Passive House Rebuild Elements

Now that we have discussed why we are building passive homes in the Marshall Fire community, lets get into the details of what makes a home meet this standard, and how our company’s values have determined what methods we use to achieve it.

Climate, Solar Orientation, and Energy Use

Passive houses take into account site conditions such as orientation of the lot/home in relation to the sun, the local climate, and energy needs of the home. A passive house should use the least amount of external energy inputs as possible, by orienting windows to capture heat during the winter, yet providing sufficient shading in the summer to keep the home cool and comfortable.

Air Sealing and Insulation

Passive House design, with its superior insulation and airtightness, significantly reduces heating and cooling demands in residential buildings. This combination not only reduces energy bills but also enhances indoor comfort and air quality for occupants. Additionally, windows and doors must meet high quality standards, including the use of triple-paned glass, and be designed to have a tight seal when closed. Attention to detail and careful planning are required to meet thermal continuity and air tightness standards.

Passive house modeling for window and wall assembly insulation
Interior Air Quality and Continuous Ventilation

A Passive House will provide a healthier indoor environment when compared to code built new construction by minimizing the use of toxic chemicals and incorporating mechanical ventilation. Each of these homes has a full house ducted ERV ( Energy Recover Ventilator), with intake and/or exhaust vents in each room. The system runs continuously, bringing in fresh filtered air and removing indoor air which may contain VOCs, excess CO2, and other pollutants that are created indoors. The air passes through a central system which exchanges the heat and humidity to maintain the indoor air temperature.

Low Carbon + Passive House

Although the Passive House standard does not currently require it, we are choosing to build with low carbon and carbon sequestering materials as much as we can. In conjunction with implementing Passive House design principles, the choice of building materials plays a crucial role in reducing carbon emissions. Low carbon building materials refer to products that have a lower carbon footprint throughout their lifecycle, from production to disposal. These materials include recycled content, sustainably sourced timber, low-emission concrete, and innovative alternatives like hempcrete.

Building materials that actively sequester carbon dioxide from the atmosphere further enhance the sustainability of residential construction. For instance, products that not only have a lower embodied carbon footprint compared to traditional construction materials but also lock in carbon during their lifespan. Examples of carbon sequestering materials include straw bale construction, which employs straw as a natural insulating material, cellulose insulation, which is made using recycled newsprint, and denim, hemp or sheep’s wool batt insulation.

In our homes, we are building double stud walls to reduce thermal bridging, and filling this entire cavity with cellulose insulation from recycled newspaper. The attic and rafter framed roofs will also be insulated with cellulose. We do have some EPS foam below grade in the basement of one of the homes. This serves in part to reduce the amount of concrete being used by eliminating a concrete slab floor. The other factors going into the decision are cost, and a decision to use the foam to provide an extra barrier between the living space and the cool concrete basement walls, without having to worry about potential condensation and moisture wicking damaging bio-based insulation.

All Electric

In another effort to minimize our contribution to climate change, these homes will be all electric, using heat pumps for heating and cooling and hot water, as well as electric induction stovetops. Colorado is already promoting all electric housing because this will reduce the consumer use of natural gas. Another benefit to all electric home is that they will have the option to add renewable energy directly (rooftop solar), which can reduce energy bills to zero. Also, as we clean up the power grid more and eliminate petroleum based energy sources, these homes will have a reduced impact on air quality and climate change, even without needing a personal solar power array.

Let’s Build More Passive Homes

Residential construction in the United States is undergoing a significant transformation as Passive House design principles and low carbon building materials start gaining more attention. Follow along with our projects on our Instagram page as we build these homes!

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.

How to Build in the Face of Climate Change

Currently the conventional construction industry contributes heavily to climate change. That cannot be debated. What if it could be changed?

Welcome to the modern world of increasing carbon emissions.

