The UK Net Zero Carbon Buildings Standard Guide: Part 7: Electricity demand management

The updated UK NZC BS introduces requirements for assessing electricity demand management, applicable to both new and existing buildings. This applies across all sectors, with the following exceptions:

• Single-family homes.
• Buildings with a total floor area of 500m² GIA (Gross Internal Area) or less.

The assessment should cover all electricity used by the building, apart from specific exceptions:

• Electric vehicle (EV) charging.
• Heavy process loads.
• External works, including street lighting and service yards.
• Car park energy use.

Electricity data must be recorded with a resolution of 1 hour or less between readings. The reporting will focus on three key metrics:

1. Peak Demand: Maximum electricity demand recorded in the top 1% of all recorded periods (99th percentile).
2. Typical Demand: Median value (50th percentile) of all recorded periods.
3. Low Demand: Minimum electricity demand in the bottom 1% of all recorded periods (1st percentile).

Each data entry should include the date, time, and kW demand.

Meter readings will form the basis of this analysis. The assessment will focus on the Operating Reporting Period (ORP), which refers to the calendar year immediately before the reporting period’s end date.

Submission requirements

Submissions must include:

• Evidence of any electricity use that isn’t metered or where metering doesn’t meet the reporting resolution requirements.
• All meter readings and data used for electricity demand management analysis.

Limits

No specific limits for electricity demand have been set yet. However, future versions of the Standard aim to introduce these limits.

Why electricity demand management matters

Electricity demand management is crucial for managing the UK’s power station capacity and achieving net-zero carbon goals. The UK’s current peak electricity demand is approximately 60 GW. This could double if heat pumps are widely adopted and even triple with the growth of EVs.

Keeping peak electricity demand low is vital, as all existing and new power stations need to transition to low- or zero-carbon technologies. 

Aspects we think work well

• Proactive Future Planning: By addressing electricity demand, the Standard takes the approach to ensure the UK’s electricity infrastructure can adapt to growing pressures like heat pump and EV adoption.
• Flexibility for Innovation: By not imposing strict demand limits at this stage, the proposals allow for innovative approaches to emerge as more data is collected, paving the way for ambitious targets in future iterations.

Aspects recommended to be considered for further development

• Metering Complexity: While the use of 1-hour resolution data provides valuable insights, there could be challenges in implementing this for buildings without advanced metering systems. Simplified approaches for smaller or less complex sites might make the Standard more accessible.
• Exclusions Clarification: More detailed guidance on excluded electricity uses, such as electric vehicle charging or external works, would reduce ambiguity during assessments. 
• Future Limits: Though it is understandable that limits are not yet set, providing indicative or interim benchmarks would give stakeholders a clearer understanding of expectations for future compliance.

The Entopia Building, Cambridge 

The Entopia Building is a pioneering deep retrofit project, achieving multiple sustainability certifications such as BREEAM Outstanding, Passivhaus EnerPHit, and WELL Gold. It incorporates advanced energy strategies to meet stringent net-zero carbon objectives while enhancing occupant comfort and building performance.

The servicing strategy integrates an all-electric scheme featuring an exhaust air heat pump, which provides efficient heating and cooling. This way, the system minimises fluctuations in electricity use, helping stabilise peak demand. It serves as a model for reducing grid strain while achieving operational efficiency, contributing to the UK's broader net-zero carbon objectives.

A robust energy management system, including sub-metering and a Synapsys logger, ensures real-time monitoring and detailed energy analysis. Final energy use intensity was measured at 52 kWh/m²/year, outperforming LETI and RIBA 2030 targets.

Corsham House is set to become a boutique hotel that blends historic character with modern sustainability. Housing 14 ensuite bedrooms, a breakfast kitchen and lounges, this hotel not only provides a high-quality visitor experience, but also prioritises environmental responsibility.

The hotel incorporates a photovoltaic (PV) array and advanced battery storage to manage electricity demand efficiently. The PV panels, spread across 275m² of active area, are estimated to generate 40,000 kWh annually, harnessing renewable energy to power the hotel’s operations. Some of the produced energy is held in a sophisticated lithium-ion battery system, ensuring that no watt goes to waste.

A 375kWh battery system is the ultimate vision and is designed to store excess solar energy and optimise grid electricity use. During peak winter conditions, when the hotel’s demand can reach 800 kWh per day, the battery support half the load, minimising grid reliance and taking advantage of energy arbitrage. In summer the system complements the PV array, storing surplus energy for use during evening hours when demand remains high.

The battery’s dual function—storing renewable energy and leveraging cheaper nighttime tariffs for daytime use—delivers both financial and environmental benefits. By shifting energy consumption to off-peak times, the hotel reduces its operational costs while lowering its carbon footprint. An initial 150kWh battery will meet immediate needs, with capacity to scale up to 375kWh based on metered demand and energy usage patterns.