Seven-person HMO ruled lawful without planning permission in Hemel Hempstead

A seven-person HMO in Hemel Hempstead has been ruled lawful without express planning permission after a Planning Inspector found that adding one resident did not, on the particular facts, amount to a material change of use.

Inspector J Moss allowed lawful-development certificate appeal APP/A1910/X/25/3365341 at Micklefield Road on 1st October 2026. The property was already being used as a six-person Class C4 HMO. The proposed seventh resident would share one of the six existing bedrooms, with no change to the physical layout.

The decision is a useful counterpoint to Planning Geek’s Greenwich seven-person HMO appeal, also reported this week. Greenwich was a planning-merits appeal in which the Inspector found unacceptable noise from the extra occupation. Hemel Hempstead asked a different legal question: did moving from six residents to seven amount to a material change of use at all?

The lawful baseline was the first battleground

The appeal followed Dacorum Borough Council’s refusal of application 24/02745/LDP, made on 4th December 2024. The application sought a certificate under section 192 of the Town and Country Planning Act 1990 for a change from a six-person HMO in Class C4 to a seven-person HMO outside the use classes.

Before the Inspector could consider the proposed seventh resident, he had to decide what use lawfully existed when the application was made.

Dacorum argued that the baseline should effectively be treated as a Class C3 dwellinghouse because the evidence had not sufficiently established that the permitted change to C4 had actually occurred. The Council did not dispute that Class L of Part 3 of the GPDO 2015 can permit a change between C3 and C4, subject to its terms.

The Inspector was not persuaded by the Council’s evidential objection. On his site visit he saw a layout typical of a six-bedroom HMO, including numbered lockable bedroom doors, occupied rooms, personal effects and food.

Tenancy agreements also supported the appellant’s account. Although one Room 5 document was incomplete and undated, the remaining agreements related to numbered rooms and shared facilities. Two pre-dated the LDC application.

Dacorum pointed to the absence of material such as council-tax records, licensing information, affidavits and bills. But it produced no contradictory council-tax, licensing or inspection evidence of its own. Applying the balance-of-probabilities test used for lawful development certificates, Inspector Moss found it more likely than not that the property was already in use as a six-person HMO when the LDC application was made.

Six people is the C4 ceiling, but not the whole planning test

Use Class C4 is limited to qualifying HMOs occupied by no more than six residents. A seven-person HMO is therefore outside C4 and is normally described as sui generis.

But crossing a use-class boundary does not automatically establish that development has taken place. The separate question is whether the change is material as a matter of fact and degree.

That distinction is the heart of this appeal. The Inspector referred to court authorities including Reed v Secretary of State for Communities and Local Government [2014] EWCA Civ 241. The Court of Appeal confirmed that intensification can amount to a material change of use, but only where it produces a material change in the definable character of the use.

So the numerical move from six to seven residents was relevant, but it was not conclusive. The Inspector had to consider what would actually change in the planning circumstances at Micklefield Road.

Why the seventh resident mattered less than the number suggests

The proposed seven-person HMO would retain six bedrooms, making the seven-person HMO arrangement notably different from a seven-bedroom layout. The seventh resident would share an existing bedroom with another occupier, rather than occupy a newly created seventh bedroom.

Inspector Moss considered it “highly likely” that the two people sharing that private living space and the communal facilities would constitute one household within the HMO.

That mattered when he assessed the intensity of the use. There could be some additional comings and goings, but he considered that two people forming one household would be likely to make some trips together, particularly for shopping and leisure.

The same reasoning was applied to parking. If the additional resident had access to a vehicle, the Inspector considered it likely that it could be shared within that household. There was no evidence demonstrating that the seventh resident would create materially greater on-street parking demand.

Deliveries were also considered. The Inspector referred to another appeal concerning post-pandemic delivery patterns, but found no reason to expect the extra resident here to have the same effect as adding a wholly separate household.

Waste generation might increase, but the property had a dedicated external bin store, a spacious garden and side access. There was no evidence of an existing refuse-storage problem.

The Chilterns Beechwoods SAC objection did not change the answer

Dacorum’s second reason for refusing the LDC concerned potential recreational pressure on the Chilterns Beechwoods Special Area of Conservation.

The Inspector drew an important distinction between an LDC and a conventional planning application. The question was not whether the proposal should receive planning permission after a planning balance, but whether the proposed use would have been lawful when begun on the application date.

Potential effects on the SAC could still matter if they changed the planning circumstances or were sufficient to engage the habitats assessment process. However, the Council did not quantify the additional recreational pressure against the existing six-person baseline or demonstrate likely adverse effects on the integrity of the SAC.

Because the seventh resident was highly unlikely to create an additional household, the Inspector considered any extra recreational pressure likely to be marginal on the evidence before him. He was not persuaded that likely significant effects had been demonstrated so as to engage the habitats assessment process.

Why Hemel Hempstead and Greenwich are not inconsistent

Read quickly, the two seven-person HMO decisions might look contradictory. They are not.

At Ceres Road in Greenwich, the appellant sought planning permission for a seven-bedroom, seven-person sui generis HMO. The Inspector accepted an extant six-person HMO permission as a genuine fallback, but still had to decide the planning merits of the larger proposal. On that site, the additional occupation was found likely to intensify external activity and noise beside the adjoining home.

Micklefield Road was a section 195 LDC appeal. The six-person Class C4 HMO was found to be the actual lawful baseline, and the Inspector had to decide whether the particular increase to seven residents changed the definable character of the use enough to amount to a material change of use.

The answers therefore depended on different statutory questions and different facts. One extra resident can be material on one site and not material on another, even as a seven-person HMO. 

This is not a blanket rule for every seven-person HMO

Inspector Moss was explicit that his conclusion depended on “the particular circumstances of this case”. The certificate itself is tightly drawn around those circumstances.

It certifies a seven-person HMO where the seven residents are accommodated within the existing six-bedroom layout shown on the approved plans. The Inspector added that a materially different arrangement, including another way of accommodating seven residents, might fall outside the certificate.

That precision matters. The decision does not establish a general rule that every move from six occupiers to a seven-person HMO is lawful without planning permission. A seventh bedroom, a different household pattern, materially greater parking or traffic, increased noise or other site-specific effects could lead to a different conclusion.

What the appeal does demonstrate is that the six-person C4 ceiling and the material-change test are separate. Practitioners should identify the lawful baseline first, then compare the actual character, scale and effects of the existing and proposed uses rather than treating the number seven as the answer.

Inspector Moss concluded that the proposal “would not result in a material change of use for which planning permission would be required”. The appeal was allowed and the lawful-development certificate granted.

Read the full Micklefield Road appeal decision. Planning Geek also has guides to lawful development certificate appeals and HMO planning.