The pros and cons of targeting ‘All Electric’ building status

However, this push is prompting many owners to replace fossil fuel systems long before the end of their useful lives, often increasing whole-life carbon in the process. The embodied emissions from prematurely scrapped equipment risk undermining the sustainability ambitions these upgrades aim to achieve.

Transition risk properties

Many newer buildings with gas boilers, or those that have replaced them in the last 15 years, are now slipping into secondary-grade status. These ‘transition risk’ assets struggle under the 2023 EPC carbon intensity changes, putting them at risk of failing the expected 2030 MEES requirement for a minimum EPC B rating and potentially becoming stranded. Yet switching to an all-electric system is often costly and disruptive, requiring heat pump installations, fan coil upgrades, and tenant area works that extend programmes and reduce revenue.

A more pragmatic middle ground exists: targeted, lower-disruption measures that reduce fossil fuel reliance can meaningfully cut emissions and improve EPC ratings. These are often the only viable option for transition risk buildings.

Seeing the whole picture

A full all-electric retrofit typically delivers the lowest operational carbon, but waiting or doing nothing can be far more damaging, potentially doubling overall emissions. For many transition risk assets, bivalent heating strategies offer a practical interim approach that cuts carbon now while avoiding premature scrappage of functioning boiler plants.

A bivalent system retains existing boilers for the coldest periods, often less than 10% of annual operation in the UK, while adding a smaller electric heat source, such as an Air Source Heat Pump (ASHP), to meet the majority of demand. In milder climates like central London, this can be more carbon-efficient in the short term than going fully electric, while also avoiding the embodied carbon waste of retiring boilers early.

These systems can be integrated more easily with existing infrastructure, often without disruptive terminal unit upgrades, and they are recognised in EPC assessments. In practice, they can lift buildings to meet anticipated 2030 MEES requirements of an EPC B or above, or even achieve an A rating, without the cost and disruption of a full electrification project, while also improving urban air quality.

Crucially, the supplementary electric heat source becomes part of any future all-electric solution. Bivalent approaches are particularly beneficial during chiller replacement projects, where considering future heating strategies helps prevent plant space constraints that could otherwise block later electrification.

The future

Achieving all-electric status remains the long-term goal and should be prioritised in retrofit and maintenance interventions. However, decisions must account for whole-life and long-term impacts.

The binary view of ‘all electric or not’ is too simplistic. A more nuanced alternative, bivalent systems, can reduce operational and capital costs for transition risk assets, extend the life of existing boiler plant, improve asset value, and enhance leasing prospects.

Most importantly, doing nothing is the most environmentally harmful option.

Further information

Contact Matthew King

Read our blog: Rethinking regional office sustainability