Article updated 24th August 2026
In July 2022, the Greater London Authority (GLA) wrote to developers warning that the electricity grid was running out of capacity for new homes in West London, specifically Hillingdon, Ealing, and Hounslow.
Four years on, the warning still holds in places - but the picture is more nuanced than "housebuilding has stopped." Here's where things stand in 2026, what's actually changed, and what it means for your due diligence.
Key Highlights
- The West London grid has been effectively full since 2022, and applicants can still be told there's no capacity for a new connection until 2035.
- London's 99 data centres now draw around 760MW at peak - roughly the electricity load of 750,000 homes - and the grid connection queue is running at about ten times what the local network can currently supply.
- Progress has been made: National Grid, SSEN, and the GLA have unlocked accelerated connections for 7,800 homes across the three boroughs, and City Hall says at least 11,690 permitted homes have now been freed up in total.
- Population trends in Ealing and Hounslow have softened rather than surged, which takes some of the edge off long-term demand - though the numbers are noisier than they first appear.
- Substation capacity still varies significantly street by street, so site-level due diligence matters more than borough-level headlines.
West London Overview
Roughly a quarter of London's population lives in West London, and the region has historically delivered new homes at a faster rate per capita than the London average. That track record is exactly why the 2022 warning landed so hard: Hillingdon, Ealing, and Hounslow alone were responsible for around 11% of London's new homes in the years leading up to the constraint being announced.
What Caused the Constraint
The short version hasn't changed: a rapid build-out of data centres along the M4 corridor, drawn by the area's fibre optic infrastructure, absorbed the spare electricity capacity that would otherwise have gone to new housing and commercial development. The GLA's original note to developers said major applications "will have to wait several years" for new connections, with some told to expect a wait until 2035.
What's different in 2026 is the scale of that data centre demand. London's data centres are now estimated to draw around 760MW at peak - the equivalent of roughly 750,000 homes - and the queue for new grid connections across the city is running at close to ten times what the network can currently supply. That's the context that makes the West London housing story part of a much bigger infrastructure conversation, not a standalone planning quirk.
The Progress That's Been Made
This is the part the original version of this article couldn't have told you, because it hadn't happened yet.
Since 2022, National Grid, SSEN, and the GLA have worked through what's known as ramped or phased connections - allowing developments to draw power in stages rather than waiting for full capacity to be available on day one. That approach has already accelerated connection dates for 7,800 homes across Hounslow, Hillingdon, and Ealing, worth 10.5 MVA of demand capacity. Projects that were previously looking at connection dates in the 2030s now, in most cases, have a pathway to connect within 12 to 24 months.
Zoom out further and the GLA's own tracking shows at least 11,690 permitted homes have now been unlocked with City Hall's support - which it describes as close to the full pipeline of stalled permitted housing it's aware of in the affected area.
None of this means the underlying constraint has been solved. The timelines for the transmission-level upgrades that would resolve the issue long-term haven't moved - they're still years out. But it does mean the "housebuilding has stopped" framing from 2022 needs updating: a meaningful chunk of the stalled pipeline has since found a way through.
LandInsight's Data: What Does Grid Capacity Look Like Now?
As part of LandInsight, we track the RAG (red, amber, green) status of substations via our Power Infrastructure layer, showing developers how much headroom is left in their target area. A red rating typically means less than 10% capacity remains, making a new connection unlikely without intervention.
What This Means for Developers
The practical guidance from 2023 mostly still holds, with one addition:
- Smaller schemes continue to have an easier path. SSEN and National Grid have confirmed that projects requiring less than 1 MVA won't be blocked.
- Phased and ramped connections are now a real route to market for larger schemes too, not just a theoretical fix — but they depend on site-specific negotiation with the network operator, so build that conversation into your timeline early.
- Population pressure has eased somewhat rather than intensified. Recent ONS estimates show Ealing's and Hounslow's populations declining slightly year-on-year, even though both remain well above their 2011 levels. Treat this as a mild tailwind rather than a reason to deprioritise capacity checks — the estimates vary enough between sources that we wouldn't lean too heavily on any single projection.
- Site-level checks still beat borough-level assumptions. With thousands of homes unlocked in some areas and constraints persisting in others, the borough you're building in tells you far less than the substation you're connecting to.
Power Up Site Sourcing With LandInsight
With LandInsight, you have substation data at your fingertips. Use our site-sourcing tools to find and assess sites, then instantly check the capacity of nearby substations with our power layer — kept current, so you're not planning around numbers from a different network reality.
Want to see how LandInsight can help you find the right site, even in constrained areas like West London?
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Related Reading
- What's Causing the Variation in South London House Prices?
- Is Development Momentum in London Shifting Further East?
- What's the Impact of Infrastructure on London's Housing Market?