Appeal 6004015

The appeal is allowed and planning permission is granted for amalgamation of ground and second floor flats to create 1 x 4 bed flat (Use Class C3). Conversion of existing basement to create 1 x 1 bed flat (Use Class C3), formation of one lightwell. Internal alterations and associated works at [site address] in accordance with the terms of the application, Ref 25/02608/FUL, subject to the conditions in the attached schedule.

A Basement Impact Assessment (BIA) was submitted with the appeal, which was not before the Council at the time the application was determined. The Council and interested parties have had the opportunity to consider and comment on the BIA. The BIA does not substantively alter or fundamentally change the scheme. I am satisfied that no party has been prejudiced by the timing of its submission and that it has been considered through the appeal process. Accordingly, having had regard to the need for procedural fairness, I have taken the BIA into account in my assessment of flood risk.

The main issues relevant to this appeal are: • Whether the proposal would cause harm to the housing stock • The effect of the proposal on the living conditions of the occupiers of the proposed amalgamated flat with regard to whether a coherent or functional living environment would be created as well as the occupiers Flat 94B with regard to noise and disturbance; and • The effect of the proposal on flood risk.

Policy H5 of the Oxford Local Plan (LP) states that planning permission will not be granted for development resulting in the net loss of one or more self-contained dwellings on a site, including family homes (with the loss of a house in multiple occupation converted from a self-contained dwelling also regarded as such), except in specified circumstances. The appeal scheme does not fall within any of those circumstances. The proposal would involve the amalgamation of two flats, one at ground-floor level and the other at second-floor level, both of which are self-contained dwellings with multiple bedrooms and capable of occupation as family homes. Whilst this would result in the loss of one self-contained dwelling, the scheme also includes the conversion of the basement to form a new one-bedroom self-contained flat. Having regard to its limited size, it is unlikely that this unit would provide accommodation suited to family occupation.

The proposal would not give rise to a net loss of self-contained dwellings overall and would therefore not conflict with the quantitative requirement of Policy H5. However, it would result in the replacement of a larger dwelling capable of family occupation with a smaller one-bedroom unit. The supporting text to Policy H5 emphasises the importance of protecting existing housing stock, particularly homes suited to family living. As such, although the proposal may accord with the policy in numerical terms, it gives rise to some tension with the qualitative objective to protect larger dwellings.

Whilst the proposal would result in the loss of a larger dwelling best suited for family living, it would deliver an additional smaller unit which would meet a different but equally important segment of Oxford’s housing need as supported by Policy H4 of the LP as well as Section 12 of the Summertown and St Margaret’s Neighbourhood Plan (NP). These set out that one-bedroom accommodation can make an important contribution to the overall housing mix, supporting a full range of local needs for present and future generations and the NP identifies that there is a shortage of small dwelling units in the NP area.

The proposal would lead to the loss of a single large family-sized dwelling; however, the scale of this change would be limited and would not materially undermine the city-wide objective of protecting family housing. Importantly, there would be no net loss of self-contained dwellings, thereby aligning with the principal aim of Policy H5 to resist reductions in overall housing stock. The creation of a new self-contained basement unit would represent an efficient use of previously underutilised space and would ensure that the site continues to contribute positively to the Oxford’s housing supply.

The basement flat could be provided independently of the appeal scheme. However, the proposal before me is a single, comprehensive development and it is on that basis that it must be determined. I have therefore assessed all elements of the scheme together in reaching my conclusions.

Whilst the development would result in the loss of a larger dwelling suited to family occupation, the degree of harm arising from this would be limited. The proposal would maintain the overall number of self-contained units on the site, thereby satisfying the quantitative objective of Policy H5. In addition, the introduction of a smaller unit would contribute towards a more balanced housing mix and address the identified need for smaller-scale accommodation. In these circumstances, the limited conflict with the qualitative aims of Policy H5 would be outweighed by compliance with its primary objective and the efficient use of the site.

The appeal property comprises a large building that has been subdivided into three self-contained flats, one on each floor. Each flat benefits from its own independent access. The first- and second-floor flats are served by separate internal staircases, with the staircase to the first-floor flat (Flat 94B) located centrally within the building and that serving the second-floor flat (Flat 94C) positioned to one side. Accordingly, each occupier can access their respective property without the need to pass through or rely upon the entrances serving the other units.

