Interest rates are at historical lows in Europe. You can get mortgage rates for as low as 0.9% in some countries! If you are at a higher rate, it might make sense to shop around and refinance.
I recently refinanced my mortgage into a 6 year term, 1.40% fixed interest rate (before deductions!). That’s amazing. Effectively it is a free loan to me, taking into account tax deductions and inflation.
Also, I took out some additional capital from my apartment, to make use of the hot real estate market we’re currently in. I invested that capital right away, hoping to make more than the 1.4% interest (should be easy).