Plug-in Solar for HMOs UK: Landlord and Tenant Guide

Houses in Multiple Occupation (HMOs) are a different beast. Five students sharing a house, or a landlord operating a licensed HMO with eight individual letting rooms—both are HMOs under UK law. Both face unique constraints when considering solar.

The core issue: electricity in an HMO is either shared (one bill for everyone) or individual (each tenant pays their own metre). Who benefits from solar generation? The answer determines whether it's viable.

This guide covers the legal and practical realities of solar in multi-tenant properties.

HMO Definitions and Licensing

HMO licensing in England applies to:

• Properties with 5+ occupants (from 3+ separate households).
• Most councils require mandatory licensing.
• Some councils have additional selective licensing (even smaller shared houses).

Scotland and Wales have broader definitions and stricter rules.

Unlicensed HMOs can face £20,000+ fines. So first check: Is your property actually licensed as an HMO, or is it just a shared house?

Why this matters for solar: Licensed HMOs have fire safety, electrical safety, and management requirements. Adding solar means notifying your local authority and ensuring compliance with additional standards. Unlicensed shared houses have fewer hurdles.

The Electricity Supply Question: Shared or Individual Meters?

Shared Electricity Supply (One Bill)

All occupants' usage goes through a single metre. The landlord receives one bill and either:

• Includes electricity in the rent. Tenants pay a fixed rate; landlord absorbs total cost.
• Charges tenants a fixed amount (e.g., £80/month) regardless of usage.
• Uses an apportionment system (each tenant pays a share based on room size or occupancy).

Solar generation in shared supply:

• Generated power reduces the total bill.
• The landlord (or management company) realises the benefit.
• Tenants don't see direct savings (unless the landlord reduces electricity charges proportionally).
• This is the most straightforward model for a landlord to install solar.

Reality: Most landlords don't reduce electricity charges when they install solar. The solar savings become landlord profit. Ethically murky, but legally sound.

Individual Electricity Meters (One Bill per Tenant)

Each tenant has their own metre and pays their own electricity bill. Common in modern HMOs or converted properties with submetering.

Solar generation in individual meters:

• If a tenant installs a 400W system on their room's circuit (if wiring allows), they benefit directly.
• The challenge: routing panels and cabling to individual room circuits without disturbing common areas.
• Landlord approval is legally required (you're installing something on the building).
• This is rare in practice because installing individual systems for each tenant is logistically complex.

More common: Landlord installs a larger system on the roof, splits the benefit among tenants (pro rata by room or equally). But then you're back to the shared benefit question.

Model 1: Landlord Installs Solar on Shared Supply (Most Common)

A landlord with a 6-bedroom HMO on a shared electricity supply installs a 400W panel (or two 400W systems for 1,600W). The annual generation saves the landlord £400–600 in electricity costs.

Advantages (for landlord):

• Clean installation (one system, one connection).
• Direct financial benefit (reduced electricity cost = improved cash flow).
• Simpler management (no individual tenant systems to coordinate).

Disadvantages (for tenants):

• No direct benefit. Rents don't decrease, electricity charges don't change.
• Landlord realises 100% of the solar benefit.

Legally compliant? Yes, provided the installation meets BS 7671 Amendment 4 and HMO fire/electrical safety standards. No regulatory body mandates that solar savings be passed to tenants.

Ethically sound? Debatable. A progressive landlord might reduce electricity charges by 20% to share the benefit. Most don't.

Model 2: Landlord Installs Multiple Systems, Allocates Benefit

A more complex but fairer model: the landlord installs 1,600W of solar (two 400W systems), saves £800/year, and reduces electricity charges for all tenants by 10% (passing 50% of the benefit).

Advantages:

• Tenants see direct savings (£40–80/year per tenant in a 6-bed).
• Landlord retains 50% of the benefit as incentive for installation.
• Positioning: "We've gone green, and you benefit."

Disadvantages:

• More complex to manage (tracking savings, adjusting charges fairly).
• If solar generation varies seasonally, charges must be averaged to avoid sudden rate changes.
• Tenants might resent that they don't capture 100% of the benefit.

Practically rare: Most HMO landlords don't implement this level of transparency.

Model 3: Tenant Installs on Individual Circuit (Edge Case)

If an HMO has individual metres and allows it, a single tenant might install a 400W system on their own circuit, connected to their own metre.

Legal requirements:

• Written landlord approval (required for any building modification).
• BS 7671 Amendment 4 compliance.
• The system must be fully isolated from other tenants' circuits (critical for safety and fairness).

