The line between needing a construction permit and not needing one can sometimes be pretty blurry. If you neglect to do your research you can find yourself in sticky situation should the authorities find out or when it comes time to sell your home. Even the smallest of remodels require permits as well as things that have nothing to do with building like removal of large trees.
Make sure you cover yourself and do the proper research before engaging in any sort of construction project. More details for the city of Tacoma permit requirements can be found here:
http://www.cityoftacoma.org/Page.aspx?nid=153
And if you aren’t in the city of Tacoma just go to your city or counties web page and do a quick search for “building permits” or give them a call.