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 1 October 2026. Ofgem cap for 1 October to 31 December 2026 applied (gas 7.97p, elec 26.32p, gas standing 29.68p, elec standing 54.83p). Next scheduled review 25 November 2026 (January cap announcement). [ref M4]
By Oliver Wakefield-Smith, Founder, Digital Signet. Corrections to oliver at digitalsignet dot com.