Solar PV and EPC Ratings: What Landlords Need to Know

Solar photovoltaic (PV) panels are one of the most visible energy efficiency measures a landlord can install — but they are not always the most cost-effective way to improve an EPC rating. A typical 4kW rooftop system adds 4–8 SAP points to your energy performance score, depending on roof orientation, pitch and shading. That can be the difference between Band D and Band C for a property sitting at 62–65 points, but for properties that need 15+ points of improvement, solar alone will not get you there.

This guide covers how solar PV affects your SAP score, what it realistically costs, how long the payback takes, and whether it makes financial sense compared to other improvements — particularly for landlords facing the October 2030 Band C deadline.

How solar PV affects your SAP score

The SAP calculation gives credit for on-site electricity generation because it reduces the property’s net energy consumption. The number of SAP points you gain depends on several factors:

• System size: A standard domestic system is 3–4kW (10–14 panels). Larger systems generate more electricity and score higher, but there are diminishing returns in the SAP model beyond about 4kW.
• Roof orientation: A south-facing roof at 30–40° pitch is ideal and will deliver the maximum SAP gain. East- or west-facing roofs lose roughly 15–20% of output. A north-facing roof loses 40%+ and is rarely worthwhile.
• Shading: Nearby trees, chimneys or taller buildings that shade the panels during peak hours reduce both real-world output and the SAP score.
• Existing efficiency: Solar PV adds more SAP points to a property that already has good fabric efficiency (insulation, double glazing) than to one that is poorly insulated. The SAP model calculates net energy use, so reducing demand first amplifies the impact of generation.

Typical costs for a rental property

Solar PV prices have fallen significantly over the past decade but have stabilised in recent years. For a standard residential installation in 2026:

• 3kW system (10 panels): £4,000–£6,000 installed
• 4kW system (12–14 panels): £5,000–£8,000 installed
• Battery storage (optional): £2,500–£5,000 additional — note that battery storage does not add SAP points under the current methodology, so it is not relevant for EPC compliance

These prices include scaffolding, mounting equipment, the inverter and connection to the consumer unit. VAT on solar panel installation is currently 0% (reduced from 5%) on residential properties, which applies until at least March 2027.

At £5,000–£8,000 for 4–8 SAP points, the cost per SAP point ranges from roughly £625 to £2,000. Compare this to loft insulation top-up at £75–£125 per SAP point, and you can see why solar is not the first measure to consider if you are purely optimising for EPC compliance. For a full comparison, see our £10,000 cost cap guide.

Payback period

The financial payback on solar PV for a rental property differs from an owner-occupied home because the landlord pays for the installation but the tenant benefits from reduced electricity bills. However, landlords can recover value through:

• Smart Export Guarantee (SEG) payments: Energy suppliers pay for surplus electricity exported to the grid. Rates vary from 3p to 15p per kWh depending on the supplier and tariff. For a 4kW system exporting roughly half its output, this generates £100–£250 per year.
• Higher rental value: Properties with lower energy bills are more attractive to tenants, particularly in a market where EPC ratings are increasingly visible on property listings.
• EPC compliance: Avoiding a £30,000 fine per property is the most significant financial consideration. If solar PV is the measure that tips your property into Band C, the “payback” is immediate in terms of avoided penalties.

For a system costing £6,000 with SEG income of £150–£200 per year, the simple payback from export income alone is 30–40 years — which is not attractive on its own. But when combined with avoided fines, higher rental yields and the 0% VAT benefit, the overall case improves significantly. A realistic payback period for a landlord, combining all factors, is 8–12 years.

Smart Export Guarantee (SEG) payments

The SEG replaced the old Feed-in Tariff in 2020. Under the SEG, licensed electricity suppliers with 150,000+ customers must offer a tariff for exported electricity, but the rate is not fixed by government — it is set by each supplier competitively.

Key points for landlords:

• You must register for SEG with a participating supplier — it is not automatic
• The system must be installed by an MCS-certified installer
• A smart meter (or export meter) is required to measure exported electricity
• SEG payments go to the system owner (the landlord), not the tenant
• You can choose any SEG supplier regardless of who supplies electricity to the property

Shop around for SEG rates. Some suppliers offer fixed-rate tariffs, others offer variable or “agile” rates that pay more during periods of high demand. The difference between the worst and best SEG tariffs can be 3–4x.

Planning permission for rental properties

Solar panels on most residential properties fall under permitted development rights, meaning no planning application is required. However, there are exceptions:

• Listed buildings: Listed building consent is required. Many listed buildings cannot have solar panels at all, though there is growing flexibility for panels on non-visible roof slopes.
• Conservation areas: Panels are usually permitted provided they are not installed on a wall or roof slope facing a highway. Check with your local planning authority.
• Flats: Panels on a flat within a larger building require planning permission as permitted development rights do not apply.
• Panel projection: Panels must not project more than 200mm from the roof surface.

For most standard rental houses and bungalows, you can proceed without planning permission. Always confirm with your local authority if you are unsure.

Does solar make sense for landlords?

The honest answer: it depends on your starting position. Solar PV is not the cheapest route to Band C compliance when measured purely on cost per SAP point. Here is how it compares:

Solar makes the most financial sense when:

• You have already exhausted the cheaper measures (insulation, heating controls, draught proofing) and still need 4–8 more points
• The property has a south-facing or east/west-facing roof with minimal shading
• You want a long-term asset improvement that increases property value, not just a compliance fix
• The property is well below the £10,000 cost cap after other improvements, leaving budget for solar

Solar does not make sense when:

• The property has a north-facing roof or significant shading
• Cheaper measures alone would get you to Band C
• You are already close to the £10,000 cost cap with more cost-effective improvements still available

Combining solar with other improvements

The most effective approach is to treat solar as part of a package rather than a standalone measure. A common combination for a Band D property (SAP 55–68) targeting Band C:

• Step 1: Loft insulation top-up (£300–£500, +4–7 points)
• Step 2: Heating controls and TRVs (£200–£500, +2–4 points)
• Step 3: LED lighting (£50–£200, +1–2 points)
• Step 4 (if needed): Solar PV (£5,000–£8,000, +4–8 points)

Steps 1–3 cost under £1,200 combined and can deliver 7–13 SAP points. If that is enough to reach 69, you do not need solar at all. If you are still a few points short, solar becomes a justified investment that tips you over the line while adding genuine long-term value to the property.

For a complete breakdown of every improvement option, costs and SAP point gains, see our guide on how to improve your rental property’s EPC rating.