2007 Year in Review
Green Building: More Popular Than the Beatles?
Due in large part to the huge focus on global warming, green building has finally made the leap to the forefront of mainstream building. The mainstreaming of green can be seen all through our society: from Brad Pitt talking about tankless water heaters and low-flow toilets on NPR to the federal government tax incentives for energy efficiency to leaders from 40 of the world's largest cities creating a plan under the Clinton Climate Initiative to adopt energy efficiency and green building guidelines within their own cities.
Austin Energy Green Building (AEGB) has seen huge growth in our programs this year. Here in Austin, the green building movement has reached a critical mass of architects, engineers, builders, developers, other professionals, and consumers. We've transitioned from creating market demand for green buildings to working with the leading edge of building professionals to provide the most successful and sought-after green homes and buildings in the market. And it's not just happening in Austin. The United States Green Building Council (USGBC) reports a ten-fold increase in membership since 2000. With over 60 chapters around the country, they now have close to 100,000 individual members and over 12,000 corporate members. In addition, the federal government, at least 20 states, and more than 60 U.S. cities already require new public buildings to meet green standards. It's no surprise that real estate and architectural experts believe that current growth in the green building market is not a short-lived trend, but the start of a permanent shift in how the world uses energy and natural resources.
AEGB's goal now is to lead the transformation of the built environment to a sustainable future. As green building processes and techniques percolate through the building industry and the public mindset, we constantly strive to stay ahead of the curve. In 2007, AEGB completed two important goals: we updated our rating tools and implemented major changes to the City of Austin energy code. We also spent a lot time guiding the first stages of the Mueller Redevelopment, see the next article for a Mueller progress report.
Rating Tool Update
All three programs, Commercial, Multi-family and Residential, made changes to their respective ratings. Because we intend rated projects to be significantly better than buildings built to code, our job is to set ever higher standards as building practices, codes and federal standards improve.
Commercial Rating Update
The Commercial Program fined-tuned its rating to better reflect the leading edge of green building in the commercial sector. For example, the new rating was specifically designed to award more points to projects located within the desired development zone, because they use existing municipal infrastructure and preserve natural resources.
Without focusing to closely on any one particular area, the Commercial Program staff raised the bar across the rating as a whole.
We also created the first comprehensive Commercial Rating Guidebook, which helps project teams better understand and meet our requirements.
The Results?
Nineteen commercial projects received ratings in 2007, including seven AISD schools. That's over 600,000 square feet of building space, nearly 4 million Kilowatt hours (kWh) of energy savings, over 200,000,000 gallons of water conserved from indoor uses, and over 3,000 tons of construction waste diverted from landfill.
The Commercial Program is currently working on 116 projects equaling over 13 million square feet. About two-thirds of the 116 projects are in the construction or commissioning stage and are due to be completed in 2008 or 2009.
Multi-Family Rating Update
The Multi-Family Program released the first major update to its rating. The Multi-Family Rating 2007 takes into account Austin’s recent growth in mixed-use development, updates to the energy code, and progress that has been made in the market. The new rating allows for both prescriptive and performance paths, accommodates a mix of uses within a development, and is the next step in moving the multi-family market toward achieving Austin’s climate protection goals.
The Results?
Twelve projects completed the Multi-family Rating this year, creating over 1,200 green rated units. Four developments earned 3-Stars. Currently, 34 multi-family projects are in process with over 3,500 units expected to rate in 2008.
Residential Rating Update
The Residential Program sought to improve home design by implementing a minimum requirement of 500 square feet of living space per ton of cooling for any rating. A home that cannot be comfortably cooled with a maximum of one ton of cooling per 500 sq ft of living space is not properly designed for the Austin climate. Homes seeking a 3-Star or higher rating are limited to 600 sq ft per ton of cooling. Five star homes must locate all duct work and mechanical equipment inside the home's thermal envelope.
The Results?
The Residential Program rated 981 homes this year. Of those, 12 were 5-star - just over 1%. Only 7 homes rated at 4-stars. It's not unusual to have more 5-star homes than 4-star. "Once people get the idea of what it takes to design and build a really green home, they skip right over 4 stars and commit to 5 stars," says Mary McLeod, Residential Program Coordinator.
The Residential Program devotes a significant amount time and energy to the affordable housing sector. All affordable housing built with any incentives from the City of Austin is required to achieve at least a one-star rating. This ensures that Austin residents with the most need get homes that are affordable to purchase and operate, are more durable and healthier to live in.
What Does This Really Mean for Austin?
In 2007, Green Building projects saved 23,733,000 KWh of electricity. Not only does this reduce air pollution by lowering energy use, it also conserves over 10 million gallons of water that would otherwise be used at power plants.
EPA tracks emissions of six principal air pollutants: carbon monoxide, lead, nitrogen oxides, particulate matter, sulfur dioxide, and volatile organic compounds. The table below lists the amount of each pollutant that was not emitted due to AEGB's work with local projects.
