LONDON — It has a lot going for it: a two-story house on a leafy cul-de-sac, a short walk from schools, parks and a train station.

And then there’s the downside.

A year after a nerve-agent attack nearly killed a Russian former spy and his daughter, the enormous job of decontaminating his former home in Salisbury, England, is complete, the government announced on Friday.

Hundreds of specialists spent a total of 13,000 hours cleaning up 13 sites in and around Salisbury that had been tainted by the nerve agent, the Department for Environment, Food and Rural Affairs said. The house where Sergei V. Skripal lived, and where he and his daughter, Yulia S. Skripal, were poisoned, was the last to be pronounced decontaminated.

Though Mr. Skripal appears to have been the target of the attack, five people were sickened by exposure to the chemical, including one who died.