Appeal 6001319

The appeal is allowed and the planning permission Ref 25/00869/FULHH for installation of an air source heat pump to be installed to the property at [site address] granted on 12 September 2025 by Melton Borough Council, is varied by deleting conditions 3 and 4 and substituting for them the following condition:

The level of noise emitted from the hereby approved air source heat pump shall not exceed 42 dB LAeq 1 hour, between 0700am and 2300pm and 40 dB LAeq 5 minutes, at any other time, as measured 1 metre from the nearest window or door of a habitable room in any neighbouring property.

Planning permission for an air source heat pump was granted subject to 4 conditions. Conditions 3 and 4 set noise levels and restrict when the air source heat pump could be operational. These conditions were attached to protect the living conditions of neighbouring occupiers.

Paragraph 57 of the National Planning Policy Framework (the Framework) advises that conditions should be kept to a minimum and only imposed where they are necessary, relevant to planning and the development permitted, enforceable, precise, and reasonable in all other aspects.

The appellant seeks to remove conditions 3 and 4, on substantive grounds. As such, the main issue of the appeal is whether conditions 3 and 4 are necessary and reasonable, with particular regard to the effect of the proposed development on the living conditions of neighbouring occupiers.

Condition 3 specifies that no noise from the proposed air source heat pump shall be audible from the boundaries of the adjacent properties. The Environmental Health Officer has indicated that background sound levels are likely to be very low, and ambient noise is minimal during night-time hours.

[name] agree with the Environmental Health Officer’s assessment, this alone does not justify requiring the air source heat pump to be inaudible from the property’s boundary. Even when having regard to the tonality and impulsivity of the proposed noise, low levels of noise would not have a materially harmful effect on the living conditions of neighbouring occupiers. The requirement for the air source heat pump to be inaudible from the property’s boundary is too strict. As such, Condition 3 is not reasonable. Condition 4

Condition 4 states that the air source heat pump shall operate between the hours of 07:00 and 22:00 only. An air source heat pump is used to provide heat and hot water. As a result of Condition 4, occupiers of the appeal property could be without heating or hot water for long periods and during the coldest part of the day. Therefore, restricting the use of the air source heat pump to day-time hours would be unreasonable. In turn, Condition 4 is not reasonable.

Notwithstanding the above, the air source heat pump would make noise and would be in proximity to a neighbouring property. Also, background noise levels are likely to be low, especially at night, due to the rural character of the area. Moreover, MCS 20(a) Planning Standard is an industry-recognised standard for assessing noise generated by air source heat pumps. The appellant’s manual sound calculation indicated that the proposed air source heat pump would generate noise in excess of the level recommended within MCS 20(a) Planning Standard.

However, the appellant contends that a calculation against MCS 20(a) Planning Standard gives the worst case scenario and is conservative. As such, they have completed a Noise Assessment1 using a methodology consistent with [name] 4142:2014+A2:2019 (BS4142). BS4142 provides guidance on assessing industrial sound. The result of the Noise Assessment is that the noise level at the nearest neighbouring window would be 29dB(A). This noise level is below the recommended acceptable noise levels specified within BS4142.

Accordingly, there is conflicting evidence on whether the proposed air source heat pump would emit unacceptable levels of noise. Therefore, a condition is necessary to ensure that the living conditions of neighbouring occupiers are preserved.

The Council indicated 2 proposed conditions that it considered should replace conditions 3 and 4 in the event that I allow the appeal. I have considered these conditions against paragraph 57 of the Framework. 1 ISO 9613-2 Site Specific Noise Map Report

The Council suggested that the noise levels emitted by the air source heat pump shall not exceed specified noise levels when measured in accordance with BS4142. This is reasonable as it is in accordance with a recognised standard for assessing industrial noise. Furthermore, although the evidence is conflicting, it appears that the proposed air source heat pump could comply with the specified noise levels. It would also provide the Council with precise noise limits against which it could enforce.

The second part of that proposed condition which is entitled “Fallback for [name]” is not necessary, as the first part of the condition provides sufficient control for the installation of all types of air source heat pumps.

With regard to the other suggested condition there is no need to attach a new condition specifying a time limit to implement the planning permission, as Condition 1 attached to the original permission still applies.

[name] 3 nor Condition 4 are reasonable. However, a condition is necessary in order to ensure that the proposed air source heat pump does not emit unacceptable noise levels. Consequently, the appeal should succeed and conditions 3 and 4 should be removed, and a new condition should be imposed. The imposition of the new condition is necessary to ensure that the proposal complies with Policy D1 of Melton Local Plan 2011-2036, October 2018, which indicates that the amenity of neighbours should not be compromised.