Cox and Yeman
Standen House and Garden, West Sussex (Accredited Museum)
Ightham Mote, Kent (Accredited Museum)
Kingston Lacy Estate, Dorset (Accredited Museum)
Canons Ashby, Northamptonshire (Accredited Museum)
Clarke
Knole, Kent (Accredited Museum)
Penrhyn Castle, Gwynedd (Accredited Museum)
Felbrigg, Norfolk (Accredited Museum)
Tyntesfield, North Somerset
Castle Drogo, Devon (Accredited Museum)
Polesden Lacey, Surrey (Accredited Museum)
Powis Castle and Garden, Powys (Accredited Museum)
The Argory, County Armagh (Accredited Museum)
Dunham Massey, Cheshire (Accredited Museum)
Knightshayes Court, Devon (Accredited Museum)
Stevens and Sons
Shugborough Estate, Staffordshire
Ickworth, Suffolk (Accredited Museum)
Burroughes and Watts Ltd
Cragside, Northumberland (Accredited Museum)
