In Genesis 8:21, this signifies that worship from charity and the faith of charity pleased the Lord. (Arcana Coelestia 924-925)

In Exodus 15:25, this signifies that truths became enjoyable. (Arcana Coelestia 8356)

'Sweet' signifies delightful things from the good of truth and the truth of good. Everything sweet in the natural world corresponds to delightful and pleasant things in the spiritual world.

(Referenties: Apocalypse Explained 618)

A "house" is essentially a container -- for a person, a family, several families or even a large group with shared interests (think of the term "houses of worship.") In the Bible, a "house" is also a container, but for spiritual things rather than natural things. In various uses a "house" can represent part of the mind, the whole mind, a whole person or even a church. The other nuance to the word "house" is that it is generally used in regards to our affections and desires rather than our thoughts and principles. This makes sense; we tend to engage our thoughts and rationality when we are out in the world doing our work, but when we are inside our houses we are driven most by love for our families and the desire to be good to those we love. So "house" tends to represent the things we want and care about -- which are ultimately the things that define us.