Whole Life Economics of Building Services – an illustrated and explanatory guide to the effects of building design on the initial and lifetime costs and economics of building services.

Authors: Ronald Hurst, Bernard Williams, Malcolm Lay
Pages: 499

This very detailed and comprehensive book provides both a useful starting point for those beginning to take an interest in whole life economics and an extensively detailed information source for readers needing comprehensive reference data.

It is the fruit of three years hard work by the three authors, with a pedigree going back to research in 1984 published as ‘Design Economics for Building Services’ and the 1994 ‘Facilities Economics’ produced by Bernard Williams and colleagues which became a standard reference for the industry. The advent of PFI and PPP as procurement routes has led to an urgent need for such detailed guidance on whole life costs which this book goes a long way to providing.

The detailed data is presented with carefully worded health warnings that ‘little or no verifiable data exists on component life in a form which entrepreneurs can make reliable predictions’ and ‘life-cycle replacement periods are only average and should not be used too readily in appraisals having commercial consequences.’ However, in Appendix B - Intelligent Life Cycle Prediction - techniques are provided for identifying and controlling attendant risks associated with using the data provided, to allow users to produce life cycle predictions related to the actual use of the installation.

The text starts with a useful introduction looking at basic principles, addressing whole life costs, maintenance, energy consumption, cost design and economics. This chapter provides valuable background information both for those seeking general information and as reference for those requiring more detailed advice.

Three appraisal techniques are included,  simple aggregation; net present value and annual equivalent. These are explained in detail with diagrams. It is noted that the life of components can be influenced by a ‘myriad factors’ with nine being listed including installation workmanship, wear and tear, and the maintenance regime.

There is a detailed discussion on maintenance and its management and the factors needed to be taken into account when assessing its potential cost. Significant cost drivers are listed, including: whether the building has mechanical ventilation, with or without cooling, the building shape and size, age of the installed services, their current state of repair, the quality of the built installation, health and safety implications and the intensity of use. Chapter 9 provides indicative maintenance and energy costs which dependent on building size can have a range respectively of £436 - £214 /m² and £579 - £372 /m².

The subject data chapters are set out under six main headings: mechanical, electrical, fire protection, transportation, security and communications. Under each are listed sub-systems which are described with general principles of type, applications, design and relevant legislation.

A detailed whole life cost is provided for each sub-system assessed for four different building types (almost cube 2,250 m², rectangular prism 22,500m², flat hollow cube 72,000m² and ‘L’ shape 111,000m²). The information includes capital cost, life cycle replacement cost, normal life cycle (in years), maintenance cost and energy cost. These are totalled into system costs and lifetime costs, and then aggregated into whole life costs/m² based on gross internal floor area.

The book is intended to help avoid the concerns being raised in the industry that if building services continue to be designed in an economic vacuum without reference to whole life implications, there may be unpleasant surprises in terms of revenue expenditure, occupant productivity and environmental sustainability.