PSDS Phase 4 for schools

The Phase 4 portal opened on 9 October 2024 and closed for applications on 25 November 2024, with grant offer letters issued to successful applicants through mid-2025. The window is closed and will not reopen: the government has committed no further investment in the scheme beyond currently awarded projects, so there is no open round to apply for. Schools that did not secure a Phase 4 award must now look to other funding routes such as CIF or a Solar for Schools PPA.

Phase 4 dropped the earlier first-come, first-served model for a targeted approach: Salix ranks bids by grant carbon cost (grant value divided by lifetime carbon saved), so lower-carbon-cost projects have a higher chance of an award. Deliverability and supply-chain readiness also weigh in. Bundled fabric plus heat-pump scopes tend to score better than standalone heat-pump retrofits.

Phase 4 expects applicants to co-fund a share of project costs rather than relying on a 100 per cent grant. Exact match-funding rules are set out in the Salix Phase 4 guidance; match can come from CIF, Salix Recycling Fund loans or trust reserves.

The headline change is the move from first-come, first-served allocation to grant-carbon-cost ranking, which favours deep, well-bundled scopes over standalone short-payback measures such as LED-only projects. Phase 4 also runs on a multi-year delivery profile out to 31 March 2028.