designed and controlled, radiant floor systems will meet dwellers’ comfort expectations13 . A main challenge in indoor environmental design is balancing the fulfillment of the, often conflicting, household needs and expectations. A first step is to understand the occupants. The left side of Figure 7 shows how main architectural decisions lead to thermal zoning, and environmental systems’ selection and design. Room-by-room heating and cooling load analyses inform architect-engineer-owner discussions on strategies to reduce ambient loads and/or use them to help regulate indoor temperatures consistent with expected occupancy patterns. The right side of Figure 7 illustrates corresponding thermal comfort requirements, questions, occupancy profiles and analyses, which inform both architectural and mechanical design processes. Asking the right thermal comfort questions is the first step in raising awareness and promoting a deeper level of thinking and discussion about key design considerations for addressing low-energy thermal comfort concerns. Thermal comfort standards, such as ASHRAE Standard 55-201714 , provide a benchmark for designers to use as a frame of reference to help them understand the conditions for comfort, ask the right questions and evaluate alternative design solutions from a thermal comfort perspective. The standard has not been developed specifically for residential applications. However, its methods and metrics part of a study funded by BC Housing. One of those houses – a high-performance, net- zero energy home in Burnaby, B.C. – was carefully designed with passive and adaptive principles in mind. Even though the house has mechanical cooling, the occupants do not use it, and feel thermally satisfied year-round. Figure 8 shows the temperature variations of the rooms monitored during the summer up to November. The basement (Bm) shows more stable temperatures, followed by the ground floor (Gd) and the top floor. Basement rooms face south. The ground office faces south and west, the kitchen faces north, the living room faces south, and the master bedroom faces south and east. Figure 7. Architectural design and mechanical system design informed by thermal comfort analysis FIGURE 7: ARCHITECTURAL DESIGN AND ENVIRONMENTAL SYSTEMS’ DESIGN INFORMED BY THERMAL COMFORT ANALYSIS. FIGURE 8: TEMPERATURE VARIATIONS IN THE ROOMS OF THE HOUSE OVER THE SUMMER AND FALL. can be generically applied to residential buildings. Standard 55 incorporates both the PMV model and the ATC model that can be used to analyze comfort depending on the application6 . As such, Standard 55 can be used with caution (aware of models’ assumptions and limitations, Figure 1 and 6 ) to guide and document residential thermal comfort analyses. In the meantime, the development of a residential thermal comfort standard specific to North American climate regions is underway. A LOCAL EXAMPLE OF THERMAL ADAPTATION AT HOME A small group of houses has been monitored as SPRING/SUMMER 2019 21