Green Construction


 

Roughly 41 percent of energy consumption in the U.S. is used to power buildings (US EIA 2010). Here in Bozeman, the energy powering our homes and commercial buildings contributes 72 percent of our greenhouse gas emissions.

A green building, also known as a high-performance or sustainable building, can be defined as one that is economical to operate and healthy and comfortable for the people inside. It conserves energy, water, raw materials and land. It limits the generation of toxic materials and waste in its design, construction, landscaping, operations and maintenance. A green building also considers access to public infrastructure systems, such as water and sewer, as well as the entire life cycle of the building and components.

 

Greening City Buildings

At the City of Bozeman, we are working to “walk the talk” by reducing the environmental impact of new construction projects. These are recent examples of projects that resulted in high-performance buildings:

  • Leadership in Energy and Environmental Design (LEED) Silver certification for the Bozeman Public Library.
  • Remodel of Bozeman City Hall achieved LEED for Existing Buildings Silver certification.
  • Our new Vehicle Maintenance Building uses 62 percent less energy than other buildings of its kind in the U.S., according to the Department of Energy’s 2003 Commercial Buildings Energy Consumption Survey.

 

The Cost of Green Construction

Most of us spend 90 percent of our time indoors, which reinforces the need to build healthy, comfortable, and efficient buildings. The benefits are clear:

  • Economic: The lifetime costs, or the second price tag, of green buildings are lower. Energy efficient and water conserving strategies yield operational savings for the lifetime of the building, which may be hundreds of years. Integrated design strategies allow tradeoffs that can reduce the initial building price tag. For example, strategies such as passive solar allow heating equipment to be downsized. Chiller size can be reduced with the use of high efficiency lighting, which generates a smaller heat load in the building.
  • Human: Daylighting, improved air quality, greater thermal control, and other indoor environmental quality strategies typically improve occupant satisfaction and health. Greater satisfaction often leads to increased productivity and morale, decreased turnover, and reduced absenteeism. Potential risk and liability may be reduced as well. Integrated design strategies reduce the risk of sick building syndrome.
  • Community: Green buildings often result in less wind and water erosion and sedimentation of waterways during construction. Sustainably designed sites permanently reduce stormwater runoff and watershed pollution. Furthermore, resource-efficient buildings place less demand on the community infrastructure for potable water, sewer services, and power generation.

Though the initial costs of building green may be higher than those of conventionally designed buildings, the savings generated in energy, water, maintenance, operations, and health costs offer surprisingly quick returns.

Cost Studies

  • The Minnesota Office of Environmental Assistance commissioned the Weidt Group to analyze the performance of 41 commercial buildings that were designed to exceed the Minnesota energy code by 30 percent or more. The modeling concluded that the mean payback for high-performance features averaged less than three years. The summary report, Top 6 Benefits of High-performance Buildings, quantifies the energy efficiency benefits of green buildings.
  • A July 2007 report by Davis Langdon, a construction consulting company, compared the costs of LEED seeking buildings to conventionally designed and constructed counterparts. 83 LEED buildings and 138 conventional buildings were chosen for the study, a total of 221 academic, laboratory, library, and community center buildings, and health care facilities. The report concludes: “As the various methods of analysis showed, there is no ‘one size fits all’ answer to the question of the cost of green. A majority of the buildings we studied were able to achieve their goals for LEED certification without any additional funding. Others required additional funding, but only for specific sustainable features, such as the installation of a photovoltaic system. Additionally, our analysis suggests that the cost per square foot for buildings seeking LEED certification falls into the existing range of costs for buildings of similar program type. From this analysis we can conclude that many projects can achieve sustainable design within their initial budget, or with very small supplemental funding.”
  • The City of Seattle reports that the average incremental cost of meeting LEED Silver standards across all projects is 1.7 percent.  The premium cost per-square-foot of LEED-certified buildings (the initial cost increase per-square-foot attributed to the inclusion of green features), is estimated at $3 to $5, an increase of just under two percent above traditional building costs.
  • Green building expert Gregory Kats broke down the increased premium of green building by collecting data on 146 buildings and concluded “we found that the perception is that building green costs about 17 percent more than building conventionally. However, the data show that the actual cost premium is closer to two percent of total design and construction costs, sometimes referred to as “first costs.” (G. Kats, Greening Our Built World: Costs, Benefits, and Strategies, Island Press, Washington, D.C.,2010)
  • The Costs and Financial Benefits of Green Buildings,” report produced by the Massachusetts Technology Collaborative for the State of California Sustainable Building Task force presenting a definitive cost benefit analysis of green building based on a review of LEED-certified buildings, states: “While the environmental and human health benefits of green building have been widely recognized, this comprehensive report confirms that minimal increases in upfront costs of about two percent to support green design would, on average, result in life cycle savings of 20 percent of total construction costs — more than ten times the initial investment. For example, an initial upfront investment of up to $100,000 to incorporate green building features into a $5 million project would result in a savings of $1 million in today’s dollars over the life of the building.”

 

Finding a Professional

The opportunities to create a more sustainable building will be greatly increased if you hire design and construction professionals who are knowledgeable and experienced in green building practices and principles. The lists below are a starting point to find professionals who best meet your needs.

