solar panels for commercial property in Cardiff

Serving Cardiff and the wider South Glamorgan area, including Penarth, Caerphilly, Barry.

Cardiff is Wales’s commercial capital, a city of 372,089 people whose office, retail and industrial stock concentrates around the city centre, Cardiff Bay and the M4 corridor estates to the east. For the owners, landlords and asset managers who hold that stock, rooftop solar is no longer a sustainability gesture. It is an asset-protection decision that touches lettability, capital value and the band on your Energy Performance Certificate. We engineer the ownership and lease structure so the right party pays for the system and the right party benefits from it.

This page is written for the people who own the building, not the businesses that occupy it. If you hold a multi-let estate on Hadfield Road, an owner-occupied headquarters near Cardiff Castle, or a logistics box at Capital Business Park, the questions are the same: who funds the array, who consumes the power, and what it does to the value of the asset on your balance sheet.

MEES and the Cardiff stranding risk

The binding rule applies across England and Wales. Since 1 April 2023 it has been unlawful to continue letting a commercial property below EPC E, including to sitting tenants. Fall below the line and you face civil penalties plus an entry on the public breach register. For Cardiff landlords the immediate exposure is not the headline net-zero target; it is any unit drifting towards an F or G rating as older certificates expire and tighter assessment methodology bites.

Beyond the law sits the market reality. The British Property Federation reported in October 2025 that around 83% of commercial buildings across seven major UK cities sit below EPC B. Welsh Government has confirmed a public-sector net-zero target of 2030, and Cardiff Council pursues the same horizon through the Cardiff One Planet Strategy. That public-sector demand pulls private valuations with it: occupiers chasing their own ESG commitments increasingly screen out lower-rated buildings, which compresses the tenant pool for any landlord holding a tired asset.

Solar typically lifts a commercial EPC by one to three bands, never a guaranteed jump, but enough to move a marginal D into safer territory and to signal a credible decarbonisation path at the next valuation. For an investor weighing a hold-versus-sell decision on a Cardiff Bay office, that band movement is the difference between a lettable asset and a stranded one.

The exposure is not evenly spread across the city. Older industrial stock around Pengam Green and the Wentloog corridor tends to sit lower on the EPC scale than the newer offices at Capital Business Park, so the stranding pressure lands hardest on exactly the high-roof-area assets where solar is easiest to install. That alignment is the opportunity: the buildings most at risk of falling below the line are often the ones with the largest, simplest roofs to fund and the highest daytime loads to absorb the generation.

Solving the split incentive on a Cardiff asset

The reason most commercial roofs in Cardiff stay bare is the split incentive: the landlord owns the roof and carries the EPC risk, but the tenant pays the electricity bill and would capture the savings. There are five routes through it, and the right one depends on your tenure.

• Common-parts and landlord supply suits multi-let estates and managed offices, where the landlord meters and supplies shared areas. Read the mechanics in our guide to common-parts landlord supply.
• Landlord-to-tenant PPA lets you install at no cost to the occupier, who buys the solar power below grid rate while you retain the asset and the EPC uplift.
• Roof or airspace lease lets you sell the roof to a third party who funds and operates the system, generating ground-rent income with no capital outlay.
• Owner-occupier captures 100% of the economics, the cleanest case, common among Cardiff trade counters and headquarters buildings.

If you hold tenanted property, start with our guide to the split incentive solved, then look at the property-type detail for multi-let commercial buildings or industrial and logistics property, which together cover most of the lettable stock around Wentloog and Pengam Green.

Local cost, payback and the grid bottleneck

Commercial solar in Cardiff runs at roughly £700 to £1,100 per kWp installed, ex VAT, falling as the system scales. Commercial installs have been zero-rated for VAT since April 2022. A 100kWp array on a city-centre office or retail unit lands around £82,000 to £110,000; a 400kWp roof on a Wentloog shed sits in the £300,000-plus range. South Wales yields around 950 kWh per kWp a year, and payback typically falls between four and eight years, sharper on high daytime-load occupiers such as cold stores, light manufacturing and trade counters where self-consumption is highest.

Self-consumption is the single biggest return driver. A solar-only estate self-consumes roughly 30 to 50% of generation; shift one daytime process and that climbs to 50 to 70%; add storage and you reach 60 to 80%. Against a Cardiff commercial energy bill averaging around £38,000 a year, displacing grid power at 24 to 28p per kWh moves the needle far harder than exporting surplus at a Smart Export Guarantee rate of roughly 12 to 16p.

The real gate on any system above about 50kW is not money or planning; it is the grid. A G99 connection application to the local Distribution Network Operator governs how much you can export and, in constrained pockets of east Cardiff and the Bay, how quickly. Factor the DNO timeline into any acquisition or refurbishment programme; on a larger array the connection study can run to several months, and on a multi-let estate you may need to design the system to self-consume rather than export if local capacity is tight. Sizing the array to the building’s daytime base load, rather than to the available roof area, is usually the move that keeps a Cardiff project both connectable and economic. Our guide to planning and grid for commercial solar walks through the process.

Wales-specific planning and rates

Cardiff is in Wales, so the planning and business-rates regime differs from England. The permitted-development rights and the business-rates exemption that English commentary often quotes do not transfer directly across the border; Welsh planning rules and Welsh non-domestic rating are devolved and set their own terms. Treat any England-specific figure with caution and check the local position before you commit capital. What does apply uniformly is MEES, which is an England-and-Wales measure and bites on every let Cardiff asset below EPC E.

In practice that means rooftop solar on most Cardiff commercial buildings is achievable, but listed structures and conservation-area assets, of which the city has several around the castle and the older civic centre, need careful handling. Welsh Government and Business Wales also run SME grant schemes that can offset cost for owner-occupiers, worth checking against your tenure.

What a Cardiff owner should do next

The named landmarks tell the story of the stock. Around Cardiff Castle sit period and civic buildings where solar is a heritage-sensitive retrofit. The Principality Stadium district and the surrounding retail and office cores carry large, simple roofs ideal for landlord-funded arrays. Mermaid Quay and the wider Cardiff Bay estate mix newer offices and leisure units where green-premium evidence, JLL recorded a rent uplift of around 11.6% on certified prime offices between 2017 and 2021, supports the investment case for owners holding for income.

Start by modelling the numbers on your specific asset. See typical figures on our cost page, then request a quote and we will return the ownership structure, the EPC movement and the payback for your building, not a generic estimate.