Plum ProExteriors

The Wellesley Building Department does not require a permit for a like-for-like window sash replacement in the same rough opening. Any opening-size change, egress conversion, or window-to-door conversion requires a building permit. The Hunnewell Estates historic district carries strict review for all exterior changes including window sash profile, grille pattern, and entry-door style — the Wellesley Historical Commission reviews these and typically requires matched-profile wood or clad-wood units rather than vinyl. Most of Wellesley's housing predates 1978, putting the majority of jobs under federal RRP lead-paint rules; expect a $50–$150 per opening lead-safe surcharge.

Wellesley window pricing is the highest in the metro outside Beacon Hill and Back Bay, driven by project size, premium product specifications, and the demand for matched historic profiles. Expect roughly $700–$1,400 per opening installed for a quality vinyl double-hung (used on a minority of homes here), $1,500–$3,500 per opening for wood or clad-wood (Andersen 400, Marvin Elevate, Pella Reserve, Marvin Signature), and $3,000–$8,000+ for an entry door with sidelights and transom in mahogany or premium fiberglass. Whole-house projects routinely run $40K–$120K.

Massachusetts requires a written contract and a Home Improvement Contractor registration for most residential window & door installation work; ask for the registration number and check it before paying a deposit.

More on permits, costs, rebates and common questions, plus every other window & door installation contractor serving the town, on the Windows & Doors in Wellesley page.