Professionals in the Area

  • Energy Star for New Homes: Find a Builder, Lender, Rater or Utility Program Search this site for active ENERGY STAR home builder partners in Montana. Every ENERGY STAR labeled home is independently verified to use at least 30% less energy than a home built to the model energy code.
  • Northwest Energy Star: Approved Builders, Raters, and Homes  This is another option to find Energy Star professionals in our cold climate region, as well as look up rated Northwest Energy Star homes.
  • Leadership in Energy and Environmental Design (LEED): Accredited Professionals Directory Search this directory for experienced building industry professionals who have demonstrated their knowledge of integrated design by passing the U.S. Green Building Council’s professional examination. The directory includes numerous Montana-based professionals.
  • The Not So Big House: Architects, Builders and Craftspeople View lists of building industry professionals who endorse Sarah Susanka’s “Not So Big House” concept, which trades “superfluous square footage for less tangible but more meaningful aspects of design that are about beauty, self-expression, and the enhancement of life.”
  • The Passive House Institute US (PHIUS): Find a Certified Passive House Consultant Search this site to find PHIUS Passive House certified consultants trained to address North America’s unique climatic, building code, and materials challenges for residential, commercial, and retrofit scenarios.
  • The National Association of Home Builder’s (NAHB) Certified Green Professional: Find a Builder, Remodeler, Architect, and Engineer The Certified Green Professional™ designation recognizes professionals who incorporate green building principles into homes— without driving up the cost of construction. Classwork leading to the designation provides a solid background in green building methods.

The City of Bozeman does not endorse or recommend as qualified any of the individuals/businesses listed on these sites. Always ask questions about a professional’s experience and approach to sustainable building. Remember to check references and verify credentials.

 

Design Guidelines, Rating Systems, and Performance Verification

This page contains links to tools for the sustainable design, construction, operation and maintenance of commercial and institutional buildings. Sustainable building strategies are most effective when they are integrated from the very beginning of a project, but the resources listed here can be useful at any point in the building process.

Design Guidelines

Design guidelines combine economic, environmental and social considerations to create buildings that are:

  • durable and flexible,
  • conserve resources, and
  • support human health and productivity.

Guidelines typically contain strategies or checklists, often combined with a point system.

  • The International Green Construction Code (IgCC) is the first model code to include sustainability measures for the entire construction project and its site—from design through construction, certificate of occupancy and beyond. The code acts as an overlay to the International Energy Conservation Code 2009, which has been adopted by the State of Montana.

Rating Systems

Rating systems use a scoring system to evaluate new and remodeled buildings against a selected standard for environmental performance.

  • LEED Green Building Rating System (U.S.Green Building Council) The Leadership in Energy and Environmental Design (LEED) building rating system is a voluntary, consensus-based rating system for commercial buildings which rapidly is becoming the de facto national standard for green building certification. LEED evaluates environmental performance from a whole building perspective over a building’s life cycle. In Montana, the USGBC Montana Chapter organizes LEED training, educational chapter events, and green building advocacy efforts.
  • Designed to Earn the ENERGY STAR Energy Star scores buildings based on their energy efficiency, comfort and indoor environmental quality. Recognizing the influence that the nation’s architects can have in reducing the environmental impact of buildings, EPA has expanded the ENERGY STAR program to include commercial new construction by encouraging the design of energy-efficient buildings. Architecture firms will now be able to distinguish projects that have been designed to be among the most efficient buildings in the country as “Designed to Earn the ENERGY STAR.”For new building design, use EPA’s Target Finder calculator. Establish a design target and compare your estimated energy consumption to the target. Integrate energy performance strategies into your building design to meet the target.Use Energy Star’s Portfolio Manager to benchmark an existing building’s energy performance. This free online, interactive tool makes benchmarking simple. Users enter information about a building’s physical/operating characteristics and energy consumption and receive a score. Buildings with benchmark scores of 75 or higher are eligible for the ENERGY STAR® label for buildings. For scores below 75, the tool will offer some customized tips to raise your building’s score.
  • Passive House Institute US (PHIUS) Certification program combines a thorough passive house design verification protocol with a stringent Quality Assurance and Quality Control program performed on site with PHIUS+ Raters. Certification includes review by experienced passive house professionals who review projects at the design stage. Project testing and inspections are conducted by experienced HERS Raters, trained by PHIUS to work on PHIUS+ projects. The on-site inspections and testing help to assure PHIUS and the project teams that the buildings will perform as designed.  Projects will receive a RESNET HERS Index score as part of the certification, which is the leading industry standard by which a home’s energy efficiency is measured.

Performance Verification

As you build a high-performance home, how do you verify that the work is being completed according to plan? This is where third party verification can be well worth your time and money.

The Residential Energy Services Network (RESNET) is a non-profit organization committed to helping homeowners reduce the cost of their utility bills by making their homes more energy efficient.

RESNET is responsible for creating the national training and certification standards for HERS Raters and Home Energy Survey Professionals, both of which are recognized by federal government agencies such as the U.S. Department of Energy, the U.S. Environmental Protection Agency and the U.S. mortgage industry.

Visit the RESNET website to learn about energy audits and ratings, and how they work. Search the RESNET directory to find qualified Home Energy Professionals. Get information on how to increase your home comfort and save money by being efficient.

Additional Resources