Electrical Demand & the Future Homes Standard
What Developers Need to Know for New Residential Schemes
As the UK transitions toward low-carbon housing, electrical infrastructure is becoming a critical early design consideration. For developments like small housing schemes, what used to be a relatively straightforward utilities exercise is now a more technical and strategic coordination task.
A recent query from a Distribution Network Operator (DNO) “Will there be more than 3.68 kW required per phase?” highlights a wider shift in how residential developments are assessed. This article explores what that means in practice and how it ties directly into the Future Homes Standard.
1. The Shift from Gas to Electrification
Traditionally, UK homes relied heavily on gas for heating and hot water, with electricity covering lighting and appliances. This kept electrical demand relatively modest.
However, with the Future Homes Standard (FHS) coming into force, new homes will be expected to:
Eliminate fossil fuel heating
Achieve significantly lower carbon emissions
Incorporate low-carbon technologies such as:
Air Source Heat Pumps (ASHPs)
Electric vehicle (EV) charging infrastructure
Solar PV systems
As a result, it is clear that modern homes are becoming electrically intensive.
2. Understanding “3.68 kW per Phase”
At first glance, 3.68 kW may sound like a measure of energy consumption. In reality, it refers to instantaneous electrical load or the amount of power required at any given moment.
3.68 kW = 16 amps on a single-phase supply, and is often used by DNOs as a threshold for low-demand connections
Anything above this suggests a standard or high-demand residential load and the need for full-capacity infrastructure design
For context, a kettle alone can draw around 3 kW. When combined with space heating, EV charging, and general usage, a modern dwelling can easily exceed 10–15 kW peak demand.
3. What “Per Phase” Actually Means
Electricity in the UK is distributed using three-phase systems, but most homes receive a single-phase connection.
Single-phase (domestic): One live conductor supplying a dwelling
Three-phase (network level): Three conductors used to distribute load efficiently
So when a DNO asks about demand “per phase,” they are effectively asking: How much load will each individual connection (i.e. each house) place on the network?
For a typical residential development, each dwelling equals one phase with the total site balanced across three phases.
4. Typical Arrangement for a Housing Development
For a scheme of around 10 dwellings, the electrical setup will usually be:
A three-phase supply brought into the site (or via a local transformer)
Each plot served by an individual single-phase connection
Plots distributed across phases to maintain balance
This approach ensures efficient load distribution, reduces the risk of network overload, and allows for future scalability.
5. The Impact of EV Charging and Heat Pumps
Two key technologies are driving increased demand:
1. Air Source Heat Pumps (ASHPs)
Continuous electrical load for heating
Typical operating range: 2–5 kW (higher during peak conditions)
2. Electric Vehicle Charging
Standard domestic chargers: ~7 kW
Increasing expectation for installation or future provision
Even with diversity (i.e. not everything running at once), these loads significantly exceed traditional assumptions.
6. What About Solar PV?
Solar PV is now common in new developments and plays an important role in reducing operational carbon.
However, from a network design perspective:
PV generation is intermittent and non-coincident with peak demand
Distribution Network Operators (DNOs) assess and often limit export capacity, rather than relying on generation to offset demand
Connection design is therefore based on maximum import requirements, regardless of on-site generation
While PV systems are fully accounted for through DNO notification and approval processes (e.g. G98/G99), they are typically controlled through export limitations rather than used to reduce required network capacity.
7. Why This Matters at Design Stage
Electrical demand is no longer a late-stage coordination item. It directly affects:
Feasibility of connections
Programme (due to DNO lead times)
Cost (particularly if reinforcement or substations are required)
Site layout (for cable routes and equipment)
Failure to address this early can lead to:
Delays in technical design stages
Redesign of site infrastructure
Unexpected cost increases
8. The Role of After Diversity Maximum Demand (ADMD)
DNOs will typically assess developments using ADMD (After Diversity Maximum Demand), which is an estimate of the average peak demand per dwelling after accounting for usage patterns.
While individual homes may peak at 10–15 kW, ADMD might reduce this to ~2–5 kW per dwelling across a development.
Even so, schemes incorporating EV charging and electric heating often sit at the upper end of these assumptions, pushing infrastructure requirements higher.
9. Aligning with the Future Homes Standard
The Future Homes Standard is accelerating a fundamental change:
Then
Gas-led homes
Low electrical demand
Simple connections
Now
All-electric homes
High peak demand
Infrastructure led design
This shift means that:
Electrical strategy should be considered alongside architectural design
Coordination with DNOs should begin early
Assumptions around “standard connections” are no longer reliable
10. Key Takeaways for Developers and Designers
3.68 kW per phase is a low-demand threshold and modern homes exceed this comfortably.
“Per phase” effectively means per dwelling in residential schemes.
Expect three-phase supply into the site, with single-phase connections to each unit.
EV charging and ASHPs significantly increase demand
PV is not typically relied upon to reduce network capacity requirements
Early engagement with DNOs is essential under the Future Homes Standard
Final thoughts
As the industry moves toward zero-carbon housing, electrical infrastructure is becoming one of the defining constraints (and opportunities) within residential development.
Early-stage coordination of electrical demand is increasingly becoming a critical part of technical design delivery.
Understanding concepts like phasing, load demand, and network capacity is no longer just for engineers. It is now a core part of delivering compliant, buildable, and future-ready schemes.
For practices operating at technical design stages, this is exactly where clarity and coordination add the most value.