3 A Best Practice Approach to Commissioning

A best practice commissioning approach starts towards the end of the design phase, continues through the construction and handover phases, and is initially completed at the end of the first year of occupation or defects liability period. Ideally it should continue over the life of the building. A best practice commissioning approach integrates and enhances the traditionally separate functions of:

design peer review and recording of design intent
management of the commissioning process by a commissioning agent
testing and commissioning verification by a commissioning agent
O&M documentation, including a user guide
staff training
facilities and environmental management.

In this section we look at the part commissioning plays in the four main commissioning phases - design, construction, warranty and post-warranty. We then cover the extent of the commissioning process and conclude by briefly examining “green” leases.

3.1 Design phase

The developer or building owner should appoint a commissioning agent during the design stage to oversee the commissioning process. (The role of the commissioning agent is defined in the Appendix A of this report.) Early selection during the design phase allows the commissioning agent to play an advisory and review role.

The designer should provide a detailed design intent for the building in addition to the normal drawings and specifications. This can then be communicated consistently to the commissioning agent, construction team and building operators. The design should be reviewed for its ability to be commissioned, operated and maintained. This review would normally be carried out by the commissioning agent and, if available, by the facilities management staff.

3.2 Construction phase

During this phase the commissioning agent should provide a commissioning plan and programme. They should also visit the construction site periodically and note any conditions that might affect system performance or operation.

The testing and commissioning process should be carried out by the installing subcontractors to accepted codes (i.e. Charted Institution of Building Services Engineers, Building Services Research and Information Association and American Society of heating, Refrigeration and Air Conditioning Engineers) and should verify the proper operation of equipment and systems according to the design intent, design drawings and specifications. Point-to-point or end-to-end testing of the BMS is highly recommended. If corrective measures are required, the commissioning agent should make sure they meet the design intent. Acceptable performance is reached when equipment or systems meet specified design parameters under full-load and part-load conditions during all modes of operation, as outlined in the commissioning plan.

A high standard of verification, completion, clearance of defects and documentation should be achieved prior to granting handover. After completing pre-handover commissioning, the commissioning agent should write a handover commissioning report, which includes all commissioning documentation, and submit it for review by the building owner and designers. Prior to handover, building operators should be trained in the operation and maintenance of equipment and systems. The commissioning agent should oversee the training sessions provided by the installing contractors, designers and manufacturers’ representatives.

The commissioning agent also verifies that operation and maintenance manuals include a user guide and are complete and available for use during the training sessions.

3.3 First-year operational or warranty phase

Even though the project is considered complete, some fine-tuning commissioning tasks should continue throughout the typical one-year defects/warranty period. The commissioning agent should initially return on a monthly basis for the first three months, and then quarterly through the defects/warranty period to review system operation and liaise with facility staff to address any performance problems. It is also helpful after six months to carry out a post-occupancy evaluation survey of the building’s occupants to identify any issues with the building, and this can inform the need for any further fine-tuning.

A monthly log of energy and water consumption should be kept and reconciled with the agreed performance targets. Any non-performance problems should be addressed as part of the system’s fine-tuning and operational practices.

An environmental management plan (EMP) should be set up at the start of this period. A typical example is given in Appendix B.

3.4 Post-warranty phase/continuous commissioning

It is a good idea for the building owner to consider re-commissioning their facilities periodically to ensure that equipment performance levels continue to meet design intent. This means that in order to maintain a high level of performance, in a sense commissioning never ends. Operation and management staff should be encouraged to audit and partially re-commission selected building systems on a regular basis, perhaps every three years depending on building usage, changes to layout equipment complexity and operating experience.

3.5 Extent of commissioning and facilities management provisions

The extent of the commissioning process will obviously vary depending on the size and complexity of the project and the ownership structure, as indicated in Table 1.

Table 1: Extent of commissioning and facilities management provisions

View extent of commissioning and facilities management provisions (large table)

3.6 Green or performance-based leases

For leased buildings, consideration should also be given to a performance-based or “green” lease, which identifies remedies if the environmental performance of a building is not met. Further information on green leases is given in the Appendix C.

An Australian Government Green Lease Template www.climatechange.gov.au/government/initiatives/eego/~/media/publications/eego/gls-schedule-d1.doc is available as a basis if this approach is being considered. It should, however, be noted that New Zealand developers and building owners are currently hostile to these types of leases. A performance-based appointment of the commissioning agent is also a possibility, with a base fee and a performance bonus if the energy target is achieved within the first year.

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