Going straight from basic engineering to construction without going through detailed engineering is, in the world of industrial projects, what we would call “a blind leap into the void.”

Although it may seem like you are saving time and money at first, the reality is that detailed engineering is the precise “instruction manual.” Without it, the risks are extremely high.

Here I explain the consequences of taking this shortcut:

1. Cost uncertainty (the budget skyrockets)

In basic engineering, budgets usually have a margin of error of between 15% and 25%.

Without detail: You don’t have an accurate bill of materials (MTO – Material Take Off). You will buy too much (waste) or too little (delays due to shortages).

Contracts: It is impossible to make a serious “lump sum” bid for the work because the builder does not know exactly what he is going to install.

2. Interference errors

This is the nightmare of the construction site. Detailed engineering uses 3D models to ensure that a pipe does not collide with a beam or that an ammonia pipe does not block an electrical tray.

Consequence: Errors are discovered during construction. Cutting steel or demolishing concrete to correct a design error costs 10 times more than correcting it on a drawing.

3. Safety and Compliance Risks

Basic engineering defines what is to be done, but detailed engineering defines how it is supported and protected.

Structural failures: Without detailed welding drawings or specific support calculations, the physical integrity of the plant is at risk.

Permits: Many regulatory agencies will not grant operating or construction permits without detailed drawings signed by specialists.

And if you want to do an EPC (Engineering, Procurement, and Construction) where the contractor assumes all the risk, even then, the contractor will do the detailed engineering internally before laying the first brick. Extremely detailed Front End Engineering Design is still required.

Rule of thumb: What you don’t spend on engineering, you pay five times over in “change orders” during construction.

Are you evaluating a specific project where they want to make this cut? I could help you identify which areas are most critical if they decide to move forward with this.