31-unit HMO extension appeal fails over daylight to existing rooms

An HMO extension appeal in Ealing has been dismissed after an Inspector found that squeezing two additional units into an already heavily subdivided building would harm daylight, sunlight and outlook for existing occupiers.

Appeal 6005995 concerned Cecilia House on Hanger Lane, a Sui Generis HMO formed from two former detached houses. The building already contained 29 residential units and the proposed single-storey rear extension would have taken the total to 31.

Inspector Carla Livingstone accepted that two additional homes would contribute to housing supply and make more efficient use of the site. However, she gave greater weight to the harm that the extension would cause to two existing rooms immediately beside it.

HMO extension appeal focused on two existing rooms

The appeal was brought by Mr Reeve of Charter Property Development Ltd after Ealing Council failed to determine application 254825FUL within the prescribed period. This was a non-determination appeal, rather than an appeal against a formal refusal.

The Council’s appeal statement said it lacked sufficient information about land use and the spatial relationship between the units. Livingstone visited the site on 21st July 2026 and identified the living conditions of the occupants of rooms 5 and 30 as the main issue.

Cecilia House has a complicated rear elevation with several existing extensions of different heights and sizes. The proposed development would add a single-storey hipped-roof extension to provide two en-suite bedrooms.

The extension would partly enclose a gap between existing rear additions. That brought it particularly close to two existing ground-floor units, identified in the appeal as rooms 5 and 30.

Room 5 relied on one large window and also contained an en-suite and small kitchen area. Room 30 was larger, with two smaller windows serving the sleeping area and a larger window to the kitchen and living area.

Livingstone found that the proposed extension would sit very close to the only window serving room 5 and the main window serving the kitchen and living space of room 30. Its height and proximity would therefore have a materially harmful effect on outlook and access to daylight and sunlight.

A daylight report from another site did not fill the evidence gap

The appellant referred to a daylight and sunlight assessment prepared for a different development at 15 Hanger Lane. That material did not clearly assess the effect of the appeal proposal on the existing rooms within Cecilia House.

Livingstone said the report did not “clearly and accurately assess the specific effect of the appeal scheme”. The assessment needed to address existing units within Cecilia House.

For the Inspector, that was a critical evidential gap. The issue was not whether similar development elsewhere could satisfy daylight standards, but whether this particular extension would leave the immediately affected occupants with acceptable living conditions.

In the absence of a site-specific assessment demonstrating otherwise, the physical relationship seen on site was enough to support the finding of harm.

Planning history disputes did not decide the HMO extension appeal

The parties disagreed about the planning history of Cecilia House and about previous development within the building. The Inspector kept that dispute separate from the application before her.

Any concerns about the lawfulness of earlier works or uses were enforcement matters and did not alter the assessment of the proposed extension. That is an important distinction in heavily altered HMO buildings, where historic planning status can become tangled with a new proposal.

The dismissal did not resolve the disputed planning history or certify the lawfulness of earlier alterations. Those issues remained separate from the merits of adding the proposed extension.

The appellant also pointed to co-living proposals on Gunnersbury Lane and at 15 Hanger Lane. Full details were not supplied, so Livingstone could not establish that their circumstances matched this HMO extension appeal.

Conservation-area duties were satisfied

The site lies within the Ealing Common Conservation Area and next to the Creffield Conservation Area. The Inspector therefore considered the statutory duty to preserve or enhance conservation-area character.

The proposed rear extension would not be visible from the public realm and would sit among a number of existing rear additions. Relative to the size of the original building, it was modest.

Livingstone therefore found no harm to the significance of the Ealing Common Conservation Area or the setting of the neighbouring conservation area. Heritage was not a reason for refusal.

Two extra homes still carried substantial weight

Livingstone considered the revised National Planning Policy Framework published on 17th August 2026. She said the changes from the December 2024 version were not substantive or determinative for this appeal.

Because the site lies within a settlement, she applied policy S3 and the settlement decision-making balance in policy S4. The efficient use of land also counted in favour under policy L3.

Even a small increase of two residential units would contribute positively to housing supply and make more efficient use of land. The associated social and economic benefits also counted in favour of the proposal.

Livingstone gave those benefits substantial weight. They were not dismissed as trivial merely because the scheme was small.

However, Livingstone attached “greater than substantial weight” to the harm to existing occupiers. She found conflict with Ealing’s development management policy 7B and Framework policy L2 d ii.

That adverse effect outweighed the benefits under the settlement balance in policy S4. The development plan conflict remained, and the material considerations did not justify a different outcome.

The harm to the living conditions of the existing occupiers carried greater weight. The appeal therefore failed despite the accepted housing benefits.

Planning Geek analysis

For us, the practical lesson from this HMO extension appeal is clear. It exposes a common tension in intensification schemes. Increasing the number of units can deliver housing benefits, but those benefits do not give an applicant licence to erode the living conditions of people already in the building.

We would start by identifying every existing window affected by the extension, the room it serves and whether there are other sources of light. A scheme drawing alone may not answer those questions where a building has been repeatedly subdivided.

The evidence point is equally important. Where a refusal turns on daylight, sunlight or outlook, a report from another development is unlikely to carry much weight unless it actually analyses the windows and rooms affected by the current proposal.

For large HMOs, co-living schemes and heavily subdivided buildings, internal amenity relationships can be just as important as impacts on neighbours. A rear extension may appear modest from outside while materially changing the environment of existing occupiers inside.

Planning Geek’s HMO minimum bedroom size guidance explains a separate aspect of shared housing, while our 45-degree rule guidance explains one common initial design check. This decision did not turn on a stated 45-degree test; the actual window relationships and lack of relevant evidence were decisive.

Read the decision

Appeal 6005995 was dismissed on 2nd October 2026 by Inspector Carla Livingstone MA(SocSci) (Hons) MSc MRTPI.

Read the full Inspector’s decision for this HMO extension appeal, or view the Planning Inspectorate appeal record.