It happens that it is inaccessible to defend your building from cold from the outside, so carrying it out on the inside is the only way to go. Such work executed from the inside, however, is more tricky than usual external solution.
There are numerous factors that can make it problematic.
Specialists believe that insulating surfaces internally is less constructive than doing it externally. However, there are occasions when it may only be done internally. Insulation from the inside is rarely used since it implies various problems. It is more difficult and hazardous than the insulating of the house from the outside, known for decades, so conclusions were drawn from the mistakes made and some solutions were recommended that exclude many of them. The biggest issue in a house insulated internally is that after such a procedure its constitution (external walls, ceilings) is placed in the unprotected zone. While there is no insulation, the whole wall has a significantly higher temperature (to our detriment, due to the high heating expenses) and just a little external fragment is below 0 ° C. After implementing the insulation from the inside, the temperature below 0 ° C will apply to the greater thickness of the surface, since the heat will stop running through it. This makes the wall relevantly colder and more susceptible to low temperatures.
Providing insulation from the inside, the surfaces must primarily be preserved from humidity. The infiltration of water vapor coming from inside the building into the center of the barrier is prevented by vapor barrier with a properly selected diffusion resistance coefficient.