Focus on building envelope design and commissioning

At GWWO, building envelope assessment begins early in the design process. We believe that an interdisciplinary approach to design includes building systems and is essential to responsible building design. We start by reviewing the owner’s project requirements for building systems: envelope, mechanical, electrical and plumbing, etc. energy consumption of the building according to its size. Early analysis is essential to properly set these building performance goals. Using Sefaira, software that allows us to perform simple energy modeling early in the design, we refine the envelope design in conjunction with the systems. We study building orientation, glazing types, location and shading, wall types and insulation values. These studies allow us to outperform designs that only meet minimum code standards and ultimately reduce overall project costs.

For example, at Old Mill West High School in Millersville, MD, an early analysis of wall types helped the project team determine that increasing cavity wall insulation by one inch would reduce the size of the building. mechanical factory.

By using 3-inch high-performance insulation, the design team was able to significantly increase the R-value and reduce the size of the mechanical plane. Courtesy of GWWO.

Additional preliminary envelope studies analyzing glazing performance, window to wall ratio and shading options for classrooms based on orientation impact assessment of building system effectiveness and the quality of space for users.

Shading studies
Shading studies conducted early in the design like the ones above allow design teams to assess light penetration throughout the day and the impact on energy performance and the learning environment . Courtesy of GWWO.

Building Envelope Commissioning (BECx) can provide an additional level of quality assurance for envelope design and construction as the design progresses. BECx is a performance-based approach that ensures that building envelope construction meets design intent. A building can be perfectly detailed, but failure during installation can affect performance for the life of the building. BECx typically focuses on the four main layers of control: water, air, steam, and thermal. The scope of BECx can be modified according to owner preferences or to meet code or rating system requirements (LEED v4 or IgCC) if pursued. BECx typically begins during the design development phase and continues through construction. Scope of work may include review of details, specifications and shop drawings; set performance expectations; perform quality assurance site inspections; and perform functional tests. Depending on the requirements of the project, the BECx can be carried out by the architect, a consultant hired by the owner or an impartial sub-consultant of the design team.

Thermal Imaging

Thermal Imaging 2
Thermal imaging photos taken during a field inspection to analyze the correct installation of the thermally broken window system. Courtesy of GWWO.

At GWWO, we have a Building Envelope Consultant on staff who is also a construction specialist and serves as a personnel resource for projects during design and construction. It performs envelope and specification reviews, conducts field inspections to meet the requirements of our IgCC projects and produces educational content to maintain staff expertise in the fast-paced world of design and construction. of envelopes.

Successful building envelope design requires early analysis and close collaboration with the design team and the client. Small improvements can have a collective impact on overall building and system performance. Integrating BECx into the project can bring additional benefits to the customer in the design and construction phases. This quality assurance process can help achieve sustainable design goals in LEED and IgCC, and limit issues caused by installation, allowing the building to truly perform as intended.