No matter the exact numbers, we know that creating buildings from new materials that have been manufactured and then shipped long distances, using machinery that consumes fuel and electricity, and assembled by workers who travel to the site daily in gas burning vehicles cannot be the greatest thing for the planet right now. We are struggling with the real effects of climate change in the present day, while also hearing every day about the potential futures we and our children will face.

How can building actually help?

We are part of a small but growing class of builders who believe we can offer some solutions to the big problems of carbon emissions associated with construction. Some ways this can be done:

Use Local Materials

If you don’t have to ship pine boards from New Zealand, but can instead use wood harvested sustainably from the same region that you are building in, this will reduce the embodied energy of that material. Unless you live in New Zealand, and then go for it with your pine. If you live somewhere where forests aren’t abundant, then you could look into other options like straw bale, masonry, or stone.

Their local abundance is part of why we love to use natural plasters. Sand, clay, and lime are harvested and processed fairly locally, not shipped from across the sea. These materials can be used for floors, walls, and more.

Use Materials with Lower Embodied Energy

If you can choose build a home out of cement blocks or adobe blocks, you can drastically reduce your building’s carbon footprint by choosing the adobe. Cement is one of the biggest greenhouse gas emitters, but adobe blocks can provide as much structural support, increased thermal mass (means more comfortable home in the face of extreme temperature swings), and a much lower embodied energy.

Similarly to how single use to-go containers made of styrofoam can’t ever be considered “green,” a home insulated with lots of foam is also not very green, because of the amount of energy it requires to manufacture that foam. Materials like straw, hemp, and cellulose can perform just as well, at a lower embodied energy cost. There are many more examples of this, so feel free to ask us about low energy materials when designing your dream home!

Use Materials that Sequester Carbon

Straw is made of carbon, and when a home is insulated with carbon-rich materials like that, you’re locking that carbon out of the atmosphere for the life of the building, How cool is that?

In contrast, a fiberglass batt or mineral wool board (or foam of any kind) takes a ton of energy to create and doesn’t sequester carbon at all. Bummer.

Other materials that sequester carbon: wood studs, hemp, cross laminated timber, and fiber boards (some made from hemp are coming onto the market soon).

Practice Efficient Home Design

Paying attention to your climate and site conditions and using principles of passive solar design will keep your home comfortable throughout the seasons while reducing your energy bills. It also lowers your carbon emissions.

Another part of designing a wall system is preventing air and water leaks. A tightly air-sealed and well-insulated home will last longer, reduce issues of mold or rot, and be more energy efficient for both heating and cooling.

Start today

It’s a good start to begin thinking about some of the factors listed above when designing and building a home. We can’t change the industry overnight, but the broader acceptance of low carbon building methods today could go a long way.

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!

Passive Solar Design Basics

solar design south face

In the sunny Front Range of Colorado, we see solar panels on a daily basis. But harnessing the power of the sun for your home is not limited to this high tech solution. People have used the sun in myriad ways in the past, and we can continue to make use of low tech, design focused options for capturing and using the sun’s free power.

Passive Solar Design

Passive solar design is a set of design tools that can be used in any part of the world to create a home that is warm in the winter and cool in the summer while using a minimal amount of energy for either cooling or heating. This means less petroleum products, wood, or other bio-fuels, which in turn means less CO2 emissions and other pollutants that are released in the burning of fuels. Burning of fuel or use of electricity also equates to direct financial burdens on those who use them, so using passive solar design can keep more of your money in your wallet.

Passive vs. Active

You might wonder how passive solar design got its name. Active solar generally refers to systems that require extra items that are attached to a building and are not already integrated into the home’s structural needs. These include solar collectors, solar panels, or rooftop systems for heating water. They often need pumps, timers, sensors, and/or wiring to get and keep them working. Passive solar doesn’t require these extras, but is able to be achieved using only the same materials that you would need to build any house, just rearranged into a design to maximize your ability to gather energy from the sun. Therefore, there is usually no added expense!

Principles of Passive Solar

Know your Location

Passive solar design works with the patterns of nature. The sun’s relative position in the sky is influenced both by the location that you live in and what time of year it is. Ideally, a builder or homeowner would have time to observe the site all year round to notice where the sun rises and sets each time of year, where winds come from, and any natural features that may provide shade, windbreaks, or create microclimates. Obviously, this isn’t always possible, but if you know your latitude, you can at least begin to calculate the angles that the sun will hit the house during different times of year. That being said, there are a variety of apps available for smart phones and online tools that make doing these calculations fast and easy.

Site to the South

Ideally, a passive home in the northern hemisphere should be sited on a south facing slope or in a location that gets plenty of southern sun. Most of the windows and entrances should be located on that side, to allow sunlight into the home where it can create heat. This means that the longest axis of the house will run east to west. Minimizing openings on your North face is important to prevent heat loss.

Don’t forget Outside Spaces

In addition to siting your home facing south, remember that outdoor spaces are best enjoyed with the sun, too. If your home shades your yard, consider moving it so that there’s more usable yard space on the sunny side for things like gardens, patio space, and hammock swinging. Planting deciduous trees on the West face of your home will minimize heat gain during the hot summer months.

Store up Heat

The heat that you are allowing in from the sun will need to be stored using thermal mass. Thermal mass can be any material that holds heat well. Water is one of the best materials for this, but not very practical for inside a home. As natural builders we often use earthen and lime plasters, as well as an earthen floor as our form of thermal mass. Interior adobe or cob walls that get direct wintertime sun are also a great heat sink.

Keep Heat in

Once you’ve got all the sun’s energy stored in your home, you need to keep it in. Use highly insulated walls and ceilings (we recommend natural insulation systems such as straw bale or hempcrete walls and cellulose for ceilings). Make sure there aren’t leaky areas in your home, around windows or doors. Even with a great insulation system, a drafty home will keep you chilly in the winter. Plasters create a monolithic wall coating¬†that are an excellent air barrier.

Not too many Windows…

So if south facing windows are good, maybe a whole south facing wall of glass would be better? Not so, usually! Over-glazing can result in too-hot-homes, any time of year. Also, windows will never be as insulative as walls, so you risk having all the heat escape at night.

Also the Right Windows…

Windows that work, and work for your home, are great! Modern windows have so many features to look for and some will do better on different sides of your house (more to come on that topic!). Vertical windows on the south wall are better for letting in the low, more direct winter sun, and reflecting away higher-angle summer sun.

solar design south face
These south facing windows gather heat from the low raking light of fall, winter, and spring, while the wide eaves of the roof keep direct sun out in the summer.

Cool Down Sometimes

You might think a passive solar house will get too hot in the summer. Opening windows and designing so your house can catch cross breezes is one way to help. So is something as simple as blinds or insulating curtains. Designing wide overhangs on a house can keep the high summer sun out of south facing windows. You can also plant (or keep existing) deciduous trees and shrubs on the south, east, and west sides of the house. That way, your windows will be shaded from summer sun.

Breathe Fresh Air

A house needs to have fresh air coming in. Particularly in modern well-insulated and air sealed homes, indoor pollutants can create unhealthy air conditions! A ventilation system is helpful, or necessary, to keep the home healthy. Using natural materials in and on your walls (straw or hemp insulation and plasters or clay paints) and floors (like earth, tile, or naturally finished wood) is another way to keep air clean by not introducing strange chemicals.

Keep Backup Systems Small

One great part of having a passive solar designed home is that your heating and cooling systems can be minimized, another immediate cost saver.

This isn’t the Passive Solar of the 1970s…

People might worry that their passive solar house is going to be the odd one on the block. Not so! Any style of architecture can be adapted to passive solar principles.

solar home
A passive solar rebuild/addition in Boulder. Designed and built by architect Brian Fuentes (

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