Objecting to an HMO conversion in an Article 4 area

If you want to object to an HMO planning application, the first thing to establish is whether an application was needed at all. Changing a family house in Class C3 to a small house in multiple occupation in Class C4 is permitted development in most of England under Class L of Part 3 of the General Permitted Development Order 2015. Where the council has made an Article 4 direction removing that right, permission is needed and there is something to object to. Where it has not, there is usually nothing, however strongly the street feels about it.

That is an unsatisfying answer for a lot of people, so it is worth understanding exactly where the line falls and what carries weight on the side of it where objections matter.

Why some HMO conversions need permission and others do not

Class C4 covers small houses in multiple occupation: three to six unrelated people sharing a house and its basic facilities. Class C3 is a dwellinghouse occupied as a single household. The permitted development right allows movement in both directions between those two classes, so in most places a landlord can convert without applying.

Two situations take a conversion outside that right. An Article 4 direction removing the C3 to C4 right means an application is required. And a house occupied by seven or more people in multiple occupation falls outside Class C4 altogether as a sui generis use, which always needs permission regardless of any direction.

Physical works are a separate question again. Extensions, dormers, outbuildings and additional bathrooms may need permission or may be permitted development, and a conversion carried out lawfully as a use can still involve unauthorised building work.

How an Article 4 direction changes the position

An Article 4 direction is made by the local planning authority under Article 4 of the General Permitted Development Order. It withdraws a specified permitted development right in a defined area, and once it takes effect an application is required for the withdrawn class of development. Councils in university towns and cities with pressure on family housing have used them widely for the C3 to C4 right.

Three things to check before objecting:

1. The exact boundary. Directions are often limited to named wards or a mapped area, and the street next to yours may be outside it. The council publishes the direction and its map, and national datasets on planning.data.gov.uk collate them.
2. The date it came into force. A use established before that date may already be lawful, which is a different argument entirely.
3. What it withdraws. Some directions cover C3 to C4 only. Others cover householder extensions or other classes in the same area, and the wording decides the answer.

National policy expects Article 4 directions to be limited to situations where they are necessary to avoid wholly unacceptable adverse impacts, and applied to the smallest area needed. That is worth knowing because it shapes how councils draft them and why the boundaries are sometimes tighter than residents expect.

Concentration thresholds in local policy

Where an application is required, the policy doing most of the work is usually a concentration policy in the adopted local plan or a supplementary planning document. The common form sets a percentage of properties within a defined radius of the application site, above which permission will be refused, and the percentage and the radius are both set locally.

Two variants appear alongside it. A sandwiching policy refuses proposals that would leave a family house with an HMO on both sides. A contiguous frontage policy refuses proposals that would create an unbroken run of shared houses along a street.

Find the policy number and read the exact wording before you write. An objection that says the street has too many HMOs carries little weight. One that says the proposal would take the figure within the stated radius above the stated threshold, and shows the working, is the objection an officer has to answer in the report.

Amenity, refuse and parking grounds

Four grounds do real work in HMO decisions, and each needs evidence rather than assertion.

Noise and disturbance from a higher number of unrelated occupants, with more comings and goings at different hours. Officers treat this cautiously, because occupancy behaviour is not a planning matter in itself, and the argument has to be framed around the intensity of the use rather than the character of the people.

Refuse. A six-person HMO generates more waste than a family house and usually has nowhere to keep the bins except the front garden. Where the council's own standards require a screened bin store of a stated capacity and the plans do not show one, that is a specific and answerable objection.

Parking. Shared houses commonly generate more car ownership per property than family houses in the same street, and where there is no off-street provision the effect falls on the kerb. A Parking Survey carried out to a recognised methodology, with overnight counts on a weekday and at the weekend outside holiday periods, is the evidence that carries weight. A resident with a clipboard doing the same counts and recording them properly is producing usable evidence too.

Standard of accommodation. Room sizes, the ratio of bathrooms and kitchens to occupants, natural light to habitable rooms and useable outdoor space are all material, and they are also licensing standards, which makes the numbers easy to find.

Where plant, extraction or a commercial element is involved, a Noise Impact Assessment may be part of the application, and it is fair to test its assumptions about background sound levels and survey timing.

Evidence about the street rather than the house

The strongest objections describe the area, because that is what a concentration policy measures. Four sources are open to anyone.

The council's public register of HMO licences, kept under the Housing Act 2004, lists licensed properties by address. The planning register shows previous applications and any Article 4 decisions on nearby properties. Council tax records are not public in detail, but student exemption patterns sometimes surface in committee reports. And photographs, dated and taken from the public highway, evidence bin presentation, parking pressure and the appearance of frontages better than any description.

Put the addresses in a table and state the radius you have used. If your figure and the officer's differ, the report will have to explain why.

Licensing as a separate regime

HMO licensing under the Housing Act 2004 is housing law, not planning. Mandatory licensing applies to houses in multiple occupation with five or more occupants in two or more households, and many councils operate additional licensing schemes covering smaller HMOs.

The two regimes do not decide each other. A council cannot refuse planning permission because a licence would be refused, and it cannot refuse a licence because planning permission is absent. Raising licensing points in a planning objection wastes the space, though raising the licensing standards as evidence of what adequate accommodation looks like is fair.

If the property is being used as an HMO without permission in an Article 4 area, the route is the council's planning enforcement team rather than an objection, since there is no application to object to. Enforcement time limits for unauthorised changes of use were altered by the Levelling-up and Regeneration Act 2023, so ask the authority what period now applies.

What a refusal actually turns on

Most refusals in Article 4 areas turn on the concentration figure, with amenity and parking as supporting reasons. Most approvals happen because the figure falls below the threshold and the accommodation meets the standards, whatever the strength of local feeling.

So write the objection the officer can use. Quote the application reference and the policy numbers. Give your figure, your radius and your address list. Attach dated photographs. Ask for the application to go to committee if the council's scheme of delegation allows a call-in, and speak to your ward councillor early, because the call-in usually has to come from a member. And send it within the publicity period, which is normally 21 days, even though most authorities accept representations up to the point of decision.

One honest caveat: a well-evidenced objection changes the reasoning in the report, and it does not always change the outcome. Applications that comply with the adopted policy are generally approved, and that is how the plan-led system is supposed to work.

Enter your postcode on PlanScope to see which reports a change of use application in your area is likely to need, and read the Planning Statement page to understand the document an applicant will have submitted.

This article is general guidance, not legal advice. Article 4 boundaries, concentration thresholds and enforcement periods vary, so check the position with your local planning authority or a qualified professional before relying on it.