You will not be able to sell a home without one. Replacement windows installed after April 1, 2002, necessitate either a FENSA certificate or a building regulations certificate to prove they adhere to local ordinances.
It is possible to install your windows if you are naturally handy, have expertise with similar home renovation jobs, or know how to install a new window. One drawback is that it can be time-consuming, particularly if several windows need to be installed. Hiring a professional window fitter for safe, durable, and efficient installation is better.
Most experts think replacing as many windows as possible at once is the best use of a customer's money. If your home's windows are older than 20 years and are beginning to exhibit wear, it's time to start saving up for a replacement.