What Is a 3-Part Specification?

Building product manufacturer specifications are essential to construction projects. They serve as directives from the product designers to construction teams in order to communicate the product design intentions. It’s critical for product manufacturers to ensure their guide specification sections are created to clearly communicate the product’s purpose and use for all involved in the construction process.

To help manufacturers write quality specifications that clearly communicate the use of their products in projects, Construction Specifications Institute (CSI) produced a formatting guide that manufacturers can follow when writing specification documents. This guide comes in three parts, also known as a 3-part specification.

Example of a 3-part spec document from Luxer One. What Is a 3-Part Specification?

Example of a 3-part specification from Luxer One (click for full document).

These guide specifications should cover all options for a product or product line. For instance, manufacturers of sealants and waterproofing for the building envelope should clearly state how their products are used for air and vapor barriers, glazing systems and sealants & adhesives. The design specs should be written to clearly convey all options and selection criteria.

CAD files of products must be included in the specification submittal in a format that is easily included in the building information modeling (BIM) file. In creating appropriate specifications, manufacturers must keep in mind how architects and other designers will use their products in 3-part guide specifications.

It is also important to understand the role of CSI specifications — which are not architectural drawings — that show visual connections, sizes and details. Project members use them to follow construction language standards for building specifications. CSI specs provide an efficient organization of information into classifications in an effort to provide simple and consistent project reports.

3-Part Specification Format

In CSI specifications each section is divided into three parts: Part 1 – General, Part 2 – Products, and Part 3 – Execution. Each part consists of specific information regarding that section of the specification. The three parts are included in all specification sections and are consistent in number and title.

Infographic describing the three parts of a 3-part specification.

Part 1 – General: Includes administrative activities, procedural requirements, and quality assurance guidelines. This includes quantities, distribution, and the responsibilities of each party in the supply chain, provided in expanded detail for the general conditions of the contract.

Part 1 sets specific requirements regarding materials and workmanship and specifies the requirements of what is to be submitted. For instance, it sets conditions for documents submitted to an architect for authorization of use, quality assurance, and the administrative requirements of mechanical insulation, i.e., installing thermal insulation on any mechanical system, including HVAC systems, ducts, boilers and piping systems.

Part 2 – Products: Identifies the specific product attributes and conditions of the product quality requirements. It describes the materials, products, equipment, and often manufacturing tolerances and testing requirements expected of the manufacturer. Part 2 also specifies where to find the descriptions of specified products or materials. Manufacturers must be clear in classifying products by name and product number in order to be clearly identified in the specification.

Part 3 – Execution: Indicates special installation requirements and specifies how the products described in Part 2 will be used in the project. It stipulates the quality of workmanship required without dictating the contractor’s processes, yet stipulates the requirements of field quality-control testing. Part 3 contains product-specific provisions and explicit conditions for the installation.


Each of the three parts includes a standard arrangement of paragraphs and articles, which only appear in the specification when applicable to the subject of the section and are arranged in the appropriate sequence. This allows for a systematic and simple recovery of information.

Building product manufacturers write guide specs in a well-planned, 3-part specification to guide the architect on how to specify the manufacturer’s product into a project. Any given construction project can have thousands of specified products, from flooring to roofing materials, electrical to door hardware, lighting to structural materials and everything in between. 3-part guide specification makes it easier for product manufacturers to tell their customers where to specify products, and it makes it easier to get their products spec’d into customer projects.

Though architects often specify products through a specific manufacturer, there is usually an “or equal” designation, particularly for public bids. Though a manufacturer with a unique or proprietary product stands a good chance of being the chosen supplier.


Why Manufacturers Should Provide 3-Part Specifications

First, it’s imperative that specifications are written according to CSI guidelines to ensure industry acceptance and consistency. Product design specifications should serve as instructions to communicate the objective of the design and how it fits within the project for the benefit of the architect and construction teams.

A manufacturer’s specification guide should incorporate all product and product line options to make it easy for architects to decide what products to select. Ultimately, it’s the product manager’s job to get their company’s products specified into Architecture, Engineering, and Construction content for a broad range of projects.

Architectural and construction teams require an enormous amount of information in building design and construction. It benefits the product manufacturer to make life as easy as possible for these customers in order to be the specified product of choice. As mentioned, most specifications will require an “or equal” to any product, yet ensuring the spec is clear benefits everyone.

4 Guidelines To Get Your Products Specified

Infographic with four guidelines to get your products specified.

