Limited-Company / Portfolio Landlords: Solar panels for landlords

Why limited-company and portfolio landlords should plan solar now

For a portfolio landlord the EPC band C by 2030 deadline is not a per-property decision, it is a capital-planning problem across the whole holding. The Warm Homes Plan confirmed on 21 January 2026 that every privately rented home in England must reach band C by 1 October 2030, with a 10,000 pound cap per property, and roughly 2.5 million sub-C rental homes need upgrading. The installer market will bottleneck hard as the deadline approaches, so the portfolio landlords who plan and roll out across their units early avoid the last-minute scramble, spread their capital expenditure, and de-risk the compliance wall. Solar panels for landlords at portfolio scale are best handled as a programme, not as a series of one-off installs.

There is also a genuine tax angle that single accidental landlords do not get. Where a portfolio is held in a limited company (an SPV), as many became after the Section 24 mortgage-interest restriction, solar is qualifying plant and machinery, so capital allowances apply in a way they simply do not for personally-held lets. Combine that with volume procurement and a single survey programme, and the per-unit cost of a portfolio rollout comes in below what the same units would cost installed one at a time. The strategy is to phase the programme across the years remaining before 2030 so capex is spread and no single year carries the whole compliance bill.

The portfolio landlord also carries a different kind of risk from the single-property owner, and it is a risk worth naming. Section 24 already removed full mortgage-interest relief for personally-held lets, squeezing margins before any green capital is spent, and the abolition of the furnished holiday let regime from April 2025 took away the capital allowances that personally-held residential lets could once use. Against that backdrop, a portfolio facing a wall of sub-C units in 2030 has a concentrated compliance liability that, left to the last minute, collides with a saturated installer market and the worst possible pricing. Treating EPC C as a multi-year capital programme rather than a panic in 2029 is the single most effective way to manage that exposure, and it is the kind of planning the homeowner-focused national installers are simply not set up to do. We model the whole portfolio's path to compliance as one piece of work, then sequence it.

What a typical install looks like and how we size it

Across a portfolio we typically design 3 to 5 kW per unit as the standard rollout array, with the panel count, roof area and generation sized per unit to each property and to who pays its bill. A programme across a portfolio frequently runs to 100,000 pounds and beyond in total. We do not apply one design to every property. For each unit we establish who pays the electricity bill, because that decides whether we size to the bare EPC model (tenant pays) or aggressively for self-consumption (landlord pays, as in bills-inclusive units), and we model the rating uplift the array delivers alongside the cheapest fabric measures to clear band C inside each property's cap. A single coordinated survey programme captures the half-hourly data and roof condition for every unit at once, which is what makes volume procurement and a sensible phasing schedule possible.

Costs, payback and tax relief

Per unit, a portfolio array typically lands between 5,000 and 9,000 pounds, with the whole programme running to 100,000 pounds and beyond, and a simple payback per unit near 9 years where the landlord captures the value. Volume procurement and a single mobilisation lower the per-unit cost compared with one-off installs. The standout financial lever for incorporated portfolios is tax: held in a limited company, solar is plant and machinery, so the Annual Investment Allowance gives 100% relief on the first 1m pounds of qualifying expenditure, with the 50% First Year Allowance potentially available above that cap, up to roughly a 25% effective corporation-tax saving on qualifying spend in year one. Personally-held (unincorporated) residential lets cannot claim this; they get only Replacement of Domestic Items Relief, because the furnished holiday let regime and its capital allowances were abolished from April 2025. Always confirm with the company's accountant. Our cost guide compares the incorporated and personal positions.

Funding routes in detail

The headline funding route for an incorporated portfolio is capital allowances: the Annual Investment Allowance (100% up to 1m pounds) and the 50% First Year Allowance on qualifying plant, which can deliver a meaningful corporation-tax saving across a large programme. The Smart Export Guarantee then pays the landlord account, typically 3 to 15p per kWh, for surplus exported from each unit. On the fabric and heating side, where individual tenants qualify, ECO4 (to December 2026) and the Warm Homes: Local Grant (to 31 March 2028) are tenant-led routes that can subsidise insulation and heating on lower-income tenancies across the portfolio, stacking with the self-funded solar to reach band C. For any off-gas units in the holding, the Boiler Upgrade Scheme funds a heat pump per property with no cap on the number of properties, which pairs naturally with the rollout array.

