New research from Savills reveals the mounting pressure to connect projects to the UK’s low voltage distribution network. The distribution network, where most residential and small commercial developments seek connections, is facing a rising pace of applications for demand connections as well as a supply shortage of available capacity at substations. Demand connection applications rose by 30% from April 2024 to June 2025, leaving the total queue capacity at 29 GW which is equivalent to the power needed to supply roughly 14.5 million homes. The analysis from the international real estate advisor tracks the evolution of available supply capacity in the distribution network from June 2024 to August 2025, highlighting the evolution of improvements and constraints across the network.
Grid IQ, developed by Savills Earth, reveals that there was around a 2 GW uplift of available capacity in primary substations from June 2024 to August 2025, placing the total available capacity at 39 GW. This figure has been largely unchanged (± 5%) over the course of the last two years. Even though the supply of capacity is about 34% higher than the demand for connections, the geographic distribution of capacity is misaligned with development needs.
According to the Energy Networks Association, applications for new distribution level connections remain high, with a total of over 9 GW of connection applications for demand, generation and storage submitted each month. To contextualise this, 1 GW could power up to 500,000 homes or around ten large data centres, highlighting the scale of projects competing for limited capacity.
Despite a strong requirement for new connections across demand, generation and storage, progress has been slow. Distribution network operators (DNOs) are working to optimise existing infrastructure, but developers continue to face delays.
Regionally, London and the South East saw an 11% increase in demand headroom, around 1 GW, due to revised peak demand calculations by UK Power Networks, which could ease constraints on housing and mixed-use developments. In contrast, the Midlands and South West experienced a 14% drop in capacity, driven by a surge in logistics development, which is absorbing available power. Further north, the B6 Boundary, a key bottleneck between Scotland’s renewable generation and England’s demand centres, saw headroom fall by 23%, exacerbating the constraint within the region.
From April 2026, rising Transmission Network Use of System (TNUoS) charges could prompt some site owners to reduce their import capacity, potentially freeing up grid capacity for new developments. With over 210,000 non-residential sites affected, even small adjustments could have a significant cumulative impact.
Kyle Rarick, Data Analyst, Energy, Renewables and Infrastructure, says: “Nearly a year on from our initial analysis of grid headroom across the UK, new data shows how the electricity grid is evolving as demand for power increases. While progress is being made through reform and reinforcement, data shows that the headroom capacity shortage persists. This shortage is increasingly shaping the pace and location of new housing, commercial, and industrial development, as grid capacity remains a key constraint on planning and delivery.”
Phil Pearson, Director,Energy, Renewables and Infrastructure, adds: “The ongoing connections reform and forthcoming TNUoS charge adjustments highlight the need for developers to monitor each part of the network to identify and secure capacity. Developers who understand these changes and incorporate grid readiness into site selection, design, and investment strategies will be best placed to deliver resilient, future-proof projects in an increasingly capacity-constrained market.”
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