Treat any doubling figure as a reasonable guess, never a promise. That said, doubling in 30 years is a fairly modest expectation by historical standards. The long run has generally run hotter than that. One family example: a Southern California house bought in the mid-1970s for roughly forty to fifty thousand dollars sold about twenty years later for around seven hundred thousand, and another bought around the turn of the 2000s is worth close to triple its purchase price in well under thirty years. We'd expect returns to moderate from those blistering rates going forward, which is exactly why doubling in thirty years reads as conservative rather than optimistic. There's also a real reason homeownership tends to build wealth beyond the price itself. Analysis from the Calculated Risk blog on real returns (appreciation above and beyond inflation) shows that owning over a long horizon produces a genuine real return. A big part of the wealth effect is leverage: a home is one of the few assets where a small down payment lets you control the whole thing, and the whole thing then grows a bit faster than inflation over time. As a long-run planning assumption, doubling in thirty years is realistic. As a guarantee for your specific home over your specific window, it doesn't exist. Buy on a long horizon and the odds work with you.