Acts of commission

There has been a great deal of interest in the changes to Part L of the Building Regulations, and the impact that they may have on the design of new buildings, especially offices and prestige developments. What has so far occasioned less comment are the requirements relating to installation, commissioning and handover.

This is not entirely surprising – design precedes construction, installation and handover, so it is not first in line for attention. But the new Part L regulations have a long reach. It is said that time spent in reconnaissance is never wasted: a quick look at what lies beyond the design stage may pay dividends.

Pages 5 to 7 of Approved Document L2 provide a summary guide. This is presented in the form of a process chart and checklist of the various tasks and activities that must be undertaken. Towards the end are four questions which are completely new to the regulatory process:

• Is the building control body reasonably convinced that the building is satisfactorily airtight (paragraph 2·2)?
  
• Has inspection and commissioning been completed satisfactorily (paragraphs 2·5 and 2·6)?
  
• Has the logbook been prepared (paragraphs 3·1 and 3·2)?
  
• Has a metering strategy been prepared and sufficient meters and sub-meters installed (paragraphs 3·3 et seq)?

These four questions illustrate the terrain that lies beyond the design phase. And as with many other aspects of the construction process, the sooner the designer begins to plan for them, the less likely they are to cause problems later, and the cheaper it will be to deal with them. So every designer needs to think ahead and ask how the design will meet these four tests:

• installation and testing;
  
• commissioning;
  
• metering;
  
• handover.

These are all new regulatory requirements. Some clients will already have had their own specifications for some or all of these areas, but for many these will be new. It may be worth thinking about them from the following perspectives:

• what is required?
  
• who is responsible?
  
• what are the consequences of failure?
  
• what is the impact on the construction programme?
  
• where can I go to find out more?

The requirements can be summarised briefly as follows: non domestic buildings over 1000 m² will need to be tested for airtightness, and tests of insulation continuity and heat loss may also be required. Commissioning will have to be certified, sub metering installed for at least 90% of all the main energy sources and the building handed over with a building logbook.

Responsibility will depend on the contract. And as with many other risks, it is liable to be the subject of a legal version of pass the parcel.

Consequences of failure are hard to predict. For an airtightness test on a large office development, it is clear that preparation for the test could require a week, with very limited access to the site for any activities not related to the test.

Failure on first testing will require remedial works of unquantifiable duration, and then a further re-test. Since you can't call the local plant hirer for a test rig and a 'suitably qualified person' (of whom more later), the re-test has to be booked, using one of a small pool of available test rigs. If they are all booked up by the people who thought of it before you did, that could be another big delay. At this point the vigilant lawyers and contract managers will begin to get active, of course.

Consequences of failure to commission properly are that another 'suitably qualified person' may not be willing to certify that commissioning has been completed. This extra requirement will not ease the already pressurised schedule to which the commissioning team must work. Indeed, where they work for the supply side, it may be that they will be under great pressure to certify the commissioning in order to meet handover dates and escape penalties. Those responsible for signing off commissioning under Part L may be placed in very difficult dilemmas.

So the impact on the construction programme will need careful thought. It will depend on the complexity of the building, and the need to allow for testing and commissioning. For large schemes it will need to be considered at the tender stage, when programmes are being drawn up and prices and risks assessed. Once the work is won, careful planning and management of these aspects of the project will be needed to ensure that work which will be tested is carried out to an acceptable quality. The earlier defects are detected, the less disruptive it will be to rectify them. It may be someone else who pays the bill for the work, but a delay ultimately affects everyone, and cannot wholely be passed off down the supply chain.

What is a 'suitably qualified person'? At present, it is not clear, but this is the phrase used in several places in Approved Document L2 to describe the person carrying out tests, certifying that commissioning has been carried out satisfactorily, and demonstrating other aspects of compliance with Part L.

CIBSE is leading a consortium of relevant bodies in the development of plans for a register of competent persons for the purposes of Part L, to provide an industry wide, open and transparent system for identifying these suitably qualified people.

There are several sources of further information. CIBSE has produced a summary of the changes to Part L, available from the members section of www.cibse.org. The CIBSE Commissioning Codes are currently in the final stages of revision, and new editions of Codes B and R should be available in October. A new Code W will not be far behind. In response to the project and programme management aspects of the requirements, a new Code M is being drafted, and will be out next year. A consultation draft is likely to appear on the CIBSE web site in the autumn. These revisions have been prepared in partnership with the Commissioning Specialists Association and BSRIA, who have also updated some of their commissioning guides.

Guidance on airtightness testing is available in CIBSE TM23. Action Energy (the new name for the Energy Efficiency Best Practice Programme) has produced a guide to sub-metering, available as GIL 65.

There are also several projects underway to produce guidance on handover, logbooks and operation and maintenance manuals. A BRE led project in which CIBSE is a partner is working on handover, and BSRIA are about to start work on operation and maintenance manuals, with CIBSE support. CIBSE is developing guidance and a template for building logbooks.

More details on all these research activities are available on the research page of the website, as well as contact details if you have questions about any of these publications and activities.