The proposed development would involve the amalgamation of the ground-floor and second-floor flats to form a single dwelling, while the first-floor flat would remain as a separate unit. This would be achieved through the insertion of a doorway within the ground-floor flat (Flat 94A) to access the existing staircase serving Flat 94C. As such, occupiers of the combined dwelling would be able to move between floors internally without exiting the building. The use of this existing staircase would provide a clear and legible means of circulation, without reliance on or interaction with the neighbouring flat. Whilst the resulting arrangement is unconventional, planning policy does not require standardised layouts, but rather functional and practical living environments. In this instance, the proposed configuration would facilitate a coherent pattern of day-to-day living, with convenient internal access and adequate separation of spaces, such that the dwelling would operate effectively as a single residential unit.

Having regard to the arrangement of the existing staircases and the limited intervention required to provide internal access, the proposed works would result in a combined dwelling that remains fully self-contained from Flat 94B. The amalgamated unit would benefit from a substantial amount of internal floorspace, and the proposed layout, which includes generously proportioned bedrooms and shared living areas with appropriate natural light, would provide a good standard of accommodation for future occupiers.

It is acknowledged that the amalgamated dwelling would have a significant internal floorspace. However, the planning system does not impose maximum size thresholds for residential units, and larger dwellings can form part of a balanced housing mix. Importantly, the proposal would also introduce a smaller unit, thereby broadening rather than narrowing the range of accommodation on the site. The size of the amalgamated dwelling would be substantial; however, this reflects a reconfiguration of existing floorspace rather than any underuse of the site and it is not evident how this scheme would not result in good quality living accommodation, particularly given the scale of it, which exceeds the [name] 1 as required by Policy H15. Additionally, the consolidated floor space into a larger unit does not inherently equate to inefficient use where three self-contained dwellings would still be retained on the site. Consequently, the scheme continues to make a comparative quantitative contribution to housing supply.

It is not disputed between the parties that the size of the proposed basement flat would be appropriate for a one-bedroom unit. Having regard to its internal layout, room sizes and intended occupation, and based on the evidence before me, I find no reason to conclude otherwise. The flat would be accessed via a side entrance and given that the existing flats are already served by separate access points, this arrangement would not appear incongruous. Taken together, these factors indicate that the overall layout of the development would not appear contrived.

Given that Flat 94C can be occupied as a separate dwelling, a degree of noise and activity associated with everyday living would already be experienced within the Flat 94B. As such, it is reasonable to expect that the type of noise and disturbance arising from use of the upper floor would not differ materially from the existing situation. Similarly, the staircase serving Flat 94C is already in regular use for access and egress, and associated levels of activity and noise would therefore already occur.

It is likely that the amalgamation of the two flats would result in more frequent use of the staircase, as occupiers move between living areas arranged across different levels. However, the use of the dwelling would be by a single household, and movements within the building would remain typical of residential occupation. Furthermore, the staircase is positioned to one side of Flat 94B, meaning that associated noise would be localised rather than broadly distributed. Any increase in activity would therefore be limited and characteristic of normal residential comings and goings within a multi-level property. For these reasons, I find that the proposal would not result in significant harm to the living conditions of the occupiers of Flat 94B.

Therefore, for the reasons given above, the proposed development would be coherent and practical and would not lead to harm to the living conditions of the occupiers of Flat 94B or the combined dwelling. Accordingly, the proposal would not conflict with Policies DH1, H15, RE7 or RE8 of the LP. These seek, amongst other matters, for development to ensure the amenity of occupiers and neighbours is protected as well as ensure new dwellings provide good quality living accommodation for the intended use.

The appeal site is located in [name] 1 and is at a low risk of flooding. However, the proposal seeks to convert the existing basement to a self-contained flat which would include sleeping accommodation. This would introduce a highly vulnerable use as per the National Planning Policy Framework’s flood risk vulnerability classification. Whilst the site is in [name] 1, with the development located in the basement, there is a risk from groundwater flooding. The BIA identifies that the rest groundwater levels in the wider area would be around 0.61 metres below the proposed basement level. Whilst there is a possibility that in very rare circumstances groundwater may rise and interact with the basement, the BIA concludes that the scheme would pose a negligible impact on groundwater flow and level and have a negligible risk of altering flood risk to either the appeal property itself, or other adjacent or nearby properties, subject to tanking the basement level to prevent water ingress which could be secured by condition.

