Eligibility vs PSDS
PSDS is the central public-estate route. Warm Homes is a cross-government scheme aimed at fuel poverty and social housing. Reach into school estates is limited.
Grant rate and bundle size
Warm Homes uses allocation rather than competitive grant for the public-estate tail-end. Bundle sizes are smaller than PSDS.
Sequencing with Phase 5
Where PSDS Phase 5 opens, Warm Homes is a complementary route for adjacent residential. They do not compete for the same school building.