How to evolve towards fully electric buildings

Electrification is a key step towards decarbonization. Here’s what you need to know to move to an all-electric building efficiently and cost-effectively.

Building professionals largely agree on the need for aggressive decarbonization to reduce greenhouse gas emissions, both in new and existing buildings. To this end, a preliminary study developed by Buro Happold illustrates what would be needed to achieve one of the most important solutions in support of this goal: the shift to fully electric buildings, connected to networks powered mainly by renewable energy sources.

The study reviews new construction typologies and their implementation in several US cities, assessing the viability of sustainable engineering solutions, including systems such as heat recovery, high performance envelopes, resilience of the system and the heat pumps. Introduced and managed correctly, these readily available and cost-effective strategies can reduce or eliminate energy consumption-related carbon output without additional strain on the power grid, according to the study’s approach to producing all-electric buildings.

To produce an overall technical assessment of various all-electric solutions, it was important to study the effect of technology and greenhouse gas emissions, as well as the impact of these strategies on the cost of the project and on the electrical network. Especially in regions with cold climates, most buildings currently depend on fossil fuels for heating and hot water. The analysis of the impact of all-electric buildings relies on shifting these loads from fuels such as oil and natural gas to renewable electricity. Additional factors such as humidification or additional plug load demands may occur in power-intensive facilities such as those supporting scientific research laboratories and hospitals.

The analyzes found in the study refer to four distinct categories of impact:

• Greenhouse gas emissions
• Network resilience
• Technology
• Cost
• Greenhouse gas emissions

Connecting 100% electric buildings to electricity networks powered by renewable energy sources is the key to significantly reducing greenhouse gas (GHG) emissions, which is the goal of decarbonization strategies. In many states, it is entirely possible to achieve an all-electric building profile with reduced GHG emissions in the near term, based on recent progress in introducing renewable energy to the grid. In other locations, the timeframe for reducing GHGs through the transition to all-electric can be significantly longer. In these geographies and jurisdictions, electricity-ready solutions may therefore be more applicable to achieve immediate and long-term carbon reductions.

Some facility owners and managers waiting for grids to connect to more renewable energy might also consider buying offsets, and there are a number of operational carbon offsets that effectively promote decarbonization. A virtual power purchase agreement can be a good choice, but only if it supports the creation of a renewable energy production plan that would not otherwise be realized. High quality offsets should align with the objective of additionality. Similarly, stakeholders considering offsets should confirm that renewable energy certificates from the renewable energy project will be retired, so that they are not double counted.

Buro Happold’s study includes an example comparing all-electric building models to the median existing building in New York to illustrate the performance of each, as well as against 2024-2050 GHG emissions thresholds set by local law 97 of New York, with similar comparisons for the Boston metro area and that city’s BERDO 2.0 standards for carbon thresholds. The resulting GHG emissions in all-electric configurations are all lower than those of a traditional fossil-fuel heating system.

Network resilience

Reliability is key in determining the feasibility and best strategies for an all-electric building. The possibility that peak electricity demand could switch from cooling to heating is a key risk factor, especially as outages can impact both comfort and safety in winter. Recent improvements in associated technologies – electricity generation and storage, demand-side management systems, efficient electric heating and high-performance building envelopes – make it increasingly promising to go all-electric without overloading the grid.

Emergency backup power continues to be primarily fossil fuel-based, and on-site power generation and storage technology that would meet GHG emissions reduction criteria may not yet be available. widely available, but will likely become better options over time. Robust strategies for reliability begin with the design of a high-performance building envelope to reduce heating and cooling needs, supported by strategies to avoid demand pressure during peak hours of electrical use. These strategies could include enforcing controls and zoning setbacks, or shifting power generation, where possible, to off-peak hours.

In particular, existing buildings present a significant challenge, requiring deep energy retrofits that can support a transition to electricity without overloading the grid. Many utilities and municipalities are currently exploring grid capacity as well as policies and incentives to support the development of resilient solutions.

Technology

Perhaps the most important pillar supporting a potential shift to all-electric buildings is heat pump technology, which is readily available and highly efficient. Likewise, the latest materials and systems supporting innovative, energy-efficient and efficient building envelope designs are also readily available, helping to reduce energy consumption and associated emissions. For all material selections, the whole building carbon footprint is an important metric for understanding embodied carbon investment alongside operational carbon savings. Where technology has yet to catch up to industry aspirations is in the field of backup power, still dominated by fossil fuel sources, as noted above.

Because these systems can be combined in multiple ways depending on strategy or approach, Buro Happold’s study compared the results of various envelope performance and system configurations between commercial offices, labs, residences and higher education buildings in five major cities representing diverse climates. All typologies showed reductions in energy consumption when a high performance envelope was used to moderate heating and cooling demand, and increased reductions with a decoupled HVAC system, in which ventilation with maximum heat recovery is separate from heating and cooling – usually hydronic or refrigerant-based rather than airflow-based. Zero-emission operation by 2050 is achievable for all typologies, assuming access to a grid powered primarily by renewable sources.

Impact on costs

There are several ways to examine and calculate the financial impact of an all-electric strategy. Owners of certain types of properties may want to consider the impact on the layout of the space, for example. The study findings suggest that the mechanical requirements for all-electric configurations can reduce the space available for rooftop tenant installations by 10-15%. Air-source heat pumps take up considerable floor space, although this can be offset by the reduced space requirement for a cooling tower, depending on the systems design and building requirements. Of course, the capital costs and operational costs of utilities are essential to a usable cost assessment and comparison.

In some areas, the difference in capital costs will be marginal because, as in Massachusetts, existing energy codes require some level of thermally efficient enclosure. The capital cost impact for all-electric projects in jurisdictions that do not meet these baseline requirements appears to be greater. But considerations for particular systems differ between typologies. For new construction office buildings, the capital cost impact is typically less than 1% and less than 2% for commercial labs. The next version of the study will look at the cost impacts of retrofitting existing buildings, including the high thermal performance upgrades to envelopes that we already know are needed to reduce heating loads in colder climates.

When it comes to utility costs, there is likely to be a slight increase in many configurations: for office buildings, the range of increase is likely between 3-5%, and potentially up to 10% for laboratories, compared to natural gas analogues.

The feasibility study referenced throughout this article acknowledges the various barriers while sharing a path to holistically assess the viability of an all-electric future. With a growing number of jurisdictions introducing codes and standards that focus on efficiency and reducing GHG emissions, there is growing pressure for stakeholders to explore all-electric approaches. Future follow-up work in this area will address embodied carbon, social equity, and other basic considerations, including existing building assessment strategies for all-electric retrofits.

Julie Janiski and John Swift are partners at Buro Happold, an integrated and sustainable design firm based in Boston. Janiski leads projects at all scales achieving cutting-edge levels of carbon reduction and water conservation, as well as social equity, human health and well-being. Swift is Buro Happold’s Global Head of Health, Science and Technology. He has over 25 years of experience creating engineered systems for research, commercial and academic facilities.

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