The Importance of Layout Drawings

Will accurate layout drawings have an impact on your field productivity?

What are Layout Drawings

Many trade contractors already use layout drawings on a day-to-day basis to improve construction speed and accuracy. Usually, we see those types of drawings being more popular in the commercial or institutional space, most likely by their nature and the complexity of the projects. Therefore, accurate layout drawings enable new methods and technologies to be used to improve the construction layout process. For those who don’t know what layout drawings are or for those who want to improve their knowledge about it, here is an interesting article.

Layout Drawings (also called installation drawings), are the final result of whether a BIM coordination process or an adaptation of the contractual drawings. They are used to accurately position key materials on a job site such as anchors, steel studs, fixtures, door frames, acoustic panels, drillings, and the list goes on. Based on our experience, trade contractors that use layout drawings can drastically improve on-site productivity by making sure that the information is accurate and easier to understand for their workers. Once layout drawings are generated, the method of layout can vary from manual measurement (tape measure and chalk line), to the total station or even the FRAMR… of course.

Contract Drawings vs Layout Drawings

Layout drawings do have similarities with Contract Drawings, for sure. But to better understand the fundamental differences between these two types of files, here is a simple explanation to guide you.

Contract drawings mostly come as a set of sheets that constitute the entirety of the work to be performed, either for structure, architecture, or mechanical work. Where layout drawings only represent the details of a floor, the section of a floor, a phase, or more. Take a look at the illustration below:

In the Wall & Ceiling Industry, layout drawings are essential to clearly differentiate the location of the steel studs versus the finish line of a wall. If we do a close up of one of the walls in the Contract Drawings, here is what a worker will see:

But in reality, the wall is composed of multiple layers of materials ranging from gypsum panels to steel studs. Those unique sets of wall types differ from region to region, depending on their respective building codes.

Those layers of materials are clearly described on another page of the Contract Drawings and can be clear for a few of them. But when you have 256+ wall types in your projects, it can also become really complicated for your field workers to manage all of them on site. This is where Layout Drawings come in handy.

Those types of drawings need to be performed by the trade contractor himself or, another sub-contractor to clearly reflect the exact position of the construction materials that need to be installed on a site. In the same example above, layout drawings could integrate the precise location of:

• Axis lines & control lines;
• Location of steel stud;
• Dimension and gauge of the steel studs;
• Window’s rough opening (need to take into consideration the manufacturer’s notice);
• Door rough opening (need to take into consideration the manufacturer’s notice);
• Finish lines representing the last layer of the gypsum panel;
• Fire resistances (in hours) and the appropriate side of it;
• and more.

Once all of that information is taken into account prior to the construction phase, the possibilities to improve on-site efficiency are almost limitless.

Is there a standardized way of creating Layout Drawings?

To date, no standardized procedure has been established to perform layout drawings effectively. Each company has their own tips and tricks to make it simpler and more productive. For hand-drawn layout, we usually add dimensions from a wall to an axis as a standard. For total station users, it is not necessarily useful to do so, but we will integrate the concept of control points.

Even though there are no clear standards, there are official tools that can improve to process of generating your layout drawings. Revit, being one of the leaders in 3D Computer-Aided Design (CAD), can easily export views of your 3D models to represent the information you need to have clearly. AutoCAD is another powerful tool to manage 2D layouts accurately and effectively.

I want layout drawings; where do I start?

First, you’ve read this article, which is a good start.

Second, you will have two options.

• Option 1 – Building your own CAD team
  • Building your own CAD team may seem intimidating, but it really is not. It just brings you a level of expertise in the pre-construction phase that improves your chances of success when it comes to construction. Your CAD team may be BIM-enabled or not, but the more tasks they can perform, the more profits you may gain. The layout will not be their sole focus, and they can also provide huge value in the clash coordination phase, prefabrication, or more. Usually, we call those team members BIM/VDC Coordinator or Manager.

• Option 2 – Subcontracting layout drawing to CAD professionals
  • Once you have the right revision of contract drawings, you always have the opportunity to subcontract the manual work of performing layout drawings with experts. Those experts will take into consideration your needs, ask you for the required documents, and then perform the work.

A few words to conclude…

Layout Drawings have always been an important part of the construction process for a multitude of trades and in many types of buildings. The idea is simple, the more accurate information you have, the better it can help field installation. Efficient layout drawings will lead to major technology breakthroughs to optimize on-site processes and even improve the design phase of a project. Who knows; probably one day, we won’t need tape measures anymore.