If people are buying houses, remodelling them and then selling, it is a normal and safe practice. It would be problematic if they had mortgages on the houses and couldn't pay them out, like during 2008. Okay, new flats are cheaper than the old ones. This is weird, but not bubbly, since low prices mean low demand, while bubbles are about very high demand for essentially empty offer. In my country real estate prices are lower now than they used to be about 5 years ago, but well-furnished new flats are obviously more expensive than the old ones.