To drive down carbon dioxide emissions, the building sector must focus on three priorities: Replace fossil fuel use through electrification, dramatically improve energy efficiency and construct efficient, low-carbon buildings, according to a report released this month by the Energy Transitions Commission.
For existing buildings, commercial building owners have many low-carbon technologies and options to improve energy efficiency — some of which may be disruptive to tenants or involve high upfront costs, ETC said in a Feb. 4 release accompanying the report.
“There is a strong case for high income countries to set earlier targets for the transition away from fossil fuel heating in commercial buildings than in residential buildings,” the report states. Bans on the installation of new boilers could be imposed in new buildings immediately and in existing buildings by 2030, for example, it says.
Commercial buildings have higher lighting and appliance energy needs and higher cooling demands and ventilation needs than residential buildings, the report notes. Cooling, ventilation and space and water heating account for approximately 57% of U.S. commercial buildings’ energy use, according to data by the U.S. Energy Information Administration.
Commercial buildings account for 20% of global building stock, but their operations account for 40% of building operation emissions and 10% of total global emissions, says the report, citing data from the International Energy Agency. Today, commercial buildings account for 35% to 50% of total energy use, compared with 25% for residential buildings.
Commercial building stock is expected to expand 50% by 2050, making efficiency improvements in commercial buildings “therefore essential,” ETC says.
Sophisticated HVAC and building management systems have “a major role to play” in achieving energy efficient improvements in commercial buildings, the commission states in the report. It notes the significant potential for energy savings in buildings that have simultaneous heating and cooling needs that can use waste heat.
While in the past, the elements of HVAC systems — heating, cooling and ventilation — have often operated in isolation, there is an opportunity to shift to combined systems that are able to simultaneously heat and cool different areas of a building, per the report.
For example, using variable refrigerant flow systems, operators can redirect residual heat from a cooling zone toward a zone requiring heat. That could help buildings be more efficient, potentially reducing energy consumption by 30% to 40%, ETC says, citing research from Trane Technologies.
There is also “huge untapped opportunity” in installing building management systems — such as sensors, smart thermostats and predictive AI — that can adjust energy consumption according to occupancy, weather and energy prices and deliver energy savings of 10% to 20% without any disruptive improvements to building fabric, such as insulating walls, double gazed windows, draught proofing and other ventilation improvements, the report states.
While strong regulation of new building design and construction can deliver efficiency improvements, in existing buildings, the introduction of new energy management systems will often deliver higher returns than retrofits to improve insulation, per the report. “But the fact that many commercial buildings are occasionally subject to major retrofit for non-energy related reasons (e.g. to meet new tenant needs) creates an opportunity to enforce strong energy efficient requirements at that point,” ETC says.
“In some cases, tenants will be willing to pay higher rents for more efficient buildings, and developers and building owners will invest in the upfront equipment required,” ETC says, noting that these market-driven incentives could be strengthened by better information on building energy efficiency.
“Regulations should be designed to ensure that when deep retrofits are occurring, buildings are brought up close to required new build standards,” the commission states.
