How Do Architects Write Construction Specifications?

By Wyatt Cooper · Published October 22, 2026 · 6 min read

Key takeaways

The drawings show quantity, location and arrangement; the specifications say quality: materials, standards, submittals, installation and testing.
Number and title each section with MasterFormat and write it in three parts: Part 1 General, Part 2 Products, Part 3 Execution.
Say each requirement once, in the right place: procedures that apply to every trade go in Division 01, not in every section.
Write each requirement so a bidder can price it and an inspector can check it: name the standard, the test and the submittal, and drop words like "first quality".

Architects write construction specifications as numbered sections, one per kind of work, using CSI's MasterFormat for the numbers and titles and its SectionFormat for the layout: Part 1 General (scope, submittals, quality, delivery, warranty), Part 2 Products (materials, manufacturers, standards) and Part 3 Execution (preparation, installation, testing, cleaning). The drawings show where and how much; the specifications state what quality, and most firms start from a master specification and edit it to the project.

What goes in the specs and what goes on the drawings

Drawings and specifications are read together as one set of contract documents, so each fact should live in one of them. The drawings show what is where and how much: the wall, its type, its extent. The specifications say what it is made of and how it is built: the studs' gauge, the board's standard, the finish level, the submittals and tests. When the same requirement is written in both, sooner or later they disagree.

Contracts settle disagreements with an order of precedence. In federal construction contracts, FAR 52.236-21(a) says "anything mentioned in the specifications and not shown on the drawings, or shown on the drawings and not mentioned in the specifications, shall be of like effect as if shown or mentioned in both. In case of difference between drawings and specifications, the specifications shall govern." Many private contracts read the other way or list no order at all, so write as though nothing will break the tie for you.

Where a requirement belongs
Information	Drawings	Specifications
Location, extent, dimensions	Yes	No
Wall, door and finish types (which goes where)	Yes, with schedules	Refer to the drawing types
Materials, products and manufacturers	Generic labels only	Yes
Reference standards (ASTM and the like)	No	Yes
Submittals, tests, inspections, warranties	No	Yes
Procedures for every trade (meetings, schedules, closeout)	No	Yes, in Division 01

The three-part section

The Construction Specifications Institute publishes the two formats most U.S. project manuals use. On CSI's standards page, MasterFormat is "the construction industry's standardized language for project documentation" and SectionFormat/PageFormat "gives guidance on organizing and formatting text for specification pages". MasterFormat gives each section its number and title (09 91 23 is interior painting, 26 05 33 raceways and boxes for electrical systems). SectionFormat divides each section into three parts. The federal guide specifications follow it too: the SpecsIntact section format page says "all Sections are divided into three Parts: GENERAL, PRODUCTS, and EXECUTION."

Part 1, General: what the section covers and what is elsewhere, references, submittals, quality assurance, delivery and storage, site conditions, warranty. SpecsIntact describes it as "specific administrative and procedural requirements unique to the Section."
Part 2, Products: manufacturers, materials, products and mixes, fabrication, and the standards each must meet.
Part 3, Execution: examining the substrate, preparation, installation or application, field testing, cleaning and protection. SpecsIntact: it "details preparatory actions and explains how the products outlined in PART 2 are to be used in the Job."

For a full, free model of the format, read any Unified Facilities Guide Specification on the Whole Building Design Guide, for example the Corps' closeout submittals section, UFGS 01 78 00. Its Part 1 defines as-built and record drawings, and its Part 3 tells the contractor how to mark them up.

A worked example: a short painting section

An outline for a fictional clinic, written for this guide. A real section is longer, but the shape is the same, and every line is something a bidder can price and an inspector can check.

