Connecticut municipalities are not required to have historic districts, but if they do, they must have at least one historic district commission. Weston's one commission covers five districts, including Historic District No. 1 (depicted above), usually referred to as the Norfield District, which includes Town Hall, the police department and Firehouse No. 1, the Weston Public Library, Norfield Congregational Church, and other properties.
The HDC's duties, limitations, and legal authority are spelled out in State law. In general, the commission is responsible for preserving and protecting historically and architecturally significant resources in historic districts. The State is exempt from HDC review, but except for matters pertaining to street improvements, towns are not.
For new buildings to be constructed in an historic district, or existing ones demolished, or alterations made to the exteriors of buildings, an application must be submitted to the HDC for a Certificate of Appropriateness, assuming the building is visible from "a public way."
The commission has no say about anything interior, or about the color of paint, or about vegetation. But it does have authority over exterior "fixed structures," which include windows, doors, shutters, signs, some parking areas, fences, walls, driveways, walkways, exterior lighting, and extremely heavy objects, such as statues, that are functionally "fixed" by virtue of gravity and weight.
The HDC cannot deny an application simply because they do not like it, would prefer it be somewhere else, or for any other arbitrary reason. Nothing about the statute implies that historic districts are meant to be frozen in time, encased in amber. The statute does not require the use of historical techniques or materials, and does not require adherence to a particular architectural period or style.
So long as members determine that whatever is to be built is "not incongruous" with the character of the historic district — essentially meaning it would not be wildly out of place — they must issue a certificate.
If a commission denies an application, it must provide a detailed explanation of why, and the specific criteria that were applied. Commissions are free, even encouraged, to recommend improvements to the application.