BASC Search | Building America Solution Center

Plan view of exterior masonry brick wall retrofitted with furring strips, three layers of rigid foam insulation staggered and taped at the seams, and 1x4 furring strips to provide a nailing surface and ventilation gap under lap siding

Publication Date

Fri, 08/13/2021 - 12:00

This home’s exterior walls include Larsen trusses, 9-inch I-joists attached through exterior sheathing to wall studs creating a 9-inch wall cavity that was filled with blown insulation and forms extra deep windowsills.

Publication Date

Wed, 12/29/2021 - 12:00

Right – This home is framed with double walls – two 2x4 walls set next to each other then sheathed with OSB on the exterior and netted on the interior face to create an extra-deep wall cavity that can be filled with blown-in insulation.

Publication Date

Thu, 09/30/2021 - 12:00

Specially designed roof trusses come with a two-foot by two-foot notch cut next to the center post providing space to install an insulated duct chase inside the home’s conditioned space but above the normal ceiling height.

A paint-on waterproofing covers the exterior and tops of the concrete block foundation walls and piers to block moisture moving up through the concrete, while foil-faced R-13 insulation lines the inside surface of the exterior walls.

Publication Date

Fri, 01/01/2016 - 12:00

ICF walls and an attic sealed and insulated to R-63 on the underside of the roof deck with 10 inches of open‐cell spray foam plus 2.7 inches of closed‐cell spray foam provide a complete thermal break around this home.

In this exterior wall retrofit of a masonry brick home, first the brick was covered with a fluid-applied water and air control layer (white), then 2x4 furring strips and two layers of rigid foam insulation, then 1x4 furring strips to attach cladding to

Publication Date

Fri, 08/13/2021 - 12:00

Thermally isolate heated garages in multifamily buildings from ambient space, and thermally isolate all garages in multifamily buildings from interior occupied space. This parking garage is thermally isolated from space above with spray foam insulation.

Publication Date

Tue, 09/17/2024 - 12:00

A simple vented attic with good air-sealing of the drywall ceiling air barrier, air flow from soffit vents to ridge vents protected by ventilation baffles, and lots of insulation covering the attic floor is unlikely to encourage ice dams.

Publication Date

Wed, 08/15/2012 - 12:00

Right – The raised slab foundation has a 3-ft stem wall of filled concrete block, then is back-filled with compacted dirt and crushed rock, then insulated with 1” rigid foam covered with taped vapor barrier, under a floor slab.

Publication Date

Mon, 09/30/2019 - 12:00

Right - Reduce condensation risks to blanket insulation by installing perforated vapor retarder covered fiberglass blankets over rigid foam that is air-sealed at all edges; staple the blanket to nailers and top/bottom plates and tape over the seams.

Publication Date

Fri, 01/01/2021 - 12:00

Right – This hot-humid climate home is constructed with concrete block that is insulated on the inside with rigid foam; the framing is borate-treated lumber; the roof design is a high-wind-resistant hip roof with only one small gable over the entry.

Publication Date

Thu, 09/30/2021 - 12:00

Wrong - Plastic-covered blanket insulation that is installed directly against concrete walls with no rigid foam or closed-cell spray foam covering the concrete could trap moisture coming through the concrete, leading to mold, moisture, and odor problems.

Publication Date

Thu, 10/26/2006 - 12:00

Plan view of exterior masonry brick wall retrofitted with furring strips, three layers of rigid mineral wool insulation staggered and taped at the seams, and topped with metal hat channel providing a ventilation gap surface to nail under the lap siding

Publication Date

Fri, 08/13/2021 - 12:00

Advanced framing techniques including 2x6 walls spaced at 24 inches on center and ladder blocking at wall intersections allow more space for insulation in the wall cavities while open-web floor joists provide space between floors for ducting.

Publication Date

Mon, 01/01/2018 - 12:00

This Habitat for Humanity builder ordered roof trusses with a 2-foot by 2-foot notch next to the center post then lined the cutout with rigid foam to form an insulated central duct chase to bring the heating and cooling ducts within the conditioned space.