Green Building Air Pollution Reductions
| Pollutant |
Description |
Amount Not Emitted (lbs) |
Carbon Dioxide (CO2) |
Released when fossil fuels such as oil, natural gas, and coal are burned. |
30,704,517 |
Sulfur Dioxide (SO2) |
Released when fossil fuels such as oil and coal are burned. |
19,356 |
Nitrogen Oxides (NOx) |
Released when fossil fuels such as oil, natural gas, and coal are burned. |
21,402 |
Volatile Organic Compounds (VOCs) |
A precursor of ozone, the major component of smog. |
738 |
Total Suspended Particulates (TSP) |
Airborne particles or aerosols less than 100 micrometers, including dust, soot, and smoke. |
2,629 |
Carbon Monoxide (CO) |
Caused by incomplete burning of carbon in fuels. |
14,877 |
TOTAL |
|
30,763,519 |
 |
The kWh savings are effectively equal to:
 |
Planting 526,317 trees in Austin’s parks |
|
Removing 3,363 cars from Austin's roads |
|
Providing electricity to 2,381 homes in Austin for one year |
Changes to the Energy Code
On October 18, 2007, Austin City Council took the first steps toward meeting the goals of the Austin Climate Protection Plan by adopting the 2006 International Energy Conservation Code with local amendments. The amendments were developed by the Zero Energy Capable Homes (ZECH) Task Force, a stakeholder group led by AEGB and comprised of local construction industry trade association members, affordable housing providers, energy efficiency advocates, and City of Austin staff, among others.
Beginning January 1, 2008, the new City of Austin Energy Code will require that residential heating, ventilating, and air conditioning (HVAC) systems be tested for duct leakage, air balancing, and static pressure. Batch testing following Energy Star procedures will be allowed for production builders. The new code will require the submittal of Manual J documentation for HVAC system sizing, and the installation of Minimum Efficiency Reporting Value (MERV) 6 or better air filters. Testing the building envelope to reduce infiltration and requiring that 25% of interior lighting be high efficacy rounds out the major code changes. These measures, combined with the new code requirement for a radiant barrier system in nonreflective roofs, will greatly reduce HVAC energy use. In fact, energy models of a home built to the new code show an improvement of 11% in total energy use over the same home built to the current code.
Other Major Changes
The 2006 IECC for Texas utilizes the climate subzones and window-to-wall ratios developed by the Energy Systems Lab at Texas A & M.
Insulation and Fenestration Requirements by Component for Austin
| Maximum Window-to-Wall Ratio |
Window
U-Factor |
Skylight U-Factor |
Glazed Window SHGC |
Ceiling R-Value |
Wood Frame Wall
R-Value |
Floor R-Value |
Basement Wall
R-Value |
Crawl Space Wall R-Value |
| 15 |
0.65 |
0.65 |
0.40 |
30 |
13 |
11 |
5 |
6 |
| 20 |
0.55 |
0.55 |
0.40 |
38 |
13 |
11 |
6 |
6 |
| 25 |
0.51 |
0.51 |
0.35 |
38 |
13 |
19 |
8 |
10 |
| 30 |
0.46 |
0.46 |
0.35 |
38 |
16 |
19 |
8 |
10 |
A certificate or label detailing energy efficient features of the building must be posted on or near the electrical panel. The certificate must include:
|
R-values of insulation |
|
U-factors of fenestration |
|
SHGC of fenestration |
|
HVAC efficiencies |
|
Water heater efficiency |
Building thermal envelope must be durably sealed at the:
|
Joints, seams, penetrations |
|
Site built doors, windows |
|
Openings between windows, doors and respective framing |
|
Dropped ceilings and chases |
|
Knee walls |
|
Walls, ceilings between garages and conditioned spaces |
|
Behind tubs, showers on exterior walls |
|
Common walls between dwelling units |
|
All other sources of infiltration |
With our humidity, the house should be as tight as possible, then ventilated as needed to avoid excessive latent loads.
Further changes to the energy code are planned for 2009, 2012, and 2015. Together, the code changes will lead to a 65% energy efficiency improvement in code-built homes by 2015. This will effectively create new homes capable of meeting their own energy usage needs through on-site generation, such as solar photovoltaic systems.
A Bright Green Future
As the market for green building continues to expand, AEGB intends to lead the transformation of the building industry to a sustainable future. Mark Lind, senior designer with the local architecture & contracting firm CG&S Design Build, recently wrote, "Green building, once perceived as the sole domain of environmentalists and sandal-wearing idealists, is unquestionably now the new paradigm not only in the U.S. but worldwide. It is a movement which promises to define all human activity in the twenty-first century, and one which affects each and every person alive on a planet overwhelmed by population growth and dwindling natural resources. Green building really is no longer an option." We couldn't have said it better.
Resources
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