How we helped a London landlord split a poorly insulated commercial building into three separately lettable units, each with a staged MEES improvement roadmap targeting Band B and a pathway to Band A.
Energy Performance Direct was commissioned to carry out a comprehensive commercial energy assessment and MEES advice report for a mixed-use building on Vyner Street in London's Bethnal Green. The client intended to split the existing single building into three separately lettable units and needed to understand the EPC implications before proceeding.
The building presented some of the worst-case fabric conditions we encounter: solid brick walls with no insulation, a flat concrete roof with minimal or no insulation, single-glazed windows in poor condition, and a combination of gas warm air blowers, electric fan heaters, and a gas boiler. The whole-building baseline EPC scored G214 — well below the MEES minimum of Band E. None of the three proposed units could legally be let without significant improvement works.
We modelled each of the three units separately using SBEM calculations, providing staged improvement pathways for each. The client could then decide which level of investment to make for each unit based on their plans — whether that was minimum compliance, future-proofing for the proposed 2030 Band B requirement, or pushing to Band A with whole-building solar PV.
G214
Whole Building Baseline
B32
Best Unit Rating
3
Units Created
72%
Max Energy Reduction
The building presented multiple challenges typical of older London commercial properties that have never been thermally upgraded:
Solid brick walls (1.70 W/m²K)
Completely uninsulated solid masonry. Over 6x worse than current Part L requirement of 0.26 W/m²K.
Flat concrete roof (up to 7.14 W/m²K)
Workshop area had effectively no roof insulation at all. First floor roof at 2.80 W/m²K — 15x worse than required.
Single-glazed windows (6.35 W/m²K)
Original windows in poor condition with fabric failure. Nearly 4x worse than the 1.60 W/m²K Part L limit.
Gas warm air blower (workshop)
High-emission gas-fired warm air heating in the rear workshop. A major drag on the EPC score.
Mixed electric fan heaters
Electric resistance heating in office areas — expensive to run and penalised in SBEM calculations.
Gas boiler (first floor)
Natural gas boiler serving the first floor offices. Gas heating carries a significant carbon factor penalty.
Offices · 126 m²
21.26
kgCO2/m²/yr
220.63
kWhpe/m²/yr
126 m²
Floor Area
Single measure achieves legal minimum for letting.
27-point headroom above Band E threshold.
Meets proposed 2030 Band B MEES target.
Just 13 points from Band A. Full summer comfort and future-proofing.
Workshop / Storage · 78.8 m²
39.6
kgCO2/m²/yr
247.46
kWhpe/m²/yr
78.8 m²
Floor Area
Removing the inefficient gas blower alone achieves MEES compliance.
29-point headroom above Band E threshold.
Just 7 points from Band A. 64% running cost reduction.
Offices · 210 m²
76.65
kgCO2/m²/yr
448.15
kWhpe/m²/yr
210 m²
Floor Area
Fabric-first approach skips Band E entirely to Band D. 63% heating demand reduction.
Meets proposed 2030 Band B MEES target.
72% energy reduction vs baseline. Full future-proofing.
With the recommended Stage 3 improvements in place across all three units, the building is positioned for a final push to Band A through whole-building renewable energy generation.
We recommended a solar PV array of up to 24 kWp on the flat roof, estimated to generate 20,000 to 22,000 kWh per year. Combined with battery storage to maximise self-consumption, this measure is expected to push all three units into Band A — far exceeding any current or proposed MEES requirement.
24 kWp
Solar PV Array
22,000
kWh/yr Generation
Band A
Projected for All Units
Each new unit requires its own EPC before it can be let. The whole-building EPC cannot be used once the building is divided. We modelled all three separately.
Decommissioning gas heating (blowers and boilers) and replacing with ASHP systems delivered the largest single improvement across all three units.
Roof insulation and window replacement were essential prerequisites. The first floor achieved Band D from fabric measures alone — a jump of 126 points.
The client could achieve minimum MEES compliance quickly and affordably, then invest in deeper upgrades as tenants were secured and income flowed.
Whether you're splitting a building, upgrading for compliance, or future-proofing for 2030, we provide clear, costed improvement roadmaps backed by full SBEM modelling.