10 Advantages of Shop Drawings
Updated: Sep 26, 2020
This post will focus on the role of shop drawings, steel fabrication, millwork drawings and HVAC systems.
When we want to present something to a client, there are a number of ways to do it such as creating sketches for a product design presentation sheet, modelling a prototype for a hands on interaction, or a visual demonstration and pitch of a product.
But these visual representations and concepts are not enough to create a product, a concept sketch of a building can stimulate the imagination of what the final real life product may look like, but can't be used to actually create the components of a building to be assembled.
For that, we need shop drawings specialized for manufacturers that can be followed to form and assemble the product within controlled and calculated constraints. But how do we take these images and concept sketches to the manufacturing stage? What can a designer do to move onto the next stage once the client is satisfied with the initial concept drawings?
For that, there is a requirement of shop drawings or technical drawings. These are drawings that show information that can instruct the manufacturer and enable them to understand what the end product should look like and how it should function.
For example, a structural engineer will need to create steel fabrication drawings for a steel manufacturing company to be able to use the drawings to understand what specification of steel beams and columns need to be produced by the company. Drawings for a HVAC (Heating, Ventilation and Air Conditioning) system map out a plan of how a building will be ventilated; the vehicular movement of indoor air quality and the transmission of thermal dissipation throughout the building. Seeing a drawing plan helps to encourage discussion and ideas. In this case, a team of HVAC designers can use a floor plan of a building to plan how air will move through it, and how and where the HVAC system will be installed to ensure company standard efficiency.
Modern day shop drawings or technical are created using CAD software like AutoCAD or Revit, hand drawn technical drawings are not so common these days and this dying art has been reduced to quick sketching for conveying ideas and concepts quickly. For this reason, this post will focus only on drawings produced by using CAD software.
The following are 10 advantages of using shop drawings.
1. PRESENT DESIGN INFORMATION AND ASSEMBLY INSTRUCTIONS CLEARLY
Shop drawings display a scaled outline of how the final product will be assembled, with supporting information of what materials are to be used, the dimensions of the product, hidden components represented by dashed lines, the intended weight of the product, the joints and connections in the product, product specific treatments such as 'galvanizing steel' and more.
A set of steel fabrication drawings for example would contain the drawing of the steel component with top or bottom views showing the specific connection details, and even a 3D detail to give a better perspective. The component will have it's measurements displayed, backed by supporting information such as 'Column to be primed with protective oxide coating' (if it's not already the manufacturing standard).
The clarity of these drawings help the fabricators to produce exactly what's required as specified for use on the construction site.
2. CREATE DUPLICATES OF THE SAME PRODUCT
Because shop drawings give very specific instructions and information, it allows the manufacturing process to be duplicated a number of times in order to create a number of the exact same product every time.
This can be useful when there is a requirement for a multiple of the same component, roof joists for example. It is also useful if the manufactured component is or becomes defected for some reason. In this case, it's exact duplicate replacement can be rolled and formed.
When there is a contractor scheme for a development of new houses, duplication can save time and money when all the houses planned to be built are the same.
Shop drawings can be used as documentation to be later referred to if something is amiss, for example if a structural steel column was delivered on site and found to be too tall, the technical designer can refer back to the drawing to pinpoint the cause and time of the defect.
It could be the designers fault or the manufacturers fault, keeping a documentation of drawings can guide a pathway to the solution of problems that may arise and can help to determine a further action to correct the error, such as;
Using the actual drawing dimensions to instruct the site installers to cut off a part of the column and ensure it matches the drawing as intended.
Such documentation can also be compiled to seek approval from a qualified and accredited engineer, which can act as supporting documents to submit to the planning authority for approval to build.
4. ACCOUNTING OF COMPONENTS
If there is a particularly large structure, say an unusual structural steel balcony support, which requires many loose parts to be assembled on the construction site because it's too large to deliver in one piece.
Then each separate component can be presented as a part that is organised into a group of drawings labelled 'Part A' and 'Part B' or for example 'BALC01-001', 'BALC01-002' and so on. This can then be supported by an overall drawing showing how the final structure is supposed to look and function when all the parts are assembled together on site.
This could also be said for the whole building itself where each part of a building can be grouped into a set of drawings, and each set of steel fabrication drawings can be organised into a schedule of delivery dates.
An example of this would be if a building project consisted of 3 blocks, then each block would be treated separately and then further separated into storeys, therefore instead of creating all the drawings for Block A, a schedule can be followed to deliver a set of drawings for 'Block A Ground Level Drawings' for manufacture, and subsequently Level 01, Level 02 and so on.
