Fill in the search criteria to search the database or view index of all documents.

climates

Very Cold - A very cold climate is defined as a region with approximately 9,000 heating degree days or greater (65°F basis) or greater and less than 12,600 heating degree days (65°F basis).

Cold - A cold climate is defined as a region with approximately 5,400 heating degree days (65°F basis) or greater and less than approximately 9,000 heating degree days (65°F basis).

Mixed-Humid - A mixed-humid and warm-humid climate is defined as a region that receives more than 20 inches of annual precipitation with approximately 4,500 cooling degree days (50°F basis) or greater and less than approximately 6,300 cooling degree days (50°F basis) and less than approximately 5,400 heating degree days (65°F basis) and where the average monthly outdoor temperature drops below 45°F during the winter months.

Hot-Humid - A hot-humid climate is defined as a region that receives more than 20 inches of annual precipitation with approximately 6,300 cooling degree days (50°F basis) or greater and where the monthly average outdoor temperature remains above 45°F throughout the year. This definition characterizes a region that is similar to the ASHRAE definition of hot-humid climates where one or both of the following occur:

  • a 67°F r higher wet bulb temperature for 3,000 or more hours during the warmest six consecutive months of the year; or
  • a 73°F or higher wet bulb temperature for 1,500 or more hours during the warmest six consecutive months of the year.

Hot-Dry/Mixed-Dry - A hot-dry climate is defined as region that receives less than 20 inches of annual precipitation with approximately 6,300 cooling degree days (50°F basis)or greater and where the monthly average outdoor temperature remains above 45°F throughout the year.

A warm-dry and mixed-dry climate is defined as a region that receives less than 20 inches of annual precipitation with approximately 4,500 cooling degree days (50°F basis) or greater and less than approximately 6,300 cooling degree days (50°F basis) and less than approximately 5,400 heating degree days (65°F basis) and where the average monthly outdoor temperature drops below 45°F during the winter months.

Marine - A marine climate meets is defined as a region where all of the following occur:

  • a mean temperature of the coldest month between 27°F and 65°F;
  • a mean temperature of the warmest month below 72°F;
  • at least four months with mean temperatures over 50°F; and
  • a dry season in the summer, the month with the heaviest precipitation in the cold season has at least three times as much precipitation as the month with the least precipitation.

information

Building Science Insights are short discussions on a particular topic of general interest. They are intended to highlight one or more building science principles. The discussion is informal and sometimes irreverent but never irrelevant.

Building Science Digests provide building professionals from different disciplinary backgrounds with concise overview of important building science topics. Digests explain the theory behind each topic and then translate this theory into practical information.

Published Articles aare a selected set of articles written by BSC personnel and published in professional and trade magazines that address building science topics. For example, our work has appeared in Fine Homebuilding, Home Energy, ASHRAE's High Performance Buildings, The Journal of Building Enclosure Design and The Journal of Building Physics. We thank these publications for their gracious permission to republish.

Conference Papers are peer-reviewed papers published in conference proceedings.

Research Reports are technical reports written for researchers but accessible to design professionals and builders. These reports typically provide an in-depth study of a particular topic or describe the results of a research project. They are often peer reviewed and also provide support for advice given in our Building Science Digests.

Building America Reports are technical reports funded by the U.S. Department of Energy (DOE) Building America research program.

Designs That Work are residential Case Studies and House Plans developed by BSC to be appropriate for residential construction in specific climate zones. Case Studies provide a summary of results for homes built in partnership with BSC’s Building America team. The case study typically includes enclosure and mechanical details, testing performed, builder profile, and unique project highlights. House Plans are fully integrated construction drawing sets that include floor plans, framing plans and wall framing elevations, exterior elevations, building and wall sections, and mechanical and electrical plans.

Enclosures That Work are Building Profiles and High R-Value Assemblies developed by BSC to be appropriate for residential construction in specific climate zones. Building Profiles are residential building cross sections that include enclosure and mechanical design recommendations. Most profiles also include field expertise notes, material compatibility analysis, and climate challenges. High R-Value Assemblies are summaries of the results of BSC's ongoing High R-Value Enclosure research — a study that BSC has undertaken for the U.S. Department of Energy (DOE) Building America research program to identify and evaluate residential assemblies that cost-effectively provide 50 percent improvement in thermal resistance.

