Here they are defined:

Perc is shorthand for Percolation Test. Before you buy your lot or start building on land you already own, a licensed surveyor will dig several post-size holes, pour water into them and make sure they drain or percolate fast enough to meet requirements for a dry foundation and trouble-free sanitary system.

Prequalify, short for prequalify for financing, is a commitment from your mortgage company or bank for a permanent mortgage and construction loan. This is based on income and asset information you provide in confidence. It lets you know how much you can comfortably budget for your home and what your monthly payments will be. Doing this at the very outset enables you to focus your attention on house plans within your price-range.

Permit indicates your building permit. Once your engineered home plans are in hand and you know exactly where your house is going to be built on the site, you or your general contractor will take them to the municipal building department for review and building permits. The building inspector will review the plans to make sure they meet local zoning and engineering standards for snow loads and the like. From time-to-time the inspector may visit the site to make sure all the plumbing, wiring, heating and construction are done safely.

Purlin. There are two traditional ways to support the roof of a house. One is with rafters, which are sturdy boards 16" on center, from the wall to the highest part of the roof or "ridge pole" The other is with Purlins that run the long way. Purlins are chunkier, further apart, usually remain exposed and greatly enhance the beauty and character of your log home.