HOW HEALTHY IS THE AIR IN YOUR HOUSE?

by Michael Gotthelf

During the first half or so of the 20th century, when energy was relatively inexpensive and insulation and weather-proofing were relatively unknown, indoor air quality was not much of an issue. This is because the homes of that era naturally replaced air through cracks in windows and walls. Since mid century, homes have become increasingly tighter. The increasing popularity of foam insulation and more effective air sealing practices has increased this trend.

The building and energy codes over time have ever increasingly required that new homes and modifications to existing homes be constructed in a much more air tight manner. Poor indoor air quality can be an unintended consequence of current energy efficient construction if careful planning and consideration are not undertaken.

In a poorly built or maintained home, moisture and mold, carbon monoxide, VOC’s (Volatile Organic Compounds) can easily build up within the home to make the air less healthy than a smoggy day outside in a big city.

A home needs to breath. It needs to change out the stale air of breathing and living and also the build up of particulate matter and gases from all manner of sources within the home for fresh air. If a house was made too tight, it will require mechanical (or passive) ventilation to provide a healthy quality of air. There are many ways to do this. A fresh air makeup can be easily added to a HVAC system. For an additional cost, an Energy Recovery Ventilator can be added to capture some of the energy lost be expelling conditioned air to the exterior. (Note that before you invest in an ERV, though, there are other investments you may want to consider for a higher energy saving return on investment.) Remember to open your windows in the spring and fall and when the humidity and pollen count is not too high; the air outside is probably cleaner than the air inside.

To determine with some certainty whether your home requires mechanical ventilation, you may want to get a blower door test. A blower door test will tell you how tight your home is and can assist inform your remodeling decisions particularly related to the home’s energy efficiency. Think about getting a blower door test in conjunction with planning for a renovation.

For more information about blower door tests, see:

http://www.energysavers.gov/your_home/energy_audits/index.cfm/mytopic=11190

MOISTURE & MOLD
• The building code requires a bath fan or a window in each bathroom for good reason. Make sure each and every full bathroom has a bath fan, ducted to the exterior, not into the attic. Install fans with a timer to allow the fan to run long enough after a bath or shower to properly vent humidity from the room.
• You may not think of it, but top loading washing machines add a lot of humidity to the home. When it’s time to replace your washer, choose a front loading, energy and water efficient model instead of a top loading one.
• Make sure your gutters are properly sized, clean and your downspouts direct water away from the home. Ensure your property is graded to direct water away from your foundation. This will limit water infiltration into your basement.
• Ensure your crawl space has a proper vapor barrier on the floor or better yet, a slab. Crawl spaces need to be either insulated and conditioned or properly ventilated. Insist that your contractor get this right!
• We do not recommend wall vapor barriers, especially in an environment such as in Washington, D.C. In a cooling environment such as up North, where human activity in the home leads to a good deal of humidity, a vapor barrier is sometimes installed inside of the insulation.
• If you still have persistent humidity in your basement, set up a dehumidifier, hard piped to a drain.

VOLITILE ORGANIC COMPOUNDS
• Remember those FEMA trailers [http://www.msnbc.msn.com/id/14011193/] provided to victims of hurricane Katrina? The formaldehyde laden plywood and insulation which sickened so many people, is not much different from what’s used by many contractors without much thought. Though formaldehyde forms naturally in wood, it is also a component of glues used in plywood. Insist your contractor uses CDX (exterior grade pressed) plywood instead of OSB (oriented strand) for sub-floors since CDX contains less added formaldehyde. See: http://www.epa.gov/iaq/formalde.html
• Insist on low or no VOC paints and caulks from your contractor. Acrylic paint technology is improving by the year.
• Drywall is often glued as well as being fastened with screws. Many commercial drywall adhesives contain nasty chemicals such as xylene. Insist that your drywall contractor uses adhesives with low VOC’s.
• Choose water based wood floor finishes rather than oil based ones. There are several excellent low VOC products available.
• Choose kitchen cabinetry made from plywood (CDX) rather than particle board.
• Make sure that if you or your contractor uses fiberglass insulation for your renovation, it is the formaldehyde free type such as from John Manville.

GAS APPLIANCES
• Ensure your gas appliances (cook-tops, fireplaces, water heaters, dryers, furnaces, etc) are operating properly and are properly vented to the outside.

FIREPLACES
• That nice smell that emanates from the fireplace in winter is not really good for you. In addition to carbon monoxide and carbon dioxide, wood burning fireplaces can bring into your home unhealthy particulate matter in the form of smoke. http://www.epa.gov/woodstoves/healtheffects.html

ATTACHED GARAGES
• Attached garages contribute to poor indoor air quality throughout the home and are not recommended. Install an exhaust fan in your garage to duct carcinogens from your cars exhaust to the exterior; avoid parking your car in a garage or best of all, do not build a garage that is attached to your home.

