When Voysey designed Prior’s Field, originally called Prior’s Garth, he was considered at the pinnacle of his career. His work was a source of Art Nouveau inspiration, but his strength was in designing well-built homes of a simple and austere style. Voysey also designed the door handles, keys and keyholes, fireplaces and hinges. The air vents with their motifs of birds and trees, which appeared in many of his houses, can still be seen in the school today in the Oak hall, the senior common room, and bursary offices. One of his most distinctive features was the Oak Hall with its fine staircase, which remains the heart of the school.

The additions to the original house – formerly known as Private Side – were designed by Voysey’s pupil, Tom Muntzer, the work being completed after Tom’s death by his father, Frederick. The garden was laid out in a Gertrude Jekyll inspired design and featured herbaceous borders, dry Bargate stone walls, a dipping pond and rock garden. Both Julia and her husband were keen gardeners and Leonard brought many of the plants back from his trips abroad with his sons. In the early years, the care of the gardens was in the hands of lady gardeners, who trained at Swanley Horticultural College.