1. Make it easy for your customers (architects, engineers, contractors, and procurement)

Be sure you do the heavy lifting for your architectural customers by providing all the information they need in the appropriate format to be easily accepted by their project manual. Supplying your specs in a 3-part specification guide makes your customer’s job much easier and significantly increases the chances you’ll be spec’d into their project. In addition, provide relevant supporting documents such as brochures, data sheets, testing and quality documentation, drawings, photos, and field-proven performance results.

Architectural firms typically maintain an Office Master Specification guide that contains product specifications and templates for all their Project Manuals. It serves as the firm’s private Sweets™ type directory for select manufactured products.

Architects can’t create product specifications from scratch, and instead rely upon their Office Master spec guidelines. Your goal is to have your products included in their Office Master Specifications, so you’re the go-to product(s) in a building’s design. This starts with having a thorough 3-part specification guide.

And, of course, the exclusivity of having a high-demand product gives you an upper hand. For example, DuPont’s Tyvek® brand. Tyvek® came on the market 60 years ago and was touted as “superior performance based on unique material science.” Sure, DuPont had the deep pockets for marketing, but they also had what was initially a proprietary waterproofing material for houses and commercial buildings. In the 1970s, it became widely used in the construction industry on a global scale and still maintains over 50 percent market share in the house wrap and weather-resistant barrier market.


2. Give your sales team the tools to succeed

Don’t let your sales team run around with off-the-shelf presentations. Give them material that can be tailored to the prospective customer’s specific needs.

An articulate and properly-formatted specification guide helps build the specifier’s faith in the manufacturer’s ability to be a supporting partner. Many manufacturers get passed up because of poorly-prepared product specifications, sometimes relying only on standard product brochures and generic documentation. Specification writers should have hands-on experience with construction materials and methods, which gives them insight into real-world applications and lets them use that insight to develop formats for specification guides that can be used as relevant sales tools.


3. Avoid competitive intrusion

Always be aware that most, if not all, of your competitors are providing up-to-date CSI 3-part specification guides. So, it’s imperative to find ways to set yourself apart from being just another “me too.” Tighter specs and unique problem-solving properties will always win the day.

But sometimes, it’s all about perception. From the 1970s through the mid-‘90s, a Cleveland-based company sold a high-grade building fastener for three times the cost of its closest competitor. It had a slight blue tint to the plating, was sold in a blue box (the primary competitive product was in a plain brown box), and implied it was made of a superior alloy. The product was equal in performance to the competition, yet for 25 years, they cornered that market segment.


4. Communicate in industry-standard language

Be sure to guide the architect on the path of least resistance and speak their language. Following industry-standard, 3-part specification guide protocol and communicating using standard terminology, architectural symbols, and familiar formats in an organized fashion demonstrates that you are meeting the needs of the architect and contractor.



3-part specifications provide comprehensive information in an orderly fashion for architects, specifying engineers, and contractors. As a manufacturer, a good place to start is to get your products listed in Dodge Construction’s Sweets database, a comprehensive, subscription-based data platform that the commercial construction industry has embraced for decades. It’s an online resource for detailed product information, BIM objects, CAD details, specs and other relevant resource information about specific products and their manufacturers.

Product manufacturers can find, bid, and get specified and installed into projects from this platform, and architects, specifiers, contractors, engineers and facility managers can access and download all the information they need on over 100,000 products.

With total construction starts jumping 27 percent in December of 2022, and manufacturing and infrastructure projects leading large gains, it’s imperative for product manufacturers to capture their piece of the pie.

CSI 3-part specs tell the architect in short and easily-formatted terms how a product can fit into their specification for a project and the product details that need to be specified. Sifting through reams of data can take hours, but when information is organized into 3-part specifications, searching can take moments.

As the name implies, 3-part specifications encompass three parts of the product specification: General, Products and Execution. And each of the three parts provides a standardized format to present specific product information. In layman’s terms:

  • General is the preamble
  • Products provides the detail
  • Execution explains how to use it

Architects, specifying engineers and construction managers shouldn’t need to dig for every available product detail. It’s like design engineers at BMW assigned to the car’s interior. They don’t want to be concerned about the design of the instrument cluster, only that suppliers like Bosch or IAC Group meet the spec and provide all documentation necessary to make an easy product selection.

By following the 3-part specification methodology, manufacturers help prospective customers find the appropriate and accurate information they need to design a structure, and they in turn improve their chances of being spec’d into construction projects.


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Kelly Obbie

Social Media Coordinator at CADENAS PARTsolutions | A 2018 graduate of The Media School at Indiana University, Kelly studied journalism, public relations, English and Spanish and has experience in news writing and editing as well as social media writing and management. She also has professional and personal experience in videography and photography. She currently lives in Ohio but has lived in four states, and in her free time, she enjoys running, hiking, learning languages, and watching Disney movies.