Guides and Manuals are "how-to" documents, giving advice and instructions on specific building techniques and methods. Longer guides and manuals include background information to help facilitate a strong understanding of the building science behind the hands-on advice. This section also contains two quick, easy-to-read series. The IRC FAQ series answers common questions about the building science approach to specific building tasks (for example, insulating a basement). The READ THIS: Before... series offers guidelines and recommendations for everyday situations such as moving into a new home or deciding to renovate.

Information Sheets are short, descriptive overviews of basic building science topics and are useful both as an introduction to building science and as a handy reference that can be easily printed for use in the field, in a design meeting, or at the building permit counter. Through illustrations, photographs, and straightforward explanations, each Information Sheet covers the essential aspects of a single topic. Common, avoidable mistakes are also examined in the What's Wrong with this Project? and What's Wrong with this Practice? mini-series.

Building America Reports
Ken Neuhauser

This project examines the implementation of an exterior insulation and over-clad strategy for brick masonry buildings in Chicago. The strategy was implemented at a free-standing two story two-family dwelling and a larger free-standing multifamily building. The test homes selected for this research represent predominant housing types for the Chicago area. The retrofit measures are evaluated in terms of feasibility, cost and performance. Through observations of the strategies implemented, the research described in this report identifies measures critical to performance as well as conditions for wider adoption. The research also identifies common factors that must be considered in determining whether the exterior insulation and over-clad strategy is appropriate for the building.

Cold
Building America Reports
Armin Rudd

This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load where the sensible cooling load has been dramatically reduced. Available supplemental humidity control options are described and discussed, with application guidance. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling (cooling below the requested set point) and avoids adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.

Mixed-Humid
Building America Reports
Armin Rudd, Daniel Bergey

Airtight homes require rational and predictable ventilation. A key gap and area of ongoing research is to allow credit for better performing ventilation systems, such as supply and balanced ventilation compared to exhaust, and systems with predictable filtration of outside air and recirculation filtration. This would yield energy savings and reduced moisture control risk in humid climates, without compromising indoor air quality relative to the least performing system allowed by ASHRAE Standard 62.2. Building on previous research dealing with ventilation air distribution, this study added new elements of ventilation effectiveness research, accounting for source of outside air, particle contaminants, and VOC contaminants.

Hot-Humid
Building America Reports
Christopher Schumacher, Robert LePage

There is little consensus on the incidence of and physics behind moisture problems in dense-packed roof assemblies. Only a handful of field research projects have considered the moisture performance of dense-packed roof assemblies and the majority of these were proprietary studies that were not made public. This document focuses on dense-packed insulation retrofits to roof assemblies in cold climates and identifies, describes and compares four strategies that designers, builders and manufacturers have implemented to avoid moisture problems in dense-packed roof assemblies.

Cold
Building America Reports
Kohta Ueno, Randy Van Straaten, Christopher Schumacher

Adding insulation to the interior side of masonry walls in cold climates may cause performance and durability problems. Four such concerns were studied in more detail in this work. Embedded wood joist ends were monitored for moisture content and relative humidity, in a solid brick building that is being retrofitted with interior insulation. The effect of dissolved salts on masonry durability was examined, including their effect on freeze-thaw behavior, subfluorescence effects, and the effect on material property testing. The methodology of the frost dilatometry testing was optimized. Changes included sample size reduction, length measurement protocols, and optimization of the freeze-thaw cycle time. These changes improve throughput without loss of test accuracy.

Building America Reports
Kohta Ueno, Honorata Loomis, Daniel Bergey

Transformations, Inc. is a residential development and building company that has partnered with Building Science Corporation to build new construction net-zero energy houses in Massachusetts under the Building America program. This report covers all of the single-family new construction homes that have been completed to date. The houses built in these developments are net zero energy capable homes built in a cold climate. The set of measures offered by the developer exceeds the 30% energy saving goals set by the Building America program for New Homes in the cold climate for 2013. The houses will contribute to developing solutions and addressing gaps in enclosures and space conditioning research.

