From $0 to . . . . Infinite
At least in frigid Minnesota, an in-ground pool can be a waste of a perfectly good backyard 8-9 months of the year.
Unless, of course, the backyard happens to sit on a third or half-acre, in which case there’s plenty of room left over for swingsets, playing ball, etc.
Even when that’s the case, though, backyard pools at this latitude are likely a net negative for home values.
I attribute that to two other issues: 1) safety concerns, particularly for families with small children; and 2) the associated maintenance headache and expense.
So, how much do you discount for a pool?
It all depends on the Buyer.
I’ve worked with some clients who simply won’t consider a home with a backyard pool; I suppose for those Buyers, the discount would technically be infinite.
At the other extreme, some Buyers seek out a home with a pool.
But they’re a definite minority.
Net everything out, and I’d estimate the average pool discount is about $25,000 — or a little more than it would likely cost to fill it in.
P.S.: The other discount question besides “how much?” is “when?”
At least in Minnesota, you’d guess that that $25,000 gets bigger in October and shrinks in April.