The question underneath the work
Everything began with a puzzle worth answering properly: in which districts do builders purchase older houses over and over again away from the marketed route, and how much weight can the record beneath each district bear? The passages below walk through the way that puzzle got tackled.
Material pulled together
For every market, transactions were gathered covering houses dating from 1980 or earlier, noting on each one whether a builder appeared on the buying side and whether fresh construction followed the purchase. Combined, the file reaches across 189 local markets and holds thousands of individual property histories.
How the ranking was decided
Three ingredients were blended rather than read in isolation: the share of older houses in the sample that passed to builders, the depth of material standing underneath that share, and the relationship between what an older house fetched and what a new house on similar ground nearby achieved. A ranking built that way rewards trustworthy evidence, not merely the loudest percentage on the page.
Reasons to stay cautious
Effort was deliberately aimed at older houses in districts builders were already known to favour, so the frequencies surfacing there run hotter than a sweep of a whole ZIP code would produce. Frequencies also describe how buyers behaved in the past. By themselves they cannot price a particular house, which always comes back to sales evidence from its immediate surroundings.
What the study does to a price
Pricing one property borrows the sums a builder runs before bidding: open with results for new houses on comparable ground, then subtract construction expense, the return the scheme must deliver, and the cost of carrying it through. The wider study shows the districts where those sums rest on the deepest footing.
Look at the work itself
The study described on this page reaches the public district by district through the research programme. Sellers who find their district in the programme can also open the city index for its selling guide, and the coverage checker settles in seconds whether a particular ZIP code is being bought in.