This is a guest article by Peter Marciano.
Our History of Wasteful Buildings
As readers of The Automatic Earth, we are all aware of the systemic collapse that rapidly approaches on the horizon. How we preserve our resources and prepare for what’s ahead has to be the priority for us all. Before we can consider alternative energy generation or sustainable living, we need to focus on our homes and how they can be built, or rebuilt, to perform in a truly energy efficient manner. Take care of shelter first, and all other things will follow.
The “green building movement” has been compromised and rendered largely counter-productive, since it feigns the illusion of “progress” when no progress is made. The market has been flooded with ideas and products that are unproven and building rating systems that are untested. The sad truth is that buildings we’ve built in the last few years have not proved to be any better at conserving energy, or to be less costly to operate than the buildings we built decades ago.
“Building energy use is probably the largest field of human endeavor in which almost nobody measures anything”
As consumers, we lust for products and gadgets. We want solar panels, we want windmills, and we want green roofs. Too many of us have been seduced by government tax credits, product advertising or unknowing building professionals who tell us that being green needs to be complex and costly, or that, by simply “throwing up some solar panels” or installing a green roof, we can solve our problems.
Nothing could be further from the truth, though. Focusing on true cost-saving energy performance should be our most important consideration.
The photos above and below are of an “energy efficient” heating system in a newly renovated single family home. This system was incredibly costly and complex to design and install and is very expensive to run. We have to consider that in the future it may not be possible to find parts to repair and maintain systems like this, and, most importantly, we have to realize that generating enough off-grid electricity to run these overly complex systems will be next to impossible.
For a fraction of the cost, the owner could have insulated and air sealed the building enclosure, thereby eliminating, or greatly reducing a lifetime of maintenance and energy costs. We need to replace complicated, costly and untested systems with simple, proven materials and methods that make up the most basic, yet the most important, foundation of energy conservation in all buildings and shelters – the building envelope.
The Critical Building Envelope
The majority of our energy consumption in this country is expended on heating, cooling, lighting and ventilating our buildings. Energy use in transportation, including automobiles, and industrial production does not even come close to the amount of energy our buildings consume to provide heat, AC and lighting. Our focus should be on how we can reduce that level of energy consumption, while also producing a durable and comfortable built environment.
Our understanding of buildings, i.e. how they are assembled and how they perform, needs to be challenged and revolutionized. We have built homes, offices, schools and businesses from entirely the wrong perspective for decades. Investing in the building envelope by air sealing and insulation is the basis of all sustainable, comfortable and durable design.
We need to follow the common sense, proven principles of thermal and air management in order to substantially reduce the heating and cooling demands of our buildings. Then, and only then, can we drastically reduce the size of our heating and cooling plants or perhaps eliminate them altogether.
If we want to make self-generated energy sources such as wind, solar electric and solar hot water start to make any financial and practical sense at all, we need to eliminate complex, costly and over-sized heating and air conditioning plants. Keeping down the costs of installing these alternative energy systems is a critical means of ensuring their viability.
The building envelope is the key to understanding a building’s efficiency and, in a way, it is also the key to our ability to survive the upcoming financial and industrial crises. Proper insulation, air sealing and ventilation are not new concepts; the Germans perfected the idea with their “Passive House” system over 20 years ago. Passive House buildings are based on proven building physics with stringent air tightness levels and honest insulation values that deliver buildings which use, on average, 80 to 90 percent less heating and cooling energy.
A true passive home would be one that has its heating demand so reduced that all the heat requirements of the building are met by passive solar gains (from direct sunlight) and internal heat gains (from the occupants and appliances) which get distributed through the building by a simple Energy Recovery Ventilator (ERV) system. In some cases, no additional heat source is ever needed.
In an ERV, the warm exhaust air heats the incoming cold air through a heat exchanger (high efficiency ERV units are now available here in the US). The Passive House requirement for their certified buildings is to have an air barrier so tight that there are only 0.6 air changes per hour at a 50 pascal pressure difference (about a 25 MPH outdoor wind). Compare that to most buildings in the United States – those that I have tested have varied from 7 to 14 air changes per hour!
This essentially means that every hour the entire cubic volume of air inside your house is potentially being replaced with outside air up to 14 times! You are heating this air only to have it escape to the outside almost immediately. Needless to say, this rate at which we lose conditioned air from our buildings is absolutely alarming and tremendously wasteful. We, and the planet, are paying dearly to heat and cool the vast outdoors (where it benefits no one) and, all the while, we are still not maintaining a comfortable interior environment for ourselves.
How many of our buildings are over heated in the winter and over cooled in the summer to simply compensate for leaky construction? My experience tells me that this is almost always what is happening. One solution could be that we build and renovate to the Passive House standard, or at least close to their standard. However, I am not suggesting that we make such a large-scale effort now, but rather we must look to smaller and more practical bottom-up changes.
