How HMO Room Sizes Are Catching Investors Out, and How We Solve This

July 22, 2026

HMO room sizes are becoming a serious and expensive problem for property investors across the UK.

During the recent landlord sell-off, many investors have purchased established HMOs because they appeared to offer an easier route into the market. The property was already converted, tenants may already have been living there, and the advertised rental income often looked attractive.

However, an existing HMO layout is not automatically a compliant, sustainable or future-proof layout.

Some investors are discovering this when they apply for a new HMO licence, renew an existing licence, change the licence holder or receive an inspection from the local authority. A room that generated rent for the previous owner may be assessed differently under the current licensing process, particularly where its usable floor area, ceiling height, layout or available amenities fall below the council’s requirements.

The result can be severe. A property purchased as a six-bedroom HMO may only be licensed for five occupants. A five-bedroom property may effectively become a four-bedroom investment. One or more rooms can be prohibited from use as sleeping accommodation, leaving the investor with less income than the original appraisal suggested.

At Foot Forward Properties, this is a problem we have spent more than 34 years designing against.

We have developed HMO properties for ourselves and for investors located across the world. Our approach has never been to squeeze the greatest possible number of bedrooms into the smallest possible residential shell. We develop larger, high-quality ensuite rooms that substantially exceed the minimum dimensions on which a marginal conversion might depend.

That decision supports compliance, tenant satisfaction and the long-term resilience of the investment.

What Are the Minimum HMO Bedroom Sizes in England?

For licensed HMOs in England, the national mandatory minimum sleeping-room sizes include:

  • 6.51 square metres for one person aged over 10
  • 10.22 square metres for two people aged over 10
  • 4.64 square metres for one child under 10
  • Any room below 4.64 square metres must not be used as sleeping accommodation

These requirements were introduced as mandatory HMO licence conditions under the Licensing of Houses in Multiple Occupation Regulations 2018.

The way a room is measured also matters. Areas where the ceiling height is below 1.5 metres are generally excluded from the calculation. This can cause particular difficulties in attic conversions, rooms with sloping ceilings and poorly designed loft extensions.

However, investors should not treat 6.51 square metres as a universal design target.

It is a statutory floor, not necessarily an indication that a room offers good-quality accommodation. It may also be insufficient when considered alongside a council’s wider HMO amenity standards, the room’s shape, available storage, an ensuite, shared facilities or the way in which the room is intended to be used.

Local authorities can apply standards and licence conditions that affect the permitted occupation of an HMO. Some councils publish guidance covering bedroom usability, communal accommodation, furniture, kitchen provision and whether ensuite floor space is included in the bedroom measurement.

This makes local due diligence essential. Investors need to understand the specific council’s current standards rather than relying on a generic national figure or an old floor plan supplied by the seller.

Why Existing HMO Room Sizes Are Catching Investors Out

A large part of the problem comes from the way many HMOs were historically developed.

For years, some landlords approached HMO conversion with one objective: cram as many lettable rooms into the property as physically possible.

Living rooms were divided. Dining rooms were converted into bedrooms. Small box rooms were marketed as full-sized accommodation. Awkward loft spaces were counted without properly considering usable floor area. Communal areas were reduced until very little shared space remained.

That approach may have produced a higher bedroom count on paper, but it also created properties with little margin for regulatory change.

Even some modern developers continue to make the same mistake. They begin with a target number of rooms and attempt to force the property to accommodate them, rather than beginning with the building and asking how many genuinely high-quality rooms it can support.

That is the wrong way to develop an HMO.

A suitable property should determine the layout. The desired bedroom count should not be used to force an unsuitable residential shell to work.

The Readymade HMO Trap

The current landlord sell-off has brought a considerable number of established HMOs onto the market.

Some may be well-designed, well-maintained and properly licensed. Others can carry hidden problems that are not apparent from the sales particulars.

An investor may be told that a property is a six-bedroom HMO because it has historically been occupied by six tenants. That does not necessarily confirm that a council will grant a new licence for the same number of occupants.

HMO licences are connected to the licence holder and the licensed property circumstances. Buyers should not assume that the seller’s licence simply transfers with the building.

