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Specification Writing

Introduction & Overview
Methods & Specifying
Defining the Scope of Work
Specification Language and Writing Style
Writing Materials Specifications Clauses
Writing Installation & Applications Clauses

The industry standard for specification organization and writing style is the Construction Specifications Institute's (1) (CSI) Manual of Practice, which has evolved for more than 30 years. The CSI Manual of Practice discusses overall organization of contract documents. Understanding the overall organizational principles of construction contract documents is essential to writing clear and concise specification sections without creating conflicting requirements.

This specification writing guide provides an overview of the concepts contained in the CSI Manual of Practice and some application techniques used by MASTERSPEC® (2) Specification System. Whether the insulation project is a part of a complex building project or a simple contract that includes only mechanical insulation, these principles apply. In every case, a contract identifies the contracting parties and defines their duties, responsibilities, and relationships. There are usually some administrative requirements for performance of the contract and procedures to follow during the execution of the contract. These contract provisions may be a series of complex standard documents or may be simple provisions written on the back of a work order.

Drawings and Specifications complete the set of construction contract documents. Drawings communicate the quantitative requirements and show graphically the shape, location, joining, and general arrangement of construction. Specifications set the quality requirements for materials and workmanship.

Specifications are organized into 16 divisions. Each division is subdivided into sections, with each section divided into three parts. For example, mechanical insulation is one or more sections in Division 15. This organizational concept helps to locate particular information for easy retrieval. Organized in a standard sequence, each document in the set of construction contract documents fulfills a particular and unique function. Each document must precisely perform its function without encroaching on the function of the other documents. This principle avoids creating conflicting requirements within the overall set of documents and reduces the chances for duplications and omissions. Construction contract documents organized by this principle must be read together to obtain the complete meaning and to understand all the requirements associated with the work or a portion of the work. Therefore, a specification section for mechanical insulation must be read with the agreement and conditions (if the insulation contractor is a subcontractor, both the prime contractor's and the subcontractor's agreement and conditions apply), Division 1 specifications, and the drawings (all drawings) to know all the requirements that apply to mechanical insulation work.

The following paragraphs generally describe the role of each document within the set of documents. Even if the project is a simple contract without a full set of drawings and specifications, these principles remain valid.

Contract Documents: The entire set of documents that make up the contract. Contract documents include the form of agreement, conditions of the contract, specifications, and drawings. They also include addenda issued during bidding and contract modifications (such as change orders, construction change directives, and others) issued after contract execution.

Agreement: The document that identifies the project, the owner, the architect and engineer, and the contractor. Among other provisions, it briefly describes the project and includes the contract time and amount and method of payment. This document sets the obligations of the contracting parties. The agreement usually has several attachments, such as bonds (performance and labor and material payment bonds) and certificates (e.g., insurance certificates).

Conditions of the Contract: General conditions are usually standard documents that apply to any project. Supplementary or special conditions modify the general conditions to make them project specific. These documents set the rights, responsibilities, and relationships for the involved parties. Along with the form of agreement, the conditions of the contract set the requirements for the contractor to provide materials, workers, tools, and equipment and to perform the work described in the rest of the documents. The conditions also set the requirements for the owner and the architect and engineer to perform certain tasks during construction (such as reviewing submittals and applications for payment, and interrupting documents and making payments).

Division 1 - General Requirements: The first division of the specifications, Division 1 includes administrative and procedural requirements that apply to all the work, whether performed by the prime contractor or subcontractors. Division 1 specifications help eliminate the need to repeat requirements throughout the rest of the specifications. Therefore, specification sections in Divisions 2 through 16 must be read together with sections in Division 1 to understand all the requirements.

In Division 1, some sections discuss the rules for product selection, such as what is meant by "or equal," if that phrase is used in the specification. Other sections include the procedures for submitting shop drawings, product data (also known as manufacturers' cut sheets), and samples. Other sections set general requirements for execution of the work and procedures for project closeout.

All these documents are important for contractors (including subcontractors) to know and understand because they contain requirements that apply to all work, and are included in Division 1 specifications to avoid repeating them in every specification section describing the work. If each document is written without encroaching on the function of other documents, it not only avoids conflicts, duplications, and omissions, it allows specification sections to be written without repeating information. Specification sections can focus on the technical requirements for a particular portion of the work (e.g., mechanical insulation). Contract provisions are omitted, in technical sections, because they are already stated in the agreement, conditions of the contract, and Division 1 specification sections. This is the keystone of specification writing principles.

