Conn. Gen. Stat. § 8-3
Governs how municipalities adopt, change, or repeal zoning regulations and district boundaries—requiring a public hearing, filing a copy of the proposed regulation or boundary for public inspection at least ten days before the hearing, the commission's consideration of (and recorded findings on consistency with) the plan of conservation and development, and a two-thirds vote of all commission members where a qualifying protest petition is filed (by owners of 20% or more of the affected area or of lots within 500 feet). It also authorizes zoning regulations to require site plans to determine conformity with the regulations; site plan applications are processed and decided within the time limits of section 8-7d (approval presumed if no timely denial or modification), and a site plan may be denied or modified only for failure to comply with the zoning or inland wetlands regulations. Approved residential site plans are protected from later zoning changes, and—as the default rule—all work must generally be completed within five years of approval (subject to statutory extensions and longer periods for large or specially situated projects), with a separate zoning district authorized for shorefront water-dependent uses.
Pin a building and we'll surface every amendment, effective-date change, and filing deadline as it happens.