Structural design documentation consists of two types of documents – drawings and calculations. Both undergo a tremendous amount of scrutiny during the process of obtaining all the necessary permits, and they are both vital when it comes to ensuring the building’s stability and ability to carry the design load. Through calculations, engineers can determine the strength, stiffness, size, and layout of members and connections, that is, the structural elements that they have decided are optimal for a given project. But when the construction commences, drawings become critical. They are the language engineers use to communicate with the contractors. Quality structural drawings are important for your project because the contractor will understand the design requirements.

Not only do clear and detailed structural drawings directly impact the contractor’s ability to comprehend what it is they need to construct, but they also speed up the permit obtaining process. In addition, they allow for accurate estimation during the contractor selection process and lower the risk of Request for Information (RFI) and change orders during the construction process. The following paragraphs will showcase how quality structural drawings affect these three points.

Reduced permitting revision cycles

Unless your home improvement is of cosmetic nature, you will have to get several permits before you can begin with the works. You and your design team will follow the industry trends when creating the scope of your project. Depending on the range of works, these permits may be for mechanical, plumbing, demolition, and electrical work. You will also need a permit for the overall project. You can obtain some of them online or over the counter by providing a few of the documents. However, most of the permit applications must go through a plan check review by the Building Department.

This process involves the assessment of compliance with local codes. Moreover, the structural design has to go through a detailed evaluation of drawings and calculations. Should the building officials uncover a mistake or have trouble understanding the drawings, they will list the revisions. Your team will have to implement these changes before you can resubmit the documentation. This could potentially delay your project for months, as the cycle will continue until the officials are entirely satisfied with compliance. Therefore, creating clear and accurate structural drawings and calculations that you will submit alongside your permit application will decrease the number and duration of the revision cycles, allowing you to begin with your project sooner rather than later.

Accurate estimations

Before the works commence, you will receive quotes from your prospective contractors for the project at hand. As mentioned, quality structural drawings will effectively convey the project requirements. And so the estimates will depend on them. The clearer and more detailed they are, the more accurate quote you will get from the contractors. This is important because you will avoid overpriced bidding, and your budget and construction costs will align.

The risk of additional costs elimination

When the construction is underway, structural drawings tell the contractor which members and connections to select and how to install them. If the drawings are imprecise or unclear, the contractor may misinterpret them, or they may need to ask for explanations through RFIs.

RFI (Request for Information) is a formal communication medium between contractors and design teams aimed at eliminating mistakes. However, they are time-consuming and require additional resources. Therefore, it would be best to avoid them through accurate, detailed, and precise drawings. Vagueness and inaccuracies can misguide the contractor during the construction resulting in schedule and cost changes. These changes are called Change Orders. They are formal procedures used for adjusting the scope of the contract, work schedule, and budget. Often, they lead to additional costs and the delay of the completion date.

Many factors can cause RFIs and Change Orders. However, quality structural drawings will significantly lessen their occurrence as your contractor will read them correctly.

Ensuring the quality of structural drawings

It is evident that clarity and accuracy are of the utmost importance when designing structural drawings. If you want these to be of high quality, you and your design team can take steps to ensure that.

  1. Limit guesswork and avoid confusion

As mentioned, contractors need to be able to understand the drawings. However, they should also be able to find all critical information to limit guesswork and eliminate confusion. Therefore, the drawings should include all dimensions but exclude irrelevant scope. Moreover, the notes must be concise, with precise wording, and in line with the drawing.

  1. Make sure that they include all essential details

Details are vital to builders. They are enlarged drawings of particular components of the structure. They enable the builders to zoom in and see all the tiny details and differences. Each of the details must be perfectly clear and relevant to the big picture. What follows are typical structural elements that structural drawings should include.

  • hangers
  • slide bearings
  • unusual connections
  • connections with significant reactions
  • critical load path connections
  • transfer girder details and connections
  • foundation connections
  • shear wall details
  • critical seismic connections
  • sloped columns
  • secondary bracing details
  • spandrel details
  • transfer force details
  • interfaces with existing buildings.

Clear and relevant details will make sure the design requirements are fulfilled to the last detail.

  1. Deal with all design issues during the design phase

Resolving all the problems during the design phase, i.e., before the construction phase, will ensure maximum effectiveness while keeping the costs at bay. But, if you leave any issue to be dealt with during construction, it will likely lead to increased costs and reduced efficiency. Again, we should underline that the design team must review structural drawings with clarity in mind. They must also check whether all sections and components function well with one another.

  1. Peer reviews are helpful

After working on a project for some time, it is natural to miss something. Also, since your design team is creating the drawings based on your ideas, everything may seem clear to you. However, to another set of eyes, specific points may seem confusing and vague. Therefore, introducing a third party to review your design is an excellent idea that will help you uncover mistakes and point to ambiguities. Moreover, an unbiased expert may contribute to the project by suggesting possibilities for enhancement and cost reduction.

Quality structural drawings are important for your project as they ensure a clear understanding on the part of your contractor, thus eliminating additional unnecessary costs. They also allow for quicker permitting revisions deeming the project more efficient. Hiring structural engineering consultants in CA is a smart idea if you want your design and calculations done in a way that will limit confusion and lessen the risks of delay and extra costs.



Adam Jacobson is an architect with over ten years of experience. His knowledge allows him to compose articles relating to structural design, Californian architecture trends, and MEP engineering services in CA. His hobby is collecting comic books.