Agenda item

Demolition of existing house and erection of a two storey, new build house consisting of 6no. bedrooms with a basement (Amended plans and description).

Recommendations: Approval

RESOLVED: That the application be approved

Demolition of existing house and erection of a two storey, new build house consisting of 6no. bedrooms with a basement (Amended plans and description).

Officers introduced the item.

The lead petitioner was in attendance and addressed the Committee:

• There had been extensive interest over this application.
• Many issues remained unresolved in the officer's report.
• Bulk, scale, and massing were out of character with the area.
• The total footprint will be three times the current footprint.
• The new height will be 9.3m which was much higher than the existing property and higher than the property next door.
• There will only be a one metre gap between the two properties.
• This would go against the character of the area.
• Neighbouring properties will lose some privacy because of the height, bulk and large first floor windows.
• Number 45a was especially affected because it was a bungalow.
• Number 53 was a residential care home where the back garden is used as an amenity for the residents who will be overlooked.
• There were concerns about subsidence and flooding in the large basement – many houses in the area had been affected by subsidence. The basement impact assessment does not refer to this.
• Sweetcroft Lane was narrow with limited parking, and was a cut-through for Long Lane.
• The demolition and construction work will require continuous heavy vehicle movement which will result in traffic restricting access to residents.

Members asked and the petitioner confirmed that they lived adjacent to the application site.

Members asked and officers confirmed that the size of the access road was unchanged.

Members asked about the number of instances of subsidence, if these were recent instances, and if people who had experienced this had signed the petition. The petitioner noted that they were aware of at least seven instances of subsidence. This was the reason for concerns about the basement.

The agent was in attendance and addressed the Committee:

• The agent thanked planning officers for their cooperation.
• The proposal had been through a long and careful design process guided directly by the Council's pre-application advice and subsequent officer feedback.
• The scheme presented here was not the original proposal, but the outcome of meaningful revisions specifically made to address previous concerns and mitigate harm to the local context to try and uphold and improve upon the high standard of housing that was present in the community.
• The site was located within a developed area of the borough where the replacement of an existing dwelling was acceptable in principle. This was confirmed during pre-application discussions and feedback.
• Importantly, the proposal did not introduce additional units, did not subdivide the plot, and did not constitute inappropriate backland development.
• It remained a single family home on a large plot of approximately 1,800 square meters, consistent with the established residential character of Sweetcroft Lane.
• A key concern raised previously related to excessive footprint and roof form. These points have been directly addressed.
• The depth of the building had been reduced, improving relationships with the neighbouring properties. The overall mass and bulk had been softened, avoiding an overbearing appearance.
• The roof design had been fundamentally revised in keeping with nearby dwellings.
• The architectural language had been deliberately reworked to reflect the Edwardian character evident along Sweetcroft Lane.
• The proposal now sits comfortably within the area of special local character, respecting established building lines, scale, and proportions.
• Neighbouring impact had been carefully assessed with the following design parameters addressed with careful consideration.
• Separation distances had been maintained and, in some cases, improved.
• There was no unacceptable loss of daylight, sunlight or privacy to neighbouring properties.
• The relationship to the rear properties, including Portman Gardens, had been sensitively considered with the Council's pre-application advice.
• The site was surrounded by mature vegetation and protected trees and the proposal had been designed around these constraints, not in conflict with them.
• Tree retention and protection strategies had been developed. Landscaping had been used to assimilate the building into the green edge context in line with the local plan policies.
• The openness to the front of the site had been preserved, including the removal of the previously proposed garage to maintain character and reduce the level of development sought on this site.
• This will also allow for the existing tree to be safeguarded through the construction of this proposal and the root protection zone to be maintained.
• The scheme incorporated renewable energy measures including solar panels consistent with the Local Plan and London plan policies.
• Matters relating to drainage, basement construction, biodiversity net gain and technical details had been robustly assessed and where necessary and capable of being appropriately controlled by planning conditions which officers had indicated was acceptable.
• In summary, this proposal fully reflected the Council's pre-application advice and officer feedback; responded constructively to previous refusals and withdrawals; delivered a high-quality replacement dwelling; preserved neighbouring amenity; respected the character and appearance of the area of special local character; and complies with the development plan.
• For these reasons, it was suggested that the application was policy compliant, well considered, and deserving of approval.

Members asked about the basement and potential for subsidence. Construction was a building regulations matter, though subsidence was a key consideration. The agent reassured Members that the development would utilise the most competent structural engineers and civil engineers. Further documentation was conditioned to be submitted.

Members highlighted that some subsidence information was not in the public domain. Officers noted that in terms of the planning process, there was a policy within Local Plan Part Two which required a set amount of information to be submitted, including structural integrity. There was a methodology within that document which outlined that the basement can be constructed without impact upon the structural integrity of neighbouring properties. If it became apparent that there could be a potential for impact upon neighbouring properties, it was expected that the building control surveyor would put in restrictions or request additional information. It was important to separate the planning process from the building regulations process. If officers were to consider the potential to refuse the application based on the fact that the applicant had not been able to obtain information which is not publicly available to them, officers and the Committee would have to be confident that the basement impact assessment was not robust and was incorrect.

