C2 12 14 Nikau Street SSCNVMP

C2 12-14 Nikau Street SSCNVMP

C2.1 Introduction

This Site Specific Construction Noise and Vibration Management Plan (SSCNVMP) is for the residential building located at 12-14 Nikau Street. It is reproduced from the Mt Eden Enabling Works CNV DWP, where construction was predicted to exceed the standards in CRL designation conditions 31 and 33. A SSCNVMP is not required for the Mt Eden Station Main Works. It is included for information to ensure consistency across project stages. This SSCNVMP has been prepared in accordance with CRL designation conditions 37 and 38 and is Appendix C2 of the Mt Eden Main Works Construction Noise and Vibration Delivery Work Plan (CNV DWP). It is a supplementary document that builds on the CNV DWP, and therefore directly references relevant sections of the CNV DWP to avoid repetition. The objective of this SSCNMP is to detail the best practicable option(s) (BPO) to avoid, remedy or mitigate the identified adverse effects from noise and vibration exceedances at 12-14 Nikau Street.

This SSCNMP has been prepared for the Link Alliance and forms part of the Construction Environmental Management Plan (CEMP) for the Mt Eden Station Main Works.

C2.2 Engagement

Mt Eden Enabling Works (for information)

Link Alliance representatives Sonya Leahy, Thibaut L'Hopital, Rick Galli, Aidan Kirkby-McLeod and Craig Fitzgerald met with Rod Pratt (building owner) on 3 September 2019. The matters discussed included:

An overview of the project General programme, demolition, piling, rock breaking/blasting and tunnelling activities

Overview of the CNV DWP and this SSCNMP, communications triggers and protocol

Building layout and identification of any noise sensitive spaces The double level commercial building has been converted into a block of 13 residential units above a basement car park. The neighbouring building will be demolished to maintain access to Flower and Shaddock Streets. It is adjacent to the portal piling and excavation works. Figures B.1 and B.3 in Appendix B of the Mt Eden Enabling Works CNV DWP shows that the south façade is predicted to be exposed to noise levels up to 93 dB L Aeq during the closest demolition and bored piling activities, exceeding the 75 dB L Aeq noise limit. Activity specific mitigation and management measures are included in Section 9 of the CNV DWP and not repeated here (e.g. Section 9.8 piling). The building has a concrete block wall with no windows on the western façade facing the works, which will mitigate noise received inside adjacent apartments. The north and south façades include operable glazing and appear to have a shallow pitched steel roof. The estimated sound level difference across the façade with the windows and doors closed is in excess of 30 decibels. The predicted construction noise effects from Table 12-1 in Section 12.1 are predicted to be typically acceptable, but with the potential for some disturbance in the western most apartments during demolition of the neighbouring building. Physical receiver mitigation, such as temporary relocation of affected receivers, alternative

Page 17 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs

ventilation and façade sound insulation improvements, have been considered, but are not required as part of the BPO for the C3 enabling works. Tunnelling activities have the potential to generate vibration induced reradiated noise (a low frequency rumble). The vibration transfer function will need to be established once the project starts as it cannot be readily predicted with any accuracy. This will be monitored to ensure compliance and inform effects on sleep. Mr Pratt agreed that prior communication of timeframes for works with the potential to exceed the relevant noise limits was an acceptable means of managing effects. No further activity specific consultation is necessary over and above regular communication (Section 10). Subsequently, vibratory roller vibration (Section 6.2 of the Enabling Works CNV DWP) from adjacent temporary road forming works is predicted to exceed the thresholds for the potential of cosmetic building damage. Cosmetic building damage effects are deemed ‘minor damage’ in the DIN Standard (Section 5.2), such as cracking in paint or plasterwork, and can generally be easily repaired. A pre-construction building condition survey in accordance with CRL designation condition 46 has been undertaken and will ensure any damage is identified for remediation.

Mt Eden Main Works

None required for the Mt Eden Station Main Works. However, noting Mr Pratt previously agreed that prior communication of timeframes for works with the potential to exceed the relevant noise limits was an acceptable means of managing effects. No further activity specific consultation is necessary over and above regular communication (Section 10).

C2.3 Review Process

If Mr Pratt requests consultation in the future, this SSCNVMP will be updated in accordance with CRL designation condition 37.5 and 38.5, with consideration given to the following:

The extent to which noise may exceed the designation standards

The timing and duration of any exceedance

The type of activity causing any exceedance

A summary of the communication and consultation with the receiver

The methods and measures to mitigate effects

A statement of why they reflect best practicable option Communications records are contained in the communication and consultation plan (CCP). This SSCNMP will be updated to summarise engagement and any agreed site-specific measures.

Page 18 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs