Land surveys don’t technically expire. They do serve as a point of reference and a snapshot of your property, though, so as soon as you make changes to your property (and even if your neighbor makes certain changes to theirs), your existing land survey becomes inaccurate, and a new one must be done. Even if you don’t make any changes to your property, many states only guarantee the accuracy of a land survey for five to ten years.

A land survey includes the layout of a single property, including precise measurements and to-scale drawings of boundary lines, land improvements, and sometimes other features, like topography and drainage information. A plat map includes the layouts and boundary lines of several adjacent plots and basic structure measurements. Surveys are normally more valuable for homeowners and buyers, and plat maps are for governmental use.

With proper training and experience, reading blueprints is fairly straightforward and not very difficult. If you don’t have the necessary knowledge to interpret the symbols, abbreviations, and other notations used, blueprints may not make sense. Learning to read blueprints can help you understand the construction process and keep you more involved and informed when you’re building a house.

Soil testers and licensed excavators are often the professionals you hire if you need a perc test. In some cases, structural engineers will also be able to conduct the test for you. In many municipalities, you’ll need your professional on-site to dig and fill the holes with water, as well as a representative from your local building department or health department. That representative is the individual who will determine whether your test passes or fails.