The Nauhaus is a high performance natural building system that combines the best of cutting edge modern building science with the advantages of traditional building techniques and lifestyles. The Nauhaus system is designed to achieve:
A dramatic increase in comfort, long-term affordability, and sensory enjoyment while fostering a healthier lifestyle through an increased connection to nature.
Fulfillment of scientifically established benchmarks for residential construction defining a drastic reduction in emissions that contribute to our present global warming crisis.
A solid contribution to a sustainable solution for our present economic crisis by focusing on local materials and workers while creating opportunities for the creation of a variety of local green construction businesses.
The name Nauhaus (pronounced “now house”) is a playful nod to the Bauhaus school of design whose work to merge mass-production and art, form and function is an inspiration to us today as we grapple with our own set of challenges.
Based on widely accepted global climate change predictions, we need to drastically cut our carbon emissions very quickly. Highly credentialed scientists like James Hansen of NASA and many others estimate that we have as little as 10 years to greatly reduce present emissions if we are to prevent a warming effect that would spiral out of control with dire consequences for humans. In our daily lives, our carbon emissions derive substantially from our energy use. Since our houses represent about ½ of our energy consumption, then making our houses more energy efficient and consequently reducing their emissions is the single most effective step we can take.
A group called Architecture 2030 has evaluated the climate research and come up with benchmarks for the construction industry that, if followed, will theoretically get us to the required reductions. They present their plan as a challenge, the 2030 Challenge. We are signatories to that challenge. The specifics can be reviewed here: www.architecture2030.com. The summary is that we have agreed to design buildings right now that will be at least 50% more energy and green house gas (GHG) efficient than the code mandated norm for our region. This percentage goes up yearly so that in 2025 we agree to design buildings that represent a 90% reduction. We have gone a step further and decided not to take an incremental approach. Our goal is to meet the 90% reduction as soon as possible.
Luckily for us, this isn’t a new idea. People have been creating buildings meeting this performance benchmark for a number of years. There is an international performance standard called Passive House that defines a clear prescriptive approach to creating designs at this level. The trick for us is to (1) apply these principles to the specifics of our climate and (2) make a 90% increase in energy efficiency affordable to people used to paying for inefficient buildings.
Too often, however, science-driven initiatives seeking
to maximize performance result in a finished product that is more
science project than home. We've has taken a different approach.
Our concept is to provide the efficiency and carbon reduction mandated
by our present environmental
crisis through a combination of high-tech building science and a
return to low-tech techniques such as site-harvested materials,
on-site food production, and an increase in outdoor living. The
resulting urban homesteads can actually surpass the energy, resource,
and environmental performance of their modern technology-focused
cousins while regaining some of the decentralized self-sufficiency
of the American homestead of the early 20th Century.
In summary, our design goals are to merge state of the art building science and technology with natural and local building materials in a package that is a contribution toward a sustainable built environment for all of us. Here are the basic housing components we have determined are necessary to achieving these goals:
Since the sun is both the energy source the fuels the earth and the
one site variable whose behavior we can predict with precision, all
design should begin by considering the sun. Passive solar design is
the conscious manipulation of the sun’s direct energy to affect the
temperature inside a building. The Nauhaus concept begins with a consideration
of how to best use the solar resource in the given situation.
The majority of energy used in a house goes to space heating and cooling. The better we can maintain interior temperatures, the less we have to heat and cool. Therefore, we specify insulation levels far in excess of code mandates. R-20 to 40 under slab (code doesn’t require sub-slab insulation), R-35 to 40 in the walls (code = R-13), R-60 in the ceiling (code = R-38).
Air-tightness goes hand in hand with super-insulation because it doesn’t matter how much insulation you have if air is leaking in or out around it. By creating an extremely air-tight building, we can greatly reduce heat loss or unwanted heat gain.
Thermal Mass In our climate, nights are always cool during the hotter months. A “thermal mass” is any material that stores heat well. By installing more interior thermal mass in a building, we can capture that nighttime cool and use it to stabilize interior temperatures during the day when it is hotter outside. This same thermal mass can collect and store heat from the winter sun that is allowed into the building through south-facing glass filled openings (windows and doors).