When the new owner applies, the council may request floor plans, room measurements, certificates and details of the property’s facilities. Some authorities state that where rooms fall below their published standards, an inspection may be carried out to determine the property’s suitability and permitted occupation.

This can expose issues such as:

  • Bedrooms that are smaller than stated
  • Floor plans that include unusable space
  • Loft rooms with insufficient head height
  • Ensuite bathrooms reducing the usable bedroom area
  • Inadequate communal space for the number of occupants
  • Poor natural light or ventilation
  • Rooms without enough usable space for suitable furniture
  • A bedroom count that exceeds the council’s permitted occupancy
  • Historic alterations that lack the necessary approvals
  • Layouts that no longer satisfy current licensing expectations

A readymade HMO should therefore be assessed as carefully as a new development. Existing rent does not prove future compliance.

What Happens When an HMO Bedroom Is Too Small?

Where a room does not satisfy the relevant requirements, a council may restrict or prohibit its use as sleeping accommodation.

This can mean that the room must remain empty, be converted to another use or become part of an adjoining bedroom or communal space. The landlord may also need to notify the local authority about rooms below the statutory threshold.

The financial implications can be substantial.

Suppose an investor purchases a six-bedroom HMO based on six separate rental incomes. If one bedroom cannot legally be occupied, approximately one-sixth of the property’s potential room income may disappear before allowing for any additional costs.

The mortgage, insurance, utilities, management costs and maintenance liabilities do not necessarily fall by the same proportion. The investor still owns and operates the entire building, but with fewer income-producing rooms.

This can affect:

  • Monthly net income
  • Mortgage affordability
  • Interest cover
  • Commercial valuation
  • Refinancing options
  • Return on capital
  • Future saleability
  • The overall investment strategy

Where an investor paid a premium because the property was described as a higher-bedroom HMO, the loss can be even more painful.

Why Investors Cannot Always Make the Rooms Larger

A common response is to assume that the problem can be corrected by moving a wall.

In practice, many existing HMO layouts offer very little flexibility.

Making one bedroom larger usually means taking space from another bedroom, a corridor, the kitchen or a communal area. The investor may solve one compliance problem while creating another.

Structural walls, staircases, chimney breasts, windows, escape routes, soil pipes and existing bathrooms can further limit the available options. Extending the building may require planning permission, building regulations approval, structural work and a substantial capital investment.

Some properties simply do not have enough internal space or external land to support the number of rooms that the investor believed they were buying.

This is why buying the correct residential shell at the beginning is so important.

A poor shell cannot always be rescued by a clever floor plan.

Minimum Compliance Should Not Be the Investment Strategy

There is also a more fundamental issue.

A good landlord should not aim to provide tenants with the smallest room that can legally be let.

The regulatory minimum should be treated as the lowest possible threshold, not the recommended standard for a professionally developed HMO.

Tenants are paying for a home. Their bedroom may need to accommodate a bed, wardrobe, drawers, personal belongings and an area where they can sit or work comfortably. Where the room includes an ensuite, the remaining sleeping and living space should still feel generous and usable.

Trying to force the maximum number of tenants into a property may improve a spreadsheet at the appraisal stage. It can produce a worse living environment, higher tenant turnover and greater exposure to future regulatory changes.

That is not responsible HMO investment.

Providing tenants with a large, well-finished ensuite room is something every professional HMO investor should consider. It is also the standard we have followed at Foot Forward Properties for more than 34 years.

How Foot Forward Solves the HMO Room-Size Problem

At Foot Forward Properties, we do not begin with an unsuitable property and force an unrealistic number of bedrooms into it.

We source residential shells that can support the proposed HMO layout properly. Our team then develops the property through a substantial refurbishment, often including a carefully designed brick extension where appropriate.

Every stage is considered as part of one connected development process, including:

  • Property acquisition
  • Initial layout assessment
  • Planning considerations
  • Architectural design
  • Building regulations
  • Structural requirements
  • HMO licensing requirements
  • Fire safety
  • Bedroom dimensions
  • Ensuite provision
  • Kitchen and communal facilities
  • Construction
  • Furnishing
  • Compliance
  • Tenanting
  • Ongoing management

This joined-up approach is important because room size cannot be considered in isolation.

