In the first quarter of 2023, San Carlos had one of the smallest quarterly average sold house sizes in years. The August 18 trends show the largest-ever quarterly average house size. This appears to go beyond variations/volatility in averages because eight San Mateo County cities also posted their largest-ever quarterly sold house sizes, with rapid spikes upwards.

San Mateo County’s quarterly average house size also shows a sharp increase in house size.

The eight San Mateo County cities showing sharp increases in house size are Foster City, Menlo Park, Millbrae, Pacifica, Portola Valley, San Carlos, San Mateo, and Woodside. Additionally, Palo Alto, which is on the border of San Mateo County, shows a sharp increase in house size.

With no known economic or employer changes, it is hard to see a reason for the change. Perhaps homeowners who are no longer motivated by children (old enough not to be at home) or by future jobs (approaching retirement) have decided they will use the advantage that few houses for sale and move away from the negative news surrounding San Francisco.