Conventional windows and doors have dismal R-values (R-1 to R-3) and are leaky. Sticking an R-2 window in an R-40 wall won’t get us towhere we want to go. We specify high efficiency windows and doors with R-values in the R-7 to R-12 range with excellent air leakage ratings.
In order to maintain a healthy indoor environment, all buildings need to provide a constant supply of fresh air. Natural ventilation (opening windows placed to maximize ventilation) is our first strategy. However, for those times that indoor air is being heated or cooled (in our case dehumidified, see discussion below), this strategy won’t work. In order to be energy efficient, we need to create air exchange while keeping a temperature differential between indoor and outdoor air. This is accomplished by closing our airtight, efficient windows and using an efficient ventilating fan that has a heat exchanger to create air exchange with minimal heat loss. This unit is called an ERV (energy recovery ventilator).
By creating an airtight, super-insulated, massive building shell, we have radically reduced our heating and cooling requirements, known as heating and cooling “loads”. By incorporating passive solar heating and cooling into our designs, we can satisfy some of these loads without any added energy input. As a combined result of these measures, our active heating and cooling systems can be small and hyper-efficient:
Heating. Based on variables such as site conditions, building layout, and client goals, we choose between two heating system options. Both use solar energy to provide most of the heat:
Solar Thermal. Solar collectors heat a liquid that is moved to a storage tank. This energy is used both to heat water for domestic use and to heat air to warm the building. This space heating is accomplished by running the hot liquid through a heating coil in the ERV duct. The ERV fan then moves the warm air where it is needed. Back-up heat is supplied by a tiny electric resistance, gas, or wood heater.
Solar Electric. A very small ductless heat pump (mini-split) and a heat pump water heater are installed to heat air and water. Since loads are small, electricity for these systems can be provided with solar electric panels (PV).
Cooling. Comfort is a function of several variables including air temperature and humidity.
Our nights are cool during the cooling season. Because our super-insulation
creates such a low cooling load, we can use our ERV as a whole house
attic fan to access cooler nighttime air to lower the temperature
of our interior mass, thereby creating a comfortable temperature
without mechanical cooling. Still, the air will sometimes be humid,
so we’ll need to dehumidify. A whole house dehumidifier should use
about 20% of the energy of a conventional air conditioner, so we’ll
achieve the same comfort with an 80% reduction in energy use. If,
however, the given situation warrants AC, then we would choose the
second heating system option above and install an efficient mini-split
both heats, cools, and dehumidifies.
A ZNE building is one that produces at least as much energy as it uses.
A CN building takes that a step further by creating enough supplemental
energy through its service life to offset the carbon emitted as a result
of its construction. These thresholds are reached by including on-site
renewable energy production, such as solar electric, wind, or hydro,
as part of the house’s integrated systems. By adding daylighting (part
of passive solar design), low energy bulbs (compact fluorescents right
now, but super efficient LED’s are on the threshold of affordability),
and very efficient appliances, our household electrical load will be
small enough to make these technologies much more affordable. Therefore,
a Nauhaus is designed to be ZNE and CN ready.
In other words, the renewable energy systems will be part of the design
included in initial construction or installed easily at a later date
when funds are available.
Reducing the energy consumption and GHG emissions of a building during it’s use is only part of the equation. We also need to be conscious of the impact of the construction of the building. By using local and site-harvested materials as much as possible, we can reduce the environmental construction footprint of the building. We specify local materials and direct the production of site-harvested materials whenever possible.
Energy isn’t the only resource we need to conserve. Clean water is becoming the next global issue. Our present societal systems approach is to dump everything imaginable into water and then go to great lengths to clean it up only to dump the same things right back in. This process creates an endless polluting cycle with dire consequences. Our approach is to first reduce demand through careful plumbing planning, installation of efficient fixtures, and inclusion of a raincatchment system in all designs. Next, we simply don’t pollute the water by educating clients about appropriate soaps and cleansers and specifying composting toilets where applicable. Finally, we reuse water by including greywater systems where legal.
