A specification-writer’s job is never done. The document he or she produces should be kept close at hand throughout the construction process. Proceed without it at your peril.
Specification production should start as early in the design process as possible and be developed continuously, in parallel with the drawings. The biggest mistake a specification-writer can make is to leave it until the last minute, take a copy of a document written for a similar project and issue it under the new project title.

An early start also helps co-ordination with other tender and procurement documents produced by the project manager, quantity surveyor and other consultants, thus avoiding contradiction. The specification will become the main quality control and compliance checking tool during the construction process, so it is vital that it co-ordinates with the other paperwork.

By developing specifications throughout the design, the designer has the best chance of achieving a clear and unambiguous document.

Unfortunately, the specification-writer’s job is often considered done when the building contracts are secured, or even worse, when the tender documents have been delivered. This is precisely the time when the specification really comes into its own, and much can be gained from the continued involvement of the specification-writer.

The reason for this is that the true test of whether a specification has done its job is not how easy it was to agree a contract, but how it performed during the construction period. Any architect or representative responsible for site supervision should keep a copy of the specification close at hand, with access to its author at all times. It may sound obvious, but it is amazing how often it does not happen.

When using the specification during construction, there are two key points to remember. First, there is no such thing as a “construction specification” or a specification issued after contract award “for construction”. This is possible with drawings, because they can develop during contract negotiation. Second, any specifications, or revisions to a specification, issued after contract award may be treated by the recipient as an instruction under the terms of the contract, which may result in variations that have cost and/or time implications.

The true test of a specification is how it performed during the construction period

As far as legal disputes are concerned, the only specification that really counts is the one that is included in the contract agreement, as that represents the contract sum, the products to be supplied, the design completion responsibilities, testing and so on. All previous versions are superseded, and all subsequent versions vary the contract in the same way as revised drawings.

There are times when a specification is required at the end of the building process. These are as-built specifications. They may be required to supplement as-built drawings, and care should be taken in such circumstances. As-built specifications must record precisely only what has been incorporated into the project at practical completion and accepted by the client. It is not a record of the final account, the process by which the project was completed or a record of all changes during the construction process. It is a record of only those elements finally incorporated into the works.

It is therefore advisable to delay starting production of such a specification until the project is complete, and the issuing of drafts during construction should be avoided. These documents can be expensive to produce, and should be done only if provided for in the consultant appointment or contract.

Whatever the project stage, the specification is a vital document, and it becomes even more important if disputes arise. In such circumstances, the test of whether the specification has done its job is when it contains clear and unambiguous statements that resolve the argument.