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