Introduction to Drafting Techniques
Why do we use drafting to communicate our ideas?
We draft our ideas so someone else can understand your designs and to construct from them. You and all those involved in a project need to use a common language or form of communication that can be understood by all parties.
The old saying that a picture paints a thousand words could not be more apt for the design industry and so it is pictures that designers use as their main form of communication. If you tried to describe how a cabinet is built in written form is nearly impossible, takes a long time to read and leaves a lot to the imagination.
For example the description of a cabinet for manufacture.
I would like you to make me a cabinet. It needs to be 2 meters long and half a meter in depth and 90% of a meter high. I would like it to be made of mahogany with the grain shown to be quite a deep look and vertically run. The top of the cabinet needs to protrude over the leading face by 40 mm and be also 40 mm deep and I would like it to be rounded to a diameter of 20mm. In fact make it a bull nose. The interior of the cabinet is also to be mahogany and to have three adjustable shelves inside it. Space the adjustment holes at 20 mm intervals and use chrome plated steel pegs to hold the shelves in position. Each peg should be about an inch long and not to protrude through the exterior of the cabinet. It will need to have four doors and they are to be hung on self closing hinges with chrome plated steel D handles fixed 100 mm down from the top of the cabinet.
By the time you have finished writing all this and the instructions for the rest of the project you will have produced a book that is very large as well as very confusing. It is also difficult for the person manufacturing the cabinet to see at a glance your intentions and the details that you would like.
Now do not confuse this with a specification, which is illustrated here and is expanded in the Contracts and Co-ordination, Project Management area. A specification is an outline document covering the specific industry standards and conditions of contract that are required. Many industry professionals such as quantity surveyors and project managers love specifications and want you as the designer to put in as much design detail and quantities as possible. They do this to make their job easier and put the responsibility on you. My advice after over twenty years in this industry is to keep the written specification to a practical minimum and retain the detail and quantities of items on your drawings. The drawings are what you as a designer have a natural ability to communicate with. Leave the “word smitthing” to the lawyers and project managers and don’t let them frighten or bully you into doing otherwise.
You are the designer. Show your designs as drawings.
Now to give the other professionals their dues we have three main forms of documents to describe a building or interior project.
By Drawing – this is your form of communication.
By Specification – this is also your form of communication but crosses into the realm of the quantity surveyor and project manager.
By Schedule – this is the specialist field of the quantity surveyor, which measures and accurately quantifies the project for the contractors to price from.
In my opinion a drawing can be all that is required for a project to go ahead and be built accurately. However if the drawing is to be used as a legal document, the scope of work and standard is based upon the drawing and a fee is offered and accepted for the work described on the drawing, then all relevant clauses such as building standards, guarantees etc should also be included or referred to on the drawing.
This is why we have specifications, to ensure that all the legal standards and guarantees are in place for the work to be done to. It describes a standard.
To include all of this information on the drawings would make them rather cumbersome and detract from the main intent of the drawing. With the use of modern word processing packages the standard document or specification can be kept and altered per project. It saves an enormous amount of time, the same way that using a standard detail or computer based drawing package can save time, these will be covered further here.
So in conclusion, drawing what you require is the most descriptive of the three documents. In larger contracts all three documents would be used, and that is what this area of the web site is based on.
The documents that you produce form a contract therefore you develop an accurate description or intent of what you require by drawing or drafting the item of work. This has to be as accurate as possible or have the intent clearly defined e.g. any interpretation that the contractor makes must be discussed with the designer and agreed to in writing before proceeding, as this document will form a legal contract. Therefore the person who constructs the item to the drafted design for payment must follow the design accurately or they have not completed their end of the contract and are in breach of it.