Modular building construction plans must include the following drawings and information. Use this checklist to be sure your plans are complete.Modular house construction plans must include the following drawings and information. The plans submitted with the permit must be neatly drawn and drawn to a usable scale. One-quarter inch to one foot is a common scale for building plans. Our Basic Plot Plan (also known as site plan) will give you the basics of your property. We will use GIS and Satellite imagery to create the draft site plan. This page provides an overview of Washington State building codes, including examples of city and county building codes, building permits and permit processes. In Washington, the dimensions of your lot often dictate the type of septic system you're permitted to install. This page provides an overview of local planning and development permit review in Washington State, including examples of permit review procedures.