DUST & CARPETING
• Avoid wall to wall carpeting. If you’ve ever lived with hardwood floors or tile you know how much dust you can sweep up in a week. If you’ve ever removed carpeting from a house, you may also know how much can collect in carpets, despite frequent vacuuming.
• Install a HEPA filter attached to your HVAC system or a media filter high MERV (Minimum Efficiency Reporting Value). Look for a filter with MERV rating of 10 or higher.

LEAD
Lead paint wasn’t completely phased out until 1978. Know that if you have house built before 1978 and especially one built before 1960, you can anticipate your home has some lead paint. For your safety and the safety of your children, ensure your painting contractor takes all necessary precaution when prepping and sanding old walls.

http://www.epa.gov/lead/

ASBESTOS
Asbestos is a naturally occurring compound, named by the ancient Greeks and used since antiquity for everything from fabric to more recently, shipbuilding, drywall compound, roofing and siding, insulation and floor tiles. It may come as some surprise that Asbestos was not banned in the US until 1989, though there was good scientific data going back decades and anecdotal evidence much further that asbestos is cancer causing. Asbestos is still used in the developing world.

The history of asbestos is emblematic of the glacial pace of change when money and big business are involved.

Many, many homes still have asbestos, most commonly as siding and basement floor tiles, but also pipe insulation. Before determining whether your asbestos should be removed, consult a professional. If asbestos is in a place which is not likely to be disturbed, in some cases it may be better to leave it. Products such as pipe insulation can be encapsulated as well as removed. Asbestos must be removed by a trained and qualified specialty abatement contractor.

http://en.wikipedia.org/wiki/Asbestos

http://www.epa.gov/iaq/asbestos.html

For more information about indoor air quality, visit the EPA website and World Health Organization website.

http://www.who.int/indoorair/en/

http://www.epa.gov/iaq/

Also we recommend the book Green Remodeling by David Johnston

What is Green Construction

By Michael Gotthelf

In recent years a huge amount of media bandwidth has been committed to the idea of “Green” and especially to “Green” construction.  Spiking energy prices, growing awareness and concern over global warming, well publicized scares about chemicals in consumer products along with a growing awareness of the vast resources poured into the construction and life cycle costs of buildings in this country have all contributed to the attention. 

Forty years ago, Rachel Carson published the landmark book Silent Spring, but since then, the environmental movement has progressed at a slower increment pace when compared to better funded momentum of the consumerist lifestyle.

Now, Green is part of the consumer lifestyle. Corporate America, the arbiter of mainstream acceptability has marketed the color Green as a way to sell almost anything and everything; flip through almost any magazine and you’ll see the advertisements; turn on the radio or the television and ditto. It’s hard not to wonder what’s environmentally sensitive about a full sized SUV, even if it’s a hybrid, or Yogurt or a plasma television, but there you go. While it may be easy to dismiss Green, cynically as the latest trend in money production, the truth is that there are shades of Green and we all have a part to play. The movement toward Green is playing out in the public discourse in the same way that change in America always happens: we vote for positive change with our voices and with our pay checks. 

why is there so much focus on the greening of homes?  Most Americans spend the majority of their time indoors.  According to the US Department of Energy website, the average family spends approximately $1300 per year on energy and in the year 2000, homes accounted for 20% of the carbon dioxide emissions.  Residential construction and renovation have a huge impact on the economy, on the environment, on our culture as a whole and on quality of life. Home is the perfect place to start.

The Green concept in the construction industry has been championed by the US Green Building Counsel (www.usgbc.org).  Notably, they have created a LEED program (Leadership in Energy and Environmental Design) to identify and promote Green building practices and materials within the format of a scientific and deliberate process.  Until very recently, LEED only applied to commercial construction; now LEED has a new house and major renovation program.

The other most well respected large scale Green building organization is the Forest Stewardship Counsel (www.fscus.org). Another non-profit organization, it promotes sustainable forestry practices and has become the gold standard for certifying lumber as sustainably grown and harvested. 

After FSC and US Green Building counsel’s LEED program, there are a variety of other organizations, businesses and governmental agencies promoting Green, selling Green or taking advantage of Green. The Kitchen Cabinet Manufacturer’s Association (KCMA) has a program called the Environmental Stewardship Program (ESV).  The US EPA has a popular and successful program called Energy Star which certifies electrical appliances, equipment and fixtures as energy efficient, ultimately for tax credit purposes.

The array of products and companies billing themselves as Green is dizzying, but ultimately heartening.  There is a water piping certified by Greenpeace, companies salvaging and reselling building materials, insulation made from recycled blue jeans, LED lighting which lasts for 20 years and uses ¼ the energy of incandescent bulbs, tile made from recycled glass, solar panels that match your skylights, solar panels which heat your hot water, composting toilets, decks and roof shingles made from recycled plastic, systems for storing rainwater coming off your roof in huge buried containers for irrigation, dumpster companies which recycle, Green cleaners, wood framing members engineered to minimize waste, companies which perform energy audits and blower door tests and on and on.