Spray foam insulation extends down the foundation wall to the slab, which has been retrofitted by cutting the slab to install drainage mat against the wall and a new perimeter footing drain, along with rigid foam plastic above the slab.

Publication Date

Mon, 07/01/2013 - 12:00

Right – The window header is filled with spray foam and sealant is used to air seal wood-to-wood seams; however, it would be preferable to design the wall to avoid so many stacked studs around the windows because they prevent wall insulation installation.

Publication Date

Fri, 12/31/2021 - 12:00

This close-up of an exterior wall retrofit of a masonry brick home shows the fluid-applied water and air control layer (white), 2x4 furring strips and two layers of rigid foam insulation (pink), then 1x4 furring which provides a ventilation gap

Publication Date

Fri, 08/13/2021 - 12:00

This attic is insulated to R-64 with a hybrid application of 11 inches of open-cell spray foam (R-4.45/in) plus 2 inches of closed-cell spray foam (R-7.4/in) that completely fills the roof rafter cavities and encases the rafters.

This Texas homes uses a slab foundation including a 4-in.-thick post-tensioned monolithic slab with turned-down edges poured over a 6-mil polyethylene vapor barrier and capillary break; slab edge insulation is not used due to termite risk.

Publication Date

Thu, 09/01/2011 - 12:00

Floors: Above Unconditioned Basement, Vented Crawlspace, Cantilevered Floors, and Floors above Garage, Code Compliance Brief

New language in the 2015 IECC allows different installation of insulation in floors over unconditioned spaces.

Skylight Shaft Walls

Guide describing insulation techniques for skylight shaft walls.

Karuna Passive House High-Density Cellulose

Publication Date

October, 2012

Video describing the high-density cellulose insulation installed in a passive house.

Walls Adjoining Porch Roof

This guide describes how to install a rigid air barrier to separate the porch attic from the conditioned space.

ROXUL Mineral Wool | Madrona Passive House

Publication Date

February, 2015

Video describing the installation of mineral wool monolithic exterior insulation.

Roof/Attic to Exterior Wall Air Control Upgrade

Guide outlining how to retrofit an exterior wall and/or attic to provide continuous air sealing.

Attic Knee Walls

Guide describing how to insulate and air-seal attic knee walls and floor joist cavities under knee walls.

Vented versus Unvented Attic

Guide describing options for designing and locating the thermal boundary at either the attic floor or along the roof line in new and existing homes.

Walls Behind Showers and Tubs (1)

Publication Date

July, 2015

Video describing how to properly insulate walls behind showers and tubs.

Attic Knee Walls

Publication Date

July, 2015

Video describing how to insulate and air seal attic knee walls.

Walls Behind Showers and Tubs (3)

Publication Date

July, 2015

Video describing how to properly insulate walls behind showers and tubs.

Monolithic slab with a grade beam

Publication Date

Fri, 05/01/2009 - 12:00

Slab independent of foundation wall

Publication Date

Fri, 05/01/2009 - 12:00

Controlling Moisture in Unvented Attics - Code Compliance Brief

Publication Date

May, 2017

The intent of this brief is to provide code-related information about controlling moisture in unvented attics by installing a vapor diffusion port/vent that would convey water vapor from an unvented attic to the outside when air-permeable insulation materials are installed and can be verified as being in compliance with the related codes and standards for residential construction. Providing consistent information to document compliance with codes and standards to all relevant parties responsible for verifying compliance (e.g., code officials, builders, contractors, designers, etc.) is expected to result in increased compliance and more timely, less challenging and more uniform plan review and field inspections.

Wind Washing

Guide describing wind washing and how to prevent it.

Designing with SIPs: Design Considerations

Author(s)

Structural Insulated Panel Association

Organization(s)

SIPA

Publication Date

July, 2020

Guide informing architects and engineers about designing buildings to be constructed with structural insulated panels.

Building with SIPs: Need to Know

Author(s)

Structural Insulated Panel Association

Organization(s)

SIPA

Publication Date

July, 2020

Guide informing builders and developers about efficient building practice for constructing homes with structural insulated panels.

Dropped Ceiling/Soffit Below Unconditioned Attic

Guide describing how to insulate and air-seal dropped ceilings and soffits to prevent air leakage.

