Energy efficiency is central to most definitions of high-performance buildings. It is also central to BSC’s consulting, research, and education activities. At BSC, we believe in promoting energy efficiency and environmental responsibility within the constraints of marketable and affordable building technology.
The documents below discuss why energy is critical to sustainability and how to define and understand energy use (for example, through energy metrics). They also touch on key issues in energy reduction in buildings, such as thermal control and advances in window technology for commercial and residential buildings.
Attics should be air sealed prior to adding insulation. Adding insulation alone does not save much energy and can lead to health and durability problems. The intent of this guide is to provide information for the preparation work necessary prior to adding attic insulation.
Providing thermal comfort without excess space conditioning costs is one of the primary requirements of buildings. Therefore, thermal control is an important aspect in almost all buildings. Understanding heat transfer and the temperature distribution through building materials and assemblies is also important for assessing energy use, thermal comfort, thermal movements, durability, and the potential for moisture problems.
Heat flow occurs through the building enclosure via opaque enclosure elements, is directly transferred into the building by solar radiation through windows, is carried along with air across the enclosure by unintentional leakage and ventilation, and can be generated within the building by occupants and their activities.
The control of heat flow in buildings requires insulation layers compromised with few thermal bridges, an effective air barrier system, good control of solar radiation, and management of interior heat generation.
The American Foursquare, a Sears, Roebuck & Co. kit home, was a staple of small American towns between 1908 and 1940. More than 100,000 of them were built in America. Homes built prior to 1980 make up 80% of the housing stock in the United States, and are responsible for a majority of the residential energy use in the country. All of the renovations used systems engineering principles to ensure good indoor air quality and longterm durability while providing deep energy reductions. This posting is permission of ASHRAE. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
The difference between site and source energy is a vital concept to understand when looking at the energy performance of buildings—failing to account for the difference will result in an apples-to-oranges comparison that does not give the true picture of a building’s energy consumption. This document explains how these two types of energy are accounted for differently and why.
Putting metrics on building energy performance is a required step to make any progress on low-energy use and/or “green” buildings. However, there are many confusing and contradictory metrics available; to speak a common language, it is necessary to understand the topics that are behind these measurements. These topics include site vs. source energy, modeled results vs. reality, US average energy use figures, and methods of normalizing energy use. The normalization of energy use intensity (EUI), or dividing by square footage is examined; several significant problems in applying this metric to residential use are demonstrated. Various other metrics are presented, as well as a proposed method to provide all of the useful building energy information in a format that allows normalization by any chosen metric.
This report is an excerpt from the 2008 Building America Annual Report. Following the almost complete destruction of Greensburg, Kansas by a tornado in May, 2007, Building Science Corporation (BSC) was contracted to provide example house plans, support for the reconstruction of energy efficient houses and training for builders and trades. This report describes the results of BSC’s work to construct more than 20 energy efficient, affordable, durable houses in Greensburg, Kansas.
This paper was first presented at the 2011 ASHRAE Annual Conference. A startup builder in the San Francisco Bay Area has a goal of producing factory built/modular houses with net zero energy performance. Their first prototype was a two-story, two bedroom, urban infill townhouse design. It has been in operation for roughly a year, and has been extensively measured and monitored, providing information about its net zero performance.
This paper was first presented at the 2011 ASHRAE Annual Conference. A homebuilder in the New England area has been building net zero energy single family homes since 2008 and is continuing with multiple small-scale subdivisions of 20 or more homes. This builder specializes in net zero affordable homes and sustainable net zero communities, while retaining houses with a familiar local vernacular appearance.
Windows and curtainwalls are ubiquitous building enclosure components. Like all parts of the building enclosure, they have to meet the fundamental functional requirements of support, control and finish (Straube & Burnett, 2005). Reprinted with permission from Journal of Building Enclosure Design, Winter 2010, pages 12 -15.