Specification Section Numbers and Titles: The Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC) jointly publish a document called MasterFormat© which is the master list of numbers and titles for organizing information about construction requirements, products, and activities into a standard sequence. In addition to other applications MasterFormat is the de facto North American standard for assigning numbers and titles to specification sections. CSI and CSC periodically update MasterFormat according to the changing construction industry. MasterFormat expands the 16 divisions by assigning a 5-digit number to construction subjects. The system of numbers is open and flexible to allow user assigned numbers for additional subjects.

MasterFormat has been adopted by all Federal government agencies and the private sector design and construction industry throughout the U.S. and Canada. ARCOM (3) uses MasterFormat to assign numbers and titles to the sections of MASTERSPEC.
Mechanical insulation is located in Division 15Mechanical, Section 15080. The first two digits of the section number are the division number followed by three more digits that provide the standard location of mechanical insulation in Division 15. The benefit of this standard location is that mechanical insulation can always be found in this location from project to project and from region to region across the U.S. The objective is ease of information retrieval.

Specifiers can choose to write a single section (15080Mechanical Insulation) or write several more narrowly scoped sections that limit the content to particular types of mechanical insulation. For example, mechanical insulation can be divided into three sections: Section 15081Duct Insulation; Section 15082Equipment Insulation; and Section 15083Pipe Insulation.

Standard arrangement of information within specification sections is the objective of the CSI/CSC SectionFormat©. Retrieval of information continues to be the objective for this concept. Each specification section is divided into three parts. These parts are Part 1-General, Part 2-Products, and Part 3-Execution. Each part includes particular information about the subject of the section. These three parts are fixed in number and title and are included in all specification sections.

Part 1 - General supplements the "general requirements" in Division 1 sections by setting particular requirements about the materials and workmanship included in the section. In the case of mechanical insulation, it sets particular requirements for submittals, quality assurance, and other administrative requirements for mechanical insulation.

Example: Division 1 Section "Submittals" specifies general requirements for the procedures, including quantities, distribution, and actions to be taken by each party. In the Part 1 "Submittals" Article of a specification section, particular requirements about what to submit are specified.

Part 2 - Products contains provisions that set the quality requirements for the products, by describing materials, products, equipment and, if applicable, manufacturing tolerances and factory testing requirements.

Part 3 - Execution specifies how the products described in Part 2 are incorporated into the work, specifies workmanship quality requirements without dictating contractor means and methods, and sets field quality-control testing requirements.

In each of the three parts, a standard sequence of articles and paragraphs exists. Suggested articles and paragraphs should be retained only if they apply to the subject of the section and, when retained, they should be arranged in the recommended sequence. This continues the objective easy retrieval of information.

Page layout and article and paragraph numbering are presented in the CSI/CSC PageFormat©. This document suggests alternative numbering schemes, recommendations for margins, spacing between articles and paragraphs, and other format issues. The most important feature of this document is the article and paragraph numbering schemes that provide an address for specification text. This addressing feature helps reference information.

Several methods exist in which to write specification requirements to describe products. These methods are presented here in summary only, and each describes each method in its purest sense. Most specifications employ combinations of these methods to create a complete set of requirements.

Descriptive: This method is a detailed, written description of the required properties of a product, material, or piece of equipment, and the workmanship required for its proper installation. In its purest form, proprietary information is not used. This method results in lengthy specifications. The burden of performance of the described product, material, or workmanship rests with the specifier. Use this method when proprietary information is prohibited (e.g., on public-funded projects) or when adequate standards are not available to use as references.

Reference Standards: Nationally recognized standards are used by reference in this method to eliminate writing lengthy descriptions. The American Society for Testing and Materials is one of many recognized standards-producing organizations in the U.S. Standards are developed by consensus and usually set minimum requirements that may not be sufficient to suit project requirements. Poor standards exist with good standards, and most standards include hidden choices that must be made and included in the citation within the specification. Such choices include grades, types, classes, and other choices to allow for various levels of quality and various alternative or optional attributes. Standards are constantly updated, withdrawn, or replaced by other standards. Use of this method requires the specifier to know the standard and to incorporate it correctly and completely within the specification. Reliance on citations in previous project specifications without current knowledge of the cited standard can result in inaccurate, incorrect, or obsolete references.

