Mixed-Use Commercial: Solar panels for commercial property

Why mixed-use commercial buildings are the most underserved opportunity in property solar

Mixed-use commercial buildings, a parade with shops below and offices above, a multi-let estate, a building with several tenants under one roof, are where solar advice is thinnest on the ground and where a building owner stands to gain the most by getting it right. The roof is usually generous and shared, the combined daytime demand across tenants is substantial, and yet most installers shy away because the metering and the lease structure are more involved than a single-occupier unit. That complexity is exactly the gap. Done properly, solar on a mixed-use building lets a landlord cut landlord-supplied loads, offer tenants cleaner cheaper power, and lift the value of the whole asset at once.

This is also the area where the published advice is weakest, which works in your favour. Most installers and most online guides treat solar as a single-occupier decision and have little to say about how a landlord shares the benefit across separately metered tenants, how the cost is recovered through a service charge, or how a sleeved arrangement actually works in practice. The result is that landlords with multi-let buildings often assume solar is too complicated to bother with, when in reality it is a solved problem with two or three well-understood routes. Getting the structure right at the outset is what turns a complicated-looking building into one of the better solar opportunities in commercial property.

For a landlord, the asset-value case is the headline. Minimum Energy Efficiency Standards apply to every let part of the building, and the threshold rises to band C by 2027 and band B by 2030 for non-domestic property, so an EPC improvement across multiple units protects the lettability and capital value of the entire holding rather than just one tenancy. Solar is one of the few measures that can move several units up a band from a single project, which is why it deserves more serious attention than it usually gets on multi-let commercial property. There is also a tenant-relations dividend: in a market where occupiers increasingly ask landlords about energy and ESG before they sign, being able to offer on-site renewable power and a better EPC is a genuine letting advantage rather than a cost to be recovered grudgingly.

What a typical install looks like and how we size it

For a mixed-use commercial building we usually design a system in the 40 to 200 kW range, which is roughly 75 to 370 panels across about 240 to 1,200 square metres of roof. A system that size generates in the region of 37,000 to 185,000 kWh a year and saves somewhere between 8 and 42 tonnes of CO2 annually. The sizing challenge here is the metering: multiple tenants and multiple meters complicate the self-consumption picture, so we map every meter and load before we propose a system. Where a single connection serves landlord areas, the array can offset those directly; where tenants are separately metered, an allocation model such as a sleeve PPA or virtual net metering is the route, and we model the option that fits your building and leases.

Because the demand on a mixed-use building is the sum of several different occupancy patterns, the load curve tends to be flatter and steadier than a single tenant would produce, which actually helps self-consumption: a shop, an office and a cafe under one roof rarely all go quiet at the same moment. We pull half-hourly data from the landlord supply and, where tenants are willing, from the tenant supplies too, so the system is sized to the genuine combined daytime demand rather than to one meter in isolation. We are careful not to oversize against the landlord-only load if a sleeved or virtual arrangement is not yet in place, because surplus exported at a low rate undermines the case. Every design is battery-retrofittable, which suits a building whose tenant mix may change over a long hold.

Costs, payback and tax relief

A mixed-use project typically lands between £36,000 and £180,000 depending on roof area and tenancy mix, with a simple payback near 7 years and effectively free electricity for the system's life after that. Cost per kW sits in the usual £900 to £1,300 band below 100 kW and falls toward £750 to £950 per kW on the larger schemes, so a sizeable shared roof buys cheaper generation. The 100% Annual Investment Allowance lets a profitable company write off the full qualifying cost against profit in year one, an effective saving of around a quarter of the project value for a limited company against current corporation tax rates, which applies to the plant the landlord owns.

The Smart Export Guarantee pays for any surplus, which is common on buildings with variable tenant occupancy, at rates that have run between 4 and 15p per kWh. The economics on mixed-use are unusually sensitive to how the benefit is allocated: a building where the landlord can pass cleaner power to tenants and recover the cost cleanly will outperform one where the array only offsets common-area lighting and lifts and exports the rest. Our cost guide works through how the economics change with the landlord-versus-tenant split and the allocation model you choose.

