Decorative windows and doors are a great addition to any home or apartment. Windows are there to let light in and doors are there for security. Security is a very important factor in this regard. A door could look good, but it also had to be strong enough that someone like a thief couldn't break through it. The same goes for windows.
Many people get alarm systems for their homes. When the alarm goes off and someone opens a window or door on the first floor, the alarm goes off and a message is usually sent to the police. You can consider the windows and doors installation services to replace old windows and doors at your home.
From a technical point of view, whoever lives in the apartment has the added security of two doors. There will be a main door to the building and then a door to the actual apartment. Many people prefer this because it gives them peace of mind that they are safe. Those who live on the ground floor usually have windows equipped with extra security measures to ensure that people cannot cross.
Many people will also insulate their homes to keep out the heat. This is especially true in countries where it can be very cold in winter. To reduce gas and electricity costs, homeowners will install secondary glass windows. For those living in older homes, this is usually a worthwhile investment.
Keep in mind that nothing lasts forever and you may have to replace windows and doors every few years. Although some people think that they have experience with this, it is usually a good idea to use a contractor. There are companies everywhere that offer such services, sometimes at discounted prices.