Adopting and Applying What Works
In fact, it may be too late for us to adapt and apply the German model on any significant scale before life as we know it comes apart at the seams. What I am suggesting, instead, are several simple, cost effective steps that we can implement immediately to make our collective futures comfortable, much less costly and more prone to surviving and thriving. In order to accomplish these goals, we must take ideas from Passive House and other proven scientific building methods and incorporate them into our homes and buildings. Below are some of the basics we must learn:
1. Insulation – The material that does all of the heavy lifting, in total silence and without any operating costs or maintenance. In most cases the ideal location of the insulation is on the outside of the structure (think: we have built everything inside out) and it could be made from rigid materials. such as polyisocyanurate or extruded polystyrene sheets.
These types of insulation are readily available and can even be sourced used. It can be installed by an unskilled workforce with minimal tools and supervision. By placing the insulation on the outside of the structure there are two obvious benefits:
(1) The building structure is kept warm in the winter which allows it to retain the heat up and radiate it back to the inside.
(2) The building structure is kept cool in the summer thereby preventing unwanted heat gains from entering the building’s interior.
We can reduce our building energy loads substantially by relocating the insulation to the outside in a continuous plane. Exterior insulation keeps the structure at a constant temperature, limiting extreme temperature swings. Possibly the most important benefit is the level of comfort you will experience inside your home. If the insulation is installed correctly, you will have never have to worry, even without a central heat source, that the temperatures inside will drop so low you will freeze, or rise so much that you will be uncomfortably hot. This is also an extremely valuable psychological benefit.
2. Install an Air Barrier – How we handle air transmission through our exterior wall and roof assemblies is critical to both the building envelope performance and to energy savings. There are many inexpensive ways to control air movement, and even though each situation is different, the basics remain the same. Stop the rapid and wasteful cycling of air through the walls and roofs of our conditioned buildings and you stop the rapid loss of energy.
Using rigid insulation and taping the seams is one way to regulate air transmission, but there are also air barrier paints and house wraps that can be applied on the structure. Air sealing can also be done by installing sealants on the interior studs at the same time you install the drywall, “gluing the drywall” to the stud. Interior plaster (not stucco or joint compound) can also serve as a good air barrier.
Defects in these barriers can obviously create air leaks. I am not spending time on the physics of green buildings here, but it’s important to understand that heated air contains moisture vapor and that will cause defects in the air barrier. So it should be held to a minimum to prevent that moisture-laden air from reaching the outer, colder surface of the building structure. Air sealing will require more supervision and skilled labor than insulation to install successfully.
The photo above shows a fantastic example of an energy efficient historic renovation. There are “peel and stick” air and water barriers in place under the roof shingles. Insulation has been placed on the exterior walls with all joints taped and sealed, and all flashing was done correctly with pre-painted wood strapping ready for the pre-painted wood siding. It was a renovation project that was durable, sensible and efficient.
3. Proper Ventilation – Our buildings, especially our larger apartment buildings, offices and homes, are over-ventilated. Large mechanical ventilation systems are very wasteful. They are costly to install and maintain and use excessive amounts of electricity to operate. In addition to their inefficiency, the ventilation systems are constantly removing the heated or cooled air from the building.
The old myths about making “airtight” buildings has always been that it’s “unhealthy”. That is not true for several reasons. The first is that we have never accomplished building airtight buildings, and the second is that we have over-ventilated them to a point that they circulate unhealthy stale air throughout our apartments and homes. If we do focus on air sealing, then ventilation becomes easier to manage.
An ERV (energy recovery ventilator) or HRV (heat recovery ventilator) can provide 100 percent fresh, filtered air to your home while extracting the stale air at a specific rate. These systems are not complicated. They are healthier for the occupants and are inexpensive to purchase and operate. In addition to eliminating the loss of air through over-ventilating, the HRV captures the heat from the exhaust air and tempers the incoming air, thereby acting as a heat distribution source.
4. Windows and doors – Look for what is sensible and forget about using double hung windows or sliding windows and doors because they leak too much air. Look for a more airtight casement or awning window with the best possible rating on the double glazing. Remember the glazing and frame of the window is a part of your continuous air barrier. Connecting the air barrier to the window frame is critical. A properly air sealed, double glazed, American made, casement window will outperform even the most expensive triple glazed European windows that are not properly installed.
To summarize, there are essentially five inter-related things that must be considered when constructing or renovating a building:
(1) Water/rain barrier – The function of a rain barrier is to keep liquid water from entering the building enclosure. Combined with flashing and other materials, the rain barrier ensures that there is a shingled assembly to direct liquid water to the exterior. A single material can function as the air barrier, vapor barrier (non-permeable air barrier), and water barrier.