Another component of environmental construction impact is the lifespan of a building. The longer a building lasts, the longer we can postpone the energy and carbon investment in constructing a new one. In Europe it is not uncommon for buildings to be in active use for hundreds of years whereas in the US it is common for a building to last only 35 years. Long lasting buildings have two characteristics: durability and flexibility to adjust to changing use requirements. Our goal is to create buildings that meet both of these criteria and consequently are in active use for a long time. One of our mantras is “the 500 year house”.
All of this performance enhancement is useless if the building isn’t a healthy nurturing place to be. As a result, we go to great lengths to make sure the building has excellent indoor air quality. We have a very good start because the efficient building envelope / ventilation / dehumidification strategy already outlined creates clean, comfortable air without drafts. In addition, we specify either site-made or commercial non-toxic, natural finishes.
We see a house as made up of indoor and outdoor rooms with transitions between them. In our climate, outdoor living space is luxurious, useful much of the year, relatively inexpensive to build, and fosters a healthy connection to nature. By integrating outdoor space with indoor space, we can create a smaller house that feels larger. We also gain a vibrant landscape that produces food, provides habitat, attenuates air movement and sunlight to increase building efficiency, and manifests a canvas of sounds, sights, smells, tastes, and feelings that change with the seasons.
Beauty for us isn’t an abstraction. It’s a tangible design category as important to the function of the building as anything else. Our goal is to create buildings that nurture people and help foster community. Of course, beauty is subjective, so a particular building can’t realistically be beautiful to and therefore appropriate for everyone. Our particular aesthetic pallet includes thick exterior walls with undulating plaster surfaces, large roof overhangs, ample natural light in all rooms, smooth transitions between indoor and outdoor rooms, and a variety of edges between outdoor living spaces and the planted and natural environment of the site. However, our performance standard does not demand a particular aesthetic and we are working on finish packages that will span the gamut of personal needs and tastes.
It’s safe to say that most people would love to have what we’re describing: a beautiful house that costs almost nothing to run and is connected seamlessly to a wondrous, productive outdoor landscape. However, you can’t get drastic performance increases without paying more per square foot. It’s our mission to make these buildings affordable for as large a cross-section of our population as possible. Here’s our strategy:
Engineering. Our system is flexible and can accommodate different wall system construction
approaches. We currently have three options on which we have done
a cost comparison analysis. In addition, we are creating customizeable
repeatable designs to lower design costs and allow a level of
construction drawings not common in residential construction.
This means that more of the thousands of decisions required to
complete a house will be defined at the outset, therefore increasing
efficiency, reducing confusion, and allowing more accurate cost
estimating from the contractor. Initially we've focused on a single
family home paradigm, but our goal is to help the construction
industry retool for carbon neutral design and construction across
the board: commercial, mixed-use, low-income, municipal, etc.
Square Footage. Our approach of combining indoor and outdoor rooms allows a smaller indoor
footprint to deliver equivalent useful living space to that of
a larger building. We call this “functional square footage”. Since
outdoor rooms are less expensive to build, our functional square
footage price will be substantially lowered in comparison to the
price for our interior square footage alone. This will bring the
overall price of our buildings more in line with their conventional
counterparts which consist solely of indoor space.
Shift. Of course, construction costs are only one component of the complete cost of
a building. Better efficiency and durability mean lower utility
and maintenance costs. You start saving money immediately when
you move into a Nauhaus. In the end, we intend to be part
of an educational movement that adjusts the present short-sighted
definition of “cost” to include the financial, environmental,
and social costs of the entire life-cycle of the building. We
feel strongly that this paradigm shift is a prerequisite for moving
toward a sustainable built environment locally and beyond.
Performance values, cost estimates, and aesthetic renderings are only
theoretical. Their manifestation in the real world requires careful
follow through of the design in the construction process. There are
presently no local codes or regional certification programs to guide
builders to realize the performance standards inherent in the Nauhaus
system. Therefore, it is important that we help the building trades
understand and adjust to high performance construction practices.
We are working to establish training sessions for builders and a tie-in
to the local Healthy Built Home certification standard.
Right now, we are careful to help clients choose builders who have the
skills required to carry our designs through in construction.
Our goal is not only to make high performance, low-embodied-energy carbon neutral
construction a reality, but to make it affordable
to a large cross-section of the population. In the process, we’ll
help to solve the climate change problem while improving the quality
of life for all involved.