Zombie homes—houses that are sitting empty and uncared for—make up 20% of those in the foreclosure processes, says RealtyTrac.

Read: Housing starts stable

The homes have been abandoned by the previous owner but as they’re not yet owned by the lender no one is taking care of them. As they crumble, they bring down the value of other houses in the neighbourhood.

Worse, cities and towns with high numbers of zombie homes are missing out on revenue, points out Daren Blomquist, vice-president of RealtyTrac. When lenders finally gain custody of the homes, they may be unsalvageable. The lenders have two choices: kill or cure.

For an infographic on those gruesome choices, read more here.

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