My suggestion would be to have a bed tool/object in the house. The owner could use it twice per game day, once to "sleep" and get a full recharge of mood & energy, and once for "nap" and get 1/2 energy and full mood. Everyone loves a nap, hence the full mood. :)
I'm not much for the "Home Sweet Home" idea as it is pretty much an easy way to stay topped off while you do tasks in your backyard or other projects that you need done.
I much prefer the idea that @Kungaloosh suggested that you need to spend some time, perhaps a minute or two, sleeping in a bed to gain full energy and mood.
I like the bed idea for recharging, but not a full recharge - not more than half the way from your level of depletion to your max energy. (yes, you could sleep over and over to get more energy, but after a while, that wouldn't really pay off, would it?) I also like the idea that activities done in your home take less energy than they would out in the wild world.
For more "realistic" gameplay I would say we should get furniture to rest and recover energy, furnishings (say art pieces to "admire") to get mood. This should be an "over time" thing. But there shouldn't be any difference when it comes to energy consumption. Why would it take less energy to make butter at home vs outside?
I use my house to cook recipes, repair tools, and do other admin stuff that does and should use energy and give xp. I'm totally fine with that.
However, I totally agree with those who suggest that energy should not continue to deplete if I'm just standing around (or laying around, I would love to interact with furniture in homes). My real-life sweetie has a house next door and sometimes one of us waits around in our house while the other does some cooking, gardening, etc. before we head out together. It would be nice not to have to log out of the game for the five or so minutes that usually takes.
Love this idea. AFK at home should not result in any ill consequences. Extra benefits to being at home would be awesome, like a slower energy loss for performing actions (where outside the house you would take full energy hit for doing them, maybe take a point or two less at home).