In the refurbishment, the exterior insulation dominates, which has the advantage of bringing the walls into the heat-protected area. Long before that, however, internal insulation was more common, walls being built to withstand the rain, after all. Ready-made industrial products for interior insulation already existed in the 19th century. The fact that interior insulation has a bad reputation today is due to typical human simplification.
The actual truth is: We have had very good experiences with interior insulation over many decades. So here we are rolling out some scenarios in which this technique could reduce your energy costs or solve your mold problem.
The text contains a personal component because my house was built in 1979 with a six-centimetre-thick internal insulation, which has since contributed to the remarkably well-preserved structure that led me to the purchase, despite many dowels, conversions and even wall displacements. That’s why I’ve always emphasized in previous building services excursions: The interior insulation is better than its reputation. Of course, such an anecdote first and foremost proves the effect of survivor’s bias, but building practice, studies and experts will confirm that the sentence is true.