construction specifications

3 Types of Construction Specifications

Communication is vital for the delivery of a successful construction project. Even before work starts on a site, the owner and planning team must have an excellent idea of how each job must be done and how the project will look in the end. If everyone is not on the same page, the project can suffer due to delays, change orders, and rising costs. Construction Specifications are, hence, needed to effectively communicate each little detail of the work that goes into completing the project.

What are Construction Specifications?

The term construction specifications, also called specs by workers, are details of the work that must be completed for a construction project. These can include a range of activities such as the scope and scale of work, the quality of the work, the installation process, the materials to be used, etc.

Subcontractors use construction specifications as guidelines for their designated jobs. This is also why any specs discussed between the project owner and the contractor become part of the legal documents for the project. 

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Why Do We Need Construction Specifications?

There are several reasons why a healthy (and successful) construction project cannot happen without proper construction specifications to match. The requirement to outline materials and labor is only the start. There are other benefits that architects and engineers reap from specs.

Set Expectations: Subcontractors interested in making a bid will appreciate having the construction specifications for the project. This makes it clear what the owner is expecting from the finished product, allowing them to make informed decisions.

Improved Communications: Imagine different workers having to work together without any proper guidelines. Chances are that they are not only going to interfere with each other’s work but also ruin the final outlook. Construction specs define how workers are supposed to finish a job, making it easier for everyone to communicate efficiently. Since everyone on-site is on the same page regarding how the job should be done, projects can be streamlined better without anything becoming lost in translation.

Quality Assurance: Thorough construction specs inform everyone how the project outcome should look by outlining quality (and technical) benchmarks. These can be based on international standards or the relevant municipal safety codes. Such quality outlines ensure that no shortcuts are taken by workers, and no oversights interfere with the finished product.

Accurate Cost Estimations: While most construction specifications deal with quality and efficiency, another important aspect to note is estimating cost. Since specs detail all the materials and labor required for a project, it becomes easier to accurately estimate how much a project will cost.

Major Types of Construction Specifications

There are three main types of construction specifications, each critical to project planning. Understanding how they work and what information they offer is important for delivering a successful construction project.

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Prescriptive Specifications

Prescriptive Specifications outline the type of materials used and the installation of said materials. They are the best representation of the final product among all three construction specifications, and can be broken down into three separate phases:

  • The general phase goes over information such as national quality standards, product handling, design requirements, and quality control. 
  • The products phase goes over different products necessary for each task as well as the individual performance levels of each product. 
  • The execution phase goes over how to prepare materials before installing them. It also involves testing the quality of materials and checking if they were installed correctly. 

It falls on architects or engineers to head project design in Prescriptive Specifications. 

Performance Specifications

The next batch of construction specifications discusses the operational requirements of a project. Performance Specifications detail what the final installed product must be capable of doing. 

Understand that the owner or general contractor does not give a subcontractor specs detailing how to finish the job. Instead, designers and architects give contractors details on how the final product has to work in this phase. 

For example, a contractor can ask the team to make a pump that pumps 300 gallons per minute. There are no directions on how to make the pumping system go that fast, so it is up to the contractor to figure it out.

The architect or engineer describes the project outcome and trusts the contractor’s experience to get there. Since the contractor has to figure out what to do, decisions about materials and strategy move away from the architect and engineers and shift toward the contractor.

Among all three construction specifications, Performance Specs involve the most testing. This is to make sure a project meets all its operational requirements.

Proprietary Specifications

Proprietary Specifications are used when contractors need to use a single type of product for any installation. These are the least common of the three types of construction specifications, but they are for jobs involving existing equipment and already completed installations. 

Contractors use Proprietary Specifications when the owner or client wants to be consistent with their materials or prefers a specific type of material.

Do note that architects and engineers tend to try and avoid Proprietary Specifications because they can lead to promoting a specific manufacturer. Favoring a manufacturer can discourage competition during the bidding phase of the project, which may increase the total project cost. The better way is to give the contractor a list of reliable suppliers to choose from.

Who’s Responsible for Construction Specs?

Construction Specifications are created by a team of qualified architects and designers before the on-site work begins, and may also involve project engineers for technical assistance. When working on large and complex projects, professional specification writers can be enlisted to pen specs for specific parts of the project. This reduces the risk of errors and oversight.

Do note that Requests for Proposals (RFPs) can be used while writing construction specifications. RFP documents can request vendors for details on the scope of work that must be completed, for example. This helps add informed and accurate information for all stakeholders of the project.

Once the specs are done, contractors can match them with architectural drawings and blueprints to document information that might not be visually clear.

Best Practices for Writing Construction Specifications

Construction Specifications are meant to provide a single set of guidelines that bring architects, engineers, project managers, workers, and owners on a single page. They should answer a range of questions relating to how the project should be finished, making it critical that any specs are written accurately. If workers and engineers are still going back and forth, for example, due to incomplete specs, project managers might end up having to re-do construction. 

  • Be as Specific as Possible: Do not leave out any important detail by assuming that workers will understand what the specs are trying to say. This can prove to be a time-consuming process, but a necessary one. The more time you spend detailing each step of the project, the more likely your vision for the project will be executed accurately. 
  • Starting Early: Creating Construction Specifications early in the project’s life cycle means having more time to review details. Since specs go through various parties, everyone must agree to the construction documents early on. This also makes room for necessary revisions in case a specific party or the owner has a proposition to change something.
  • Check the Specs for Errors: It is important to carefully go through a set of specs to make sure they are crystal clear. There should be no ambiguity or open-ended details. Check the grammar, spelling, and sentence structures to ensure every worker can read the specifications without issue. This is also done to ensure that the wording clearly represents the interests of all parties involved.
  • Avoid Repetitions: While it is a good practice to mention every detail, do not repeat the same set of requirements in different wording. This may confuse the reader.