Planning permission for a purpose-built shared house
Building a shared house from scratch takes you outside Class C4 and outside permitted development. Here is what the council will test and what evidence to file with the application.
A purpose-built shared house needs full planning permission. There is no permitted development route into a new building, and once the scheme is designed for seven or more people sharing a kitchen or bathroom it sits outside Class C4 altogether as a sui generis use. That combination is what makes new build HMO planning permission harder than converting a terraced house: you are asking for a use the Use Classes Order does not name, on a site where the council may already be counting how many shared houses sit within a short walk.
The route is a full application, not a prior approval and not a certificate. Everything below assumes England.
Where C3, C4 and sui generis actually divide
The Town and Country Planning (Use Classes) Order 1987, as amended, puts single households in Class C3 and small houses in multiple occupation in Class C4. Class C4 covers a dwellinghouse occupied by between three and six residents as their only or main residence who share a basic amenity such as a kitchen or bathroom. Seven residents and the use falls out of the Order and becomes sui generis.
That boundary does more work than most applicants expect. Schedule 2 Part 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015 allows movement between C3 and C4 in both directions without an application, so a landlord converting a house for five sharers may need nothing at all. Move to seven bedrooms and the permitted change disappears, because sui generis uses are never covered by the Order.
A new building has no existing lawful use to change from. So the question is not which class you are moving between but whether the council will grant the use you are proposing on that plot, judged against its adopted local plan and any housing or HMO supplementary planning document.
Article 4 directions and why they still matter
Councils in university towns and areas of dense terraced housing routinely remove the C3 to C4 permitted change by Article 4 direction. Where a direction is in force, converting a family house to a small HMO needs a planning application even though the national rule would allow it.
For a purpose-built scheme the direction does not change whether you need permission, because you need it anyway. It changes the policy climate. An Article 4 area is, by definition, an area where the council decided that unmanaged growth in shared housing was harming the balance of the neighbourhood, and the decision notice and the supporting statement that accompanied the direction will tell you exactly what harm it was worried about. Read both before you design the scheme.
You can check whether a direction covers your site on the council's own planning pages and on the national Article 4 direction dataset on the government's planning data service. Do not rely on a plan you were sent by an agent. Directions get amended.
Room sizes, amenity and the licensing overlap
Planning and licensing run on separate tracks and are decided by different teams, sometimes in different buildings. The Housing Act 2004 licensing regime sets mandatory minimum sleeping room sizes for licensable HMOs in England, and a room below the prescribed floor area cannot lawfully be used for sleeping under the licence conditions. Those figures are set in regulations and are the floor, not the target.
A planning officer will look past the licence minimum to the living arrangements as a whole. Communal kitchen and dining space in proportion to the number of bedrooms, natural light and outlook to every habitable room, sound separation between rooms and circulation space, and usable private amenity space or a designed courtyard. A scheme that squeezes ten en-suite rooms around a galley kitchen will be refused on internal amenity even where every room clears the licensing threshold.
Design the two consents together. Applying for permission on a layout the licensing team will later reject wastes a decision period, and the fix usually means losing a bedroom.
Parking stress evidence
Shared houses generate a car ownership pattern that is different from a family dwelling and different again from a block of flats. Where the council's parking standards give a range, or where an objector claims the street is already full, the evidence that settles the argument is a parking stress survey rather than an assertion.
The commonly accepted approach is the Lambeth methodology: a beat survey of the available legal kerbside within a defined walking distance of the site, repeated overnight midweek and at a weekend, counting parked vehicles against measured capacity to give a stress percentage. Surveys are normally run outside school holidays and outside the fortnight around Christmas, because both distort residential parking. A parking survey done properly gives the highway officer a number to work with instead of a dispute.
If the site sits in a controlled parking zone and the council can exclude future occupiers from permits by condition or obligation, say so in the application and offer it. That single point resolves a large share of highway objections to shared housing.
Refuse, cycles and management
Bin storage is where shared housing applications quietly fail. Ten sharers on separate tenancies produce household waste on a different pattern from one family, and councils will ask for storage sized to the collection frequency and the number of containers their own service issues, positioned within a stated drag distance of the collection point and screened from the street. Work from the council's own waste storage guidance, not from a standard detail.
Cycle parking should be secure, covered, at ground level and not stacked behind the bins. A Waste Management Strategy that sets out container numbers, storage dimensions, the drag route and who moves the bins on collection day answers the environmental services consultation before it is raised.
Management is the other half. A short management plan covering the letting model, who the responsible person is, how anti-social behaviour is dealt with and how the property is maintained can be secured by condition and often carries weight where the objection is about neighbourhood impact rather than physical form.
How concentration policies are measured
Many councils apply a concentration or threshold policy: a limit on the proportion of shared or licensed properties within a defined radius of the application site, or on the number of adjoining properties already in that use. The radius, the percentage and the counting method are set locally in the local plan or an HMO supplementary planning document, so check the adopted wording rather than assuming a national figure exists, because there is not one.
What varies most is the data source. Some authorities count from the licensing register, which captures only licensable HMOs and so undercounts. Others count council tax records, using exemptions and single occupancy discounts as a proxy, which captures more but includes properties that stopped being shared years ago. If your site fails the threshold on the council's count, ask for the underlying data and check it. Errors in this evidence are common and correcting them is a legitimate part of the case.
The evidence base to file
For a purpose-built scheme on a small urban site the pack usually runs to a Planning Statement dealing with the sui generis use and the concentration policy head on, a Design and Access Statement covering internal layout and amenity, drawings including a bin and cycle store detail, the parking survey, and a management plan. New build also brings the biodiversity gain condition into play under the Environment Act 2021 regime, with the statutory metric completed by a competent person.
Where the site adjoins gardens, a daylight and sunlight note may be needed. Where the plot was previously in commercial use, a Phase 1 desk study will be. And if you are subdividing an existing building rather than building new, the tests are different enough that our note on adding a second dwelling by subdividing a large house is the better starting point.
Take the concentration policy seriously at feasibility stage. It is the reason most of these schemes are refused, and it is the one constraint you cannot design around once the site is bought.
This is general guidance rather than legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
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Frequently asked questions
Do I need planning permission for a new build HMO?
Yes. A new building has no existing lawful use, so a full planning application is always required. If the scheme is designed for seven or more sharers it is a sui generis use rather than Class C4, which means no permitted development right can apply and the council judges the proposal against its local plan policies on shared housing.
At what number of occupants does an HMO stop being Class C4?
Class C4 covers a dwellinghouse occupied by three to six residents as their only or main residence who share a kitchen or bathroom. From seven residents the use falls outside the Use Classes Order and becomes sui generis. The dividing line is the number of residents, not the number of bedrooms, so a seven bedroom house let to six people can still sit in C4.
Does an Article 4 direction affect a purpose-built shared house?
Not directly, because permission is needed regardless. It matters because a direction shows the council has already judged that shared housing growth in that area was causing harm. The statement published with the direction sets out that reasoning and usually points to the same concentration policy your application will be assessed against.
What is a parking stress survey and when will I need one?
It is a survey of parked vehicles against measured legal kerbside capacity within a set walking distance, run overnight midweek and at a weekend under the Lambeth methodology. Councils ask for one where parking standards give a range, where the site has no off street provision, or where objectors say the street is already at capacity.
How do councils count existing HMOs near my site?
Usually from the licensing register or from council tax records, within a radius fixed by the local plan or an HMO supplementary planning document. Both data sources have known weaknesses. Licensing registers omit smaller unlicensed HMOs and council tax data can be out of date, so ask for the underlying figures if your site is said to fail the threshold.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.