Building codes vary by locality, and while most routine maintenance items don’t require permits, remodeling changes often do.

You might not know that you need permits for jobs like adding a bedroom, replacing a window or modifying plumbing, or that while your friend in the next town was able to redo her driveway without a permit, your town requires one.

Proceeding without the right permits could result in fines, delays, problems selling your house or even having to redo your project.

To get those permits — and many jobs require several — you’ll have to meet your city’s requirements for safe design and construction.

Even a small bathroom remodel requires permits in San Francisco, where interior designer Katie Anderson is based, and these can’t be obtained without construction drawings, she says.

Unless you are working with a design-build firm, you will need a designer or architect to create those drawings, because contractors do not draft plans.

Doing the work yourself? DIY jobs require permits, too.