Tools

High-Performance Residential Wall Assemblies

Author/Contributor: ENBIX, Beyond Code, Performance Haus

We’ve heard from Alberta’s building industry about the challenges of improving home airtightness, enhancing occupant comfort, and helping tradespeople install new technologies while keeping projects affordable, especially in our climate zones.

To help address these issues, Alberta Ecotrust Foundation, through the ENBIX initiative, has worked with Beyond Code (with funding from the Peter Gilgan Foundation) in developing 3D models of high-performance residential building envelope assemblies.

These models show different wall assembly options and methods for building cost-effective, energy-efficient homes made for Alberta. The project goal is to support builders, designers, and homeowners, whether you’re aiming to construct a new net-zero home, retrofit existing walls for better thermal performance, or simply understand how the components of a building envelope work together.

These 3D wall models allow trades to see specific details for the wall design, from multiple views. These models can viewed on the job site using low-cost technologies such as tablets. The designs can be commissioned from Beyond Code to show a builder’s preferred wall design and methods. This creates another tool to supplement training for trades that goes beyond the traditional limitations of architectural plans and details. It also allows for revisions to be made to the models when mistakes are found rather than making those mistakes on-site, costing time, money, and wasted materials.

Getting started guide to the 3D models:

The navigation menu is on the edge of the screen. If viewing on a laptop, to pan, hold the shift key, click and drag. Drag the model to orbit around, and use the mouse wheel to zoom in and out.

The menu is on the right edge of the screen. To watch the animation in order of construction, select the “Scenes” tab. The play button on the left will start the animation. The settings cog on the right lets you change the transition and delay time between animations. You can also click on any of the individual scenes under “my scenes” and see that detail.

Check it out on any of the models below.

New Construction:

High-Performance: Poly Core Wall

Net Zero: Double Stud Wall

Net Zero: Steel Stud Exterior Insulation Wall

For comparison to new construction:

Passive House Wall

A super-insulated Passive House wall. Passive houses require high levels of insulation, sometimes referred to as super insulation, to achieve a U-value between 0.08 W/m2K to 0.15 W/m2K. Typical walls might be 12″ to 24″ thick (R35 to R60) and roofs might be 18″ to 36″ thick (R50 to R100) for Passive House construction.

Business-as-usual Wall

What the City of Edmonton and Calgary are most commonly seeing in residential construction in 2024:

Retrofits:

High-Performance: Retrofit Wall

Net Zero: Retrofit Wall

Summary:

The 3D models include the control layers (at the bottom of scenes) that highlight the materials of the building envelope that apply to each. The control layers to address when you are trying to attain higher levels of energy performance are:

Air
Thermal
Water
Vapour

Air control layers are achieved through an air barrier material that is continuous. Air control materials can be: sheet materials (plywood, OSB), fluid and self-applied membranes, or are mechanically fastened.

The thermal control layer is the insulation and is often referred to as the building’s blanket.

The water control layer is important to keep rain, snow, and sleet from damaging the wood sheathing and frame within the building envelope. This layer includes items such as rain screens to promote drainage. To help prevent water from damaging further, properly installed and sequenced weather-resistant barriers, flashing, and drainage are all crucial components of this layer.

Vapour is moisture when it’s airborne and it can infiltrate into building envelopes and cause damage. If vapour becomes trapped inside an assembly, it can condense and turn into a liquid, which will mold. The vapour control layer mitigates this by controlling the movement of water vapor through the building envelope. Poly vapour barriers or self-adhered underlayments are the most common.

Looking ahead, ENBIX will be expanding on this work with more high-performance wall assembly content in the coming months. This will include physical wall assemblies and presentations at BuildEX and the Canmore Building for Sustainability conferences. Stay tuned to enbix.ca/resources and subscribe to our newsletter for these updates and more resources to help you build more efficiently.