4 Considerations for Sustainable Multifamily Design
According to the Global Status Report for Buildings and Construction, published by the UN Environment Programme and the Global Alliance for Buildings and Construction, the building industry is responsible for the largest share of energy and process-related carbon dioxide emissions, or 37% globally. With yearly increases in the frequency and severity of hurricanes, wildfires, record-setting temperatures and rising sea levels, the impacts of climate change affect our daily lives in dramatic and tangible ways. Lasting change will depend on creativity and innovation. In the multifamily housing sector, change means reimagining new development from a variety of different angles.
ORIENTATION MATTERS: Shade devices designed for each different orientation of a multifamily building can passively balance solar exposure and heat gain. It may seem simple, but studying sun angles to guide the size, angle and placement of the shading devices significantly improves interior comfort without overreliance on mechanical systems, lowering operational carbon. Considering that more than two thirds of the carbon emissions generated by the building industry is attributed to building operations, these small considerations have a big impact.
CLIMATE MATTERS: Natural ventilation works particularly well in hot, dry climates. KTGY’s Research and Development concept design, Elements, incorporates the windcatcher technique commonly found in Middle Eastern architecture, drawing inspiration from termite mounds. Warm air is drawn underground through shafts and tunnels, where it is cooled by underground thermal mass. In multifamily applications, fresh air is drawn in through intake shafts located along the exterior façade of the building, where it travels down below the foundation of the building to be cooled by the thermal mass of the shafts as well as the underground soil. The air then travels up to the units where it cools interior spaces before leaving through exhaust shafts along the corridor edge of the units. This strategy is particularly effective in southwestern states, but it should be noted that this technique is not as effective in highly humid regions.
REGULATIONS MATTER: New regulations can seem overly restrictive, but certain jurisdictional changes expand the opportunities for sustainable design. For example, the 2021 International Building Code addition of new mass timber construction types allowing buildings up to 18 stories has led to expanded use of this renewable material within the building industry. Numerous states including California, Colorado, Virginia and, most recently, Ohio and Tennessee, have adopted these changes, leading to expansion of mass timber construction. KTGY’s R+D concept, Timber Tower, takes a closer look at how new construction types of mass timber can maximize the use of wood for high-rise residential construction. Mass timber construction for multifamily housing reduces embodied carbon, especially compared to its concrete counterpart, cuts construction waste and supports biophilic design, aligning with current sustainability goals. Other regulations expanding design and development opportunities for multifamily housing include parking reductions (particularly in transit-oriented communities) and new accommodations for adaptive reuse.
Marissa Kasdan is director of research and development with KTGY, representing KTGY nationally from Washington, DC.
