Built to house three teams of horses and store winter hay, the "Big Barn" replaced a similar building that burned in 1902 and was completed in 1904. The Lords constructed it with high-quality materials and technological improvements, including a hay-wagon floor scale to track the harvest, a chute that delivered oats from a second-floor storage bin to the stalls, an electric hoist to lift hay to the storage area above, and plumbing to refill each horse's water bowl. Horses served farm work, pleasure, and transportation; when George Clement Lord II took the train to Boston, he rode a mile on horseback or by carriage to Elms Station, told his horses to go home, and they returned to the barn. Farmers also used the barn's weathervane, along with their knowledge of cloud forms, to predict the weather, since hay stored too wet could mold or even ignite and fields needed to be dry when cut. The barn had nine single horse stalls, three large box stalls for horses or cows giving birth, a basement water tank with a capacity of 1,600 gallons, a hay-wagon scale that measured up to six tons, and a main floor 100 feet long and 47 feet wide. A draft horse ate 40 pounds of hay daily in winter, the barn was last used for livestock in 1970, and the weathervane on top today is a replica while the original is displayed in the Visitor Center.