For any planned leisure development, rigorous site investigations are essential to establish a realistic project cost. Denis O’Brien, senior surveyor from international construction services company ISG – a key Alliance Leisure contractor – explains the basics of the process

For potential leisure projects, how important are the site investigations in the Alliance design and build process?
Site investigations may not be the most exciting part of the process to talk about, but without very detailed and rigorous surveys at this key stage, it’s impossible to come up with a realistic project cost. Alliance Leisure always works to a fixed price contract, so we need to know about every potential pitfall of the proposed development site.

What’s involved?
It depends whether we’re looking at a new build or an extension to an existing facility. There are obviously a lot more unknowns – particularly relating to the ground works – with a site that doesn’t already have a building on it.

We undertake ground investigation surveys, tree surveys, environmental impact surveys, assess the proximity and ease of access to utilities. We also try to look for the potential show-stoppers such as former coal mines or sink holes. Of course, there are always some things you can’t plan for which might significantly delay the start of the project, such as undiscovered munitions or archaeological remains, but in reality these are very rare occurrences.

When it comes to extensions and redevelopments, there’s another whole tier of investigations to carry out before the project can be accurately costed.

The majority of leisure centres we’re now redeveloping date back to the 60s and 70s, so we have to consider the presence of asbestos and the quality of the drains, as well as undertaking structural surveys to see if the existing structure can take the new load.

We also need to check whether the existing services provision is sufficient to supply a larger site, and carry out a dilapidation survey to check structures such as the original roof, which might be nearing the end of its life.

What are the site problems that add most to the budget?
If there are inadequate services, then the need, for example, to build a sub-station could easily add £100,000–£120,000 to the project cost.

With existing leisure centres, it might be that it’s best to knock down a quarter to a third of the existing building in order to properly develop the site.

However, in the case of older buildings, it’s almost always better to plan to replace some elements of the building right at the start, as the payback on this can be relatively quick. For example, we’ll always introduce modern, efficient lighting to any building project we’re working on from top to bottom, as the energy savings this yields over time can enable the leisure centre to recoup the cost of the capital outlay in just a few years.

It’s a false economy to cut elements like this out of the budget just to bring proposed costs down.

How do the site findings feed into the overall process?
On the basis of these investigations, we’re able to carry out a block planning exercise that comes up with the overall size and shape of the development, together with the content and what it will cost (usually within 10–15 per cent of the final fixed cost).

If there are any real show-stoppers at this stage, which is very rare, the client can choose to walk away and just bear the cost of the site investigations.

Sometimes, at this stage, the local authority might want to scale down some elements of the project to make savings.

If they proceed with the plan, the site investigation costs are absorbed into Alliance’s overall development costs. We then go on to commission architects, and draw up a more robust cost plan and a bill of quantities.