I SPENT my professional life in the construction industry and was involved in many projects of the type that featured the collapse of a wall at a school in Edinburgh. In general I would concur with Professor John Cole's conclusion, particularly his concern about inspections (“Fresh fears on school buildings over quality of council inspections”, The Herald, June 13). Over the past 30 years or so we have seen the almost complete disappearance of clerks of works, the client's and architect's representative on site. Regarded by main contractors and sub-contractors alike as interfering busy-bodies they, nonetheless, ensured the quality of the building works and that they were carried out according to the letter of the specification.

Although Prof Cole does not attribute fault to the PFI funding model I would suggest that the "design and build" nature of most of these projects does little to ensure quality of build or materials. At the outset the architect, working as a consultant to the client, will spend a lot of time on the design and will carefully research the suitability, quality and durability of the materials intended for use on the project. Formerly, tendering was done on the basis of these drawings and a detailed Bill of Quantities that ensured every contractor tendered on exactly the same basis and ensured a fair comparison of tenderers. With design-and-build the tender process to choose a suitable contractor will typically be done on the basis of drawings and specification only from which each of the tendering contractors must base his price. There is much room for interpretation, and comparison of quotations is therefore more difficult.

Having chosen the contractor for the project, usually the lowest tendered, the architect is then employed by that contractor, not the client. From this point onwards it is difficult to imagine how the architect can retain his/her design integrity when relying on the main contractor for income.

Thereafter the successful main contractor starts a process of what they call "value engineering", which is nothing more than cost-cutting, usually with little regard for the quality requirements established by the architect at the outset. Good contractors will employ good sub-contractors and use high-quality products but such a combination makes the end product dearer and, consequently, uncompetitive. In order to be competitive many main contractors will overlook well established, experienced sub-contractors in favour of one-man-and-a-van outfits, and materials will be switched for cheaper alternatives with little regard for durability or quality. If there is no difference between the cheaper and dearer products then there is good reason to change but my experience is that this is rarely the case.

None of this, of course, is to the benefit of the client in the long run and merely serves to increase the return for the main contractor who had under-priced the project in the first place to win it with the knowledge that specification changes will restore his profit.

I paraphrase John Ruskin's Common Law of Business Balance – "It’s unwise to pay too much, but it’s worse to pay too little. When you pay too much, you lose a little money – that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do." His perceptions were never more appropriate than when applied to the building industry.

Iain MacDonald,

Herdsmanshill, Knockbuckle Lane, Kilmacolm.