The Glebe House was previously the Southill Estate Office but is now a private house. It was listed by the former Department of Environment in 1952 as Grade II, of special interest. The department considered it to be a late 18th century building, though perhaps encasing an earlier structure. It is mainly built of red brick with clay tile roofs, later additions being in mottled yellow brick. The main block has two storeys with a lower two storey block projecting to the rear. The later, 19th century, additions are on both gable ends and to the rear.

In 1927 Southill was valued under the Rating Valuation Act 1925; every piece of land and building in the country was assessed to determine the rates to be paid on it. The valuer visiting Glebe House [DV1/R47/24] noted that it was owned by the Whitbread Estate and occupied by Samuel Gilbert Isitt, the Estate's Agent. The property comprised a hall; General Estate Office and strong room; private office; drawing room ("poor"); dining room; kitchen, scullery and larder, coal shed and stoke hole. On the first floor were three bedrooms, a sitting room, bathroom, wc and two maids' bedrooms. Outside was a garage for one car, a barn and earth closet as well as the garden. The house had mains water and electric light and the valuer noted: "Mr.Isitt has the flat over his offices".