Performance: The end result is specified in this method rather than the way to achieve the end result. A performance specification also must include criteria by which performance is verified. Contractors are free to use products of their choosing that can comply with the performance requirements. The burden of performance rests with the contractor. Specifiers should not include unnecessary restrictions on how to achieve the results.

Proprietary: Use of proprietary information provides the specifier the greatest control over product selection. This method is the simplest and shortest to write. As with the descriptive method, the burden of performance of the specified products rests with the specifier, and this method limits competition. For this reason, proprietary specifications are often prohibited on public-funded projects. Proprietary specifications can be open or closed. Open proprietary specifications are used to allow the consideration of substitution requests, and closed proprietary specifications are used if substitutions are prohibited. Nonrestrictive proprietary specifications include the use of proprietary information to set a level of quality by which other products are judged when substitutions are proposed. This requires rules about how other products will be evaluated, who will evaluate and decide, and how decisions will be documented. These rules are generally included in Division 1 specifications.

The function of specifications is to define the quality of products, materials, and workmanship. The function of the agreement and conditions of the contract is to set obligations for contract performance. Therefore, specification sections should not include "scope of work" statements. These statements belong in the form of agreement. Excluding scope statements from specifications allows specification sections to focus on the technical requirements without encumbering them with contract requirements. This practice avoids the problem of attempting to determine who performs each task. Division of the work varies among contractors, depending on many factors. For the benefit of the reader, opening articles and paragraphs in most specification sections include statements about what is included in that section. It is similar to an "executive summary" for a report. Avoiding assignment of the work within the specification section also allows for more concise and direct sentence construction, and helps make the specifications easier to read and understand.

Writing Style:
Short, simple sentences are easier to read and understand. Specifications are contract requirements written as communication between the two contracting parties: the owner to the contractor. The communication in these documents is in one direction: from the owner to the contractor. With this in mind, sentences in specifications can be written assuming that they are directives from one party (the owner) to another (the contractor). Sentences should be simple declarative statements. For this reason, not only can we eliminate statements that assign work (i.e., the mechanical contractor shall . . .), we can further eliminate the phrase: "the Contractor shall." Style also means passive or active voice. Active voice is when the subject of the sentence acts, but if the subject is acted on, the voice is passive. Passive voice nearly always takes more words and is less direct. Active voice takes fewer words and is more direct. Active voice is preferred in most cases, but is not always appropriate.

Example: If the subject does not take action, but is something being described (such as a product), passive voice is clearer. If the subject is "the Contractor" then the subject is being directed to take action and the active voice is shorter and clearer.

Vocabulary (Terminology): Use terms with precise meanings and avoid jargon and ambiguous terms. Avoid the use of abbreviations unless they are well-known industry standards or are defined in the specification. Avoid the use of symbols. Use numerals consistently and set particular rules for capitalization. Set rules for spelling and select a particular dictionary for specification production. If there are optional ways to spell a word (e.g., calk and caulk), the shorter spelling is preferred in specifications.

Grammar Rules: English grammar rules apply. Proper sentence construction means that the subject and verb must agree, that sentences have parallel construction for both parts of compound subject or predicate, and that the style for nouns, adverbs, or prepositional phrases are identical. Avoid the use of unnecessary words and the excessive use of prepositional phrases.

Product and materials are described in Part 2-Products. When describing products, use streamlining to make clear and concise sentences. This method employs a title (preferably a generic, descriptive term for a product or material) followed by a colon, and then a concise description. The title of the paragraph should match the term on the drawings used to identify the product being described. Within the context of construction documents, this presents concise statements and avoids duplicating requirements from the agreement, the general conditions, and Division 1 specifications. As previously stated, these other documents set the obligation to provide all labor, materials, tools, and equipment to perform the work (also defined there) of the contract. Specifications do not need to repeat these requirements. Sentences can be limited to describing products and materials.

In Part 3 - Execution, concisely describe the qualitative requirements for installation and application of products described in Part 2Products. These are actions the owner is directing the contractor to perform as a part of the work of the contract. Use imperative mood, active voice to create concise, declarative statements. Since specifications are communicating requirements from the owner to the contractor, the understood subject of these sentences is "the Contractor" or "you." Begin sentences with the action word (predicate).

Example: Install insulation materials, accessories, and finishes with smooth, straight, and even surfaces; free of voids.

In the example above, the subject of the sentence is "you," which in the context of specifications means "the Contractor." It is also important to avoid dictating means and methods. back to top

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