Funding routes in detail

For a landlord, the 100% Annual Investment Allowance applies to the qualifying plant the landlord owns, and asset finance over five to seven years can keep the project cash-flow positive against the recovered savings. Where the install benefits tenants, cost recovery through the service charge is often the cleanest mechanism, subject to the lease and the RICS Code on Service Charges, and a green-lease addendum is the usual way to put the right to install and the recovery of cost on a firm footing for both sides. Done well, the service-charge route can be neutral or positive for tenants, because the cleaner power they receive offsets the recovered cost.

Several combined authorities, including Greater Manchester, the West Midlands, West Yorkshire and Liverpool City Region, have run SME decarbonisation grant rounds worth roughly £5,000 to £50,000 under names that change between rounds, which can apply to occupying SMEs within the building, and the British Business Bank Recovery Loan and Growth Guarantee scheme can fund capital investment from £25,000 upwards with a government-backed guarantee. A power purchase agreement is another route for landlords who want no capital outlay, with a funder owning the array and selling its output into the building. We model the funding around your ownership and lease structure rather than assuming a single owner-occupier, and we bring in your managing agent and accountant where the recovery mechanics need it.

Compliance and sector considerations

The defining compliance issue on mixed-use property is the lease, not the roof. The service charge and lease structure need review before anything is committed, because the right to install, the recovery of cost and the allocation of benefit all flow from those documents, and the RICS Code on Service Charges 2018 applies to how any cost is shared. A green-lease addendum is often the tidiest way to set the terms. Beyond that, the building may straddle different planning positions, with industrial parts under Permitted Development and a retail or conservation frontage needing consent, and any pre-2000 part needs an Asbestos Management Survey.

Grid connection on a multi-let building can be more involved than on a single occupier, because the supply arrangement, the position of the metering and whether a new landlord connection is needed all feed into the application: below 100 kW the faster G98 route usually applies, while above 100 kW it is the longer G99 process. Where a sleeved or virtual net metering arrangement is used to pass power to tenants, we make sure the metering and the supplier contracts support it before committing to the design. We provide the post-install EPCs for the affected units so the rating uplift is recorded against each tenancy, notify the insurer with the certification they need, and we are MCS certified for commercial work, NICEIC registered, and RECC and TrustMark licensed.

How we approach this kind of project

We start by mapping every meter and lease, because on mixed-use property the metering and tenancy structure decide what is even possible before any panel is sized. We model from half-hourly data across the relevant supplies, size for genuine self-consumption rather than nameplate, and recommend the allocation model, direct offset, sleeve PPA or virtual net metering, that fits your building. We check the roof build-up and any asbestos before quoting, and we submit the grid application early, G98 below 100 kW and G99 above, so the connection does not stall the programme.

What sets a mixed-use project apart is the groundwork most installers leave you to sort out alone. We help frame the green-lease addendum, work alongside your managing agent on the service-charge recovery, and set out clearly how the benefit reaches each tenant, so the scheme is defensible to occupiers and to any future buyer of the building. You get a fixed-price proposal backed by PVSyst modelling that we share rather than withhold, a clean handover pack for your accountant and managing agent, optional live generation displays for common areas, and a 10-year insurance-backed workmanship warranty behind the install with a long-term output warranty behind the panels. Timescales from contract to commissioning typically run eight to sixteen weeks for sub-100 kW systems, with the connection the usual variable.

An illustrative example

As an illustrative composite based on typical mixed-use projects: a landlord-owned parade with ground-floor retail and first-floor offices, several separately metered tenants and a shared roof, installed around 120 kW across the roof, about 220 panels generating in the region of 110,000 kWh a year. The landlord offset the common-area and landlord supplies directly and used a sleeved arrangement to pass cleaner power to tenants through the service charge under a green-lease addendum, the qualifying plant was written off under the Annual Investment Allowance, and the EPC uplift improved the lettable value across multiple units. The payback landed near 7 years. The figures are illustrative and depend on your building, tenancy mix, leases and tariff.

For the single-use building types that often sit within a mixed estate, see solar for offices and retail and showrooms. When you are ready, read the cost guide, check the grants and funding routes, request a free feasibility, or read the commercial solar FAQs.