My wife loves her some HGTV. Home & Garden TV makes home makeovers, renovations and purchasing look easier than putting up a shelf in the garage.
As an engineer, I’m used to putting cost opinions for large construction projects together. It would be considered foolish to not include a contingency in your cost opinion: you may start off with a 30-40% contingency during preliminary design and reduce it to 10-15% when design is complete.
The contingency accounts for the unknowns. It’s not a safety net if something goes wrong; it’s a fund to cover the things that will come up that aren’t specifically accounted for in the design.
That’s why HGTV drives me crazy. Every time they have a renovation project, they plan to spend every penny (or more) on the project without leaving any money in the contingency. Then when the inevitable unknown comes up, like bad electrical wiring throughout the house, they’re forced to either go over budget or to cut something from the project.
Going into a sizable project without a contingency is irresponsible. And I’d go so far as to say that this should apply to web development projects as well. Not everything will go to plan and it’s not fair to blame it on the developer and expect him to correct it at his own expense.
Whether you’re flipping a house or building a web application, be responsible and set aside a contingency.