Multi-unit residential

Decarbonization efforts in MURBs aim to drastically reduce greenhouse gas emissions by transitioning away from fossil fuels and towards electrification powered by renewable energy sources. High-performance building design focuses on enhancing energy efficiency and occupant comfort through improved building envelopes, efficient mechanical systems, and smart controls. Both aim to improve the quality of life for inhabitants, create more sustainable communities, and contribute to climate goals.

The building envelope significantly impacts energy consumption by influencing heat loss/gain, air leakage, and moisture management. Strategies to improve envelope performance include increasing insulation in walls, roofs, and floors; using high-performance windows with thermal breaks and low-e coatings; implementing effective air sealing to reduce air leakage; and employing rainscreen wall systems to control moisture. Reducing thermal bridging through balconies and other building elements is also vital.

In decarbonization, the primary focus is moving from fossil fuel-based systems to electric systems. Heat pumps (air-to-water, air-source, variable refrigerant flow) are preferred as they are highly efficient at providing both heating and cooling. Electrification of DHW using heat pumps is also essential, paired with low-flow plumbing fixtures. System design should consider submetering and proper controls.

Ventilation is crucial for maintaining indoor air quality by removing pollutants, controlling moisture, and ensuring fresh air circulation. Strategies such as Energy Recovery Ventilators (ERVs) and Heat Recovery Ventilators (HRVs) are recommended to improve ventilation efficiency. Proper design and installation are required, including ductwork concealment, appropriate air intake and exhaust placement, and preventing contamination of fresh air intakes with exhaust. A balance between natural and mechanical ventilation should be considered.

Sustainable massing involves breaking down large building masses to allow for light and air penetration. Leaner, thinner floorplates should be preferred over deep ones. Buildings should be oriented to maximize sunlight exposure, especially towards the south. Unit design should prioritize access to light and air through proper aspect ratios (minimum 2x3), windows in bedrooms, and flexible layouts. Consideration of exterior elements such as balconies and their impact on shading is also essential.

Submetering of utilities such as electricity, gas, and water is critical because it provides occupants with feedback on their consumption, promoting behavioral changes that can result in decreased energy and water usage. It also allows for more accurate billing, and encourages residents to conserve since they are directly responsible for costs. Submetering technology, along with smart building automation systems (BAS), enables ongoing monitoring and verification of building performance.

Resilience in MURBs aims to ensure that buildings remain habitable and functional during extreme events such as power outages or severe weather. Strategies include decentralizing energy and water systems by utilizing renewable energy generation and on-site storage, using rainwater harvesting systems, "armoring" the building with enhanced fire or seismic safety features, and utilizing backup power systems located above flood levels. Designs that promote thermal autonomy and passive survivability are critical, including high-performance enclosures and materials that maintain effectiveness under a wide range of conditions.

Post-occupancy evaluation (POE) is critical for assessing the actual performance of a building after it has been occupied. It involves collecting data on operational performance, indoor environmental quality, and occupant satisfaction to identify any areas for improvement. Commissioning, particularly enhanced commissioning, ensures building systems are properly installed and functional, aligning with design specifications. This combination of approaches promotes ongoing refinement of designs, ensuring high building performance and comfortable, healthy environments for occupants.