This week London’s precarious relationship between the development community and its planning polity was tested once again — and the results, taken together, tell you almost everything you need to know about why the brownfield emergency is not resolving.
In Lambeth, success — but only just. The sizeable Vauxhall Square scheme was approved on a 4-3 committee vote, with affordable contributions reduced to 25%. A majority of one. In Southwark, Berkeley Homes was not so fortunate. Its S73 application to revise the Borough Triangle scheme at Newington Causeway — reducing the affordable housing offer from 35% to 10% — was refused.
Two boroughs. Two committees. Two decisions going in different directions within days of each other. That is not a planning system operating with clarity or confidence. It is a system feeling its way in the dark.
What Berkeley asked for — and why
The Borough Triangle site has been in play for the best part of a decade. It is a 1.12 hectare allocated regeneration site in the Elephant and Castle Opportunity Area — one of the most accessible locations in inner London, with a PTAL of 6b. Planning permission was finally granted in June 2025 for 892 homes across four towers, the tallest at 44 storeys, alongside a new food hall for Mercato Metropolitano, community facilities, workspace and nearly 1,800sqm of public realm. That permission was at 35% affordable housing — 153 social rented and 77 intermediate homes — despite the viability assessment at the time showing a deficit. Berkeley took that as a commercial decision, expressing confidence that value growth across a 13-year programme would make the numbers work.
Just over a year later, Berkeley came back via Section 73 to reduce the affordable housing to 10% — 42 social rented and 18 intermediate homes. The buildings are unchanged. The height, massing, design and footprint are identical. The scheme that was too tall to build without 35% affordable housing is now being offered at 10%.
The numbers behind that reduction are stark. Of the 230 affordable homes approved in 2025, 170 are gone. Of the 153 social rented homes, 111 have disappeared. It’s undoubtedly a difficult message to take.
The viability case — and its weaknesses
Berkeley’s Financial Viability Assessment claimed a deficit of £290.6m — 31.9% on GDV. The council’s independent assessors, BPS, came back with a deficit of £82.9m — 9% on GDV. That is a £207m disagreement, which is itself an extraordinary gap. But the critical point is that BPS accepts the scheme is in deficit even on their own more favourable assumptions. Nobody is arguing the scheme is viable. The fight is about how deep the hole is.
The primary dispute is the construction programme. Berkeley’s revised programme runs to 144 months rather than the 108 months previously assumed, because they are pacing private sales to avoid completed units accruing interest while sitting empty. BPS recalculated on standard viability assumptions and the deficit shrank accordingly.
The GLA’s emergency LPG package, published in March 2026, offers a fast-track route at 20% affordable housing with GLA grant funding for affordable units above the first 10%, plus 50% CIL relief on eligible brownfield schemes. Officers asked Berkeley whether they had explored this route. No evidence was produced that they had. Berkeley went straight to 10%. BPS ran the sensitivity test on the council’s behalf and found the scheme remains in substantial deficit even with grant — but that analysis was done by the council, not by the applicant, and Berkeley have not engaged with it formally. That omission was noted and it tells us that the emergency measures are not landing.
Officers, the Aylesham Centre, and the planning balance
Officers recommended refusal on a single ground: the 10% affordable housing offer fails to deliver sufficient public benefits to outweigh the heritage harm to Trinity Church Square Conservation Area. The heritage harm — less than substantial at the upper end of the scale — was accepted in the 2025 permission because 35% affordable housing was judged to outweigh it. With the affordable housing removed, the balance tips.
This is the Aylesham Centre logic applied to a live consent. As PropViews reported earlier this year, the Aylesham Centre in Peckham — another Southwark site, another Berkeley scheme, another council-allocated brownfield location — was refused on less than substantial heritage harm to a clocktower on a site the local plan said should be built on. The refusal was greeted as a great day for Peckham. Eight hundred and sixty-seven homes were not built.
