Every once in awhile, I work for a client bound and determined to take on a project themselves. I have no issues with someone taking on their own project as I often fall into the category of weekend DIY warrior myself. However, there are times that the benefits of experience far outweigh the cost of not hiring the right help.

Example 1: Plumbing waste lines. It should need no explanation as to why your waste lines in your house, in your walls, under your floors, need to be constructed to last. Yes, it is pretty simple to cut and glue abs pipe together but it also needs to drain. To shallow of a slope on the pipe, you’ll get clogs, to steep is also a problem. Not enough bracing can mean fatigued pipes and joints, a recipe for wet walls, ruined sheetrock, and soggy floors. Needless to say, the cost of repairs can exceed the initial cost of the plumber.

Example 2: Plumbing of gas lines. Does this really need an explanation?

Example 3: Any work that involves climbing up a ladder in which a fall would mean a lengthy stay at the hospital. I don’t spend much time balancing on ladders and from my experience, practice makes perfect. Let the guys/gals with practice do the dangerous stuff.

What do these examples have in common? The benefit to cost ratio is greater than 1. Thank you engineering economics! When the potential benefit is greater than the cost getting the project completed right the first time, then the decision should be an easy one. Now, determining the benefits of each item of work will be different for everyone but the principles of engineering economics can help with the decision of when to hire experience vs. when to DIY.