During the construction of the house, it was never assumed that the residents would once connect the balcony with the living room, thus increasing their living area. After all, as a rule, the area of apartments received in Soviet times was always too small. But to start work, you first need to calculate whether the base of the balcony will withstand. And agree on your actions with the authorities. So that in the room after unification with the balcony it is comfortable, the balcony should be insulated. Insulation requires the entire space of the balcony, not just the walls. There is a variety of thermal insulation materials with different characteristics of insulation. Mandatory use of sealants for sealing cracks and seams. In addition, there should be a warm floor on the balcony without fail. Otherwise, it will be possible to use additional area only in the summer.
It can be done with heated, after conducting hot water or laying the heating cable. But if the old radiator batteries with new ones on the balcony cannot be replaced by the furniture while furniture is carried out. The balcony also needs to glaze. Installation of a three -chamber PVC package is one of the best options for warm glazing. There are a lot of wall demolition options, but the best in this case is when an increase in the window opening and the installation of the table is made instead of the windowsill. If there is a difference of floors between a room and a balcony, you can build a step. And you can use the newly acquired area at the discretion, for example, build a recreation corner or install a small bed. It all depends on what size the balcony.