Agenda item

Use of basement and ground floors as two Class A1 retail units at ground floor level and a Class D2 gym at basement level, installation of a new shopfronts and entrance doors and associated alterations at ground floor level.

An additional representation was received from Planning Resolution (08.09.16).

The presenting officer tabled the following amendments to conditions 14 and 16 and informative:

“Revised Criteria for Condition 14

General noise

Noise generated by the proposed new development (including noise from general operations, gym equipment, new plant and equipment, amplified sound, music etc.) in terms of L_Aeq,5mins should be demonstrated to be 10 dB below the existing background noise level measured in terms of L_A90,5mins inside the existing residential dwellings. The background noise level used in the assessment should be representative of the most sensitive times (quietest) at which the new development is in operation (and generating noise).

Maximum noise levels

Maximum noise levels generated by the proposed new development in terms of L_AFmax should be demonstrated not to exceed the NR 15 curve inside the existing residential dwellings. This includes noise from all sources (including amplified sound, music, impact noise from gym activities, activities in the retail unit). This is based on the assumption that existing background noise levels in the properties during the most sensitive periods are approximately NR 25 (approximately equivalent to 30 dB L_Aeq).

Music Noise

For music noise, the design of the separating structures should be such that the received music noise level in the residential habitable spaces, with music playing, should be demonstrated to be 10 dB below the existing ambient and maximum noise levels in the residential habitable spaces when music is not playing, at the quietest time of day and night, measured over a period of 5 minutes and in the indices of L_eq and L_Fmax in the octave bands 63 Hz and 125 Hz; The overall music noise level in terms of L_Aeq,5mins should be at least 10 dB below the existing background noise level in terms of dB L_A90,5mins.

A Sound Limiter shall be installed and set by a competent acoustic engineer so that it maintains compliance with the above criteria. All amplification equipment within the development including music generating equipment and fitness instructor’s announcement equipment shall be routed and controlled through the sound limiter. The operational panel of the noise limiter shall be secured by key or password so that only persons with management responsibility have access. No additional sound generating equipment shall be used on the premises without being routed through the sound limiter device.

External Noise

Any external noise generated by new plant and equipment associated with the proposed development should meet the standard Westminster City Council planning conditions C46AB(1) and C46AB(2)

Revised Wording of Condition 16

“No vibration shall be transmitted to adjoining or other premises and structures through the building structure and fabric of this development as to cause a vibration dose value of greater than 0.2m/s (1.75) 16 hour day-time nor 0.2 m/s (1.75) 8 hour night-time as defined by BS 6472 (2008) in any part of a residential and other noise sensitive property.

Informative relevant to these requirements

It is possible that existing background, ambient and maximum levels within the residential dwellings could be very low for measurement and assessment purposes. It is expected that the accuracy of results should be taken into consideration when dealing with the measurement of low noise levels. Standard Deviation of measurement is a recognised measure of accuracy of results and reasonable consideration should be given to Standard Deviation as well as the capabilities of the instrumentation used for the assessment. It is acknowledged that it is impossible to physically measure noise which is 10 dB below existing noise levels or measure NR criteria which is below existing NR levels. Therefore, it is anticipated that the assessment of Condition 14 will include a comparison of ‘on/off’ conditions and seek to investigate the ‘increase’ in measured levels with the above points taken into consideration. For example; a level 10 dB below existing levels would increase existing levels by 0.4 dB. The assessment of Condition 14 might also include a calculation approach where measurement is impracticable or a combination of measurement and calculation. Measurement assessment of Condition 14 and 16 requires that residents allow the applicant access to carry out Acoustic testing to demonstrate compliance with Condition 14 and 16 through measurement. If access is not made available the applicant may deploy a calculation approach and base the criteria on reasonable assumptions of the existing acoustic conditions within the residential properties.”

RESOLVED

That conditional permission be granted, subject to revised conditions 14 and 16 tabled at the meeting, and to the amendment of condition 8 to read:

“You must apply to us for approval of a Servicing Management Plan (SMP) that includes details of the following aspects of servicing of the retail units and gym:

(a) the location of servicing vehicles when loading/unloading on the highway;

(b) the size of servicing vehicles and the process for transporting goods to and from the service entrance to the retail premises, including staffing in relation to servicing;

(c) the storage location for any crates or trolleys required for servicing (which must not be on the highway);

(d) measures to reduce noise associated with servicing activities;

(e) schedule of deliveries and time periods during which all servicing will take place (which shall only be between the hours of 07.00 and 20.00 Mondays to Friday, 08.00 to 18.00 Saturdays and 0.900 to 13.00 on Sundays and Bank Holidays)

You must not open the two reconfigured retail shop premises to customers until we approve the SMP you send us.

You must then operate and manage the two retail shop premises and gym according to the Servicing Management Plan we approve.

Reason:

To avoid blocking the surrounding streets and to protect the environment of people in

neighbouring properties as set out in S29, S32 and S42 of Westminster's City Plan: Strategic Policies adopted November 2013 and ENV6, SS6, STRA 25, TRANS 20 and TRANS 21 of our Unitary Development Plan that we adopted in January 2007.”