How can these improvements really be completely free?

The funding comes from major energy suppliers (like British Gas, EDF, Scottish Power) who are legally required to contribute to these government schemes. They pay into a fund that covers all costs – materials, labor, and administration. You’re not getting a loan or entering a payment plan. The energy companies essentially pay for your improvements as part of their regulatory obligations. Think of it like how the NHS is “free” – it’s funded through a system you’re already part of.