Building Codes & Zoning Laws

It’s time to pinch your nose and swallow the medicine. The sooner you get it over with, the sooner you can go out and play. By checking into the building and zoning rules for your area you can avoid the mistake of spending time on elaborate plans only to run into a brick wall of bureaucracy.

When it comes to building codes and treehous-es, the official word is that there is no official word. Many municipalities—the governing powers over building and zoning laws—consider treehouses to be “temporary” structures when they fit within certain size limits, typically about 100-120 square ft. and not more than 10-12 ft. tall. If you have concerns about the restrictiveness of the local laws, keeping your treehouse within their size limits for temporary structures is a good precaution to take.

It’s often likely that city officials consider tree-houses too minor to be concerned with them. On top of that, building codes for earth-bound buildings are based on measurable, predictable factors that engineers use to calculate things like strength requirements. Drafting a set of standards for structures built on living, moving, and infinitely variable foundations (trees) quickly becomes a cat-herding exercise for engineers. Thus, few codes exist that set construction standards for treehouses. This means more responsibility is placed on the builder.

When it comes to zoning laws, the city planning office is concerned less with a treehouse’s construction and more with its impact on your property. They may state that you can’t build anything within 3 ft. or more of your property line (called setback restriction) or that you can’t build a treehouse in your front yard (the Joneses might not be the tree-house type).

The bottom line is this: Your local planning office might require you to get a building permit and pass inspections for your treehouse, or they might not care what you do, provided you keep the building within specific parameters. It’s up to you to learn the rules.

Although city laws are all over the place regarding treehouses, here are a few tips that might help you avoid trouble with your treehouse:

• Talk with your neighbors about your treehouse plans. A show of respect and diplomacy on your partis likely to prevent them from filing a complaintwith the authorities. It also smooths the way forlater when you have to borrow tools for the project.

• Be careful where you place windows (and decks) inyour treehouse. Your neighbors might be a touchuncomfortable if you suddenly have a commandingview of their hot tub or a straight shot into their second-story windows.

• Electricity and, especially, plumbing services running to a treehouse tell the authorities that you planto live there, thus your house crosses a big line from “temporary structure” to “residence” or “dwelling” and becomes subject to all the requirements of thestandard building code.

• Don’t build in a front-yard tree or any place that’seasily viewed from a public road. The point is not tohide from the authorities, it’s that conspicuous tree-houses attract too much attention for the city’s comfort, and the house might annoy your neighbors.

• In addition to keeping the size of your house incheck, pay attention to any height restriction forbackyard structures. Treehouses can easily exceedthese, for obvious reasons, but nevertheless maybe held to the same height limits as sheds,garages, etcetera.

• Even if the local building laws don’t cover tree-houses, you can look to the regular building codefor guidance. It outlines construction standards forthings like railings, floor joist spans, and accommodations for local weather and geologic (earthquake) conditions. With appropriate adaptationsfor the treehouse environment, many of the standards established for ground-houses will work foryour perched palace.