Between 1998 and 1999 a renovation that was "one of the most extensive changes in the homestead's history" set out to "restore the grounds around the house to exactly the way it was when Priestley lived" there. This involved reconstructing exact replicas of the original carriage barn, hog sties, horse stalls, gardens, fences, and even the privy. These structures were based on T. Lambourne's drawings of the house and grounds that had been discovered in 1983, other records, and excavations. Priestley left no written description of his laboratory, but much is known of his experiments and late-18th-century laboratories. Extensive research on the laboratory within the house was completed in 1996, including excavations that revealed two underground ovens, as well as evidence of a primitive fume hood. The 1998 renovations also included work to restore the laboratory to a condition as close to its original state as possible.