Building life-cycle performance depends on the quality of process from planning through to demolition, including testing and commissioning. The costs for commissioning depend on the scope of work and quality of management oversight, with the benefits also dependent on the persistence of the commissioning outcomes.

Scope of New Building Commissioning

World-wide the scope and depth of building commissioning varies, from minimal or no testing to full building commissioning embracing all phases of a project. Essentially the scope of commissioning activity can be summarised as illustrate in the following illustration [1].

Testing & Commissioning

In Hong Kong Testing and Commissioning (T&C) is generally regarded as testing of equipment and systems separately, generally towards the end of the construction phase, as illustrated in the figure above.

The outcomes from Hong Kong’s T&C practice are often unsatisfactory, especially HVAC systems [2].  Whilst ArchD’s T&C specifications and instructions are comprehensive, the extent to which systems will be fully commissioned will depend on the skill and diligence of the various sub-contractors employed, and the engineers and inspectors who vet the outcomes. Even if T&C for each system is complete, and there is much evidence to suggest otherwise, it is unlikely that conflicts between systems will be fully resolved. The private sector, whilst adopting Government T&C specifications, is perhaps under less due diligence with respect to quality assurance, so it seems that there is even less likelihood that T&C will be fully implemented [1].

Completion of fire services installations (FSI) is prerequisite to obtaining an occupation permit for a building, with potentially significant economic losses if delayed. According to a survey by Fong et al [3] the principal factors contributed to construction delays were: improper site co-ordination and management of the electrical and mechanical installations, lack of timely decision making by the client, and defects identified during the fire services inspection by local authorities. The factors contributing to the delays included inadequate site management and supervision, workload of the project staff, procedures for equipment approval, and working experience of the parties involved.

According to McMahon T&C of Hong Kong’s ultra-modern buildings is routinely undertaken by inexperienced, unqualified technicians. T&C is viewed as a low-class activity, which is largely carried out by contractors for contractors, with problems routinely undetected or deliberately concealed. The potential for long-term substandard performance and energy wastage as a result of poor T&C are obvious, yet the practice as a whole never receives the status and importance that it deserves. McMahon’s observation is that project managers rarely approach commissioning in a thorough, co-ordinated manner and instead of being considered and addressed at the design and installation phases, T&C is routinely “squeezed into the latter stages of a project when it is often too late to address the problems that come to light”.

“Much of the construction process is heavily reliant on the skill and knowledge of site personnel …. Adequate site supervision is, therefore, crucial to ensure the delivery of works to specifications…. Otherwise, costly rectification and programme delays would result.”
“it is crucial to ensure that adequate supervisory provision (especially at professional level) is made for critical stages of construction...” (4.34) “Independent auditing provides checks and balances to guard against unsatisfactory work...”

Commissioning Management

In the UK Commissioning Management places emphasis on a more integrated approach to the commissioning of building services systems, i.e. the advancement of installations from static completion to full working order, including the regulation and fine tuning of systems [4], and is now a requirement of the UK building regulationscovering the energy performance of non-domestic buildings.

Until recently, commissioning practice in the UK also tended to be fragmented and undertaken towards the end of construction. According to CIBSE [4], “the commissioning programmes produced by building services installers and their sub-contractors are frequently over-optimistic and uncoordinated. They assume that others will co-operate in providing water, gas and electric supplies, a weather-tight building, unobstructed access and a dust-free environment. A risk of project overrun will exist unless the interdependencies of all the building services systems and plant are identified, together with their integration with on-going construction activities. This complex, and highly fragmented part of the construction process demands good management”.

Commissioning Process

ASHRAE’s guideline [5] details the process, responsibilities of the commissioning team, role of the Commissioning Agent, and a model framework for developing a Commissioning Plan, specifications and reports, together with general requirements for operator training and documentation. The guideline makes reference to other technical guidelines for specific commissioning information for the building systems.

The US General Services Administration’s (GSA) guide details the commissioning team members, commissioning activities and responsibilities for each phase of a project, from pre-design through to handover and early stages of occupancy and operations (figure below). The Commissioning Agent is one having the technical background and expertise with the commissioning process including verification techniques, functional performance testing, system and equipment, and O&M knowledge in order to successfully manage the process on behalf of the client.

The Commissioning Process as envisaged by GSA and ASHRAE is not seen as an additional layer of construction or project management, rather its purpose is to reduce the cost of delivering construction projects and increase value to owners, occupants, and users. It assumes that owners, designers, contractors, and operations and maintenance entities are fully accountable for the quality of their work, but seeks to provide for better co-ordination of commissioning activities. Emphasis is placed on documentation of the Client’s requirements at an early stage of a project, and the proper transfer of information between all parties involved in design, construction and commissioning.

Commissioning Existing Buildings

Re-Commissioning occurs when a building that has already been commissioned undergoes further commissioning. The decision to recommission may be triggered by a change in building use or ownership, or because of operational problems. A plan for recommissioning should be established as part of the original commissioning process for a new building, or for the retrocommissioning process for an existing building (Commissioning Collaborative Cx Guide).

Retro-commissioning is a process that intends to improve how building systems function together. Retrocommissioning can often resolve problems that have occurred during design or construction, or address problems that have developed throughout the building’s life. It improves a building’s operations and maintenance (O&M) practices to enhance overall building performance.

Building Commissioning Association (BCA) regards Existing Building Commissioning as a systematic process for investigating, analysing, and optimising the performance of building systems through the identification and implementation of low/no cost and capital intensive facility Improvement measures and ensuring their continued performance over time. The Existing Building Commissioning process assists in making the building systems perform interactively to meet the current facility requirements.

[1] Burnett J. Costs and Benefits of Building Commissioning. Trans. HKIE Vol. 15. No. 2. (2008).
[2] Lau, K.F., Chan, Y. C., An Overview of Testing and Commissioning of HVAC Systems in Hong Kong. Proc. ASHRAE/CIBSE/HKIE Joint Symposium. Hong Kong (2002).
[3] Fong, N.K., Wong, L.Y., Wong, L.T. Fire services installation related contributors of construction delays. Building and Environment. Volume 41, pp211-222. (2006)
[4] The Chartered Institution of Building Services Engineers. Commissioning management. CIBSE Commissioning Code M. (2003)
[5] ASHRAE Guideline 0-2005 The Commissioning Process (2005).