Definition of whole life performance

One of the issues relating to whole life performance is that of boundaries and inclusion. Where do whole life costs begin and end? What should be included in the process? Any definition of whole life costs should be absolutely transparent about what has been taken into consideration.

On a practical level it is as well to limit whole life costing to that information which is readily available and easily assessed, otherwise the logistics and effort required to carry out whole life costings may become disproportionate to the overall aims.

Building Research Establishment Digest 452 defines whole life costing as:

'... the systematic consideration of all relevant costs and revenues associated with the acquisition, use and maintenance and disposal of an asset'.

In many respects this definition is little different from what has historically been known as life-cycle costs (LCC) or through-life costs (TLC).

Three inter-related but separate definitions cover:

• whole life costs - costs for the life of the component;
• whole life performance - performance issues associated with the life of the component;
• life cycle assessment - energy and environmental issues associated with the component.

This section is mainly concerned with whole life costs and whole life performance.

Whole life costs are defined as:

'... the systematic consideration of all relevant costs and revenues associated with the acquisition, use and maintenance and disposal of an asset'.
BRE Digest 452, Whole life costing and life-cycle assessment for sustainable building design, 2000

This definition is little different from what has historically been known as life-cycle costs (LCC) or through-life costs (TLC).

Whole life performance is not expressly defined in the BRE report. A working definitions of Whole life performance is:

'... the systematic consideration of all relevant performance issues associated with the acquisition, use and maintenance and disposal of an asset'.

Whole life issues related to the built environment are not just about cost. Cost can be associated with most issues one way or another but links between cost and less tangible issues such as patient recovery time and well-being in a hospital are more difficult to define.

A study by Mackenzie and Airey (2000) on the effects of acoustics in healthcare buildings showed that noise levels in hospitals in Scotland adversely affected recovery time. In whole life cost terms putting a cost on achieving a given level of acoustic performance by specifying ceiling tiles with good acoustic properties is relatively straightforward. Assessing the whole life costs of increased hospital stays and additional medicine is less readily quantifiable.

The term 'whole life performance' provides a framework within which to consider issues related to the long-term performance of building components as well as the indirect consequences of component decisions.

Life cycle assessment is a method which assesses the overall environmental and energy impacts of components. It considers environmental and energy issues from 'cradle to grave'.

The BRE Digest 452, Whole life costing and life-cycle assessment for sustainable building design, defines life cycle assessment as:

'A method to measure and evaluate the environmental burdens associated with a product or system or activity by describing and assessing the energy and materials used and released in the environment over the life cycle.'

This method is also known as life cycle analysis.