Glossary definition
Windfall Site
A development site that comes forward for housing unexpectedly, outside the planned allocations in a local authority's local plan. Windfall sites are typically smaller infill plots, garden land, or brownfield sites that become available through changes of ownership or market conditions.
Definition
A development site that comes forward for housing unexpectedly, outside the planned allocations in a local authority's local plan. Windfall sites are typically smaller infill plots, garden land, or brownfield sites that become available through changes of ownership or market conditions. Local planning authorities are required to include a windfall allowance in their housing supply calculations under the NPPF, and lenders will fund windfall developments provided they have satisfactory planning consent.
See also
Closely related terms.
Planning Permission
Formal consent from the local planning authority required before carrying out most types of development, including new construction, material changes of use, and significant alterations to existing buildings.
Site Acquisition
The process of purchasing a development site, including negotiation, due diligence, exchange of contracts, and completion.
Residual Land Value
The value of a development site calculated by taking the gross development value of the completed scheme and deducting all development costs including build costs, professional fees, finance costs, and developer profit.
Further reading
Guides that touch this term.
Guide
How Does Development Finance Work? A Complete Guide for UK Developers
A ground-up guide to how development finance is structured in the UK, covering loan mechanics, drawdown schedules, monitoring surveyors, and what lenders look for in your application.
5 min read readReadGuide
UK Development Finance Market 2026: Rates, Trends and Outlook
A comprehensive overview of the UK development finance market in 2026, covering current interest rates, lender appetite, emerging trends, and what developers should expect over the coming 12 months.
9 min read readRead
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