Working file M4
Retrofit renewables cost (UK 2026)
Solar PV and battery storage in a 2026 retrofit: installed cost ranges, 0% VAT, Smart Export Guarantee.
Renewables sit in the fourth stratum because their sizing depends on the post-fabric, post-HP electrical demand. A battery sized to a pre-retrofit house is a battery that runs through one charge cycle a day rather than two.
Surveyed 22 June 2026. Ofgem Q3 2026 cap applied (gas 7.33p, elec 26.11p, gas standing 29.04p). Next scheduled review 26 September 2026 (Q4 cap publication). [ref M4]
By Oliver Wakefield-Smith, Founder, Digital Signet. Corrections to oliver at digitalsignet dot com.