Breathing Easy

Indoor air quality takes centre stage in Seattle’s High Point redevelopment
by Dr. Matthias Krups

High Point is a residential redevelopment in the state of Washington, United States, that is transforming an outdated low-income housing project into a progressive community setting new benchmarks in sustainable design. The development counts 1,600 healthy homes for a range of incomes and ages and features environmentally friendly drainage, landscaping and an array of community services. It also includes a new housing concept: “Breathe Easy Homes” are designed to provide optimal indoor air quality for children with asthma conditions.

Air pollution is well-documented in many parts of Asia. An estimated four-fifths of China’s largest cities have unacceptable air quality. The estimated number of premture deaths in China each year directly attributable to air pollution ranges from 250,000 to 300,000.

Less well-known is the fact that chronic pulmonary problems are also prevalent in other parts of the world, including North America: asthma is the leading chronic illness of children in the United States. Between 1980 and 1994, asthma among preschool children grew by 160 percent—that is double the rate for the overall US population, according to one study.

To address this health issue, the Seattle Housing Authority teamed up with the King County Health Department and the University of Washington’s Department of Environmental and Occupational Health Sciences to implement a long-range program designed to measure the effects of improved residential air quality, hoping to reduce the occurrence of asthma attacks in children. The result is High Point’s Breathe Easy Homes program. Although all High Point housing will qualify for the local 3-Star Built Green certification, many units exceed those standards, placing even greater emphasis on protecting indoor air quality and on using energy and other resources efficiently.

Thirty-five High Point homes have been built to Breathe Easy specifications and made available for rent to low-income families. These homes have special features to improve overall indoor air quality and reduce indoor air pollutants (see figure on page 24). Residents will take part in a study into the impact of new ‘green’ construction methods on incidence and severity of asthma attacks. According to Brian Cloward of Mithun, the architectural firm responsible for the homes’ design, High Point’s Breathe Easy Homes program is the largest and most comprehensive of its kind in the US.

In pursuit of the best indoor air quality
Nearly all rental units at High Point will be built to meet the US Energy Star standards, which establish some basic air quality improvements. (Energy Star is a US-government-backed program helping businesses and individuals protect the environment through superior energy efficiency.) Energy Star requires the careful air-sealing of all units, followed by testing to ensure the sealing was done properly. Because construction crews know their work will be tested, overall quality tends to be high.

The Breathe Easy rental homes are designed to minimise exposure to indoor and outside asthma triggers, which range from formaldehyde and volatile organic compounds (VOCs) to mould, dust and insect remains. (VOCs are substances that easily convert to gas at room temperature, harming inhabitants when inhaled.) Crews use low-VOC paints, adhesives, caulks and other materials whenever possible, and they avoid using materials that contain formaldehyde. True linoleum, a natural flooring product that is easy to clean, is used throughout the units except on stairs, where low-pile carpeting is installed.

Windows can be opened, but they all seal firmly when shut. The houses are equipped with positive-pressure ventilation systems with air filters, tempered fresh air supply and heat recovery. Radiant hydronic heating reduces airborne particles and organisms often associated with forced-air heating systems. Landscaping consists of plants that do not produce much allergytriggering pollen.

Asthma prevention measures even extend to rules on how builders and residents should behave. Construction crews are not allowed to smoke inside the buildings and they have to clean thoroughly as they work. Residents are not allowed to keep furry pets, smoke cigarettes or use certain aggressive cleaning agents. Before a family moves in, the housing agency steamcleans all upholstered furniture and provides the family with a new filtered vacuum cleaner.

A look at costs
Because much of the housing at High Point is for families of low or modest income, the housing authority was careful to invest in green strategies only where they make economic sense. Mithun estimates that construction costs of a Breathe Easy unit would be no more than US$7,500 higher than a conventional rental house of similar dimensions.

Low-allergen, drought-tolerant plants and low-VOC paint cost the same as standard options. For some purchases, such as the heating system and the linoleum floors, the initial costs were higher but longterm costs should be lower. The heating system should yield energy savings: it uses a gas-fired, tankless water heater to supply wall-mounted radiators, enabling residents to heat only the rooms they are using. Also, the fact that the same water heater supplies water to taps makes the system efficient to operate. Finally the linoleum floor is wearresistant- it should last for at least for 40 years.

Careful planning and coordination
Before construction could begin, the old buildings had to go. Rather than simply bulldoze the lot, the housing authority had 22 buildings taken apart by hand to assess what was salvageable for reuse. This enabled them to gauge what quantity of materials might be salvageable once the main contractor started a general demolition.

The construction details at High Point pay off in a variety of ways. Builders get Built Green points for using advanced framing techniques that use less wood. With fewer studs, the buildings become more energy efficient because more wall space is covered with insulation. Drywall is not fastened to as many studs, so it is less likely to crack. Builders also get Built Green points for installing airtight drywall, which saves energy. Airtight walls let less dust inside and stop airflow that can contribute to mildew and mould, which in turn improves indoor air quality.