Specification method

How to write a construction specification: method, structure and pitfalls

A construction specification describes, package by package, the works to be carried out and their requirements. Written well, it secures the tender and limits disputes. Here is a method to structure it effectively.

What is a construction specification?

The specification is a written document of the works contract. It is part of the tender package and describes, for each package, the nature and technical characteristics of the works: materials, installation, expected performance and applicable standards.

It differs from the administrative clauses, the priced schedule and the drawings: the specification says "what" and "how", the priced schedule says "how much".

The structure of a specification

A specification is generally organized on two levels: general clauses common to the project, then a description package by package.

  • General clauses: project overview, site constraints, common requirements, applicable standards.
  • Description by package: one chapter per trade (structural work, plumbing, electrical, etc.), with articles describing each item of work.
  • Articles: clear label, technical description, location, and where relevant the variants or options.

A step-by-step writing method

Reliable writing follows a logical thread, from scope to detail.

  • Define the scope: which packages actually concern the project?
  • Start from a template or a library of standardized clauses rather than a blank page.
  • Adapt each article to the project: materials, performance, precise location.
  • Check consistency with the drawings, the take-off and the priced schedule.
  • Have it proofread: an ambiguous specification is paid for in extra work.

Common mistakes to avoid

  • Copy-pasting a specification from another project without adapting it: risk of off-topic or contradictory clauses.
  • Describing a proprietary product without an "or equivalent" mention: against public procurement rules.
  • Forgetting consistency between specification, take-off and priced schedule: mismatched quantities distort the bids.
  • Staying vague on performance: prefer measurable requirements and cited standards.

Saving time without losing quality

Writing a specification is time-consuming if you start from scratch every time. A library of clauses by package, ready-made variants and a clean Word export save entire days.

That is exactly what BuildOS offers: you tick the articles that concern your project, adjust them, and the specification is generated, structured and ready to share.