Crawlspaces – Either In or Out, BSI-115

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

March, 2020

Article discussing whether or not to seal and insulate crawlspaces.

Vinyl Siding with Integrated Rigid Foam for Existing Walls

Guide describing the design and installation considerations for recladding of above grade walls using insulated vinyl siding.

ICF bricks are stacked to form hollow walls that are reinforced with steel rebar before the concrete is poured in

Publication Date

Mon, 10/01/2012 - 12:00

Proper flashing around windows is especially important when the rigid foam serves as the drainage plane in the wall

Publication Date

Mon, 10/01/2007 - 12:00

Passive House Wall Assembly Mock | Hammer & Hand

Publication Date

March, 2015

Video showing a mock wall assembly used in Hammer and Hand’s passive houses.

Air Sealing Attic Access Panels/Doors/Stairs

Guide describing how to air-seal attic access panels, doors, and stairs to provide a continuous air barrier at the ceiling.

High Performance Builder Spotlight: Scott Homes Inc.

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

January, 2011

Case study describing a new home construction project in the marine climate.

High-Performance Homes - A Simpler Design Strategy

Author(s)

Tom Patton

Organization(s)

Fox Blocks,

EEBA

Publication Date

August, 2020

Webinar from Tom Patton of Fox Blocks on how changes to building codes are driving changes to framing assemblies and insulation, highlighting how ICFs can take over for traditional wood frame wall assemblies. Free EEBA login required.

Westford House, BSI-018

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

March, 2009

Report describing sloped roof assemblies with high levels of thermal performance.

Advanced Framing vs Traditional Framing

Publication Date

December, 2012

Author(s)

Risinger

Organization(s)

Build with Matt Risinger

Video describing traditional 2x4 16 inch on center framing versus advanced framing with 2x6 stud walls at 24 inch on center, insulated corners and headers, wall stud-ceiling joist alignment, etc. providing a strong wall with more room for insulation.

High Performance Builder Spotlight: Clifton View Homes

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

January, 2011

Case study describing a new home construction project in the marine climate.

Compact Buried Ducts in a Hot-Humid Climate House

Author(s)

Mallay David

Organization(s)

Home Innovation Research Labs,

HIRL

Publication Date

January, 2016

Report on heating and cooling air-distribution ducts that are insulated, installed close to the ceiling in a vented attic and covered with attic insulation to minimize energy loss.

Three inches of closed-cell spray foam (R-19) and 7.5 inches (R-28) of open-cell spray foam was installed below the roof sheathing in this cathedral ceiling.

Publication Date

Sun, 12/01/2013 - 12:00

Building America Top Innovations 2013: Buried and Encapsulated Ducts

Author(s)

Pacific Northwest National Laboratory,

Steven Winter Associates

Organization(s)

PNNL,

CARB,

SWA

Publication Date

September, 2013

Case study describing a DOE Building America Top Innovation on HVAC ducts located in vented attics that are encapsulated in foam and buried in attic insulation.

Encapsulated Ducts

Guide that illustrates how and when to encapsulate ductwork in unconditioned attics, increases the R-value of duct insulation, mitigating condensation issues and reducing air leakage.

The Perfect Wall Explained

Publication Date

September, 2020

Author(s)

Todd Usher

Organization(s)

Addison Homes

Video describing a technique to insulate walls to a higher R-value using a foam board on the exterior side.

Sill Plates (2)

Publication Date

July, 2015

Video describing how to insulate and air seal sill plates.

Upgrading Below Grade Spaces

Author(s)

University of Minnesota

Organization(s)

NorthernSTAR,

NSTAR

Presentation describing basement insulation and potential problems.

Your Northern Home: Understanding Crawl Spaces

Publication Date

December, 2011

Author(s)

Benesch

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing crawlspace insulation configurations and problems that may arise in cold climates like Alaska.

Cold Climate Building Techniques & Concepts: Furring In an Outside Wall

Publication Date

January, 2017

Author(s)

Benesch

Organization(s)

Cold Climate Housing Research Center,

CCHRC

Video describing a furring in framing technique to further insulate a pre-existing Alaskan house.

