BLOGS

A sector that looks healthy on the surface

Walk through any REalyse regional pipeline view and the build-to-rent (BTR) story looks reassuring. Completed stock keeps climbing, brand-new schemes keep letting up in weeks rather than months, and institutional capital keeps talking up the UK as a structurally undersupplied rental market. London alone now accounts for tens of thousands of completed BTR units, with the North West and South East following as the next-largest established markets.

But completions are a lagging indicator. They reflect decisions made three, four, even five years ago, when funding costs were lower and planning conditions were less punishing. The number that matters for where the market is heading — starts — tells a very different story, and it is not a comfortable one for anyone underwriting rental demand in 2028 and beyond.

Annual BTR starts have fallen 79% to just 3,455 homes, and the number of BTR homes under construction is down 21% year on year. That is not a soft patch. That is a near-collapse in the pipeline replenishment rate, arriving at precisely the moment the sector needs to be building more, not less, to keep pace with structural rental demand.

Starts have fallen off a cliff — construction hasn't caught up yet

The scale of the drop is worth sitting with. A 79% fall in annual starts is not a cyclical wobble; it is consistent with a near-total pause in new scheme launches across large parts of the market. Even allowing for lumpiness in how large single schemes get counted year to year, REalyse planning data shows the volume of newly-started BTR units has stepped down sharply from the highs seen a few years ago, when annual starts were running into the tens of thousands of units.

The 21% fall in homes under construction is, in some ways, the more telling number. Under-construction volumes should lag starts by 18-30 months given typical BTR build programmes, which means today's live construction pipeline is still substantially built on decisions taken before the recent collapse in starts. In other words: the 21% decline is the shadow of a much sharper cliff still working its way through the data. If starts remain depressed at anything close to current levels, under-construction volumes have further to fall before they find a floor.

Why the drop happened

A combination of factors has squeezed BTR starts simultaneously rather than sequentially:

• Higher-for-longer funding costs have compressed development margins on schemes underwritten at 2020-2022 land values and yield assumptions, pushing IRRs below institutional investment thresholds.

• Build cost inflation, while easing from its 2022-23 peak, has not fully unwound, keeping GDV-to-cost ratios tight on marginal sites.

• Planning and building safety requirements — including post-Building Safety Act sign-off processes for taller schemes — have lengthened the time between consent and start on site, particularly for the high-density urban schemes that make up a large share of BTR volume.

• Land competition from build-to-sell and affordable-led schemes has, in some local authorities, made BTR-specific land assembly harder to justify at current rents.

None of these factors is BTR-specific in isolation, but their combined effect has landed disproportionately on a sector that depends on large, single-let schemes with long lead times and thin margins for error.

The regional divergence hiding inside the national number

The national headline masks a sharper regional story. REalyse planning and pipeline data shows BTR supply — both completed and in the pipeline — remains heavily concentrated in London, which holds the largest share of completed stock and a pipeline roughly double the size of its next largest regional competitor.

Outside London, the picture is more fragile. Regional markets such as the North West, South East, West Midlands and Yorkshire and the Humber have built meaningful completed BTR bases over the past cycle, but their forward pipelines — while still sizeable in aggregate — are dependent on a comparatively small number of large schemes progressing on schedule. Smaller regional markets, including Wales, the North East and Northern Ireland, have negligible pipeline volumes in absolute terms, meaning any further slippage on starts there could stall BTR delivery in those markets almost entirely for several years.

For institutional investors and lenders benchmarking regional diversification strategies, this matters. A national narrative of "record completed stock" can obscure the fact that several regional markets are now running on a pipeline thin enough that a handful of stalled or delayed schemes would materially change the local supply outlook.

What a two-to-three-year gap could mean for rents and yields

If starts remain depressed through 2026-2027, the practical effect will show up first in completions data around 2028-2029 — precisely when current under-construction schemes are due to finish and hand over. A thinner completions pipeline landing into markets with structurally tight rental supply is, on past form, a set-up for further asking rent growth rather than the moderation that some forecasters have pencilled in.

For investors and lenders, this creates a genuine underwriting tension. Schemes reaching practical completion over the next 12-18 months are stepping into markets where competing new supply is scarcer than at any point in recent years — a potentially favourable backdrop for achieved rents and lease-up speed. But the same dynamic that supports near-term rental growth also signals a widening supply gap that could constrain portfolio growth ambitions for anyone planning to scale BTR exposure through new development rather than acquisition.

Gross yields on existing BTR assets may hold up better than headline cap rate compression elsewhere in real estate, simply because replacement supply is not coming through fast enough to compete away pricing power. For lenders assessing forward-funding and development finance applications, the case for supporting well-located, planning-secured schemes arguably strengthens the longer this starts drought persists — scarcity value is building in real time.

Outlook: the gap will show up, the question is where first

The UK BTR sector is not shrinking — completed stock and total pipeline volumes remain substantial by historical standards. What is shrinking is the rate of replenishment, and that gap will not stay hidden behind strong completions data for much longer. The most exposed markets will be those regions where pipeline was already thin relative to rental demand before this slowdown began.

For developers, the opportunity lies in being among the few bringing forward viable schemes while land and construction competition is muted. For investors and lenders, the priority is distinguishing between markets where completed stock reflects a genuinely mature, well-supplied sector and those where today's numbers are the last wave of a pipeline that is not being refilled. REalyse's planning, pipeline and rental comparables data can help separate the two — because by the time the completions numbers turn, the underwriting decisions will already have been made.