A bedroom may look sufficiently large on a basic floor plan, but its usable space can change once an ensuite, fire door, radiator, furniture, service boxing and storage are included. A design that works mathematically may not work as a comfortable home.

Our experience allows us to evaluate the finished room rather than relying solely on an early-stage measurement.

We Build Rooms Larger Than the Minimum

For more than 34 years, we have deliberately developed rooms that are substantially larger than the minimum required size.

Every bedroom in the HMO properties we develop includes an ensuite. However, we do not add an ensuite by sacrificing the quality and usability of the remaining room.

Our objective is to create bedrooms that tenants actively want to occupy. That means providing enough space for comfortable furniture, storage and day-to-day living.

Building above minimum standards can offer several long-term advantages:

Greater Protection Against Regulatory Change

Regulations and local standards can evolve.

A room designed only a few centimetres above today’s minimum has almost no tolerance for a revised measurement, a different interpretation or a future increase in standards.

A significantly larger room offers a more meaningful margin of protection.

No developer can guarantee what every council or future government will require indefinitely. However, designing generously rather than marginally provides a stronger starting position.

Better Tenant Demand

Larger ensuite rooms generally provide a more attractive living environment than small rooms with limited storage or awkward layouts.

Professional tenants can compare properties quickly. A generous room, quality ensuite and well-designed communal area can help an HMO compete on quality rather than price alone.

More Sustainable Occupancy

Tenants who feel comfortable in their accommodation may have fewer reasons to move solely because the room is too small for their needs.

Occupancy depends on numerous factors, including location, rent, management and local demand. Room quality remains an important part of that experience.

Stronger Long-Term Marketability

An HMO developed around genuine space and quality may appeal to a broader pool of future buyers than a highly compressed conversion whose profitability depends on every marginal room remaining lettable.

Sophisticated buyers, lenders and valuers are likely to scrutinise the property’s layout, compliance position and sustainable rental capacity.

The Renters’ Rights Act Has Raised the Standard of Professional Landlordism

The Renters’ Rights Act changes took effect in England from 1 May 2026, introducing significant changes to private tenancies and stronger rights and protections for tenants.

The Act does not itself replace the national HMO room-size regulations. However, it forms part of a much wider shift in the private rented sector.

Tenants are becoming more informed about their rights. Councils are under pressure to address poor housing conditions. Professional management, transparent tenancy practices and good-quality accommodation are becoming increasingly important.

Tenant expectations are also likely to continue rising.

An investor who purchases a cheap, poorly designed HMO simply because the asking price appears low may inherit years of underinvestment, compromised layouts and regulatory risk.

The lowest purchase price does not necessarily produce the lowest long-term cost.

A cheap HMO can become extremely expensive where the investor later discovers that:

  • One bedroom cannot be licensed
  • Extensive remodelling is required
  • Fire-safety upgrades are necessary
  • Communal facilities are inadequate
  • The property cannot support the advertised occupancy
  • Tenant demand is weaker because the rooms are poor
  • Refinancing assumptions relied on unsustainable rent
  • The purchase price reflected an income level that cannot continue

Investors need to assess the quality and durability of the income, not merely the initial yield presented by the seller.

Why “Cheap Because It Is Already an HMO” Can Be a Warning

There is often a reason why a readymade HMO appears unusually cheap.

The seller may be leaving the sector because of management pressures, refinancing difficulties, licensing concerns, poor occupancy or upcoming capital expenditure. None of these issues should automatically prevent a purchase, but they need to be identified and priced correctly.

Investors should be especially cautious where the sales information relies heavily on the historic number of rooms without providing clear evidence of:

  • Current room measurements
  • The current HMO licence
  • The permitted number of occupants
  • The licence expiry date
  • Council correspondence
  • Approved plans
  • Planning status
  • Building regulations documentation
  • Fire-risk assessments
  • Compliance certificates
  • Current tenancy information
  • Evidence that the stated rents are sustainable

A property being physically arranged as an HMO does not prove that every room can continue to be used lawfully.

