Renovation is an important point, especially if you live in Kanton Zurich like I do. You have to replace oil based heating systems. Mine is more than 20 years old, always maintained, 98+something percent efficiency, 30+months with one tank of oil. So, if it breaks down I am probably allowed to fix it but not to replace it with a new one. If I want to sell or rent out the house I have to replace it with another system.
Tax deduction will have some influence on my decision, spend a lot of time and money on bureaucracy (permits) and a suboptimal heating system or sell the house. If I sell my house, it will be teared down and some blocks will be constructed.