Section 09 91 23, Interior Painting: Fernhill Medical Clinic

1.1 Summary: Painting of interior gypsum board, hollow metal frames and exposed conduit in finished rooms. Shop-primed steel is in Section 05 12 00; factory-finished items are not painted.
1.2 Submittals: Product data for each paint system; color samples on 8 by 10 inch cards; one mock-up wall per system, approved before work starts.
1.3 Quality assurance: Applicator with five completed commercial projects of similar size, listed with the bid.
2.1 Products: Acrylic latex systems from one manufacturer per system, low-VOC, as scheduled in the finish schedule on A-601.
2.2 Systems: Gypsum board, eggshell: one coat primer, two coats finish. Metal frames, semi-gloss: one coat rust-inhibitive primer, two coats finish.
3.1 Examination: Confirm board finish level and substrate dryness; report defects in writing before starting.
3.2 Application: Apply at the manufacturer's spread rates; finish coats free of runs, sags and holidays when viewed from 5 feet.
3.3 Field quality control and cleaning: Architect's review of each room before final coat; remove spatter from adjacent finishes; protect finished work until turnover.

An outline of a specification section for a fictional project, written for this article.

Note what it doesn't do. It doesn't say where the walls are or which rooms get which color; the finish schedule on the drawings does. It doesn't repeat the submittal procedure; Division 01 does that once for every trade, and the GC builds its submittal log from these Part 1 lists. And it doesn't say "first-class workmanship": it says what will be looked at, from how far.

Writing habits that prevent RFIs

Pick a method per product: proprietary (named products), descriptive, performance, or reference standard. Mixing them in one paragraph creates loopholes.
If you name products, say whether substitutions are allowed and how they are requested.
Write in the imperative to the contractor ("Apply two coats"), and drop "shall be" where it adds nothing.
Edit the master. A section about a product the job doesn't have is a common spec error, and bidders price what is there.
Coordinate with the drawings before issue: every type tag on the drawings has a matching product in the specs, and nothing in the specs refers to a detail that was cut.
Keep Part 1 complete: every submittal, test and closeout document you'll want later must be asked for here, or the GC can't ask the sub for it. The sub's side is in how to prepare a submittal and the CA guide.

The bottom line

Specifications state the quality the drawings can't: products, standards, submittals, installation and tests, in MasterFormat sections of three parts.

Say each thing once, in the right place, so that a bidder can price it and an inspector can check it, and the RFIs during construction get fewer. Conflo is built for the GCs, subs and design teams who work from them; the project lifecycle shows where the specs are used.

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Sources

CSI Standards: MasterFormat, UniFormat and SectionFormat/PageFormat — Construction Specifications Institute. Read October 22, 2026.
SpecsIntact help: Section Format — Whole Building Design Guide (National Institute of Building Sciences), SpecsIntact. Read October 22, 2026.
FAR 52.236-21, Specifications and Drawings for Construction, paragraph (a) — Acquisition.gov (General Services Administration). Read October 22, 2026.
UFGS 01 78 00, Closeout Submittals (August 2026) — U.S. Army Corps of Engineers (Whole Building Design Guide). Read October 22, 2026.

Questions

What is the three-part specification format?

CSI's SectionFormat: every section has Part 1 General (administrative and procedural requirements for that section), Part 2 Products (materials and products) and Part 3 Execution (preparation, installation, testing and cleaning).

What is MasterFormat?

CSI's numbering and titling system for specification sections. Each kind of work has a number and title, such as 09 91 23 for interior painting, so every project manual is organized the same way.

Do the drawings or the specifications take precedence?

Whatever the contract's order of precedence says. On federal work, FAR 52.236-21 says the specifications govern when they differ from the drawings. Avoid relying on it by saying each requirement in only one place.

What goes in Division 01?

Requirements that apply to every trade: summary of work, price and payment procedures, meetings, the schedule, submittal procedures, quality requirements, temporary facilities and closeout. Technical sections refer to it instead of repeating it.

Do architects write specifications from scratch?

Rarely. Most firms edit a master specification, their own or a commercial one, to the project. Federal guide specifications are free to read on the Whole Building Design Guide and show the format in full.