(2) Insulation barrier (example of one product that can be used) – PERMAX™ by Henry is an advanced spray polyurethane foam (SPF) technology offering design professionals, building owners, property managers and OEM (Original Equipment Manufacturers) significant benefits including Increased thermal performance of roofs and walls, applicability to a variety of OEM applications, sustainability of the building envelope, waterproofing, non CFC, non-ozone depleting technology.
(3) Air barrier – An air barrier must first and foremost resist air leakage. Air leakage loads are significantly greater than most designers and architects realize. In the past, many materials were considered suitable air barriers, including building felt, concrete block, building wraps,and gypsum wallboard. A more enlightened understanding of the physics of air movement demands a more aggressive solution.
(4) Vapor barrier – Vapor barriers limit the amount of water vapor diffusing through the wall as a result of different vapor pressures. With the advent of modern building science, it has been found that air leakage – and not vapor diffusion – is the real problem. In fact, air leakage accounts for over 200 times the amount of moisture transmitted by diffusion.
(4) Ventilation – Highly efficient ERVs and HRVs can be purchased at low cost and replace the wasteful mechanical ventilation systems that many buildings currently use.
These are the bare minimums that even poor quality, code compliant construction dictates. You are not adding anything new to the mix. When building and renovating, you will be paying for and installing some type of insulation, water and drainage barriers, air barriers and ventilation anyway. Having an understanding of just where these various elements should be placed and how they should be installed will dictate how well your building performs from an energy standpoint.
Reducing Energy Costs While Building Communities
Large apartment buildings that have one central heat source are, for the most part, more energy efficient than single family dwellings. Higher density occupancy uses less energy and incurs less energy costs per square foot than people scattered throughout suburbia struggling to heat their homes and McMansions and fuel their SUV’s. Our large apartment buildings are all in cities, close to public transport and what’s left of the employment market in this country.
The survivability in the city will change if there is a systemic collapse of the financial, energy and transportation systems. There will be no funds available to support the infrastructure that makes cities livable, but we should still explore medium to higher density urban living by rebuilding communities that are all but abandoned along rivers and those canal systems which still exist.
Places like Troy and Utica, NY come to mind, because the housing stock and the structures are there even if the community may not be. The idea of “community” housing has all but been ignored in the United States. It conjures up images of poor people, shared kitchens, bathrooms, hippies and bedbugs. But, in reality, community based living is exactly what our large apartment buildings are made to be.
Consumers and real estate developers find it beneficial to call them condominiums or co-operative apartments, but, regardless of the specific label, we are all breathing the same air under the same roof. Buildings that house multiple families reduce operating and energy costs, nurture relationships and can foster a sense of community. Sharing the expense as well as our collective expertise in building shelter is just one more way to move forward in a period of rapidly contracting wealth.
Cluster housing or “co-housing” would allow individual family housing units to be built while creating common facilities that are shared by all. Co-housing is a great way to promote and energize our sense of community, since it will be developed around the common idea of shelter as a bonding experience. Co-housing could also be built on shared land and must be highly compact in design, leaving the majority of the land open for farming or work.
The compact designs would focus on simplicity, highly energy efficiency and would incorporate one foundation, one heating source and one water supply to service multiple family units. Co-housing clusters would share common elements like workshops, some living and community space, barns, tools and even automobiles and machinery.
A more large-scale and popular initiative is captured by the concept of “net-zero” homes and buildings. For example, California’s Energy Commission has developed a program to transition buildings towards zero net energy use, through both energy efficiency strategies and the use of on-site renewable power. The goals of these initiatives are a bit “pie in the sky”, especially with regards to renewable power and at large scales, but they still offer important information and avenues to help people and businesses reduce their energy costs.
“Achieving ZNE begins with an efficient building energy design. A building design that factors in environmental characteristics and building features to maximize passive opportunities to reduce energy needed for heating and cooling is arguably the most cost-effective strategy for improving building performance and a logical first step toward making ZNE building a reality.
Design concepts that consider climatic characteristics of a region such as weather and seasonal temperature variations, and site-specific optimization, including orientation, daylight, shade, and prevailing wind, can significantly minimize building energy demand.“
It’s time to start putting together a team that can form your future community. Right now, each of us is surrounded by people who have ideas, knowledge and skills that can be shared. Builders, mechanics, bakers, farmers, herbalists, welders, fisherman, engineers, acupuncturists, solar panel system designers, doctors, electricians, equipment operators and veterinarians, to name but a few, are existing all around us and ready to work together with us in productive ways.
Everything that I have touched upon here is based on using tested and proven methods and ideas to simplify and develop functional, comfortable buildings. Anyone can use this information in a variety of ways in order to get the same essential results – safe, comfortable and energy-efficient “green” buildings that will form the basis of future living arrangements within many of our communities.