What officers are now doing at Borough Triangle is using heritage as the mechanism through which affordable housing policy is enforced on a viability-tested scheme where the direct policy route is unavailable. They cannot refuse on affordable housing grounds alone because the FVA — independently reviewed — shows the scheme genuinely cannot support more than 10%. So the heritage harm, unchanged since 2025, does the work instead. It is a qualitative judgment, and it is not an unreasonable one in policy terms. But it means the planning system is using different levers to ignore the brownfield viability collapse, and that has consequences for future investment in London.
There is one further point from the committee report that deserves wider attention and did not receive it in the room. Officers advised at committee that even if Berkeley had offered 20% affordable housing, it was not clear that would have been acceptable — because Southwark is actively supporting the legal challenge to the GLA’s emergency LPG measures. That challenge argues the LPG cannot lawfully change development plan policy through supplementary guidance. If the challenge succeeds, the 20% fast-track route disappears entirely. But even before it is determined, Southwark’s participation in the challenge effectively means the emergency measures are unworkable in the borough regardless of what any individual developer offers. The floor has been pulled out from under the very mechanism the government created to address exactly this situation.
What the committee couldn’t hear
Listening to the committee debate, it is clear that Members are finding it genuinely difficult to come to terms with the speed at which the brownfield emergency has gripped the housing market. Councillor Richard Livingstone was careful, thorough and consistently negative throughout, methodically building a case against approval. The drop from 35% to 10% was greeted with scepticism that hardened into something closer to disbelief.
Members found it extremely difficult to understand why a scheme could be in deficit and yet be progressed at all. Berkeley tried to explain that they were banking on growth — that current-day values were the floor, not the ceiling, and that the 13-year programme gave headroom for the market to recover. It didn’t land. That is the same argument Berkeley made in 2025 to get the permission. Members had given them the benefit of the doubt once. They were not prepared to give it again.
What was also striking is what the committee did not engage with. The other community benefits — the new public realm, the Mercato food hall, the community facility, the workspace, the jobs — were largely ignored or pocketed as baseline. You begin to wonder whether schemes of this complexity should strip back everything except the affordable housing cross-subsidy and make that the singular negotiating currency. The more benefits a scheme offers, the more hostages it gives.
Berkeley also accepted a late stage review mechanism — an offer to share any future surplus 50/50 with the council if the scheme performs better than the FVA assumes. This is not nothing. A late stage review on a 13-year programme with current-day value assumptions baked in could materially increase affordable housing delivery if the market recovers. Officers noted it. Members did not treat it as material.
The reset London needs
The broader picture is bleak and getting bleaker. Schemes such as Borough Triangle have almost certainly got worse since they started — changes in regulation, the Building Safety Levy, Gateway 2 and 3 requirements, geopolitical cost pressures, weakening demand and sustained cost inflation have all compounded. What looked like a challenging scheme in 2020 is a fundamentally different proposition in 2026. The planning system has not adapted to that reality. Members are still measuring schemes against the world as it was when the policy was written.
Meanwhile the government’s emergency measures — the fast-track route, the grant funding, the CIL relief — are not landing. The market is not using them because the viability gap is too large for 20% affordable housing to be achievable even with grant on many central London sites. And planners in many Boroughs are supporting a legal challenge that would remove those measures entirely. The emergency package is being flanked from both sides simultaneously.
What London needs is a committee room conversation that starts from a different place. Not: how do we get the maximum affordable housing from this scheme? But: what is the minimum viable offer that gets this scheme built, delivers homes of all tenures into a borough facing acute housing need that everyone can live with. Maybe this isn’t something that can be done now without a more material intervention or more public subsidy. This should not be acapitulation to developers. It is an acknowledgement that a consented scheme with a hole in the ground, a demolished building and a temporary food market is not an asset. It is a liability. And the 832 private homes that get built alongside 42 social rented ones are still 892 households who are not in temporary accommodation.
