I was asked recently to consider an issue of importance to construction designers - who is responsible for locating underground services?
I expect that now I have identified the central issue you can guess the plot from here on. Suffice to say that no, it is not the case where road menders inadvertently severed the main telephone link with the Isle of Wight. Nor is it the case where contractors failed to realise that their foundation works had punctured an unidentified sewer, until the contents of a Readymix lorry had been poured down it and still the concrete failed to reach the desired level. No, it is a domestic drama involving a family who returned from a summer holiday expecting to find a nearly completed extension and instead found a group of individuals standing around a big hole wondering who should have discovered that a sewer ran in the path of the piled foundations.
It seems that the general practice is to rely upon the local authority to notify those seeking Building Regulation approval that their works are to be carried out over an existing drain or sewer.
Certainly section 18 of the Building Act 1984 imposes a dual duty upon the local authority to reject plans for works over sewers and drains unless they can properly consent to the works by imposing conditions or otherwise, and to notify the relevant water authority of the proposed works. Once the existence of the services has been established, the employer can decide whether to proceed with the works and to enter into the necessary Build Over agreement with the water authority - giving the authority the right to repair their services, through the living room floor, if necessary - or to revise, or even abandon, the proposals.
Experience dictates that designers should not rely upon the local authority to fulfil their statutory obligations: very often they fail to do so. More importantly perhaps, since the House of Lords decided in Murphy v Brentwood that local authorities owe no duty of care in respect of their statutory obligations where the only loss is a financial one, neither the home-owner nor the designer has any claim against them for such failure. So does the designer end up carrying the can?
The starting point seems to be that a designer needs to ascertain the nature of the site before deciding what is to go on it. The nature of the site may be such that extensive tests are required to ascertain its condition. Many of the leading cases involve construction on made up ground or infilled land. When the foundations turn out to be inadequate, the finger is pointed at those responsible for their design. Liability is usually only attributed to the architect where no proper ground investigation has been carried out at all. In Eames v North Hertfordshire District Council no soil examination of made up ground was carried out by the architect who had designed the foundations on the basis of what would 'get by' the local authority. Conversely in Investors in Industry v South Bedfordshire District Council the architects were exonerated from blame because they ensured that consulting engineers were appointed to decide upon the appropriate design for the foundations.
By an extension of logic, therefore, an architect could argue that where an engineer has designed the foundations, that engineer ought to be responsible for ascertaining whether they are affected by any underground services. Traditionally, however, the courts take the view that the architect is responsible for orchestrating the piece and should have overall responsibility for site matters, which are not limited just to drains and sewers. Thus architects may be responsible for finding out about neighbours rights, easements, restrictive covenants and planning restrictions, all of which may be affected by the proposed construction.
In case of the extension and the sewer it is, of course, easy to be wise after the event. Had anyone thought to ask the local authority about underground services, the sewer would have been discovered and a lot of heartache saved.
Similarly, had the designer warned the client that no specific enquiries had been made, he could have saved himself a lot of trouble.