MEES 2030 — the headline
Today the legal floor to let a commercial property in England and Wales is EPC E, and letting below it can bring a civil penalty of up to £150,000. The government's June 2026 interim response to the MEES consultation dropped the interim EPC C by 2027 milestone that had been proposed. EPC B is now proposed for 2031, and only for buildings over 1,000 m². That is a proposal, not law yet, but it is the direction of travel, and solar is one of the cheaper ways to move a band.
How EPCs are calculated for commercial
Commercial EPC scoring uses SBEM (Simplified Building Energy Model) — measures the building's modelled energy demand per m² per year, factoring in heating, lighting, HVAC, hot water. The score is 1–150+ on a continuous scale, banded A (≤25) to G (151+). Solar PV directly reduces the modelled energy demand → directly improves EPC band.
Solar's impact on EPC band
Rough rule: 1 kWp of solar per 50 m² of floor area moves the EPC roughly one band higher. A 1,500 m² office building (typical) needs ~30 kWp to move D → C, or ~60 kWp to move D → B. Treat these as rough guides only: the actual band change depends on the building, so get an EPC assessor to model it before you size for a target band.
Why landlords are panic-acting now
Landlords with portfolios face an exposure: 2027 deadline is 11 months away as of May 2026. EPCs take 4–8 weeks to commission and lodge. PV install takes 8–16 weeks. DNO approvals take 6–18 weeks. Backwards from April 2027 deadline = start planning now or risk uplift gap.
The valuation case for landlords
RICS guidance in 2024 acknowledged EPC-driven valuation gaps: D-rated commercial in London commands 4–7% rent discount vs B-rated comparable. Outside London the gap is smaller but still real. PV install of £80k–£200k on a typical office often returns its cost via uplift in rentable value within 24 months — before counting the energy bill saving.
Tenant pressure is real
Big-corporate tenants now refuse to lease E/F rated commercial. Their own ESG reporting (SBTi, CDP, scope-2 disclosure) requires their leased buildings to meet a renewable threshold. Landlords without solar are losing prime tenants.
The PPA route for cash-strapped landlords
Where capex isn't possible, a PPA can secure the EPC uplift without owning the asset. EPC C/B is achieved through verifiable on-site generation (REGO-backed) — same outcome for the band. Landlord then passes lease premium through to tenants while paying PPA per-kWh.
If your building doesn't suit solar
Some buildings genuinely can't host PV — listed buildings without permitted roof access, multi-tenancy office blocks where roof is leased to telecoms, deep-set basements with no sun access. Alternatives: building-mounted vertical PV (low yield but legal compliance), heat pump retrofit, LED + controls, fabric upgrades. KMM can advise on the lowest-cost route per building.
