Really: No one, absolutely no one, converts a fireplace to save money! Including the chimney, people easily spend 20K + X on such a thing (not a stove). With that, you could heat for a very, very long time with gas, oil, or electricity. You don’t need it, you want it. Or not. As a Porsche driver you want it – because of the smile on your face after every drive and the tingling in your stomach when accelerating, braking, cornering, and the goosebumps from the sound of the engine; not to save time. On the contrary... you want to sit inside and drive as long as possible... Similar to a pool owner; he doesn’t want to save the entry fees at the public pool, he wants his own pool at home. And just like the fireplace owner, he knows that - monetarily - it will never pay off. It doesn’t have to and shouldn’t! This is about “nice to have.” That a fireplace heated more than four times a year also adds some heat to the house – typically the thing burns exactly when the main heating system has to do most of the work, in winter – is a pleasant side effect. This varies depending on the construction of the house and (fireplace) heating habits. In our last rental apartment, we also had one, which felt like it burned every Saturday and Sunday evening from November to February (no records kept). Madame and I always enjoyed only the beautiful flickering and crackling of the fire and never thought for a second about “saving heating costs.” That’s how it is and there’s no need to start a cost discussion. Whoever wants it, takes it; with or without “savings effect.” By the way, there are people who never light it; it just stands there and looks good. Like a beautiful picture on the wall...