Another advantage of documenting shop drawings here is that they can be used to account for all the parts that are required for construction, if any part is missing, the set of drawings and the overall plan can be referred back to for the missing component.
5. ACCURATE COSTING
Costs are a big part of the manufacturing business and must be taken into consideration carefully. Shop drawings help to determine accurately the cost of materials needed for manufacture. They help to prevent too much or too less of a material being ordered and consequently help to prevent time wastage and overstock of items.
They can help to plan a schedule of orders to be in line with a current or future project and to maximize storage periods. Usually the manufacturer might order the exact measurement of materials required plus 10% to cover any problems that might arise during production.
Problems can include incorrect sizes of a component; if it's not possible to form it again, it can perhaps be recycled and the component can be remade using the extra material ordered.
The good thing about using CAD software like Revit is that it is a 'Building Information Modelling' tool, meaning that if a building model is created in Revit to the exact specifications and the model components fit together well and as intended; then Revit can use the information contained within the model components to create various schedules.
These schedules can be used to find out how much of what material is being used in the model and the weight of the components. This information can then be used to determine how much material is to order and how much it will cost.
The schedules even calculate the grand totals of everything so that the figures can be used to determine quotes for orders. As you can probably tell by now, scheduling is a large part of the construction world.
6. CORRECTIONS BEFORE ISSUE
As said before; one of the best advantages of creating shop drawings using a CAD software like Revit is that you can see the Model in 3D and it's building information. This means a designer can pinpoint any clashes, voids or anything irregular in the model before it is constructed on site.
You can literally take the model and conduct a visual walk-through of it from any angle, any corner and any room. CAD software allows you to dissect a model and get insight into how a building is being constructed and how it fits together.
An experienced designer with good eyes can locate any possible errors and fix them and therefore provide accurate building costs, accurate manufacturing of materials and accurate site construction and save a lot of time in the process.
Shop drawings also offer the designer a chance to explore different possibilities or ways of constructing with ease before reaching a conclusive set of drawings. If anything seems to be missing for example: a continuous line of structural support that transfers loads into the ground, then the designer will be able to see it and add the necessary elements very quickly.
Because of the nature of modern day electronically stored information, shop drawings can be carried around anywhere and can be accessed at any time. Copies of the drawings can be stored as a backup in a shared network or cloud storage and can be accessed from multiple devices that have access to the network.
Imagine the ease for an architect who can walk around site and inspect construction elements while comparing it to a drawing on his/her tablet versus leaving the drawings in the "cabin" and relying on memory and experience to walk around and spot any defects.
The main thing here is that shop drawings are more of a reliable source of information to refer to and having easy access to them during the inspection stages of a project is incredibly practical.
To a budding architectural graduate who knows how to draw nice pictures of buildings; shop drawings are an astounding source of information and knowledge to absorb. A trainee can look at the construction information on a shop drawing learn how to really make a building work.
Looking at a piece of technical drawing and trying to understand it is probably better than reading an informational book. Because the technical drawing shows you exactly what's going on and how something is going to work.
It is a really good idea for a student to get some industry experience by pursuing an internship, the wealth of knowledge that is contained within a few expertly crafted technical drawings can really boost the student's technical ability in his/her assignments.
When an intern understands technical shop drawing, not only is he/she able to produce more technically sound projects for university assignments, but will also have opened themselves into a world of possibility; where the student can provide value to a company just by knowing how things work.
The backup of shop drawings from previous projects can help to standardize the sheet presentation and drawing style of a shop drawing. It is professional practice to have a uniform style of presentation to the client/contractor and shop drawings can help to develop that.
A uniform style of presentation can also act as branding promotion. For example, when you receive documents from a company, there is uniform style and layout of the document which is unique to the company and the style alone can be enough to enable others to recognize the prestige of a well established company, more about this in number 10 below.
10. DRAWING SHEETS CAN ACT AS PROMOTION
As well as presenting the manufacturing/construction of an element, the drawing sheet itself can be used to promote the company that produced the drawing. Generally, shop drawings tend to contain a 'title box' either in the side or the corner of the sheet.
This box can not only display information about the drawing such as scale, date, drawn by, checked by, drawing number and other information. But it can also house the company logo and contact information of the originator of the drawings.
This not only stamps the drawing company's attribution to the work, but if the results and work is particularly good, it acts as a reminder or a promotion of the originator to perhaps negotiate more work in the future.
These are 10 advantages of using shop drawings. I hope this post helped you to understand the many benefits of technical drawing sheets. Do let me know your thoughts in the comment section below and if you know any other advantages of using shop drawings for manufacture. I look forward to reading your comments.