Condensation Control for Walls in Cold Weather

Guide describing ways to construct wall assemblies in cold climates to minimize the likelihood of condensation formation inside the walls.

Water Managed Existing Sill Beams and Sill Plates

Guide describing how to insulate the sill beam or sill plate on the exterior side in a way that allows drying to the exterior, as part of an exterior wall upgrade.

Concrete Solutions, BSI-118

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

October, 2020

Report covering insulating crawlspaces.

Passive House Geofoam Foundation Installation: Karuna Video #1

Publication Date

October, 2011

Video showing the installation of a foundation in a passive house.

SIPschool's SIP Installation Basics: The Most Important Joint in the SIP Envelope

Publication Date

May, 2011

Author(s)

SIPschool

Organization(s)

SIPschool

Video from SIPschool on sealing joints using SIP panels.

Mea Culpa Roofs, BSI-083

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

December, 2014

Article describing methods for insulating and air sealing vented and unvented roofs in various climates zones.

Home Energy Saver

Author(s)

Lawrence Berkeley National Laboratory

Organization(s)

LBNL

Publication Date

September, 2024

Online calculator for estimating payback of adding additional insulation to your house.

Ceilings and Attics

Author(s)

Southface Energy Institute,

Oak Ridge National Laboratory

Organization(s)

ORNL,

SEI

Publication Date

February, 2000

Information sheet with information about insulating and ventilating attics.

Technology Solutions Case Study: Stand-Off Furring in Deep Energy Retrofits

Author(s)

IBACOS

Organization(s)

IBACOS

Publication Date

May, 2014

Case study describing a stand-off furring strategy that minimizes the physical connections to each existing wall stud, uses spray foam to encapsulate existing siding materials (including lead paint), and creates a vented rain screen assembly to promote drying.

Avoiding Wet Roofs - Part I

Author(s)

Yost Peter

Organization(s)

Journal of Light Construction,

JLC

Publication Date

June, 2018

Article describing the building science implications of insulating vented or unvented attics.

Lay out the rigid foam sheathing joints so they do not align with the window and door edges

Publication Date

Mon, 10/01/2007 - 12:00

Air leaking through the home's envelope wastes a lot of energy and increases energy costs.

Publication Date

Wed, 01/01/2020 - 12:00

Analysis of Joint Masonry Moisture Content Monitoring

Author(s)

Ueno Kohta

Organization(s)

Building Science Corporation,

BSC

Publication Date

October, 2015

Report on adding insulation to load-bearing mass masonry buildings.

Avoiding Wet Roofs - Part II

Author(s)

Yost Peter

Organization(s)

Journal of Light Construction,

JLC

Publication Date

July, 2018

Article describing the research into insulating vented versus unvented attics.

ETW: Wall - ICF Wall Construction

Author(s)

Building Science Corporation

Organization(s)

BSC

Publication Date

November, 2014

Information sheet that summarizes Insulated Concrete Form (ICF) construction including advantages and disadvantages of this construction strategy.

Hybrid Assemblies, BSI-100

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

October, 2017

Article describing issues with condensation in unvented attics insulated with open-cell spray foam.

Sealed Attics?

Author(s)

Coble Brian

Organization(s)

Home Energy Magazine

Publication Date

January, 2010

Article describing how insulating and air sealing unfinished attic spaces can lead to reduced energy bills in some homes.

Passive House Underslab Foam & Vapor Barrier: Karuna Video #6

Publication Date

February, 2012

Video describing the under slab and vapor barrier used on a passive house.

Great Fire of London, BSI–098

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

August, 2017

Report covering the fire performance of combustible cladding over combustible insulation.

Builders Challenge High Performance Builder Spotlight: David Weekley Homes, Houston, Texas

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

December, 2009

Case study describing new home construction in the hot-humid climate, optimizing thermal enclosure, HVAC, water heating and lighting measures.

Diagram of buried ducts

Publication Date

Thu, 08/01/2013 - 12:00

Rocks Don’t Burn, BSI–068

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

May, 2013

Report covering non-combustible continuous exterior insulation and non-combustible roof venting.

