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Commissioning data from design to completion and beyond is the key to giving end users the buildings they want, argues Roger Clark*.

ASHRAE president Richard Rooley recently challenged the building services design profession to come clean about why so many buildings fail to meet even basic comfort and energy performance criteria.

“How often do we examine the commissioning data and compare it with the design brief?” he asked an audience at the Institution of Mechanical Engineers (IMechE) last month. An excellent question.
Too often the headlong dash for completion at lowest capital cost can leave building occupants with long-term running problems, with the design engineer in an impossible position to properly influence the process. They know they are designing for an end user, but during the construction or refurbishment process it is the developer or contractor who calls the shots. However, responsibility will come back to the designer if things go wrong – so we have to be tough, but above all we need to be better organised.

To win arguments with architects and clients over system design, engineers need to be sure of their facts and they need to be flexible. It is important to stress that commissioning needs to take place at all stages of the design process from concept, through installation and pre-commissioning on to balancing, performance testing and final handover. Ideally, the systems should also be subject to ongoing independent validation after the occupier takes possession to meet Mr Rooley’s criteria and ensure that buildings continue to perform to their design targets throughout their lifetime.

This is particularly important in buildings that are in use 24 hours a day, seven days a week such as hospitals, hotels and prisons. We have to ensure they are set up properly from the outset – you only have one chance with 24/7 buildings as you can’t shut them down and start again once they are occupied. That means commissioning managers should be involved at every stage from concept design onwards.To make this possible building services designers should recognise they may have to compromise during discussions with other members of the project team, but the critical factor is ensuring that any compromise does not jeopardise the on going performance of the building.
On PFI projects this should, at least in theory, be an easier argument to win as the construction team usually has an interest in the running of the building for 25 years after completion.

‘Keep things simple’ is pretty good advice for many things in life and holds true for buildings as does making sure the design objectives are clear and everyone on the construction team is clear about their areas of responsibility. Clarity of purpose makes the commissioning engineer’s job much simpler and helps remove areas of potential conflict. By ensuring as much testing and commissioning takes place off site, for example, the services designer gives himself much more room to maneuver.

Some key rules of thumb include:

The long view:
Our industry is very good at developing new ideas and coming up with clever technical solutions to problems, but we are not so good at taking the long view and designing for maintenance, validation and replacement of plant at the end of its life. Issues like plantroom access and providing lifting beams can avoid serious problems in the future, but are often overlooked at design stage.

Architects love to streamline their service cores, but they can make service and maintenance difficult as a result. We have to be firm - the chances are that our first thoughts were right and if we compromise it will be to the detriment of the building occupants. However, persuading the architect to change course depends on us being very clear about our strategy and having a detailed programme to support our arguments.
Designing spare capacity into the system to allow for changes in the use of a building and to give occupants the flexibility to move wards, offices, classrooms and people around and to accommodate new tenants is another vital area often overlooked. And it doesn't have to be expensive if you do it at Day One. Some developers are looking to lower end user expectations to keep commercial rental costs down, which means they will go for cheaper alternatives including allowing openable windows and providing only minimal background lighting. As members of the design team we should be able to pose the question: ‘Is that the best way – can the building operate more effectively if we do things differently?’

We need to be sympathetic to the economic pressure on developers. They are constantly pushing for maximum lettable area, so any spare space that could be used to accommodate extra plant for the potential needs of future tenants is often used up, but with the facts at our fingertips we can make a case for changes that will benefit the building occupants in the future.
These economic concerns may actually have a positive effect on energy use, however. Owners are packing as many people into their floor space as possible and so are beginning to see the benefits of bringing energy costs down because of the relationship between National Insurance contributions and the Climate Change Levy or Carbon Tax.

The revised Part L of the Building Regulations is also going to concentrate minds - particularly in highly glazed buildings. Better control strategies and improved insulation levels will be required to get the building through the inspection process.
There is a growing clamour for ‘Building MOT’s’, which would ensure that, at least once a year, the safety and business critical processes of a building – like fire alarms and power back-up systems – are in full working order.

The legal climate surrounding our projects is heating up too. Defects liability clauses that put the onus on contractors to make sure systems work as intended are becoming more common - another persuasive reason to get this right.

It is generally accepted that engineering systems, which are straightforward in commissioning and familiar to the commissioning engineer can be put to work within the short timeframe craved by developers. However, if there is complexity and the systems are prototypes, commissioning may be left incomplete for several heating and cooling seasons or until the owners of the building put things right themselves – perhaps before resorting to litigation or arbitration.
It doesn't’t have to be like this.
If commissioning of services is an integral part of the concept design, we can ensure buildings work as intended and that the commissioning data meets the performance levels set in the design brief – as Mr Rooley would expect.

We do design wonderful systems, but if they are not tested properly and commissioned, then they will not work as intended and the design will be a failure.
Sometimes it takes years to fathom why systems are not working properly and because of the time pressures to finish buildings, it is often difficult to complete testing, but a proper commissioning strategy means testing can go on at all stages of the project and does not need to be left to the end.
We need to think about design for commissioning and testing, to record the process and then ensure the documents are kept safely somewhere on site so that the occupants can continue to run the building as intended. By keeping this documentation up-to-date, building users have a full record of the current status of the building rather than an historic record of how it was meant to be.

At the end of the day, being too clever or complicated doesn’t help anyone – least of all the end user. It is designing something that works and will continue to work that matters.