solar panels for commercial property in London

Serving London and the wider Greater London area, including Croydon, Bromley, Dartford.

London holds the densest concentration of let commercial property in the UK, and with that density comes the country’s largest pool of stranding risk. For the owners, investors and asset managers behind those buildings, solar is no longer a sustainability gesture; it is a tool for protecting lettability, defending capital value and resolving the split incentive that has held rooftop investment back for two decades. This page is written for the people who own the asset, not the people who occupy it.

Why London’s commercial stock faces the sharpest stranding risk

The capital is home to roughly 8.9 million people and the deepest commercial market in Europe, spanning City and West End offices, the industrial and logistics belt at Park Royal, mixed-use regeneration at Greenwich Peninsula and Stratford, and the retail and trade stock along the Old Kent Road industrial area and Brent Cross. A large share of that stock predates modern energy standards.

The binding law is clear: since 1 April 2023 it has been unlawful to continue letting a commercial property in England and Wales below EPC E, including to sitting tenants. That floor already catches a meaningful slice of older London buildings. Above it sits a proposal, not yet law: the government’s interim response of 18 June 2026 set out EPC B by 2031 for privately-rented non-domestic buildings over 1,000 m², only where cost-effective and subject to secondary legislation. The earlier “EPC C by 2027” idea was scrapped, and “EPC B by 2030” was never law. We will not pretend the proposal is settled, but London’s exposure to it is real: CBRE has estimated that around 58% of Central London offices sit below EPC B, and the BPF reported in October 2025 that roughly 83% of commercial buildings across seven major UK cities fall short of a B rating.

For a London landlord, the financial mechanics of MEES are not abstract. Breach the EPC E floor and the penalty runs up to 10% of rateable value (capped at £50,000) under three months, rising to 20% (capped at £150,000) at three months or more, alongside entry on a public breach register. On prime central rateable values, those caps are reached quickly.

What solar actually does for the asset

Rooftop solar typically lifts a commercial EPC by one to three bands; it is not a guaranteed jump, and on a deep-plan building it may need to sit alongside other measures. But for a landlord pushing a borderline D or E asset toward a more defensible position, it is one of the few interventions that improves the rating and pays for itself.

The value story is narrower and should be stated honestly. JLL’s analysis of prime central London offices (BREEAM-rated, 2017–21) found green-certified buildings associated with around 11.6% higher rent and 20.6% higher capital value, with roughly 4.2% rent and 3.7% capital value attributable per EPC band. Knight Frank has put the rental premium in the 3.7–12.3% range. Those figures are specific to prime central London offices and should not be stretched across the whole market, but for a Shard-adjacent or Canary Wharf institutional asset they describe a premium worth engineering toward.

Solving the split incentive

The reason most London roofs are still bare is structural: the landlord owns the roof and pays for the system, while the tenant under a full-repairing-and-insuring lease pays the energy bills and the rates. There are five routes through this, and the right one depends on the lease structure:

• Common-parts / landlord supply — the array feeds landlord-controlled load (lifts, lighting, mechanical plant in a multi-let building), with the landlord taking the full benefit. See common-parts landlord supply.
• Landlord-to-tenant PPA — the landlord owns the system and sells the generated power to occupiers below grid rate via a private wire.
• Roof or airspace lease — the landlord leases the roof to an operator who funds, owns and runs the array, paying rent for space that previously earned nothing.
• Green leases — service-charge and rent-review mechanisms aligned so the cost and benefit of the array land with the same party.
• Owner-occupier — the simplest case, where one entity captures 100% of the economics.

For multi-let assets the route usually involves a combination; for single-let logistics it is often a clean tenant PPA. We work through the structures in detail at the split incentive solved and across our work on multi-let commercial buildings and office investment property.

Local cost and the grid reality

Commercial solar in London runs broadly £700–£1,100 per kWp installed, before VAT (commercial installs have been zero-rated since April 2022), falling with scale. A 200kWp office array sits around £150,000–£170,000; a 100kWp warehouse roof at Park Royal lands nearer £82,000–£110,000. At a London yield of roughly 950 kWh/kWp per year and with self-consumption as the dominant return driver, payback typically lands in the four-to-eight-year range, faster on high-load industrial or data-adjacent buildings.

With an average commercial energy spend around £95,000 a year for London occupiers, displacing grid power at 24–28p/kWh self-consumed is where the money is; exported surplus earns a supplier-set SEG rate (commonly about 12p) and should be treated as a top-up, not the headline.

The real gate is not the roof, the cost or the planning regime; it is the grid. Since 21 December 2023 the 1 MW cap on commercial rooftop solar has been removed, and rooftop arrays are permitted development under Class J with a 56-day prior-approval check on design and glint-glare. Business rates on rooftop solar and co-located storage are 100% exempt in England to 31 March 2035. But any system above roughly 50kW needs a G99 connection agreement from the DNO (UK Power Networks across most of London), and in parts of the capital’s congested network that is the item that sets your timeline. We cover the connection process in full at planning and grid for commercial solar.

A worked London example

Consider a 90,000 sq ft multi-let office on the City fringe, currently EPC D, with a landlord facing tenant pressure on scope-3 emissions and a refinancing on the horizon. The available roof supports a 200kWp array at roughly £155,000. Structured as a common-parts supply feeding the building’s shared mechanical and lighting load, with a private-wire PPA offered to the occupied floors below grid rate, the system displaces a large share of landlord and tenant grid draw, lifts the EPC toward a more lettable band, and removes the rates liability on the generating asset to 2035. This figure is illustrative; the actual outcome depends on roof orientation, the DNO connection offer and the lease terms. But it shows the shape of the opportunity: idle roof space converted into a lettability, valuation and ESG instrument that the right party pays for and the right party benefits from.

The Greater London Authority is targeting net zero by 2030 under the London Environment Strategy, with the London Plan (Policy SI 2) expecting solar on major new commercial development and the London Energy Efficiency Fund supporting retrofit finance. That policy backdrop, combined with the capital’s stranding exposure, makes London the market where engineering the ownership structure correctly matters most.

See typical numbers at our cost page, or to model your specific building, lease structure and DNO position, request a quote.