What Are Construction Specifications?

The specifications ("specs," also called the project manual) are the written requirements that go with the drawings. Together they make up the construction documents.

Drawings vs. specs

A common saying: "the drawings show where and how much; the specs tell what and how good." Drawings give dimensions, quantities, and locations. Specs describe the materials, products, quality, and methods in words.

Why they matter

The specs control what you're allowed to install and the quality standard — you build to the specs, not to whatever's cheapest. Ignoring them gets work rejected and redone.

Going Deeper (Intermediate)

The specifications (the project manual) are the written requirements that pair with the drawings: "drawings show where and how much; specs tell what and how good." They control materials, quality, and methods — you build to the spec, not to whatever's cheapest.

Advanced / Pro-Level

Know the types of specifications so you read them right:

• Prescriptive — exact product/method to use.
• Performance — meet a defined result/criteria (your choice how).
• Proprietary — a named product ("or equal" allows substitution with approval).
• Reference standard — comply with an ASTM/ANSI/etc. standard. The project manual also holds bidding requirements, contract forms, conditions, and Divisions 00–01. Submittals are how you prove your materials meet the spec before you install.

Practice Challenge

A spec says "concrete shall achieve 4,000 psi at 28 days" but doesn't name a mix. What spec type is this, and what's your obligation? (Answer: a performance specification — you choose the mix design, but you must prove it meets the 4,000 psi result (via mix submittal and test cylinders); performance specs give means flexibility but hold you to the outcome.)

In Practice

The drawings show a wall; the specs say it's '5/8" Type X fire-rated gypsum board.' Build it with regular drywall and you've made the wall — but failed the spec and lost the fire rating.

Common Mistakes to Avoid

• Treating the specs as optional
• Building to the drawings while ignoring the specs
• Substituting materials the spec doesn't allow

Takeaway: Drawings show where and how much; specs tell what and how good. Build to the specs, not the cheapest option.

Educational overview — always follow your specific project's contract documents and your supervisor's direction.