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Why is commissioning always compressed and late?

So what's gone wrong with commissioning and how can we stop it being squeezed? BSRIA experts review the issues.

Commissioning a building is often treated by construction teams as a chore - the thing that stands between them and achievement of practical completion. By definition it is one of the final acts prior to finishing a job and leaving site.

Even the best laid construction plans can be compromised by events - client, variations, contractor insolvency, severe weather - the result of which is usually compressed commissioning. While construction is often a fluid process, completion dates are always fixed. Therein lies the problem: expedience rules when the client has to move in.

The nature of the problem

The consequence of squeezing commissioning into shorter timescales will almost certainly backfire both on the client and the project team. Poorly commissioned systems will not self-correct afterwards. The truth will out, and clients will demand action.

Faced with unexpected challenges and remedial work, some contractors simply disappear. Contractors will walk away from a £25,000 retention if doing so allows them to resource a £25 million project elsewhere.

BSRIA has reviewed evidence of commissioning practice gathered by the Carbon Trust under its Low Carbon Buildings Programme (LCBP). Evidence of both successful and less successful commissioning has lifted the lid on the causes and effects.

Figure 1: How commissioning is often carried out

Figure 1: How commissioning is often carried out

Figure 1 shows how commissioning was conducted on those projects that suffered shortcomings in commissioning management. In some cases the commissioning plan was rudimentary and threadbare, and little thought was given to the activity until systems were installed and needed verifying against the specification.

The problems were most acute with innovative low and zero carbon technologies that proved relatively more fragile than conventional systems, and needed far more attention than they got. The Carbon Trust found that the operational savings in energy and carbon dioxide were nowhere near the design estimates. It wasn't the technology itself - it was the way it was commissioned.

A possible solution

The Carbon Trust's LCBP research has led to a rethink of the commissioning process. The LCBP studies showed that commissioning should not be a single operation carried out prior to building completion, but should routinely be far more of a continuous process that extends through and beyond the contracted completion date. Table 1 illustrates the component parts of a commissioning management plan that takes into account fine tuning and professional aftercare in the weeks and months following completion.

Commissioning management plan			Initial (static) commissioning to satisfy the specification		Continuous commissioning, incorporating seasonal commissioning and system fine-tuning
Preparation	Design	Pre-construction	Construction	Commissioning of engineering services	Pre-handover	Initial occupation	Post-occupancy aftercare
The commission-ing team should be formed to develop the process and strategy	Commission-ing team to review design to ensure commission-ability and maintainability	Ensure that all commission-ing information is carried to the construction phase and contractor	Ensure that the engineering systems are physically complete and correct, including static testing	Carry out functional performance tests to verify performance before sign-off and handover	Training and familiarisation of the building occupants and managers to ensure the building operation is understood	Apply feedback from the building's initial performance and experience of occupants to fine-tune and debug systems	Fine-tune of the building to reflect changes in energy load and patterns of use

Table 1: A model approach to commissioning derived from commissioning experiences on the Carbon Trust's Low Carbon Building Performance and Low Carbon Accelerator research programmes

Essentially, the plan breaks down into three distinct phases: Planning, initial (static) commissioning, and continuous commissioning and fine-tuning. This is the Soft Landings view of the world: that commissioning activities should be extended across the design, construction and occupation phases of the building, rather than considered a single activity.

Features over the following months will explain this process in more detail.

Further information

BSRIA runs a series of commissioning training courses, including 'Management of the commissioning process' and also publishes a range of commissioning guides.