Again, Ove makes decisions (and is deterred from committing suicide) by thinking about what Sonja would want. The fact that Sonja would've liked having a houseguest makes the idea of opening his home up to community far more palatable for Ove. Notice too that houses symbolize fairness and offer to their residents what the residents put into them. Ove is beginning to put people and community into his house, and he'll get the same in return.