BLOGS

The UK's residential development pipeline is under severe strain. Housing starts have collapsed, planning approvals have hit 15-year lows, and developers across the country are pausing or shelving projects that no longer stack up financially. The situation is most acute in London, where just 5,500 to 7,500 homes broke ground in 2025 — a fraction of the capital's 88,000-unit annual requirement.

This is not a cyclical slowdown. Industry leaders describe it as a structural crisis, where the economics of housebuilding have fundamentally shifted. For investors, developers and lenders, understanding the scale of the challenge — and the policy responses now emerging — is essential for navigating the years ahead.

The viability squeeze: costs outpacing values

At the heart of the crisis lies a widening gap between build costs and achievable sales values. According to BCIS data, construction costs rose by 21.8% between Q3 2021 and Q3 2025, while average sales values increased by just 13.1% over the same period. The Home Builders Federation's "Viability Crunch" report found that the cost of building a single home has risen by £76,000 since 2020 — equivalent to roughly a fifth of the average UK house price.

For high-density and tall-building schemes, the picture is even starker. Tender price inflation for London apartment projects has exceeded 23% over five years, with some industry forecasts suggesting construction costs could rise a further 27% before house price growth catches up.

REalyse data shows significant volumes of residential planning applications across the UK, with withdrawn applications and projects stuck in pending status reflecting the difficult viability environment. Major schemes of 50 or more units face particularly challenging conditions, with many developers unable to achieve the forward sales needed to unlock development finance.

Development finance remains available but has become increasingly selective and expensive, with typical borrowing costs ranging from 7% to 12% per annum. Many lenders report struggling to deploy capital due to a lack of viable schemes coming forward.

Planning and regulatory bottlenecks

The viability challenge is compounded by planning delays that stretch timelines and erode returns. Planning permission was granted for just 209,781 new homes in the year to September 2025 — the lowest figure since 2013 and 38% below the peak seen in early 2022. In Q2 2025 alone, approvals fell 19% year-on-year to just 42,239 homes.

High-rise residential schemes face additional friction from the Building Safety Regulator, which introduced new Gateway 2 checks for buildings over 18 metres. These checks have added an average of 26 weeks to planning timescales, with many applications ruled invalid at first pass due to missing information. As of January 2026, there were 170 live new-build cases at the BSR covering over 37,000 units, creating a significant backlog.

For developers, these delays translate directly into increased costs and greater uncertainty. Higher interest rates have amplified the time value of money, meaning every additional month in planning erodes scheme viability. REalyse analysis of planning application data shows substantial volumes of applications remaining in pending status month after month, with approval rates for major schemes well below historical norms.

London: the epicentre of the crisis

London's housing delivery has fallen to what industry figures describe as "crisis levels." Only 3,248 private housing starts were recorded in the first nine months of 2025, and completions for the year reached just 33,000 — only 37% of the 88,000 homes needed annually.

The off-plan sales market that traditionally underwrites development finance has collapsed. A decade ago, more than half of all new London homes were sold before completion. In 2025, that figure fell to just 11%. Developers are now sitting on more than 22,000 unsold homes in the capital, including 3,600 completed units lying empty and a further 18,700 still under construction.

Affordable housing delivery has been hit particularly hard. Starts in London collapsed from 26,386 units two years earlier to just 4,522 in 2024/25. The GLA's Affordable Homes Programme target for 2021–2026 was cut by more than a fifth, yet developers would still need to start over 11,000 affordable dwellings before March 2026 to meet even the revised goal.

Build-to-rent, often seen as a more resilient sector, has not been spared. Construction of new rental homes in London fell by 80% in 2025, while regional build-to-rent starts dropped 37%. Completions have outpaced starts for eight consecutive quarters, pointing to long-term pipeline problems.

REalyse planning data for London shows ongoing activity concentrated in a narrow band of boroughs, with pipeline units heavily weighted towards schemes still awaiting commencement. The gap between consented units and actual construction starts reflects the viability pressures that have frozen much of the development pipeline.

Policy responses and the path forward

The government has acknowledged the scale of the challenge. In October 2025, Housing Secretary Steve Reed and Mayor Sadiq Khan announced a package of emergency measures for London, including a time-limited planning route for stalled schemes, a 50% Community Infrastructure Levy discount for qualifying developments, and an initial £322 million allocation for a new City Hall Developer Investment Fund.

From May 2026, the Mayor will gain expanded powers to call in and review applications for schemes of 50 homes or more where boroughs are minded to refuse. The measures are designed to run until March 2028, providing a window for developers to bring forward stalled projects.

At the national level, the £16 billion National Housing Bank is set to launch as a subsidiary of Homes England, offering lending products targeted at smaller developers. The updated National Planning Policy Framework introduces a distinct medium-site category for schemes of 10 to 49 homes, easing some administrative burden.

However, new cost pressures loom. The Building Safety Levy, launching in October 2026, will add between £12.70 and £100.35 per square metre depending on location — hitting London particularly hard. Landfill Tax is set to double in April 2026 and rise further in subsequent years. Industry bodies estimate these measures could add around £3,000 to the cost of delivering each new home.

The Bank of England has cut rates six times since 2024, bringing the base rate to 3.75%, which should help improve development finance pricing and buyer affordability. Further cuts are expected through 2026. If planning reforms and funding measures begin to unlock stalled schemes, the market could stabilise — but the lag between policy action and housing delivery means completions will likely fall further in 2027 and 2028 before any recovery materialises.

Outlook for the pipeline

The next 12 to 18 months will be critical. REalyse data shows substantial residential pipeline capacity across UK regions, but converting planning permissions into active construction remains the central challenge. Developers report that buyer confidence, rather than planning delays alone, has become the primary constraint on bringing schemes forward.

For investors and lenders, the focus should be on scheme-level viability assessment, monitoring local pipeline data, and understanding which markets and product types can still achieve acceptable returns. Medium-rise apartment blocks and family housing formats are gaining favour over high-rise schemes, reflecting both buyer preferences and the regulatory complexities of tall buildings.

The government's 1.5 million homes target by the next election looks increasingly out of reach without sustained improvement in viability conditions. But the combination of policy reform, funding intervention and eventual cost stabilisation should help rebuild the pipeline over time. For those with the capital and appetite to proceed, opportunities will emerge — particularly in locations where emergency measures apply and where REalyse market intelligence can identify schemes trading below viability thresholds that may unlock with modest policy support.