Appeal 3368484

The appeal is allowed and planning permission is granted for the installation of an additional air conditioning unit to the east elevation at [site address] in accordance with the terms of the application, Ref PLAN/2025/0120, subject to the following conditions:

The development hereby permitted shall be carried out in accordance with drawing nos: 21.935 L.201 (Location Plan), dated 25.02.25, 21.935 P.201 (Proposed Site Layout), dated 25.02.25, 21.935 P.202 ([name] and Elevations), dated 25.02.25, Toshiba Air Conditioning - RAV-GM1101ATP-[name] (1pp), Acoustic Assessment at [site address] , prepared by Ned Johnson Acoustic Consultants Limited ([name]: 562425 [name], Date: 18/03/2025) (41pp).

The air conditioning unit shall not operate unless and until the provisions of the Acoustic Assessment at [site address] , prepared by Ned Johnson Acoustic Consultants Limited ([name]: 562425 [name], Date: 18/03/2025) (41pp), have been implemented. Including: (i) the installation of an acoustic enclosure to the Toshiba RAVGM1101ATP-E condenser unit in accordance with the minimum performance for the enclosure which is specified in Table 4 of Section 6 and (ii) the attachment of absorptive panels to the wall behind the condenser unit to reduce sound reflections (as per paragraph 6.5). The preceding mitigation features must be installed prior to any operation of the development hereby permitted and thereafter be permanently retained and maintained for the lifetime of the development hereby permitted.

It appears that the air conditioning unit has already been installed. Nevertheless, for the avoidance of doubt, the fact that development has occurred has not altered my decision.

The main issue is the effect of the proposed development on the living conditions of neighbouring occupiers with particular regard to noise at 2 The Pines.

Planning permission was granted in 2022 for a two storey detached dwelling on this site (Ref: PLAN/2022/0681). At present, there are four external plant units close to the eastern boundary. Two air conditioning units and one air source heat pump were approved pursuant to a condition of the 2022 planning permission. This appeal seeks planning permission for the fourth unit. The noise from the three units which have permission is therefore permitted and forms part of the existing noise level. Any breach of this condition or the 2022 permission is outside the scope of this appeal.

This is a quiet suburban area. The unit which is the subject of this appeal is located to the eastern side of [site address] , close to the boundary with 2 The Pines., where there is a 2m high fence. This neighbouring house is orientated at an angle to [site address] , with its main rear elevation facing in a north westerly direction. There are multiple windows at ground and first floor serving main rooms, including a bedroom, around 14-17m from the boundary. The main private garden space is also to the rear of the property and adjoins this shared boundary.

Representations indicate that neighbouring occupiers have been disturbed by noise from the plant at [site address] and changed their behaviour including use of rooms and the garden. However, they indicate that this relates to all plant along the boundary, the majority of which is not seeking planning permission as part of this appeal. Nonetheless, the neighbouring occupiers are evidently sensitive receptors to noise from the proposed plant.

The appellant submitted an Acoustic Assessment (Ref 562425 [name]) (AA) which provided a sound pressure (dBA) level using the measured data from the new air conditioning unit at the receptor (the windows at 2 The Pines). This includes measurements of the units in situ and accounts for reflections. Observations on site of the operation of the unit were that the plant does not have tonality or impulsivity characteristics. It calculates that with a 2m high barrier, the noise level would be around 30dBA 12m away at a height of around first floor level and 10m away at a height of 1.5m, which would be around the centre of the garden. An acoustic enclosure is proposed, which would reduce the level to 24dBA at these receptors and the AA also recommends absorptive panels are attached to the wall behind the condenser units. These could be secured by condition.

I am also provided with a detailed letter from [name] on behalf of the owners of 2 The Pines. This includes measured plant noise levels of the garden 42dB, patio 40dB and bedroom 40dB at 2 The Pines. As well as a narrow band frequency spectrum analysis which shows low frequency noise. However, these measurements do not appear to relate only to the single proposed unit, and would not take into consideration the proposed enclosure. Therefore, I do not consider these to be representative of the noise level that is proposed for this appeal. Consequently, on the basis of the evidence before me in this appeal, subject to the mitigation proposed, the noise levels at the receptor from this air conditioning unit would be 24dB.

The noise specialists also include different assessments of the background noise level. Interested parties carried out a survey over 4 days. They submit that levels of LA90T 37dB during the day, 34dB in the evening and 27dB at night are considered characteristic of when the plant may operate. These therefore do not appear to include any consideration of noise from the three permitted units. The appellants measured the background sound level over one day but also excluded any impact on the background sound level of the other three mechanical plant units. This found a higher typical background sound level of 32dB at night and 43 dB during the daytime.

I am not presented with evidence that there is a requirement in this area for noise levels to be a specific level below the background sound level. However, where the rating level does not exceed the background sound level, this is an indication of the specific source having a low impact.

Even taking the lowest nighttime level with no permitted plant operating, the background noise level would be 27dB. The unit proposed as part of this appeal would be 3dB lower than this noise level. Therefore, even taking this precautionary approach to the existing noise level, the proposed unit would have a low impact. Therefore, this is unlikely to cause significant disturbance to the occupiers at 2 The Pines. Given these conclusions are for the quietest time overnight, it follows that the effects would be less when the background noise levels are higher during the day and evening.

The proposed unit would contribute to noise levels when all four units were operating. However, in this scenario, the three permitted units would be likely to increase the background noise level. Given the noise from the proposed unit falls below the background noise level with no plant operating, it follows that with the three permitted units operating it would still fall below the background noise level. Therefore, cumulative sound levels relating to all 4 units are not required in this case.

The differences between the parameters for the assessment for the first and second revisions of the appellants AA is unhelpful. Nevertheless, the differences including whether one single unit or all four units were assessed, along with the provision of an acoustic enclosure clearly justify the different outcomes between the two schemes.

Taking into account that the proposed unit would have a low impact on noise levels, I do not have detailed evidence that there would be harm to wildlife in this regard.

Therefore, the proposed development would not have an unacceptable effect on the living conditions of neighbouring occupiers with particular regard to noise at 2 The Pines. As such, it would be in accordance with Policy CS21 of the [name] (2012) and Policy DM7 of the Woking Development Management Policies Development Plan Document (2016). Together these seek that development should be designed to avoid significant harm to general amenity resulting from noise, and ensure noise is reduced to an acceptable level, amongst other things.

I have considered the Council’s suggested conditions. In the interests of certainty, a condition to define the plans with which the scheme should accord is attached. However, as development has taken place the standard implementation condition is unnecessary and has not been included.

A condition securing the implementation of the mitigation measures is required for the reasons set out above, in the interests of neighbouring living conditions. The wording has been altered to reflect that the unit has been installed but should not operate until these measures are in place.

For the reasons given above the appeal should be allowed.