Costs of water automatic sprinkler systems

This article was originally published as part of The impact of automatic sprinklers on building design, an independent report produced by WSP, sponsored by the Business Sprinkler Alliance (BSA), published in September 2017.

An approximate estimate of installing automatic sprinkler systems to establish viability is given as follows:

Sprinkler infrastructure: equipment installation, pipework, valve sets, booster pumps and water storage = £60,000 - £80,000
Price per sprinkler head; including pipework valves and supports = £180 per head

Whilst the infrastructure cost (£60,000-£80,000) does vary depending on the building size, it only does so in a minor fashion due to fact that automatic sprinklers are designed to operate a fixed number of heads independent of floor area. Therefore as the building grows in size, the cost associated with the infrastructure does not vary significantly. This means that the cost efficiency of automatic sprinklers generally increases with building size.

The number of sprinkler heads required varies depending principally on the type of risk to be protected (i.e. category of building type) and layout. For most building types, automatic sprinklers are orientated on a 4m x 3m ceiling grid which gives 1 sprinkler head per 12m2 but as noted above, that is an ideal situation and further heads will be required to suit internal partitions and different building footprints. Therefore 15% has been added to the above figure to give a £/m2:

£180 per head;
3m x 4m coverage from a single head;
15% layout allowance.
Total = £17.25/m2 GIA [note 6] + Sprinkler infrastructure (£70,000)

Other factors may influence the area of coverage such as whether a building has deep ceiling voids which may need protection or sterile areas such as stairs and toilets that may not.

For a comparison the rates shown in Table 5-1 are “Shell and Core” costs for installing automatic sprinkler systems (including the water supply) for Offices with GIA between 3,000 – 15,000 m2 and hotels (2 to 5 stars). These rates highlight the variability in costs between building types.

[Table 5-1: Generic pricing – sprinkler system installation]

Building use	Installed as part of building shell Rate /m2	Installed as part of building fit-out Rate /m2
Office – central London	£16.37	£21.21
Office – regional (average)	£14.73	£19.08
Warehouse ( fitted racking installed)	£42.32	n/a
Hotels (2 – 5*)	£20 – 30	n/a

To ensure these generic rates shown above (Table 5-1) are reasonable, specific cases of cost analyses provided by Spon’s price book (shown in Table 5-2) are reviewed;

Installing a sprinkler system in the office building example shown in Table 5-2 costs £316k and averages to £16.37/m2 GIA. This rate is within the generic ranges quoted earlier (i.e. £17.25/m2 + £70k and £15-20/m2).
In another example, the costs of providing automatic sprinkler system and dry risers to a 4* hotel were £596k and averaging to £36.12/m2. In order to compare this figure (£36.12/m2) with £20-30/m2 from Table 5-1 the cost of dry risers has to be discounted leaving the rate as £26.12/m2. This rate £26.12/m2 falls almost in the middle of the generic price range shown in Table 5-1 and confidence can be placed in the values presented.

These examples demonstrate that the actual cost of installing automatic sprinkler system for each building depends on many factors, however the rates quoted in Table 5-1 can be used as a guide for estimating costs based on GIA.

[Table 5-2: Real examples of installing sprinkler system costs in different types of buildings]

Case study

Total Sprinkler Cost

Cost / m2 GIA

Office building located in Central London, 15 floors, GIA = 19,300 m2

£316,000

£16.37/m2

4* Hotel, 200 bedrooms, located in Central London, 10 floors, GIA = 16,500 m2

(inc. dry risers) = £596,000

(inc. dry risers) =

£36.12/m2

Airport terminal building located in the South East, GIA= 25,000 m2