Cold
Building America Reports
Kohta Ueno, Phil Kerrigan, Honorata Loomis, Randy Van Straaten

Merrimack Valley Habitat for Humanity (MVHfH) has partnered with Building Science Corporation to provide high performance affordable housing for 10 families in the retrofit of an existing brick building (a former convent) into condominiums. The condominium conversion project will contribute to several areas of space conditioning, water heating, and enclosures research. Enclosure items include insulation of mass masonry building on the interior, airtightness of these types of retrofits, multi-unit building compartmentalization, window selection and roof insulation strategies. Mechanical system items include combined hydronic and space heating systems with hydronic distribution in small (low load) units, and ventilation system retrofits for multifamily buildings.

Building America Reports
Aaron Grin, Joseph Lstiburek

This research provides simple, long term, and durable solutions when using tapes and flashing membranes in conjunction with the exterior face of rigid polymeric foam sheathing to create the drainage plane of a wall system. The knowledge gained from this research will be used in future Building America construction prototypes and well as other residential construction projects to increase the long-term moisture related durability of the enclosure, and reduce the risk of liquid water intrusion. The following are best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience.

Building America Reports
Aaron Grin, Joseph Lstiburek

Based on past experience in the Building America program, BSC has found that combinations of materials and approaches—in other words, systems—usually provide optimum performance. No single manufacturer typically provides all of the components for an assembly, or has the specific understanding of all the individual components necessary for optimum performance. Integration is necessary and is the reason for the teaming approach that has been taken with this research project. The hybrid walls analyzed utilize a combination of exterior insulation, diagonal metal strapping, and spray polyurethane foam and leave room for cavity-fill insulation. These systems can provide effective thermal, air, moisture, and water barrier systems in one assembly and provide structure.

Building America Reports
Kohta Ueno, Joseph Lstiburek, Daniel Bergey

In multifamily buildings, central (typically rooftop) ventilation systems often have poor overall performance, overventilating some portions of the building (resulting in excess energy use), while simultaneously underventilating other portions of the building (resulting in diminished indoor air quality). These issues are often tied to multistory stack effects (warm air rising at cold outdoor conditions), and a lack of compartmentalization (airtightness) between floors and between units. These issues are exacerbated by the presence of multistory shafts (e.g., elevator shafts, stairwells, and ventilation shafts). Central corridor supply and makeup air systems combined with rooftop central exhaust systems are particularly problematic. The recommended solution is to isolate the units from one another and from corridors, shafts, elevators, and stairwells by means of greater airtightness.

Building America Reports
Rosie Osser, Phil Kerrigan

Project Home Again is a development in New Orleans, Louisiana, created to provide new homes to victims of Hurricane Katrina. BSC acted as a consultant for the project, advocating design strategies for durability, flood resistance, occupant comfort, and low energy use while maintaining cost effectiveness. These techniques include the use of high density spray foam insulation, LowE glazing, and supplemental dehumidification to maintain comfortable humidity levels without unnecessary cooling. Stringent airtightness goals were achieved by the project, helping to meet the Builder’s Challenge targets set by Project Home Again. Floor plans, enclosures, and heating, ventilation, and air conditioning attributes are quite similar among different homes in the project.

Hot-Humid
Building America Reports
Armin Rudd

This guideline pertains to design and application guidance for combination space and tankless domestic hot water (DHW) heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multifamily residential buildings, both new and retrofitted. In order to be assured of meeting the Building America savings goals, and the persistence of those savings after installation, continued sharing of lab and field testing results is needed.

Building America Reports
Ken Neuhauser

This project examines implementation of advanced retrofit measures in the context of a large-scale weatherization program and the archetypal Chicago, Illinois, brick bungalow. In response to the apparent weatherization program limitations with respect to homes with masonry bearing wall construction, this research project examines two distinct strategies for insulating and air sealing the top of houses. One strategy applies best practice air sealing methods and a standard insulation method to the attic floor. The other strategy creates an unvented roof assembly using materials and methods typically available to weatherization contractors.

