Part L has been an important influence on thinking about energy use in buildings. The next iteration of the legislation is now here, and it continues to set more stringent targets for the reduction of CO2 emissions from buildings by cutting energy use.

One of the most important changes for Part L 2010 has been the increasing emphasis on ensuring that the building operates as it was designed to. This is a significant step, because one of the main criticisms of Part L 2006 was a lack of enforcement, so a building that looked good at the design stage may very well not achieve that energy performance in real life.

Keeping control of energy is therefore going to be very important for operators and owners. Making claims for a building’s sustainability just as it is first occupied is one thing – the question is how will it perform in 12 or 24 months? And that is the responsibility of the people in the building.

Part L 2010 continues to raise the importance of good handover practices, including commissioning and log books. Although the commissioning is largely targeted at the function of fixed building services systems such as hot water, it is useful to include the building controls in any commissioning plan.

Depending on the type of controls system installed, it is possible that they control almost all of the HVAC plant including heating, cooling, ventilation, hot water, and lighting. In a modern building there are very few items of building services that are not part of a building management system.

The building log book is also important for long-term energy efficient operation. As Part L states: “The owner of the building should be provided with sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.”

There can be no doubt, reading this, that the building controls should be clearly understood by the building operator. Unfortunately, commissioning time is often cut to a minimum so handover is squeezed into a small amount of time. This does not leave much time to educate users about the best way to use controls to maximise the benefits.

The BCIA hopes that with a greater emphasis on commissioning this will allow our industry more time to ensure that users can take advantage of the benefits of building controls – and save themselves a lot of energy and money in the long run.