HMO Design & Conversion Services in Sussex
Considering converting a residential property into a House in Multiple Occupation? Downland Studio provides architectural design and technical drawing services to help landlords and property investors explore a property's potential, develop practical accommodation layouts and prepare drawings for planning, licensing and Building Regulations.
From initial feasibility and measured surveys through to detailed technical design, the service is clear, practical and scoped around the property and proposed use.
Could your property work as an HMO?
Explore the main questions around room sizes, occupancy, shared facilities and planning. This free guide gives an initial indication only; the local authority makes decisions on licensing and planning.
No email address or personal details are needed to see your result.
Start with the property and the accommodation you have in mind.
01 · Property details
Illustrative accommodation summary only. A separate 4.64 m² minimum may apply to a child under 10 where relevant. This is not an architectural floor plan or confirmation of regulatory compliance.
What counts as an HMO?
Housing law, planning use and licensing each use their own tests. A property may meet the housing-law definition of an HMO without falling into the same planning or licensing category.
In general, housing legislation treats a property as an HMO where at least three people from two or more households occupy it as their main home and share facilities such as a kitchen or bathroom, subject to the detailed statutory tests.
In planning terms, a shared house occupied by three to six unrelated people is generally Use Class C4. Larger HMOs with more than six occupants are generally treated as sui generis. A change from a single dwelling to a C4 HMO may benefit from permitted development rights, but Article 4 Directions, planning conditions, listed status and the property's planning history can change the position.
Mandatory HMO licensing normally applies where five or more people from two or more households share facilities, but additional or selective licensing can apply locally at lower occupancies. Check the exact address and proposed occupancy with the relevant council.
Use class, Article 4 Directions, planning history, lawful use and any physical alterations are separate planning questions.
Licensing depends on occupancy and local schemes. Councils can apply amenity and room standards above the national minimums.
Building work, means of escape, compartmentation, alarms, ventilation and other measures depend on the building and proposal.
Room-size screening uses the statutory minimums for licensed HMOs: 6.51 m² for one person aged 10 or over; 10.22 m² for two people aged 10 or over. Areas below 1.5 m headroom are excluded from the measurement. The council may set higher standards, and age, room shape, layout and facilities matter.
HMO design and conversion services
Choose the stage you need. Each proposal confirms the drawings, coordination and application support included for your project.
Existing information, measured clearly
Measured surveys and existing-property drawings establish a reliable basis for feasibility, design development and technical drawings.
Test the potential first
A preliminary professional assessment considers occupancy potential, accommodation layouts, planning requirements and likely constraints.
Plans with room information
Dimensioned architectural plans showing room names and floor areas for relevant licensing applications. A measured survey may be separately required.
Develop a practical layout
Design development and architectural drawings for proposed HMO layouts, alterations and planning applications where applicable.
Prepare the technical package
Building Regulations technical design and construction drawings, including relevant technical coordination within the agreed scope.
Application support when required
Preparation, submission, validation and routine planning-authority correspondence for the agreed application.
Statutory charges, specialist fire engineering, structural calculations, acoustic testing and other third-party services are excluded unless expressly agreed. Specialist consultants are normally appointed separately.
How much would your HMO conversion drawings cost?
Build an itemised guide price from the services you need. The result is indicative, does not require contact details and is not a fixed quotation.
Size-based design and technical fees below are for relatively straightforward projects. Substantial alterations or unusual constraints need a tailored proposal. No complexity percentage uplift is applied.
| Existing floor area | Conversion design | Technical drawings |
|---|---|---|
| Up to 90 m² | £1,495 | £1,850 |
| 91–120 m² | £1,595 | £2,050 |
| 121–150 m² | £1,695 | £2,250 |
| 151–200 m² | £1,995 | £2,650 |
| Over 200 m² | Bespoke quotation | Bespoke quotation |
For a representative 135 m² four-bedroom semi-detached home with moderate internal reconfiguration and five or six proposed occupants: survey £550, feasibility £495, conversion design £1,695, planning submission £400 and technical drawings £2,250 — £5,390 before any qualifying survey credit.
Choose the services that match your project. You can adjust every selection.
Indicative professional fees only. Statutory fees, specialist consultants and third-party charges are additional. A measured survey fee is credited against the final Building Regulations invoice only where the agreed full-package conditions are met.
Before you convert a property
Does an HMO always need planning permission?
No single answer applies to every property. Planning use class, the proposed number of occupants, Article 4 Directions, conditions and planning history all matter. Confirm the position for the exact address with the local planning authority.
Does planning permission mean the HMO is licensed?
No. Planning, HMO licensing and Building Regulations are separate processes with different requirements and decision-makers.
Are the national bedroom sizes the only standard?
No. The 6.51 m² and 10.22 m² minimums apply to specified sleeping rooms in licensed HMOs. Local authorities may require higher standards, and room shape, headroom, facilities and the intended occupants also matter.
Does the calculator confirm that a property is suitable?
No. It highlights early questions and potential constraints. A measured survey, review of the property and checks with the relevant planning and licensing teams may be needed before design decisions are made.
Are consultants included in the fees?
Structural engineers and other specialists are normally appointed separately. Their information can be coordinated with the architectural package where agreed. Their professional services and specialist fire engineering are not included unless specifically stated.
Start with a clear view of the opportunities.
Use the feasibility checker to frame the early questions, then choose the design or technical services that fit the property and proposed occupancy. The next step is a project-specific discussion and itemised proposal.