A replacement window must be sized, supported, fastened, insulated, flashed or sealed as appropriate for the opening, and finished according to the product instructions and project scope. The unit should operate smoothly, lock correctly, and have continuous, neat seals.
Get the details in writing
A trustworthy proposal should identify the exact product and installation scope. If a term is important to your decision, ask that it be included in the agreement rather than relying on a verbal statement.