Study: Ultra Green Buildings Can Eliminate Energy, Water Bills

A new study finds that the most financially responsible design approach to new construction in the mid- to long-term is a “Living Building.”

Such a building generates its own power as well as cleans and reuses its water. In fact, a building that is only slightly green may end up costing more in 10 years than a building that is designed and built as high performance as is currently possible. Living Buildings offer significantly larger savings in water and energy costs, and cost less to construct than previously believed, according to an April 14 press release about the study.

Given the rising cost of energy and water, Living Buildings, as defined by the Cascadia Region Green Building Council, are the smartest financial option in today’s economy. The only exceptions, according to a study team led by SERA Architects with Skanska USA Building, Gerding Edlen Development, New Buildings Institute, and Interface Engineering, are “spec” buildings meant to be “flipped” in a few years.

The study was initiated in an effort to put a price tag on the Living Building Challenge rating system – a relatively new program that has sparked interest in North America with at least 60 proposed Living Buildings in some stage of design or actual construction.

Jason F. McLennan, chief executive officer of Cascadia and the author of the Living Building Challenge, says, “Some people have thought this idea was 'pie in the sky' and unachievable. But the study clearly demonstrates that we can increase green jobs, greatly enhance our energy security, and most effectively utilize federal stimulus money by constructing Living Buildings, especially for those in the public sector where taxpayers are going to own and operate a building for the long term.”

The study was done by examining construction documentation on nine buildings, ranging from schools to homes and high-rises, in four different U.S. cities representing various climate zones. Each of these reference buildings were certified LEED Gold, already incorporating many green features and representing current best practices. The construction documents were modified to meet the goals of a Living Building and then re-priced based on the modifications, with the purpose of comparing the cost difference of making the leap to net-zero energy and water. The science behind the study is the same methodology that is typically used by the construction industry for cost-estimating projects prior to construction.

While initial costs are higher, the bottom-line finding is that investing in Living Buildings will have significant economic impact – with less than a 10-year payback in several instances. The study finds that Living Buildings can cost as little as 5 percent to no more than 49 percent more depending on the building type and location, representing paybacks for many buildings that are well within the range (less than 7-15 yrs) for any institution, corporation, or homeowner looking at holding onto their asset for a few years.

The degree of cost effectiveness depends on the following five key factors:

  • Use of the building: Public schools and classrooms had the lowest cost. Private sector developers building spec buildings had the largest cost differential.
  • Size of the building and the roof: The larger the building and roof size (for solar and water catchment systems), the lower the cost premium.
  • Climate matters: A mild climate with regular rainfall provides the most cost-effective opportunity for a Living Building, although net-zero energy and water is technically possible for all regions in the study.
  • Incentives and rebates matter: When communities offer incentives and rebates for saving energy and using renewable energy, it reduces the cost premium significantly.
  • Cost of resources matter: The higher the cost of energy and water, the shorter the payback period, making a Living Building more feasible in areas with high energy rates.