Buying an HMO Property: What to Check Before You Purchase

Buying an HMO is not the same as buying a standard buy-to-let property. There are additional checks you must carry out before exchanging contracts — licensing status, planning permission, fire safety compliance, room sizes, and mortgage lender requirements all need verification. Missing any one of these can result in a property that is unlettable, unmortgageable, or subject to enforcement action from the council.

This guide is a practical due diligence checklist covering everything to verify before you commit to an HMO purchase.

1. Check the Licensing Position

Before anything else, confirm the property's licensing status.

Is the property currently licensed? If the property is already operating as an HMO, it should hold a valid HMO licence. Ask the vendor for a copy of the licence and check:

Is the licence current (not expired)?
Does the licence match the property address?
What are the maximum occupancy conditions?
Are there any outstanding conditions or works required?
Who is the licence holder? (The licence does not transfer to you — you will need to apply for a new licence in your name)

Does it need a licence? If the property is not currently an HMO but you plan to use it as one, confirm whether a licence will be required:

Properties housing 5+ people from 2+ households need a mandatory licence (nationwide)
Smaller HMOs may need an additional licence (check your council)
Properties in selective licensing areas need a selective licence regardless of HMO status

Is the property licensable? A property that requires a licence but cannot meet the licensing standards (room sizes too small, fire safety impossible to achieve, layout prevents adequate escape routes) is effectively unbuyable for HMO purposes. Check standards before committing.

2. Check the Planning Position

Is the property lawfully used as an HMO? If it is currently operating as an HMO, confirm that the use is lawful. This means either:

The property has planning permission for HMO use, or
The HMO use began under permitted development (C3 to C4) before any Article 4 Direction came into force, or
The HMO use has been continuous for 10+ years (establishing lawful use through the passage of time — a certificate of lawful existing use can be applied for)

A property operating as an HMO without lawful planning status is at risk of enforcement action. The council can issue an enforcement notice requiring the HMO use to cease.

If you plan to convert:

Check for Article 4 Directions in the area
Determine whether you need planning permission
Consider getting pre-application planning advice before committing to the purchase
Budget for the planning application process (fees, consultant, time)

3. Measure the Rooms

Do not rely on estate agent floor plans. They are frequently inaccurate and do not follow the measurement methodology used for HMO licensing.

Measure every intended bedroom yourself using the correct method:

For more on this topic, see our guide to The Blueprint to Financing Your HMO Refurbishment.

Wall-to-wall at 1.5 metres height from the floor
Exclude areas where ceiling height is below 1.5m (sloped ceilings, eaves)
Exclude en-suite bathrooms
Include built-in wardrobes and cupboards

Compare against the statutory minimums:

6.51 sqm for one person (age 10+)
10.22 sqm for two persons
4.64 sqm for one child under 10

A room that falls below the threshold cannot be used as a bedroom at that occupancy. This directly affects your rental income projection and your mortgage affordability calculation.

4. Assess Fire Safety

Walk the property with fire safety in mind:

Escape routes:

Can every occupant reach the front door without passing through the kitchen?
Are corridors and stairways wide enough and free from obstruction?
Are there alternative escape routes for upper floors if the main stairway is blocked?

Existing fire measures:

Are there mains-wired interlinked smoke alarms? (Battery-only are not acceptable)
Are fire doors installed to bedrooms and the kitchen? What condition are they in?
Is there emergency lighting (for properties of three or more storeys)?

Cost to comply: If the property does not currently meet discover more, estimate the cost of bringing it into compliance. Fire doors, detection systems, emergency lighting, and escape route improvements can cost £2,000–£5,000+ on a standard six-bed HMO.

5. Check the EPC

The property needs an Energy Performance Certificate rated E or above to be legally lettable. Check:

Does the property have a valid EPC?
What is the current rating?
If the rating is below E, what improvements are needed and at what cost?
Monitor upcoming changes to minimum EPC requirements — there are proposals to raise the minimum to C for new tenancies

An EPC is valid for 10 years. You can check existing EPCs for any property on the government's EPC register at gov.uk.

6. Review the Utilities

HMO utility costs are typically higher than single-let properties because of higher occupancy and shared facilities.

Check:

Gas and electricity meter type — is there a single meter (landlord pays) or individual meters?
Current utility costs — ask the vendor for 12 months of bills
Water meter — most water companies charge HMOs on a higher tariff
Broadband — tenants will expect a reliable internet connection; check what speeds are available

Budget for utilities: For a six-bed HMO where the landlord pays utilities, budget £250–£500/month for gas, electricity, water, broadband, and TV licence (if required).

7. Inspect the Structure and Condition

Beyond standard survey concerns, pay attention to:

Damp and mould — higher occupancy means more moisture. Check for condensation issues, particularly in bathrooms, kitchens, and poorly ventilated bedrooms
Drainage — can the drainage system handle the demand from multiple bathrooms and a heavily-used kitchen?
Electrics — is the consumer unit adequate for the number of circuits needed? Old wiring may need upgrading
Plumbing — is the hot water system adequate for multiple users? A combi boiler may struggle with simultaneous demand from several showers
Sound insulation — thin walls between bedrooms lead to tenant complaints and turnover. Consider whether sound insulation improvements are needed

Commission a full building survey (not just a homebuyer report) for any HMO purchase. The additional cost (typically £400–£800 more than a homebuyer report) is justified by the more detailed assessment of condition.