Officers referred to Condition 8 which required the strengthening of the basement impact assessment specifically around flooding which could also have an impact upon structural integrity. It was therefore recognised that there were elements of the basement impact assessment that could need strengthening, however officers were of the opinion that the documents that had been submitted did conform with the requirements of that condition and therefore it would be unreasonable to refuse on that basis.

Councillor Bridges attended as Ward Councillor and addressed the Committee:

• Councillor Bridges thanked the Committee for the opportunity to speak and noted that this application did not meet key requirements of the Hillingdon Local Plan, the London Plan, or national policy.
• Scale and character: this was a backland site within the Hillingdon Court Park area of special local character. The proposed footprint was about 236m with an additional basement of roughly 292m and a height of around 9.2m. Taken together, that represented a substantial increase over the existing dwelling and would appear over-dominant in this sensitive location that conflicted with Local Plan policies DMHB5 area of special local character; DMHB11 design of new development; and DMHB12 streets and public realm, which expect new developments to respect local character and the established pattern of development.
• Effect on neighbours: the combined bulk and the accommodation in the roof introduces a third level of presence and raised reasonable concerns about the outlook, privacy, and overshadowing, particularly for 43 Sweetcroft Lane and other nearby homes. Local planning policy DMHB11 required that development does not harm neighbouring immunity. The Committee report acknowledged the need to rely on tests like the 45° lines and daylight sunlight methodology with sensitivities here at upper levels.
• Basement: the basement policy DMHD3 required robust evidence that basements will not increase flood risk or compromise structural stability. The officer report notes inaccuracies and gaps in the assessment and had had to rely on conditions to secure an updated drainage strategy and structural safeguards in a critical drainage area. Deferring essentials such as basement drainage, groundwater control and structural measures to conditions did not provide the necessary certainty at decision stage and conflicted with DMHD3 and DMEI 10 underwater management efficiency and quality as well as London Plan policies SI 12 and 13 on flood risk and sustainable drainage. When taking into consideration trees and biodiversity, two trees are to be felled and further works undertaken. Whilst these are lower grade, the scheme also conceded that on-site biodiversity net gain may fall short and sought to fix this later by condition. That sat uneasily with DMHB14 under trees and landscaping and with the requirement to secure genuine 10% biodiversity net gain for a deliverable plan as now reflected in the conditions and narrative.
• Construction: construction access and safety access was via a narrow drive between 45a and 49 Sweetcroft Lane and adjacent to a care home. The highway section proposes a construction management plan by condition. Given the tight geometry and the duration and intensity of basement works, there remained a risk of unacceptable disruption contrary to local plans policy DMT1 and DMT2 which required impacts to be avoided or fully mitigated.

Officers clarified that, on footprint, the property on the right-hand side of the application property had benefited from a similar consent. While the properties were oriented slightly differently, there were similar footprints. A considerable amount of properties along Sweetcroft Lane had either a similar or slightly larger footprint.

On scale, bulk and massing, attention was drawn to two properties on the adjacent site which had an approved height of nine metres, which was comparable to the application site.

When looking at development on backland sites, officers looked for intensification as opposed to replacement. Whilst this may have the character of a backland site, it was not considered to be backland development. It did not intensify the residential use of the site.

On access, the access road served the existing property.

On construction, the MPPF paragraph 56 stated that where harm can be identified which would normally warrant refusal, where conditions can bring about a positive recommendation but secure mitigation to address the harm, those conditions should be used. If the application was refused on the grounds that the applicant had not submitted a CMP, this would be in direct conflict with the MPPF. Furthermore, the access road was no shorter or less wide than that which served the neighbouring properties which were also subject to redevelopment. The property directly to the right was not subject to a construction management plan.

45a was 62m away from the front elevation. The existing front elevation was in the same location as the new front elevation. The window-to-window distance was 61m, while the Local Plan set a separation distance of 21m. In terms of the care home, that was 43m window-to-window in distance.

Officers clarified that inaccuracies in the report were based on the fact that throughout the consultation process, neighbours who took part in the consultation identified that there were reports of subsidence made to building control which were not available within the public domain. It was therefore not possible to explain that there were not inaccuracies because that would not be factual. Inaccuracies were caused by the fact that this information was not publicly available. Officers also emphasised that the impact reports conformed with requirements, though officers were still seeking enhancements to demonstrate that the drainage, particularly for the basement, would be robust.

Members asked for clarity on traffic management and hours of operation of delivery. Officers noted that Condition 11, Part C related to hours of development works and Pard D related to how vehicles accessed the site. Part F related to traffic management and access. Therefore, all of these points were covered by condition.

Members asked about protecting trees during construction. There was a tree retention condition which required trees to be retained.

Officers’ recommendations were moved, seconded and when put to a vote, agreed.

RESOLVED: That the application be approved