Compliance and sector considerations

For incorporated portfolios the Annual Investment Allowance (100% up to 1m pounds) and the 50% First Year Allowance can apply to qualifying plant, but the entitlement turns on the company structure, so it must be confirmed with the company's accountant; personally-held lets cannot claim capital allowances on solar at all. Across the units, the domestic MEES regime applies (EPC C by 1 October 2030, 10,000 pound cap per property, improvements from October 2025 counting), each unit needs an MCS-certified install for SEG eligibility, and Part P and Part A apply per property. Larger per-unit arrays above 3.68 kW per phase need DNO G99 approval, and a portfolio programme should batch these applications. Mixed tenure within a portfolio (houses, flats, HMOs) means different consent and metering realities per property, which is why a single survey programme that records who pays the bill and what consent is needed for each unit is the foundation of the whole rollout.

The cost cap also operates per property, which has a practical consequence for how a programme is planned. Each unit has its own 10,000 pound envelope and its own starting EPC, so the cheapest route to band C is genuinely different from one property to the next, and a programme that treats every unit identically will overspend on the easy cases and underspend on the hard ones. We model each property's least-cost path inside its own cap, dating works correctly from October 2025 so they count, and where a unit genuinely cannot reach band C within its cap, we identify that early and prepare the evidence for a properly registered exemption rather than discovering the problem at the deadline. Doing this across the whole portfolio in one exercise turns a vague compliance worry into a costed, scheduled plan, which is exactly the visibility a portfolio landlord needs to make capital decisions and to satisfy a lender or buyer that the EPC risk across the holding is under control.

How we approach this kind of project

We run a portfolio rollout as a programme. We start with a single coordinated survey across the units that records, for each property, who pays the electricity bill, the roof condition and any asbestos, the consent position, and the EPC starting point. We then model the least-cost route to band C per unit, sizing to the rating model where the tenant pays and to self-consumption where you do, and we phase the works across the years to 2030 to spread capex and beat the installer bottleneck. We batch the DNO G99 applications, negotiate volume procurement to cut the per-unit price, and submit grid applications early so the network does not hold the schedule up. You get a programme-level fixed-price proposal, an insurance-backed warranty across every install, and the capital-allowance position flagged for your accountant to confirm.

The phasing logic is not arbitrary. We tend to prioritise the units where the return is real cash first, the bills-inclusive HMOs and any communal-supply or commercial-floor buildings, because those start paying back immediately and effectively help fund the rest of the programme. Next come the units closest to band C, where a small, cheap intervention tips them over the line for the least spend. The hardest cases, typically off-gas or solid-wall properties that need a heat pump or significant fabric work, are planned with their grant funding in mind and given the longest runway. Sequencing this way means your capital is working from the first install, your easiest compliance wins are banked early, and the difficult properties are tackled with time to spare rather than against the clock. We give you a unit-by-unit schedule with the spend, the expected EPC movement and the funding route for each property, so the whole portfolio's path to 2030 is visible on a single plan rather than discovered property by property as the deadline closes in.

An illustrative example

As an illustrative composite based on typical UK portfolio programmes: a landlord holding a mix of houses and HMOs through a limited company (an SPV), facing a wall of sub-C units ahead of 2030, opted for a phased rollout rather than a last-minute scramble. A single survey programme captured the data for every unit, establishing who paid the bill in each, and the units were sized accordingly, modestly to the EPC model where tenants paid and more aggressively for self-consumption on the bills-inclusive HMOs. Volume procurement lowered the per-unit cost, the company used the Annual Investment Allowance on the qualifying plant for a year-one corporation-tax saving, and the works were phased across several years to spread the capex and avoid the installer bottleneck. The figures are illustrative and depend on your portfolio, ownership structure, the mix of who pays the bills, and the terms available.

The earlier a portfolio landlord starts, the more options remain open and the lower the per-unit cost, so the worst plan is to wait until the 2030 deadline forces a rushed, expensive scramble. For the per-property detail behind a programme, see solar for buy-to-let houses and solar for HMOs. When you are ready, see the cost guide, the grants and funding options, or request a free feasibility, and read the landlord solar FAQs first.