solar panels for commercial property in Exeter

Serving Exeter and the wider Devon area, including Topsham, Exmouth, Crediton.

If you own or let commercial property in Exeter, the question is no longer whether to put solar on the roof — it is what the roof is doing to the asset value while it sits empty. Devon’s commercial stock skews older than the national average, and a large share of the units across Marsh Barton, Sowton and the EX postcodes carry EPCs in the D and E bands. Under the Minimum Energy Efficiency Standard (MEES), it has been unlawful to grant or continue a commercial letting below EPC E since 1 April 2023. That is current law in England and Wales, not a proposal — and an E-rated unit with no headroom is one survey revision away from being unlettable.

Rooftop solar is one of the few measures that moves the EPC number, cuts the building’s running cost, and earns a direct return at the same time. For an Exeter landlord, that combination is what makes it an asset decision rather than an energy one.

The stranding risk hiding in Exeter’s commercial stock

The EPC E floor is the line you cannot cross. Above it sits a proposed tightening to EPC B by 2031 — but read that carefully. The B-by-2031 target applies only to non-domestic properties over 1,000 m², it is England and Wales only, and it remains subject to legislation that has not yet been passed. The earlier C-by-2027 milestone was scrapped and a B-by-2030 version never became law, so anyone quoting fixed dates to you is guessing. What is certain is the direction: the standard ratchets upward, and large floorplates feel it first.

That is precisely the Exeter profile. The big single-storey warehouse and trade-counter units on Marsh Barton Trading Estate and Sowton Industrial Estate routinely exceed 1,000 m², which means they are the local stock most exposed to a future B threshold and most worth protecting now. An owner who lifts a unit from E to C today is buying years of letting certainty; one who waits is betting that a tightening standard will not arrive before the next lease event. Our MEES and EPC guide for commercial property sets out how the bands and exemptions actually work so you can model the risk against your own rent roll.

The value side is the other half. JLL’s analysis of prime offices found a green premium of around 11.6% on rent and 20.6% on capital value associated with strong sustainability credentials. Exeter is not central London, so do not transplant those exact figures — but the mechanism travels. A better-rated, lower-running-cost building lets faster, holds tenants longer, and surveys higher. Our green premium and asset value guide explains how to translate efficiency into a valuation case your lender and any future buyer will recognise.

Why Marsh Barton and Sowton are made for solar

Marsh Barton is one of the largest trading estates in the country, and its building stock is close to the ideal solar substrate: low-rise units with broad, flat or shallow-pitched roofs and largely unshaded south-facing area. Sowton, Exeter Business Park and the wider Sowton corridor share that shape. Large roofs spread the fixed costs of an installation over more kWp, which pushes the project into the lowest cost band — typically the £700–£1,100 per kWp range (ex-VAT, with the 0% VAT rate currently applying to commercial solar). The bigger and simpler the roof, the closer you sit to the bottom of that range.

The economics for these estates are essentially the warehouse case, and our industrial and logistics property guide walks through it in full: daytime operations on trade and distribution units mean high self-consumption, and self-consumption — not export — is what drives the return. Every kWh generated and used on site displaces grid electricity at full retail rate. With South West irradiance giving roughly 950 kWh per kWp each year, a well-matched system on a Marsh Barton unit pays back inside the usual 4–8 year window and runs for 25-plus years after that.

Exeter City Council has set a 2030 net-zero target, well ahead of the national 2050 date. That sharpens the case for landlords letting to public bodies, NHS supply chains and ESG-conscious occupiers across the EX area — tenants increasingly screen buildings on carbon, and an estate that can show on-site generation has a real letting advantage over one that cannot.

Ownership routes: who pays, who benefits

The recurring problem in let commercial property is the split incentive. Under a full repairing and insuring (FRI) lease the tenant pays the energy bills, so a landlord who funds solar can find the tenant captures the saving while the owner carries the cost. There are four established ways an Exeter landlord can solve this:

• Common-parts supply. On multi-let estates and managed buildings, power the landlord-controlled load — lighting, lifts, pumps, EV bays, shared services — and recover the benefit through the service charge. Clean and uncontested.
• Tenant PPA. Install the system, then sell the generated electricity to the occupier under a power purchase agreement at a rate below grid. The tenant saves from day one, the landlord earns a metered return, and the asset keeps its EPC uplift.
• Sell the roof. Lease the roof space to a third-party operator who funds, owns and runs the array. You take a rent and the EPC benefit with no capital outlay — useful where you would rather not deploy your own funds across an estate.
• Owner-occupier. If you trade from the building yourself, the case is simplest of all: you fund it, you use the power, you bank the full saving and claim the capital allowances.

Our split incentive guide compares these structures side by side and shows how to draft the green-lease clauses that make them stick. For investment offices and mixed-use blocks elsewhere in your portfolio, the office investment property guide covers the same routes against a multi-tenant rent roll.

On tax, solar counts as special-rate plant, so it qualifies for 100% relief under the Annual Investment Allowance (up to £1m) rather than full expensing — and the panels are exempt from business rates through to 2035. Both materially improve the after-tax return.

Local cost and grid notes

Planning is rarely the obstacle in Exeter. The 1MW cap on rooftop permitted development was removed in December 2023, and most commercial rooftop arrays now proceed under Class J with a 56-day prior approval — fast and predictable for the estate units around Marsh Barton and Sowton.

The genuine bottleneck is the grid. Any system above roughly 50kW needs a G99 connection agreement from the local Distribution Network Operator, and on a constrained part of the network that approval — not the roofers — sets your timeline. We check the connection position before anyone climbs a roof. Our planning and grid guide explains what the DNO assesses and how to design around an export limit if the network is tight.

A worked Exeter example

Take a single-let 2,000 m² trade unit on Marsh Barton, currently EPC E and let on an FRI lease. A roof of that size carries roughly a 250kWp array — comfortably in the lowest £/kWp band, so figure the order of £200,000 ex-VAT at 0% VAT. The occupier runs daytime hours, so self-consumption is high and the system displaces grid power at full rate. Structured as a tenant PPA, the tenant buys that solar below grid and the landlord earns a metered return on the asset; the EPC lifts out of the danger zone, restoring letting headroom and protecting the rent on review. Treat these figures as illustrative — the real numbers turn on your roof, load profile and the G99 outcome.

The point holds whatever route you choose: solar on an Exeter commercial roof is an asset move, not a utility one. See what a commercial system costs for the cost-per-kWp bands, then request a fixed-price feasibility and we will model your specific Exeter building against MEES, the grid and your lease structure.