Mortgages with low interest rates are also one of the (main) reasons houses are so "expensive" in the first place.
The cheaper money (credit) is, the "higher" the prices will go.
It's not so much that houses became expensive, it's more that money to buy a house (specifically mortgages) became relatively cheaper. Low interest rates did that.
I don't know about this - when I see quotes on build cost in my area they add up to more than similar properties sell for in some cases, and generally aren't a whole lot different than buying to the point that I've wondered why it's like that.
This is a one-time effect, though. Or at least, an effect that only changes periodically (and should reverse) when interest rates change. 30-year mortgages have been standard in the US for most of my life, and houses have gotten a lot more expensive during that time.
The effect may pause when interest rates change, but it's unlikely to reverse significantly. People who have homes now aren't going to want to sell for less than they paid for them, so there's a lot of inertia against prices going down.
Home prices have doubled in most areas since 2009 (and worse in many areas.) when people complain about prices in 2025, this is what they’re talking about. This is not driven by the novel existence of 30-year mortgages and interest rates are at a near-term high.
Median home prices aren’t very interesting because most of the increase is limited to specific competitive areas, and median US home prices hides that effect. I’m sure houses in deeply rural areas haven’t gotten much more expensive, but it isn’t relevant to me.
Well over half of Americans are living in Urban areas so median here is a measure of urban home prices.
Further average home prices reflects overall economic gains. The top 10%, 1%, 0.1%, etc getting richer buy nicer stuff driving up the average but that says little about overall affordability.
House size, build "quality" (the details in the house), resource scarcity, and zoning policy are the drivers of cost. Cheap credit and lifetime loans allow the system to continue.
Every time a municipality levies a requirement upon new development the price of everything that could be used the same way goes up by that amount since it's the "next best thing". I got told I need to spend $20-50k on engineered assessments and plans to clear an old farm field that was left to grown over for 30yr and is now considered "forest" by (a single unelected employee of) the municipality.
Game out the economic implications of that sort of regulatory behavior across the entire real estate and housing sectors and suddenly a lot of stuff that makes no sense makes a lot more sense.
The cheaper money (credit) is, the "higher" the prices will go.
It's not so much that houses became expensive, it's more that money to buy a house (specifically mortgages) became relatively cheaper. Low interest rates did that.