Build 150,000 social homes: note

Central fiscal result

+£18.0bn - Net fiscal impact in 2028-29

Low case: +£8.0bn. High case: +£40.0bn. Positive numbers are fiscal costs or borrowing pressure. Negative numbers are Exchequer savings or receipts.

Scenario and baseline

• Models build 150,000 social homes by 2028-29.
• Baseline is current policy or published departmental plans.
• Central case uses published party or official anchors where available.
• Wider manifesto interactions are excluded unless stated.

Affected population

• Affected units are people, firms, households or providers depending on policy.
• Direct exposure follows the manifesto or government target group.
• Indirect exposure includes suppliers, workers, consumers and taxpayers.
• Weakest counts are widened in the low and high cases.

Gross impact

• Published anchor or scenario central is +£18.0bn in 2028-29.
• Gross costs or receipts are adjusted for behaviour and delivery risk.
• Tax, benefit or procurement offsets are separated in the fiscal build-up.
• The range is deliberately wider where implementation detail is thin.

Fiscal build-up, central case

• Gross programme or delivery cost: +£20.7bn
• Tax and receipt offsets: -£1.4bn
• Administration and evaluation: +£0.1bn
• Behavioural and pass-through effects: -£1.4bn

Central net impact: +£18.0bn in 2028-29.

Behaviour and pass-through

• Low case assumes stronger delivery or receipts than central.
• Central case applies moderate behavioural leakage and pass-through.
• High case allows weaker delivery, larger take-up or higher costs.
• Output effects follow incidence, capacity and investment channels.
• Distributional gains do not automatically imply GDP gains.

Phasing

• 2026-27: +£1.8bn. Phased implementation and take-up.
• 2027-28: +£9.9bn. Phased implementation and take-up.
• 2028-29: +£18.0bn. Phased implementation and take-up.
• 2029-30: +£18.0bn. Phased implementation and take-up.

Main source groups

• Glaeser and Gyourko, "The Economic Implications of Housing Supply" (Journal of Economic Perspectives, 2018): Constrained housing supply raises prices and can damage mobility and productivity; explains why supply reform can raise GDP.
• Institute for Fiscal Studies, "Green Party manifesto: a reaction" (2024): IFS warned Green spending plans involve very large additional public investment; supports wide fiscal bounds for housing capital policy.
• Local Government Association, "Green Party manifesto summary" (2024): Used to define the pledge wording, policy scope and implementation scenario being modelled.
• Hilber and Vermeulen, "The Impact of Supply Constraints on House Prices" (Economic Journal, 2016): Tight planning constraints raise house prices and limit the effect of demand-side policy; supports planning and housing-supply analysis.
• Office for National Statistics, "Housing supply indicators, UK" (2025): ONS housing indicators show supply constraints and affordability pressures across UK housing markets; anchors the affected-market scale and supply-side caveat.
• Green Party of England and Wales, "Manifesto for a Fairer, Greener Country" (2024): The manifesto defines the tax, spending, climate, housing and public-service proposals modelled here; used to define the scenario, not as an official costing.