The Green Belt Lie
The Green Belt Lie: How Affordable Housing Is Being Used to Justify Development That Doesn't Deliver It
Every time a developer wants to build on green belt land, they reach for the same argument. Housing crisis. Unaffordable homes. Failing targets. Your green belt is the solution.
It isn't. And in Elmbridge, the numbers prove it.
The delivery failure hiding in plain sight
Between 2013 and 2025, 4,240 homes were built in Elmbridge. Elmbridge's own planning policy — Core Strategy Policy CS21 — required affordable housing contributions from virtually all development: 40% on larger sites, tapering down to 20% on sites as small as five homes. The council applied this policy to everything, right down to single-digit developments, explicitly going further than national guidance because local need was so acute.
Actual affordable delivery across those 12 years: 781 homes, or 18.4% of the total. Below the lowest policy threshold. Below the rate required on the smallest sites.
The council's own evidence base puts genuine need at 269 affordable homes per year. Actual average delivery: 65. In 2022/23, thirteen affordable homes were built in a borough of 140,000 people. In 2021/22 — the biggest building year on record, with 768 homes completed — 111 were affordable, 95% of them shared ownership products. Not one was social rent.
This is not a land supply problem. This is a delivery problem. More permissions have not produced more affordable homes. The gap between what is promised at planning stage and what is built has remained stubbornly, consistently wide.
(Source: Elmbridge AMR 2024/25, Tables 3.2 and 3.15; Core Strategy Policy CS21, para 3.46)
How the promise disappears: the Hersham case
The mechanism is best illustrated by what just happened at the former Hersham Place Technology Park.
Berkeley Homes applied for 262 homes with zero affordable housing. Their viability assessment, prepared by BNP Paribas Real Estate, claimed a deficit of £22,595,273 — meaning the scheme supposedly couldn't support a single affordable unit. The council commissioned independent reviewers Dixon Searle Partnership to check the figures. Their December 2025 report found the deficit was almost entirely manufactured by an inflated land value assumption — specifically, that the vacant offices could be fully refurbished and 100% let within 18 months, a scenario the reviewer called "highly unlikely."
When a more defensible land value was applied, the £22.6 million deficit shrank to £74,474. The scheme was generating a profit of around 17.45% of gross development value — within the government's own recommended range. The independent review reduced the claimed deficit by over 99%.
The result? Permission granted for 262 homes. Affordable housing: 14%. Policy requirement: 40%. Average house price in Elmbridge: £743,000. Average price of Berkeley's family homes: £986,000. Social rent: zero.
This is not one bad actor. This is the viability system doing what it routinely does — allowing developers to construct a financial case for reducing affordable obligations, with independent review moderating but not overriding the outcome. It happens across hundreds of applications. CPRE's State of the Green Belt 2021 found that nationally, only 10% of homes built on greenfield green belt land were affordable. Only 5% were social rent. The average policy requirement was 34%. The gap between promise and delivery is not a local quirk. It is the national norm.
The permissions that aren't being built
Here is the part developers don't mention when they invoke Elmbridge's housing delivery failure to justify green belt release.
Elmbridge's own Housing Delivery Test Action Plan — published because the borough delivered only 79% of required homes — explicitly names "landowner and developer circumstances" as a cause of under-delivery, and requires the council to investigate land banking. In 2022/23, 240 homes were built against a requirement of 647. Not for lack of planning permissions. For lack of building.
Elmbridge's AMR records 523 homes with extant planning permission through permitted development currently unimplemented. A further 486 permitted affordable homes are in the pipeline, unbuilt.
The most documented local example is Abbey House, Wellington Way, Weybridge. Five prior approval applications for residential conversion between 2020 and 2021 — none implemented, each allowed to approach expiry before the next was filed. Full permission for 106 homes granted March 2024. Thirteen months on, four minor pre-commencement conditions discharged. No construction. The office building still stands.
The JTI Building on Members Hill: 176 homes consented April 2024, no construction. The Hawker Building, Queens Road: original 2021 permission expired unbuilt after three years, fresh application required.
The contradiction is direct. Developers cite Elmbridge's delivery failure to argue for green belt release. Some of that failure is caused by developers not building what they've already been given permission to build. Releasing more green belt land does not fix this. It adds to the backlog of unbuilt homes while permanently removing open countryside.
The circular argument
The Annual Infrastructure Funding Statement 2023/24 adds one more data point. New S106 affordable housing commitments in Elmbridge collapsed from 130 units in 2022/23 to 26 in 2023/24 — an 80% fall in a single year. Meanwhile £4.8 million of S106 money already collected was sitting unallocated.
The system is failing at every stage: fewer affordable homes being promised, obligations stripped out through viability, permitted homes not being built, and collected money not being spent. Green belt release adds land into a broken pipeline. It does not fix the pipeline.
What would actually work
Elmbridge needs affordable homes. Genuinely affordable homes — social rent linked to local incomes, not shared ownership at 80% of £743,000. The twelve-year record shows the current system does not deliver them at anywhere near the rate required.
What would make a difference: enforceable build-out requirements so developers can't hold permissions indefinitely; a real brownfield-first approach with compulsory purchase powers to unlock stalled sites; affordable housing obligations set as firm minimums rather than opening positions in a negotiation; and social rent — not shared ownership, not 80% market rent — as a required proportion of every major scheme.
The green belt should be protected not because no development should ever happen, but because releasing this land to these developers under these rules will not build the homes Elmbridge needs. It will build the homes that are profitable. Twelve years of the council's own data say so.
Sources
Elmbridge AMR 2024/25 — elmbridge.gov.uk
Elmbridge Core Strategy (Policy CS21) — elmbridge.gov.uk
Elmbridge AIFS 2023/24 — elmbridge.gov.uk
Elmbridge HDT Action Plan 2025 — elmbridge.gov.uk
Hersham Place viability review — EBC portal, application 2025/2530
Abbey House planning history — EBC portal, application 2022/1272
ONS Elmbridge house prices — ons.gov.uk
CPRE State of the Green Belt 2021 — cpre.org.uk
CPRE State of the Green Belt 2023 — cpreherts.org.uk
CPRE brownfield land research — cpreherts.org.uk
Surrey Live on Hersham Place — getsurrey.co.uk
