Flawed energy efficiency modeling is the reason many green buildings fail to live up to expectations on energy efficiency, according to a U.K. researcher.
David Coley, a University of Bath specialist, led a team that surveyed 108 architects, engineers, and energy consultants who routinely use energy performance models. They asked participants to look at a typical British semi-detached home recently updated to meet current building codes. Then they asked test subjects to rank which improvements made the most difference to energy performance.
Their answers didn’t match up with reality, suggesting a performance gap between modeling and the real world. There were cases where the modelers produced a savings measure that was more than the energy use of the house.
Energy models showing unreasonable results are evident at the preliminary stage on half of projects going through the LEED certification process, according to a U.S. Green Building Council official. Designers have a tendency to accept outputs without evaluating the reasonability of the results, she said.
Part of the reason for the performance gap is that modelers do not usually go onsite to see how the building operates and compare that to the design. Typically there is no expectation that they’ll even talk to the building manager at year one and ask how energy usage compares with the original model.
Related Stories
| Oct 13, 2011
New Law: California Building Standards Commission Must Include Green Expert
A new California law, AB 930, requires that one member of the California Building Standards Commission be “experienced and knowledgeable in sustainable building, design, construction, and operation.”
| Oct 13, 2011
AGC Urges Repeal of 3% Withholding On Government Contracts
The U.S. House of Representatives is planning a vote in October on a bill to repeal the 3% withholding requirement on all federal and state contracts for goods and services.
| Oct 13, 2011
House Bill Would Block New OSHA Regulations
Proposed riders in a U.S. House of Representatives spending bill would block the Occupational Safety and Health Administration (OSHA) from issuing controversial workplace safety and health regulations.
| Oct 11, 2011
AIA introduces five new documents for use on sustainable projects
These new documents will be available in the first quarter of 2012 as part of the new AIA Contract Documents service and AIA Documents on Demand.
| Oct 7, 2011
GREENBUILD 2011: UL Environment releases industry-wide sustainability requirements for doors
ASSA ABLOY Trio-E door is the first to be certified to these sustainability requirements.
| Oct 6, 2011
Taking tenant behavior into account on building energy codes
Over the past few years, Seattle, San Francisco, Austin, and Washington, D.C., have passed laws requiring property owners to measure and disclose their energy use, which would help place a market value on a building’s efficiency and provide a benchmark for improvements.
| Oct 6, 2011
Constructed properly, green roofs hold up well in a hurricane
The heavy rains and high winds of Hurricane Irene didn’t cause any problems for a Con Edison green roof in New York City. The roof contains sedum, a plant that adapts well to drought and handles periods of heavy rain well.
| Oct 6, 2011
RoofPoint: A new green standard for roofs
Structured much like other rating systems, RoofPoint, establishes green standards specifically for roofs.
| Oct 6, 2011
Roofers critical of new OSHA harness rules
Roofers say a new OSHA rule requiring all residential roofers to wear a safety harness makes workers less safe, and is causing lost business for those who comply with the rule.
| Oct 6, 2011
Florida county proposes saving on construction costs by trumping city regulations
This summer, Pinellas County, FL wanted to save money on an $81 million public safety complex in Largo by using the county’s own building regulations and permit fees, not the city’s more expensive fees.