Questions to Ask Before Buying a Readymade HMO

Before purchasing an existing HMO, an investor should consider asking the seller, agent, solicitor and relevant professional advisers the following questions.

1. What is the exact usable floor area of every bedroom?

Measurements should account for ceiling height, fixed structures and the council’s method of calculating usable space.

2. Does the council include or exclude the ensuite area?

This may affect whether the remaining bedroom space satisfies the relevant standard.

3. What occupancy does the existing licence permit?

The number of physical bedrooms and the licensed number of occupants may not be the same.

4. When does the licence expire?

A property approaching renewal may face closer scrutiny than the sales particulars suggest.

5. Will the buyer need to submit a new licence application?

Investors should not proceed on the assumption that the seller’s licence will transfer automatically.

6. Are there local HMO amenity standards above the national minimum?

The council may publish requirements relating to room dimensions, shared facilities, kitchens, bathrooms, storage and communal areas.

7. Is every bedroom shown on an accurate floor plan?

The plan should reflect the property as it exists, including ensuites, restricted head height and later alterations.

8. Has the property previously received licence conditions or improvement notices?

Historic council correspondence can reveal issues that are not apparent during a standard viewing.

9. Can the investment still work if one room is lost?

A prudent appraisal should test a lower-occupancy scenario rather than assuming every advertised room will remain available permanently.

10. Was the property designed as a high-quality HMO or merely adapted to maximise room count?

This question often reveals the difference between a sustainable investment and a conversion that depends on marginal compliance.

Our HMO Development Philosophy

Our philosophy is simple. Develop the right property, in the right area, with the right number of rooms.

We do not chase bedroom counts that the building cannot comfortably support. We do not create small rooms merely to increase the advertised gross income. We do not believe tenants should be expected to accept the minimum possible amount of personal space.

Instead, we acquire suitable residential shells and complete extensive refurbishments that create quality, fully ensuite HMO accommodation for professional tenants.

Our investors receive an end-to-end service that covers the development and ongoing management of the property. Once complete, our in-house management team handles the operational requirements, including tenanting, rent collection, property inspections, utilities, maintenance coordination and compliance oversight.

We only manage the HMOs we develop. This means our management team inherits properties designed around the practical realities of operating an HMO, rather than having to manage the consequences of somebody else’s compromised conversion.

A Larger Room Is Not Wasted Space

Some investors look at a larger bedroom and see an opportunity to create another room.

We see protection.

We see a more comfortable home for the tenant, greater flexibility in the layout and less reliance on the lowest legal threshold.

Every square metre does not have to be monetised through another tenancy. Space can contribute value by improving the quality, resilience and marketability of the existing rooms.

The HMO market is becoming more professional and more closely regulated. Investors who continue to rely on overcrowded layouts may find that the apparent efficiency of the property becomes its greatest weakness.

How HMO Room Sizes Affect Commercial Valuation

HMO valuations can consider the property’s income-producing capability, alongside the valuer’s methodology, comparable evidence, location, condition and regulatory position.

Where a property has six physical bedrooms but only five can legally or sustainably be occupied, an investor should not assume that a valuer or lender will treat it as a fully operational six-bedroom HMO.

Any reduction in sustainable rental income may influence:

  • The assessed investment value
  • Interest-cover calculations
  • Available loan size
  • Refinancing proceeds
  • The amount of capital left in the investment
  • The ease of selling the property later

This is another reason why investors should not calculate returns using an unverified bedroom count.

The relevant question is not, “How many bedroom doors are there?”

It is, “How many good-quality rooms can lawfully and sustainably produce income?”

Why Experience Matters in HMO Development

An HMO is not simply a residential property with locks on the bedroom doors.

Good development requires an understanding of property selection, space planning, planning policy, licensing, fire safety, building regulations, tenant expectations, maintenance and long-term management.

Over more than 34 years, we have seen standards increase and the HMO market become more closely regulated. We have also seen investors lose money by buying the wrong property, relying on old licences or trusting a floor plan that was designed to sell the maximum number of rooms rather than provide suitable accommodation.

Our experience influences the decisions made before construction begins.

We consider whether the shell is genuinely suitable, whether the rooms remain spacious after ensuites and furniture are added, whether the communal facilities support the planned occupancy and whether the finished property can operate effectively for our management team.