Practical challenges:

• Most HMOs have shared roof or common walls. Getting a single tenant's system installed without affecting others is complex.
• Landlord is likely to deny permission to avoid liability if the tenant's system causes interference or damage.

Reality: This model is vanishingly rare. Landlords typically prefer to install (and own) any solar systems to avoid tenant safety disputes and liability.

Insurance and Liability: The Critical Issue

This is where HMO solar gets complicated.

Landlord's insurance:

• Standard landlord buildings insurance may not cover solar panels.
• You'll need an endorsement or rider (usually £50–150/year additional premium).
• Responsibility for maintenance is the landlord's.

Tenant's liability:

• If a tenant installs an unauthorised system and it causes damage, the tenant is liable.
• If a tenant installs an approved system and it damages the building, responsibility depends on the installation agreement (get it in writing).

Electrical safety:

• BS 7671 Amendment 4 requires that all electrical work is certified by a qualified person.
• An HMO with multiple occupants means fire and electrical risk affect everyone.
• A tenant installing a system without proper certification could put others at risk—and expose the landlord to prosecution.

Building control and fire safety:

• HMOs are subject to enhanced fire safety standards (Mandatory Licensing, Fire Safety Order, etc.).
• Adding electrical generation on the roof or walls affects the fire safety risk assessment.
• Local authority must be notified if the property's electrical setup changes significantly.

Most councils will require the landlord to submit a revised electrical safety certificate when adding solar.

The Grey Area: Who Notifies Ofgem?

G98 notification (for grid-connected systems under 3.68 kW) must be submitted by the building's electrical system owner. In an HMO:

• If the landlord owns the system and installation, the landlord (or their installer) notifies Ofgem.
• If a tenant owns and installs, the tenant (or installer) notifies Ofgem. But this is legally murky—Ofgem's G98 form requires the "building" to be named, and a tenant doesn't own the building.

In practice, most DNOs don't chase tenants for G98 registration on small systems. But it's technically required. Landlords should do it to ensure compliance.

Practical Recommendations

If You're a Landlord Operating an HMO

1. Check your licence. Confirm the property is properly licensed (if required in your area).

2. Consult your insurance. Email your landlord insurance provider: "We're considering adding a 400W solar panel to the roof. Do we need an endorsement?" Most will say yes and quote additional premium.

3. Install a single system or multiple independent systems (you want one G98 notification per system, not complex split-benefit arrangements). Two 400W systems (1,600W total) is the practical limit.

4. Get written confirmation from the DNO. Submit a G98 notification form before installation. Takes 2–4 weeks, no cost.

5. Notify the local authority. In an HMO context, send a letter to the local council's building control and licensing department: "We're adding a solar panel installation (details attached). Fire safety risk remains unchanged. Here's our electrical certification (from the installer)."

6. Ensure BS 7671 Amendment 4 compliance. Your installer must provide a certificate of compliance. This protects you legally.

7. Document everything. Keep copies of insurance endorsements, Ofgem notifications, council letters, and installer certificates. If you sell, future owners will appreciate the clarity.

If You're a Tenant in an HMO

1. Ask the landlord or managing agent if they've considered solar. Make the case: "It reduces shared electricity costs, which indirectly benefits everyone."

2. Don't install without permission. Unauthorised installation is grounds for eviction in most leases.

3. If you get approval, get it in writing. Specify: "You approve a 400W solar panel on [location], provided it causes no damage and is removed when I move out."

4. Accept that you might not benefit directly. In a shared-supply HMO, the landlord pockets the savings. It's unfair, but it's how most HMOs work.

5. Use the Renters' Rights Act 2025 if the landlord refuses without good reason. Request mediation through a dispute resolution scheme. But be realistic: HMO landlords control the property and often resist tenant improvements.

The Bottom Line

HMO solar works best when the landlord installs it, takes responsibility, and notifies all relevant parties (insurer, council, DNO). This costs effort but ensures compliance and liability clarity.

Tenant-installed solar in an HMO is legally and logistically complex. Most landlords won't permit it; most insurance policies don't cover it; and Ofgem's registration process isn't designed for it.

For landlords: Solar in an HMO is worth 1–1.5 year payback and reduces operating costs. Install it properly, notify authorities, and update insurance.

For tenants: Advocate for your landlord to install solar, but don't expect direct financial benefit in a shared-supply HMO. Your gain is a greener building and (theoretically) lower electricity charges down the line.

For more on landlord responsibilities and tenant rights, see our renter's guide and leasehold guide. Both cover similar permission and compliance issues.