Multi-Let Office, Manchester — 320 kWp, Landlord + Tenant PPA

This is a representative project profile, not a named real client. It is drawn from the kind of multi-let office work we do and uses illustrative but realistic figures so you can see how the ownership and lease mechanics fit together. We have anonymised the building and the fund because the structuring is the point, not the address.

The challenge

A regional property fund owned a 1980s multi-let office in Manchester M2 — roughly 4,200 m² of lettable space across six floors, EPC D, three tenants on full repairing and insuring (FRI) leases with around four to six years left to run. The roof was a large, unshaded flat membrane in good condition: physically ideal for solar.

The problem was not the roof. It was who pays and who benefits. Under FRI leases each tenant buys their own electricity directly from their supplier, so a rooftop array does nothing for the landlord’s own position unless the power has somewhere to go. The landlord’s only metered consumption was the common parts — lifts, landlord lighting, the comms room, the ventilation plant — which on its own could not absorb a 320 kWp system. The asset manager had looked at funding the install through the service charge, but the schedule did not allow capital improvements of this size to be recharged to sitting tenants, and three tenants paying for an asset the landlord retains is a hard conversation to win.

Underneath that sat the asset risk. EPC D is lawful to let today, but the building was a long way from the proposed EPC B by 2031 standard now under consultation (the government’s interim response of 18 June 2026 confirmed B by 2031 as a proposal for privately-rented non-domestic buildings over 1,000 m², subject to secondary legislation and a cost-effectiveness test). The fund’s own net-zero pathway, and the next valuation, both flagged the building as exposed.

The structure

We started with the half-hourly (HH) data, not the roof. Pulling 12 months of HH consumption for the landlord supply and modelling the three tenant supplies gave us a real load shape across 14 sub-meters rather than a guessed annual figure. That told us two things: the common parts had a steady daytime base load, and two of the three tenants were daytime-heavy office occupiers whose demand lined up well with a solar generation curve.

That shaped a 320 kWp system feeding three routes through the split incentive:

• Common-parts supply. Solar offsets the landlord’s own metered consumption first, at the landlord’s commercial rate. This is the cleanest economics on the site because there is no counterparty — the landlord generates and consumes behind its own meter.
• Landlord–tenant PPA. The balance is sold to the two daytime-heavy tenants through a behind-the-meter power purchase agreement at 22p/kWh against a grid rate of around 27p. The tenants pay less than the grid for the solar they use; the landlord earns a margin on power it would otherwise export at a much lower rate. Any genuine surplus is exported under the Smart Export Guarantee as a top-up, not the headline.
• Green-lease addendum. Both PPAs were wrapped in a green-lease addendum so the arrangement survives a change of occupier, sets out metering and data-sharing, and aligns the building’s ESG reporting between landlord and tenant.

For the detail on why this matters and how the routes compare, see our guide to the split incentive solved.

The build

The system was specified at 320 kWp on the existing flat roof using ballasted, non-penetrative mounting to protect the membrane warranty. Because the array sits above 50 kW, the real timeline driver was the DNO G99 connection process, not the panels — that application went in early and ran in parallel with everything else. Rooftop solar of this size is permitted development under Class J (the 1 MW cap on commercial rooftop was removed on 21 December 2023), so planning was a 56-day prior approval on design and glint-glare rather than a full application.

Metering was the unglamorous heart of the job. We installed generation and export metering plus sub-metering so that each tenant’s solar consumption is measured independently and billed transparently under the PPA — no estimates, no apportionment arguments. The business-rates exemption for rooftop solar and co-located storage (100% to 31 March 2035 in England) was confirmed with the billing authority so the array did not add to the rates bill.

The outcome

The 320 kWp system generates around 304,000 kWh a year at a typical UK yield of roughly 950 kWh/kWp. Self-consumption across the common parts and the two tenant PPAs sits in the daytime-shift band, with the SEG export as a small top-up. The blended annual saving — landlord margin plus tenant bill reduction — comes to about £71,000 a year, for a payback of around 5.8 years on this representative build.

The asset move was as important as the cash. Solar typically lifts a commercial EPC by one to three bands rather than guaranteeing a fixed jump; on this building, combined with lighting and controls already in train, it took the whole building from EPC D to EPC B. That moved the MEES risk rating from red to green against the proposed 2031 standard and removed the stranding flag from the fund’s net-zero pathway and its next valuation.

“We had looked at solar twice and both times it died on the same question — the tenants buy their own power, so what does the landlord actually get out of it. The honest answer here was the metering and the lease, not the panels. Once the PPA and the green-lease addendum were in place, the numbers worked for everyone and the EPC moved at the same time.” — illustrative asset manager, regional property fund (representative quote)

This is the pattern across most multi-let offices: the engineering is straightforward, and the value is unlocked by getting the supply route and the lease structure right so the right party pays and the right party benefits.

If you own or manage a multi-let building and want to know whether the load shape and lease structure support a project like this, request a quote or read how we approach multi-let commercial buildings — we will model it from your half-hourly data before anyone talks about panels.