The Orangery at Knole, Sevenoaks

Oxford Archaeology have been commissioned by The National Trust to undertake a programme of building recording and archaeological investigation on the Orangery at Knole House in Sevenoaks. Knole is among the great English country houses and it has grown in a series of phases largely from the mid 15th to the 18th centuries.
The current investigation centred on Green Court which was established in the late 15th or early 16th century and in particular the southern range, which was probably added in the early 17th century to enclose or enlarge the court. The most likely use of such a range would be as lodgings but considerable doubt on this is cast by the fact that historical views show the range without chimney stacks.
The original internal form of the building and evidence of its primary use have been substantially lost by secondary changes. The main phase of alterations were undertaken in
1823 when the building was converted to a 'new orange house' but documentary evidence suggests that there was at least on other phase of alterations, possibly in the mid 18th century. At the end of the 18th century the building was called the 'old green house' and it may be that the structure had been converted in the 18th century to a garden building for growing or protecting vulnerable fruits and plants. Known secondary alterations include the
removal of a first floor (either in 1823 or potentially earlier) and the rebuilding of the south wall in 1823 with tall Gothic windows appropriate for an orangery. Other works included raising the ground level inside the building and covering the internal walls with plaster.
The building would presumably originally have had a staircase, doors, partitions and possibly a chimney stack but the evidence of these have either been removed or obscured by the internal plaster. The attic floor remained in use as part of the private houses of the manor.
Some metres to the north of the building, in the southern lawn of Green Court, a parch mark can be seen when the weather is dry. This mark is believed to extend between a vertical scar in the eastern wall of Green Court's western range and the north-west corner of Kings Tower. The current project included a programme of trial trenching in the area immediately north of the Orangery to investigate this parch mark and this has revealed apparent evidence of the foundations for a wall across the southern part of Green Court. This may have been a former curtain wall enclosing the court rather than a previous building.
Although the exact alignment of the former wall could not be established evidence points to the possibility that it is not quite parallel with the north wall of the orangery and instead is aligned with (at right angles to) very early surviving remains in the east range which predate
Archbishop Bourchier's Palace. The evidence is too tentative to firmly link the dates of these two areas but it raises interesting possibilities and areas for potential further investigation.
Two small test pits were also opened within the Orangery adjacent to the central doorway in the north wall. These two trenches each revealed aligned footings from a former brick wall.
This wall would almost certainly have been a partition subdividing the primary building and it is directly beneath a joist visible within the ceiling. These footings only survive below the primary ground floor level (c.65 cm below the current floor level) which was raised in the
19th century when the building was converted to an Orangery.
In addition to the specific information revealed in the trenches the current work has also provided a fuller record of the Orangery building and it has identified features relating to its original form. These include evidence suggesting that the eastern part of the north elevation
is older than the rest of this wall. However the work has not greatly enhanced understanding of the building's original form because the internal walls, which must hold
evidence of the previous layout, remain plastered.