8. Verify the Rental Income

If the property is already let as an HMO:

Ask for current tenancy agreements for each room
Verify rent payment history — bank statements or letting agent records
Check void periods — how often are rooms empty, and for how long?
Compare current rents to market rates for comparable HMO rooms in the area (check SpareRoom, Rightmove)
Check tenancy terms — are tenants on fixed terms, periodic tenancies, or licences to occupy?

If the property is not yet an HMO:

Research comparable HMO room rents in the area
Factor in a void rate of 5–10% (expect some rooms to be empty for part of the year)
Be conservative in your projections — base your appraisal on achievable rents, not aspirational ones

9. Check Mortgage Readiness

Your HMO mortgage lender will assess the property against their criteria. Common lender requirements include:

Valid HMO licence (or licensable property)
Minimum property value (some lenders have a £100,000 minimum)
Maximum number of bedrooms (some lenders cap at 6, others accept 10+)
Standard construction (brick/stone with tile/slate roof — non-standard construction restricts lenders)
Rental income must pass the stress test (typically 125–145% coverage at 5.5%)
Adequate condition — lenders instruct their own valuation and will flag issues

Working with a specialist HMO mortgage broker ensures you know which lenders will accept the property before you commit to the purchase. Contact The HMO Mortgage Broker for a pre-purchase assessment.

10. Run the Numbers

Before making an offer, model the full financial picture:

Income / cost	Monthly	Annual
Gross rental income (all rooms let)	£3,000	£36,000
Less void allowance (8%)	-£240	-£2,880
Effective gross income	£2,760	£33,120
Mortgage payment	-£1,200	-£14,400
Insurance	-£70	-£840
Utilities (landlord-paid)	-£350	-£4,200
Council tax	-£170	-£2,040
Management (if using agent, 10-15%)	-£300	-£3,600
Maintenance provision (10% of rent)	-£300	-£3,600
Licence cost (annualised)	-£15	-£180
Gas/electrical certificates	-£20	-£240
Net monthly cashflow	£335	£4,020

If the numbers do not work with conservative assumptions (8% voids, realistic rents, all costs included), the deal is not strong enough. Move on.

Use our HMO valuation calculator to estimate the property's investment value based on rental income, and our HMO stamp duty calculator to calculate the exact stamp duty payable — including the 5% additional property surcharge that applies to most HMO purchases.

For more on this topic, see our guide to HMO Stamp Duty: Rates, Surcharges & What HMO Investors Pay.

Summary Checklist

Before exchanging contracts on an HMO purchase:

[ ] Licensing status confirmed — current licence or property licensable
[ ] Planning status confirmed — lawful HMO use or planning permission secured/obtainable
[ ] Room sizes measured — all intended bedrooms meet statutory minimums
[ ] Fire safety assessed — compliance costs estimated
[ ] EPC obtained — rated E or above
[ ] Utilities reviewed — costs budgeted
[ ] Structural survey commissioned — full building survey
[ ] Rental income verified — comparable evidence, realistic projections
[ ] Mortgage readiness confirmed — broker pre-assessment completed
[ ] Financial appraisal modelled — deal works with conservative assumptions

Getting these checks right before you commit protects you from buying a property that cannot be licensed, cannot be mortgaged, or cannot generate the income you projected.

Frequently Asked Questions

What should I check before buying an HMO property?

Before purchasing, verify: the property's planning status (C4 or Sui Generis), whether an Article 4 direction applies, existing HMO licence status, fire safety compliance, room sizes meeting minimum standards, structural condition, EPC rating, local rental demand, and any restrictive covenants on the title. A specialist HMO surveyor can identify issues that standard surveys might miss.

Can I buy an existing HMO with tenants already in place?

Yes, buying a tenanted HMO can be advantageous — you inherit immediate rental income and avoid void periods. However, you also inherit the existing tenancy agreements, deposit protections, and any management issues. Review all tenancy agreements, check deposit protection compliance, verify the HMO licence can be transferred, and inspect the property thoroughly before exchange.

How do I value an HMO property?

HMOs can be valued on a bricks-and-mortar basis (comparable property sales) or an investment basis (based on rental income and yield). The investment value often exceeds the bricks-and-mortar value for well-performing HMOs. Lenders use the lower of the two for mortgage purposes. Key factors include: location, room count, rental income, condition, and licensing status.

Is it better to buy a ready-made HMO or convert a property?

Both approaches have merits. A ready-made HMO offers immediate income and proven rental demand but may cost more. Converting a property lets you add value through refurbishment and create a layout optimised for current tenant expectations (en-suites, modern kitchens). The best choice depends on your budget, timeline, and whether suitable properties are available in your target area.

For more on this topic, see our guide to HMO Conversion Finance: Refurbishment Loan Options.