BLOGS

The mega-site pipeline is bigger than most people realise

Halfway through this Parliament, the housing debate has shifted from "will enough sites get permission?" to "will enough of them get built?" REalyse planning data shows 76 residential schemes of 1,000+ units have secured approval across Great Britain in the past 24 months alone, totalling in the region of 163,000 consented units, with individual scheme sizes ranging from 1,000 units up to Gilston Garden Town's 8,500 units in Essex.

This is not a thin pipeline. Alongside Gilston, The Green Quarter in Southall (8,010 units), Waterbeach Village near Cambridge (6,500 units) and Welborne Garden Village in Hampshire (6,000 units) all sit within the current top tier of consented schemes. Projects like the 4,000+ home Elms Park development fit a now well-established pattern: large, phased, garden-community-style masterplans clustered around growth corridors rather than standalone estates.

The geography is telling. Cambridgeshire alone accounts for over 15,000 approved units, driven by Northstowe and Waterbeach's garden town expansions, while Greater Manchester (12,300+ units) and a cluster of South East counties — Kent, West Sussex and Wiltshire, each above 10,000 units — round out the leading growth corridors. Central London still leads on scheme count, with 1,348 approvals since January 2025, but the largest individual sites by unit volume increasingly sit outside the capital, on garden town and urban extension land where infrastructure funding has been pre-committed.

New towns and delegated powers: from taskforce to test case

The New Towns Taskforce reported in September 2025 with 12 candidate locations, each expected to deliver at least 10,000 homes as part of genuinely new or substantially expanded settlements. That list has since been narrowed to seven locations, with a formal government consultation launched on 22 March 2026 running to 19 May — a shift the sector reads as prioritising deliverability over headline volume. Ministers have committed to starting construction on at least three new towns within this Parliament, with final site decisions and a full government response expected by spring 2026, alongside new development corporation powers modelled partly on the Olympic Park delivery vehicle.

The parallel policy lever is delegation. The Planning and Infrastructure Bill, alongside a revised National Planning Policy Framework consulted on through to March 2026, aims to streamline local decision-making, introduce a "default yes" for suitable housing near rail stations, and give the Secretary of State stronger intervention powers where local authorities consistently under-deliver against housing targets. Combined with a further £48 million committed at the Autumn Budget for planning capacity, and existing New Homes Accelerator activity, the direction of travel favours large, pre-approved, infrastructure-led sites over piecemeal permissions — precisely the mega-scheme model REalyse's planning data is now capturing at scale.

Does the pipeline support the 1.5 million target?

The arithmetic remains the central tension. Meeting 1.5 million homes over this Parliament requires roughly 300,000 net additional dwellings a year. Official data shows 208,600 net additions in 2024/25, down from 221,410 the year before, and approximately 275,600 net additions delivered between the start of Parliament (9 July 2024) and 9 November 2025 — around 18% of the target against 27% of the parliamentary term elapsed. The Office for Budget Responsibility's central case now points to 1.1–1.3 million net additions in England by 2029/30, materially short of the 1.5 million ambition.

Against that backdrop, the mega-site and new towns pipeline matters less for its total unit count and more for its sequencing. Garden towns like Waterbeach and Northstowe are being delivered in phases — REalyse data captures reserved matters approvals moving through incrementally (Waterbeach Village Masterplan's reserved matters granted in September 2025, Northstowe Phase 3A in July 2025) rather than single bulk consents converting instantly into completions. That phased structure is by design: it lets housebuilders match delivery to sales absorption and mortgage market conditions, but it also means large approved unit counts can sit on the books for years before meaningful volumes of homes complete.

For investors and lenders, this creates a genuine analytical opportunity rather than a simple bottleneck. Comparable data across garden town phases can help underwrite realistic absorption rates and price growth assumptions, rather than relying on developer-stated delivery timetables. Areas with strong approved pipelines — Cambridgeshire, Greater Manchester, parts of the South East — are also the markets where land values and rental supply are most likely to move first, often 18–36 months ahead of first completions, as local comparables and REalyse-tracked planning stage data start to reflect anticipated new supply.

Outlook: volume is no longer the constraint — delivery capacity is

The planning system has, in a genuine sense, done its job of generating large-scale consents. The binding constraints now sit downstream: construction capacity, mortgage affordability with rates still around 4.5–5% on typical two-year fixed products, Building Safety Levy costs, and the compulsory purchase and funding mechanics needed to get new towns' development corporations acquiring land by spring 2026 as planned.

For developers and investors, the practical takeaway is to treat the mega-scheme and new towns pipeline as a leading indicator rather than a guaranteed outcome. Tracking planning stage progression — from outline to reserved matters to first completions — alongside local comparables, absorption rates and rental yield data will matter more over the next 24 months than the headline size of any single consented scheme. The 1.5 million target may ultimately be missed on the government's own timetable, but the mega-site pipeline it has unlocked is likely to reshape supply and pricing dynamics in its target growth corridors regardless of whether the national number is hit.