What are Building Specifications in Construction?

Contracts are essential in many different industries and generally need to be as detailed as possible. One way to document details correctly is through the specification section of a contract. In the construction industry, owners, architects, and designers must be specific about the project’s necessary work for completion. Building specifications in construction describe the materials, labor, and skill required for construction development. If contractors are not able to communicate these specifications, delays, change orders, and cost overruns will occur. There is a formal process dedicated to building specifications because they are such a keystone in construction.

Article Highlights

— Types of construction specifications: Performance, Prescriptive, Proprietary
— Who deals with building specifications? Architects, Contractors, Engineers, Owners
How to improve specs: Tips to improving construction/building specifications

building specifications
Photo by Dragon Images on Shutterstock

Why Are Building Specifications Important?

Building Specifications (also called “specs”) are used by subcontractors and teams as a guide to choosing the right materials for the specialized project. Their overall purpose is to define the requirements for project execution regarding installation, materials, products, procedures, and quality aspects. The specifics that the owner and contractor discuss become the legal documents for the project and a keystone for the project design. The project is more likely to be correctly executed when the description and information are more precise. Specifications can be categorized similar to data because as project complexity increases, access to data is critical to making the right decisions. Additionally, if the contract states the specs precisely, there will be a considerable reduction in risk.

Who Handles Building Specifications?

Architects and designers create building specifications BEFORE construction starts in the design phase as part of contract documents and drawings. Typically, architects delegate them to other team members, but sometimes, engineers handle them because of their technical knowledge. If it is a large-scale project, companies will call in processional specification writers to ensure that all details are marked.

Even though specs are separate from the design drawings themselves, details should be updated as plans get more complicated. In every construction project, there are three types of construction specifications that help layout the workflow: Performance, Prescriptive, and Proprietary.

1. Performance Specifications

A performance specification specifies the operational for a project. They also tell the contractor what the final installed product is capable of accomplishing. The focus of performance specifications is on the project outcome and how it functions. Architects will give direction to the general contractor on what is necessary for the project. Then, the general contractor must determine the plan to achieve the end result. This approach gives flexibility and creativity in his construction plan, and it limits the architect’s or engineer’s extent of authority for the project.

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2. Prescriptive Specifications

Different from determining the project plan, prescriptive specifications list the materials the contractor must use as well as the process of installing them. This approach falls more on the architect and engineer as opposed to the general contractor because of their knowledge and to ensure proper installation. Typically, prescriptive specs have three key components.

General – consists of design requirements, national quality standards, product handling, & quality control

Products – incorporates the different products needed for each task & the performance level for each product

Execution – overview of how to prepare & install materials & to test the quality after the installation of the product

3. Proprietary Specifications

In general, proprietary specifications require the use of a single type of product for any particular installation. When there is only one specific equipment piece for an accomplishment of a specific task, one uses a proprietary spec. More often, they’re used where there is existing equipment or installations already on site.

Architects and engineers avoid using this type of building specification unless it is imperative; this allows the contractor to pick and choose from a list of approved suppliers. Using one specific product type can influence the perception of nepotism towards a particular manufacturer and may increase product cost because of the elimination of competitors in the bid phase.

Tips to Improve Building Specifications

Overall, the design and planning phase is crucial to the success of the development of a project. The construction industry is introduced with technology innovations like BIM, which provides companies an explicit depiction of what needs to be done prior to construction and ultimately increases the importance of specs.

Earlier is better than later! The first step to creating a valuable building specification is punctuality, and not waiting until the last minute. Project risk is reduced as a whole because performance requirements are established at the start.

Use construction management software with tools for documentation and submittals that can assist in a project to run more efficiently and effectively.


Construction specifics may seem tedious and in the building process, but they are essential for a successful project. In these processes, architects, engineers, and contractors need to communicate effectively to ensure that they have the right time and vision to execute the project correctly. Specificity can never hurt anything in the construction process. It’s crucial to have all the precise and accurate information you and your team need to carry out the task on time and budget.