Cold
Building America Reports
Peter Baker

The use of exterior insulation is an effective means to increase the overall thermal resistance of wall assemblies that also has other advantages of improved water management and often increased air tightness of the building. However, the engineering basis and support for this work has not been conducted, resulting in obstacles for building official and building code acceptance. Additionally, the water management and integration of window systems, door systems, decks, balconies, and roof-wall intersections have not been adequately developed. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation (2” to 8”) on existing masonry walls and wood framed walls and as well as relevant water management details.

Building America Reports
Peter Baker

There is a significant push for energy performance upgrades to existing homes. An important target is often the windows. Old single-glazed windows have such low thermal resistance that their effect on the overall thermal resistance of the walls can be staggering. Improving the performance of the window stock is therefore central to the goal of reducing the energy consumption of the existing building stock. This measure guideline provides information and guidance about rehabilitating, retrofitting, and replacing wood window assemblies in residential construction. It is intended primarily to help contractors and homeowners understand the options for safely improving the performance of their wood windows.

Building America Reports
Honorata Loomis, Kohta Ueno, Randy Van Straaten

Building Science Corporation (BSC) has been working with Byggmeister, a partner on the Building America (BA) team, on retrofit projects under the BA program. Byggmeister is a local design-build firm that specializes in energy efficient retrofits and new construction. The Byggmeister multifamily test home located in Jamaica Plain, Massachusetts (Jamaica Plain or J.P. Three-Family) is a three-story brick row house. The test home is examined with the goal of producing a case study that could be applied to similar New England homes. Basic areas of research that this report is expected to contribute include finding the combination of measures that are feasible, affordable, and suitable for this type of construction and acceptable to homeowners.

Cold
Building America Reports
Ken Neuhauser

Through discussion of five case studies (test homes), this project evaluates strategies to elevate the performance of existing homes to a level commensurate with best-in-class implementation of high performance new construction homes. The test homes featured in this research activity participated in Deep Energy Retrofit (DER) Pilot Program sponsored by the electric and gas utility National Grid in Massachusetts and Rhode Island. Retrofit strategies are evaluated for impact on durability and indoor air quality in addition to energy performance.

Cold
Building America Reports
Christopher Schumacher

Historically, weatherization programs have required that cellulose insulation materials be dense-packed to a minimum installed density of 3.5 pcf. This density limit was, in part, required to realize beneficial reductions in air leakage. The Building Performance Institute (BPI) currently has under development two standards that will set requirements for the airflow resistance of insulations used in retrofit cavity (i.e. dense-pack) installations and define acceptable test methods to measure the airflow resistance of insulation materials used in dense-pack applications. An experimental apparatus and test method were developed for the purpose of measuring the airflow resistance of dense-packed fiber insulation installed as a retrofit to empty wood-frame wall cavities.

Building America Reports
Kohta Ueno, Joseph Lstiburek

Basements can account for up to one quarter of the typical energy consumption in a house. Therefore, insulating foundations is a critical measure for achieving high performance buildings. However, many foundations are damp (either due to bulk water or capillary “wicking” of moisture) or of a type of construction that is not easy or straightforward to insulate (such as rubble foundations). Damp foundation repair methods can be “leveraged” to provide energy efficiency benefits. An example of this “hybrid” approach is spray foam insulation, which can be an effective means of liquid phase water control (leaking basement), vapor phase water control (diffusion and air leakage transported condensation) as well as an effective insulation.

Building America Reports
Rosie Osser, Ken Neuhauser, Kohta Ueno

Building Science Corporation seeks to further the energy efficiency market for cold climate, New England area retrofits by supporting projects based on solid building science fundamentals and verified implementation. The utility company National Grid engaged BSC as a partner to develop guidelines for its Deep Energy Retrofit Pilot Program. In addition to guideline development, BSC has acted as a consultant for these projects and others following similar retrofit strategies. Costs of each project are presented, with an attempt to isolate the costs of measures specific to DERs and not regular home maintenance and aesthetic upgrades. Finally, occupant feedback from the retrofits is discussed to determine overall satisfaction with the retrofit efforts. For more information about retrofits, see Popular Topics/High R-value Retrofits.

Cold

Pages