I don't keep any of the original houses on the lots, the decor and furniture is usually either too dark or too cluttered. I bulldoze them and rebuild. I like houses with no wall hangings/plants/trees/clutter, are that are neutral colours. I don't know why they use dark brown flooring in every house! Its horrible and by the time I've deleted all the stuff I don't like about a house its easier to just bulldoze it and start again.
I have 5 favourite houses that I use that I created myself, one looks like shipping containers stacked in different angles with ladders to each level and a little garden/balcony on each level that's good for my single pet less sims. My favourite is a family home and the layout is perfect for walls half down viewing, nothing getting in the way. I love to build so i dont always use the same houses as I like to try and do challenge myself to build something different each time. Some of the lots have beautiful views so I like to build roof terraces to appreciate the views.