Remodeling always costs more than you initially expect, especially if you’re not familiar with all the things that might go wrong.

Consulting with a professional before starting work will help you plan for contingencies and account for unexpected items like rewiring a kitchen that’s not up to code.

Older homes and larger jobs are more likely to have hidden expenses, as are projects involving plumbing, electrical or other work that is hidden behind existing walls or infrastructure. There could be mold, leaks, corroded pipes, termite damage, fire hazards or asbestos.

Even the best contractor won’t always be able to identify these potential problems before work begins, so don’t assume the contract’s cost is what you’re going to pay.

Expect to spend 10% to 15% beyond that amount. If you can’t afford the higher, more realistic price, scale back the work, downgrade the materials or keep saving.

Any changes to the job once it’s underway should be added to your written contract and described in the same detail as the original work.