With all of the conflicting information being set forth as fact, the most effective way to analyze the Green-ness of a construction project is to think in terms of a spectrum of Green. In the Green spectrum there are dedicated people and organizations and there are Green washers. As conscientious consumers, we all also need to do our research and to ask the right questions and to make rational decisions.  In the DC area, it’s pretty difficult to live in a tent and eat roots, nuts and berries, but we don’t all need to live in ten thousand square foot houses without insulation either. 

I would describe Green construction according to at least four ideas: (1) Energy Efficiency; (2) Indoor Air Quality; (3) sustainability; and (4) life cycle.  In analyzing a Green home, one might also include such important factors as: rational design with human scale as well as fair labor practices for the construction of the building. 

Ultimately, the life of a home is comparable to the life of a person: how the home is built, how it’s oriented, how it’s cared for and what one puts into it are all important.  A successful “Green” home has the same characteristics as a successful person: wealth, health, happiness and longevity.  Not coincidentally, these qualities correspond to the four ideas above. 

Energy Efficiency – Wealth (or Frugality)
Energy Efficiency is probably one of the first things you think about when you think “Green” construction.  It is also, not coincidentally, the aspect which can most easily fit into an economic cost / benefit model.  That is to say, for every dollar you spend on more efficient insulation, windows, HVAC equipment, water heater, lighting and appliances, etc. it is possible to calculate a payback period at today’s energy prices or at anticipated future energy prices.  Except for notable spikes in price, energy has been relatively cheap and plentiful in this country.  In the Washington, DC area the majority of the housing stock was built in the first half of the 20th century with inadequate and often no insulation, leaky windows and mechanical systems which guzzle energy.  Even if a homeowner plans to sell the house in two to five years, if the money is spent wisely, the cost of energy efficiency improvements can be recouped.  Moreover, a home with such upgrades is more comfortable to live in and easier to sell to a new owner.

Indoor Air Quality – Health
It often shocks people to discover that the indoor air quality in many homes can be many times worse than that in the middle of a little city park on a smoggy day.  This is because new homes are built more tightly than older homes and do not have the same number of natural air changes through gaps and cracks in the houses. While we no longer use asbestos and lead in building products, and oil based paints have been phased out in many areas of the country, there are still many reasons for concern. Volatile Organic Compounds (VOC’s) in paints, sealers, caulks, adhesives and finishes, chemicals in household cleaners, formaldehyde in pressed wood products and some other building materials, gas fired appliances and equipment, mold and mildew and VOC’s in plastics can all contribute to poor indoor air quality.  With careful planning, materials which off-gas less or not at all can be used instead of the more toxic ones. 

At the same time building sciences have created materials such as foam insulation which, though effective at saving energy, act as an air barrier and can prevent a home from breathing adequately.  Like people, homes need to breathe.  If a home is too tight, serious issues such as mold growth can occur. With careful planning, mechanical systems can be integrated into tighter homes to bring fresh air, filter out dust, pollen and other outside pollution and then to dehumidify or humidify the air as necessary. Energy recovery ventilators can also be added to capture some of the energy from the outgoing exhaust. 

Sustainability – Happiness
How does sustainability equate with happiness?  Sustainability is a broad term but generally it refers specifically to materials and methods of construction which seek to waste as little as possible.  The conscience of a Green building is in its sustainability and this aspect requires diligence and dedication.  It is much easier, after all, to throw all of the debris from demolition and construction into a dumpster; it’s a bit more difficult to find a dumpster company who sorts and recycles waste and ever more difficult for a contractor to sort and salvage or recycle debris. Likewise, it’s quite easy for an architect to over engineer a project, but it takes dedication and time to research and specify materials such as engineered wood beams or Trusses which stretch a tree to build more house.  Likewise, building a slightly smaller, better space and using fewer resources is a sustainable practice.

The equation, though, can get complicated when all of the environmental costs are considered.  Bamboo flooring, made from what is a quickly maturing and rapidly renewable grass can take a short time while an Oak tree can take decades to grow.  But you must also consider that the bamboo flooring may have been shipped from China and may have created pollution in the manufacturing process (not to mention contributed to our national debt).  Likewise, a compact fluorescent contains mercury, but I have been told that the mercury saved from being belched out by a coal burning plant is greater than the mercury in the bulb. The more you evaluate a product according to its hidden attributes, the consumption of energy and natural resources used in its creation and shipping  the clearer is the picture of a product’s sustainability.  That is to say: is it made from endangered baby seals? Does its manufacture pollute the environment? Are rain forests cut down to make the product? What is the likely end result after the products useful life is over? Does it last forever and stay in style forever or is it quickly dumped in a landfill or recycled?

Life Cycle – Longevity
Ultimately, a home or a home renovation which is sensibly designed and built to last with high quality building materials, well designed integrated building systems, thoughtfully selected finishes and a rational floor plan is a Green home. Renovation is a necessary and sometimes desirable process for all homes eventually, but the better a home is designed and constructed, the less likely that it, or a large chunk of it, will wind up in a landfill in the near future. 

Homes, like people, don’t last forever, but they can usually be made better with thoughtful care and good advice.  If we put good things in our homes they can enrich our lives.