Moisture Management in Residential Construction Series - Building Enclosure: Window Installation

Publication Date

January, 2011

Author(s)

Home Innovation Research Labs

Organization(s)

Home Innovation Research Labs

Video describing the installation of windows to be air- and water-tight, including recommendations on flashing, air-sealing, and insulation, from Home Innovation Research Labs

DOE ZERH HIA 2013 Case Study: Weiss Building & Development, System House, River Forest, IL

Author(s)

Pacific Northwest National Laboratory,

U.S. Department of Energy

Organization(s)

PNNL,

DOE

Publication Date

September, 2013

Case study describing a 4,763 ft2 certified Passive House that achieved HERS 27 without PV through the construction of R-54 walls that use ICF plus fiberglass cavity insulation, an R-100 vented attic, extensive air sealing and flashing, triple-pane windows, ductless heat pumps, and solar hot water.

Burlingame Ranch Phase I

Author(s)

Building Science Corporation

Organization(s)

BSC

Publication Date

February, 2009

Case study describing a building project in the cold and very-cold climate zones.

High Performance Builder Spotlight: Clifton View Homes II

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

January, 2011

Case study describing a new home construction project in the marine climate.

High Performance Builder Spotlight: Imagine Homes

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

January, 2011

Case study describing a new home construction project in the hot-humid climate.

With a quality installation, tape can last a long time

Publication Date

Sun, 04/01/2012 - 12:00

Encapsulated ducts are sprayed with ccSPF in an unconditioned attic

Publication Date

Thu, 08/01/2013 - 12:00

Ceiling gypsum board has been installed

Publication Date

Thu, 08/01/2013 - 12:00

Burried and encapsulated ducts in a ceiling plane

Publication Date

Fri, 02/01/2013 - 12:00

Moisture Management in Residential Construction Series - Building Enclosure: Exterior Wall Overview

Publication Date

January, 2011

Author(s)

Home Innovation Research Labs

Organization(s)

Home Innovation Research Labs

Video from Home Innovation Research Labs giving an overview of moisture problems common to exterior walls and how to mitigate these problems with proper framing, flashing, sheathing, cladding, and insulation.

Slab-on-grade termite control techniques

Publication Date

Tue, 01/01/2013 - 12:00

Slab Happy, BSI-059

Author(s)

Lstiburek Joseph W

Organization(s)

Building Science Corporation,

BSC

Publication Date

April, 2012

How hard can it be to insulate a flat sheet of concrete? I mean you only have three choices – on the top, on the bottom, or on the edge. OK, you might have some combination of the three as well.

Freeze Protection for CPVC Fire Sprinkler Piping Guide

Author(s)

City of Gresham,

State of Oregon

Organization(s)

City of Gresham,

State of Oregon

Publication Date

April, 2021

A guideline containing fire sprinkler insulation requirements from the Prescott, Arizona Fire Department.

HUD 2024 Housing Innovation Showcase Poster: Re-Siding your Home?

Author(s)

Patricia Gunderson,

Theresa Gilbride

Organization(s)

Pacific Northwest National Laboratory

Publication Date

September, 2024

Factsheet describing re-siding retrofits containing exterior insulation and window upgrades aimed at improved energy savings and comfort.

Building Code Training - Residential Thermal Envelope - Air Sealing

Author(s)

Southface Energy Institute

Organization(s)

SEI

Publication Date

May, 2020

Presentation describing the Georgia State Minimum Standard Energy Code air barrier requirements, envelope concepts including air flow and thermal properties, and common missed insulation and air-sealing opportunities.

Garage Rim/Band Joist Adjoining Conditioned Space

Publication Date

July, 2015

Video describing best practices for air sealing an attached garage during construction using plywood and spray foam in the band joist and providing an exhaust fan to ventilate and depressurize the attic.

Coastal Habitats

Author(s)

Building Science Corporation

Organization(s)

BSC

Publication Date

December, 2008

Case study describing a construction project in Hilton Head, SC utilizing a whole-house performance approach.

High Performance Builder Spotlight: GreenCraft, Lewisville, TX

Author(s)

Pacific Northwest National Laboratory

Organization(s)

PNNL

Publication Date

January, 2011

Case study describing a new home construction project in the hot-humid climate.