With regard to the proposed lightwell for the basement flat, the plans show a vertical window but do not show whether the lightwell would be open or covered. If left open at ground level water could pool within the lightwell and it is not evident how this would be drained nor how surface water flooding would be prevented from flowing overland into the lightwell. This could put the future occupants of the development at risk. However, the Planning Practice Guidance identifies conditions can enhance the quality of development and enable development to proceed where it would otherwise have been necessary to refuse planning permission, by mitigating the adverse effects. In this instance, a condition ensuring the details of the lightwell are submitted to and approved by the Council could mitigate the flood risk concerns regarding the lightwell.

Therefore, subject to the discharging of suitably worded conditions, the development would not lead to an increased risk of flooding on site or elsewhere. Consequently, the development would comply with Policies RE3 and RE4 of the LP which seek, amongst other matters, to ensure development will not put any future occupants of the development at risk or have an adverse impact on groundwater flow.

The appeal site is located in the [address] Character Area of the North Oxford Victorian Suburb Conservation Area and Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 requires special attention to be paid to preserving or enhancing the character or appearance of the Conservation Area. The Conservation Area Appraisal North [name] sets out that the significance of this Character Area comes from the wide roads and pavements lined with trees with large houses set back from the street as well as the high-quality buildings set within large spacious plots. These buildings are a mix of styles including [name] and Arts and Crafts. The appeal property is a [name] dwelling set back from the road within a large plot and as such, it positively contributes towards the significance of the CA. The appeal proposal includes mostly internal works, other than the lightwell and window for the basement flat, the details of which could be secured by condition. Given the very limited scale of this, the dwelling would still be viewed as a large [name] dwelling set back from the road within a large plot. Accordingly, the scheme would not harm the contribution the building makes towards the significance of the CA and thus would preserve the character and appearance of it.

Concerns have been raised regarding the possible amalgamation of Flat 94B with the proposed dwelling. However, this is not what is proposed and I have only had regard to the merits of the scheme before me.

Further to the statutory commencement condition, a condition requiring the development is carried out in accordance with the permitted plans is necessary in the interests of certainty.

A condition requiring approval of details related to the lightwell and lightwell window is necessary in the interests of the character and appearance of the CA as well as flood risk. However, it is not necessary for the suggested condition to be pre-commencement. It is necessary that such details are provided and secured before occupation of the basement flat in the interests of flood risk and as such, I have changed the condition to reflect this. Additionally, I have combined two suggested conditions and simplified the details to be approved. The details would still need to be approved by the Council and can be approved as part of one all-encompassing condition.

With regard to flood risk, a condition requiring the tanking and waterproofing measures is approved and implemented is necessary.

A condition requiring the basement flat is made available for occupation prior to the occupation of the amalgamated dwelling is necessary in the interests of ensuring the scheme would not result in the net loss of a self-contained dwelling.

The proposed development would accord with the development plan as a whole and the material considerations do not indicate that the decision should be made other than in accordance with it. Therefore, for the reasons given above, I conclude that the appeal should be allowed.

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following drawings: 2024/438 12; 2024/438 04; 2024/438 05; 2024/438 06; and 2024/438 07.

Prior to the occupation of the basement flat hereby approved, details of the design and appearance of the basement lightwell window and measures of how to make the basement lightwell shown on drawing nos. 2024/438 06 and 2024/438 04 safe from flooding shall be submitted to and approved in writing by the local planning authority before the lightwell is installed. The works shall be carried out in accordance with the approved details prior to occupation of the basement flat and retained as such thereafter.

Prior to occupation of the basement flat hereby permitted, details of the tanking and waterproofing measures shall be submitted to and approved in writing by the local planning authority. The basement flat shall be tanked in accordance with the approved details prior to occupation of it and retained as such thereafter.

Prior to the occupation of the amalgamated dwelling hereby permitted, the basement flat as shown on drawing no. 2024/438 04 shall be made capable of occupation and carried out in accordance with the approved drawings. The basement flat hereby permitted shall thereafter be retained as a self-contained dwelling. End of Schedule