ASHRAE Completed Research Q&A
Designing Low-to-Mid-Rise Multifamily Residential Buildings
From ASHRAE Journal Newsletter, August 25, 2020
Multifamily buildings are often built like commercial buildings and used as residential buildings, making them challenging to design. This research explores codes, standards and best practices to help designers and practitioners achieve high performance, such as better energy efficiency and improved indoor environmental quality, in these buildings.
A research project and its corresponding guide discusses best practices in designing multifamily buildings. Sean Denniston, senior project manager at the New Buildings Institute, discusses the research, which became the ASHRAE Design Guide for Low- to Mid-Rise Multifamily Residential Buildings.
1. What is the significance of this research?
Multifamily can be a challenging building type to design. Except for very small projects, multifamily buildings are generally built like commercial buildings but used like residential buildings. This research brings together best practices to help designers and practitioners with this unique building type.
2. Why is it important to explore this topic now?
The multifamily market continues to grow. Additionally, multifamily is an essential part of addressing the continuing affordable housing crisis in this country. Therefore, it is important to ensure that there are good tools and guidance for practitioners to design multifamily buildings that deliver good indoor environmental quality and energy efficiency.
3. What lessons, facts, and/or guidance can an engineer working in the field take away from this research?
The ASHRAE Design Guide for Low- to Mid-Rise Multifamily Residential Buildings provides comprehensive guidance for multifamily design. It provides fundamentals for issues like sustainability, building science, codes and standards and the design process, with an emphasis on how they apply to multifamily projects. It then provides in-depth guidance on IEQ and energy efficiency for all major systems in a multifamily building, such as the envelope, space conditioning, ventilation, water heating, lighting and plug loads. Finally, it covers how to bring these topics together for a high-performance building that is pursuing zero net energy.
The major value here is that the guide addresses these systems specifically for multifamily. Most of the guidance available to the market is focused for commercial buildings and single-family homes, but and that guidance is often not as valuable, because the systems and their design can be very different in multifamily.
4. How can this research further the industry's knowledge on this topic?
The major opportunity here is that the guide provides a new baseline for knowledge for the industry. Research focused on advancing the field of multifamily design can use this guide as a solid foundation to push even further.
5. Were there any surprises or unforeseen challenges for you when preparing this research?
The main surprise was how the multifamily topic created a need to structure the guide differently from how it was originally proposed by ASHRAE and from other design guides that the New Buildings Institute had done in the past. For example, the RFP for this project had a section outline that would have had HVAC and water heating all in one section. However, ventilation and water heating are such major issues in multifamily—perhaps the biggest issues right now—that they really needed their own sections.