Specification (Spec)

A detailed written description of the materials, products, finishes, and standards to be used in a renovation project, ensuring everyone agrees on exactly what will be delivered.

A specification (commonly shortened to spec) is a detailed document that describes the exact materials, products, finishes, and workmanship standards for your renovation project. While a scope of work tells your contractor what to do, the specification tells them how and with what.

What a specification includes

A good specification covers:

  • Materials — exact product names, brands, and model numbers (e.g., “Dulux Trade Diamond Matt, colour: White Cotton” rather than just “white paint”)
  • Finishes — tile size, grout colour, worktop material and edge profile, floor finish
  • Fixtures and fittings — specific taps, sanitaryware, door handles, light fittings
  • Standards — how the work should be done (e.g., “plasterboard to be fixed at 300mm centres” or “tiling to include waterproof membrane behind shower area”)
  • Performance requirements — insulation values, sound ratings, or fire resistance where applicable

Why specifications matter

Without a clear specification, you leave decisions to your contractor — and their choices may not match your expectations or budget. Common problems that arise from vague specifications:

  • Contractor uses a cheaper material than you expected
  • Tile layout or grout colour does not match your vision
  • Paint finish is wrong (matt vs. eggshell)
  • Fittings are functional but visually different from what you wanted

A detailed spec also makes it easier to compare quotations from different contractors. If everyone is pricing the same specification, you are comparing like for like.

How to create a specification

You do not need professional help to write a basic spec, though architects and designers do produce them. At a minimum:

  1. Walk through each room and list every material and product you want
  2. Note the brand, model, colour, and size where possible
  3. Include links to products or attach images
  4. Note any special requirements (e.g., “underfloor heating compatible”)
  5. Share the specification with contractors alongside the scope of work when requesting quotes

If you have items you have not yet chosen, use a PC sum or provisional sum as a placeholder allowance.