That practical experience cannot be replaced by drawing extra lines on a floor plan.

Should You Buy an Existing HMO?

Buying an existing HMO is not automatically a bad decision.

A properly developed, accurately valued and fully compliant property may provide a suitable investment. However, it should be examined with the same level of care as any other regulated property asset.

Investors should avoid assuming that:

  • Historic use confirms current compliance
  • An existing licence guarantees renewal
  • Every advertised room is legally lettable
  • The seller’s occupancy will be approved for the buyer
  • The national minimum is the only applicable standard
  • A small room can always be enlarged later
  • Historic rental income will continue unchanged
  • A low purchase price compensates for a weak layout

Independent legal, surveying, licensing, planning, valuation, financial and tax advice may be appropriate before committing to a purchase.

Develop for the Future, Not the Minimum

HMO regulation is unlikely to return to the lightly controlled environment in which many older properties were created.

Councils are scrutinising standards, tenants expect better accommodation, and investors need their properties to remain attractive and operational through changing market conditions.

The answer is not to search for more creative ways to squeeze an additional bedroom into an unsuitable house.

The answer is to develop better HMOs.

At Foot Forward Properties, we have followed this approach for more than 34 years. We develop spacious, fully ensuite rooms that substantially exceed minimum size requirements, within properties selected specifically for their suitability as professional HMOs.

This helps protect our investors from the problems now affecting owners of marginal, overcrowded and poorly planned conversions.

A room should not merely be large enough to pass an inspection. It should be a place in which a tenant can live comfortably.

That is better for the tenant, better for the landlord and better for the long-term investment.

Explore Fully Managed HMO Investments

For investors who want to own an HMO without having to source, design, refurbish, licence and manage the property themselves, Foot Forward Properties provides a complete end-to-end service.

We acquire suitable residential shells, develop high-quality ensuite HMOs and manage the completed properties through our in-house team.

Learn more about our approach and view our available opportunities:

Explore fully managed HMO properties for sale

Frequently Asked Questions

What is the minimum size for a single HMO bedroom?

For licensed HMOs in England, the national mandatory minimum for a sleeping room occupied by one person aged over 10 is 6.51 square metres. Local standards, room layout, usable floor area and the provision of other facilities may still affect whether the room is considered suitable.

Can a council require larger HMO rooms?

The national regulations establish mandatory minimum sleeping-room sizes. Councils can also apply local amenity standards and determine permitted occupancy through the licensing process, taking account of the property’s layout, facilities and suitability. Investors should check the current published requirements of the relevant local authority.

Does an ensuite count towards the HMO bedroom size?

The treatment of ensuite space can depend on the council’s measurement policy and local standards. Some council guidance expressly excludes space occupied by an ensuite from the usable bedroom measurement. This should be confirmed before a layout is designed or a property is purchased.

Can an HMO licence transfer to the new owner?

Investors should not assume that an existing HMO licence transfers automatically with the property. The buyer should confirm the position with the relevant council and obtain legal advice before completion.

What happens if an HMO bedroom is below the minimum size?

The room may be prohibited from use as sleeping accommodation. The property’s permitted occupancy may also be reduced, which can lower rental income and affect the investment’s value.

Are attic rooms measured differently?

Floor areas where the ceiling height is below 1.5 metres are generally excluded from the statutory room-size calculation. This can significantly reduce the measured usable area of rooms with sloping ceilings.

Is buying a readymade HMO safer than developing one?

Not necessarily. An existing HMO may contain historic licensing, layout, planning or compliance problems. A buyer should verify the room sizes, permitted occupancy, licence history, planning status, certificates and council requirements before proceeding.

Why does Foot Forward build rooms above minimum standards?

Larger rooms provide better accommodation for tenants while giving the property more resilience against measurement issues, changing standards and increasing tenant expectations. They also reduce the investment’s dependence on marginal compliance.

This article provides general information about HMO development and licensing in England. Requirements vary by property and local authority. Investors and landlords should obtain property-specific advice from the relevant council and suitably qualified legal, surveying, planning, licensing, financial and tax professionals.