King's Knoll


Heritage Category:
Listed Building
List Entry Number:
Date first listed:
Statutory Address:
Broomheath, Woodbridge, Suffolk, IP12 4DN


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Statutory Address:
Broomheath, Woodbridge, Suffolk, IP12 4DN

The building or site itself may lie within the boundary of more than one authority.

East Suffolk (District Authority)
National Grid Reference:


A house in the International Style, built in 1933 and designed by Hilda Mason as her own residence.

Reasons for Designation

King’s Knoll at Woodbridge in Suffolk, built in 1933 to the designs of Hilda Mason ARIBA as her own dwelling, is listed at Grade II for the following principal reasons:

Architectural and design interest:

* as a well-executed and yet locally unusual example of a house built in the International Style, which despite alterations still retains significant design interest;

* for the use of the natural landscape to such dramatic effect in the building design and plan form.

Historic interest:

* as a building designed by one of the earliest practicing female architects as her own residence.


The early C20 was a time of significant stylistic debates and change. The years of the Belle Epoque were influenced variously by the Arts and Crafts movement and the 'Battle of the Styles', and later superseded by Art Nouveau and Art Deco. Interest in the great ocean liners of the time also influenced the growth in popularity of the international style in the 1920s and 1930s. Throughout these years there were significant tensions between proponents of the different styles. Another inherent theme of the debate was a tension between traditionalist and modernists.

King’s Knoll was designed by Hilda Mason in 1933 as her own residence. It stands on a promontory above the confluence of the Martlesham Creek and the River Deben. From this vantage point, which was integral to the design of the building for its location and orientation, the house overlooks the natural landscape. She lived at King’s Knoll with her unmarried sister Elfrida who outlived her but did not remain in the house beyond 1956. The house was then sold to new owners in 1956. An itemisation of the specification in the 1956 sales particulars, and the identification of the sequence of further changes since then, as far as they can be discerned, has been undertaken by the current owners and contributes to the understanding of the evolution of the building. The original design included a pair of columns on the south elevation which have been removed. Other alterations include the construction of the sun room on the ground floor, and the related blocking up of a large window and double doors from the drawing room, although scars remain on the wall. The drawing room has been extended with a larger bay and the workroom has also been enlarged. The principal bedrooms which are above the dining room and drawing room, also face towards the river tributary and the sloping natural landscape to the south. The bedroom belonging to Hilda Mason has been extended with a larger window; the bedroom of her sister retains its door opening and tubular steel balcony overlooking the formal terrace. A guest suite with bedroom, dressing room and bathroom was added to the northern end of the building in the late C20.

Hilda Mason ARIBA (1879-1955) was a very early female architect to practice in her own right. She was born in Ipswich to Frank Mason, a cement and timber merchant, and Bertha nee Turner. As a practicing architect she worked with a range of materials and initially favoured the Arts and Crafts style. She is also particularly known for her use of concrete. Specifically she worked with Raymond Erith on St Andrew’s Church in Felixstowe which is a pioneering example of the use of reinforced concrete (see National Heritage List for England entry: 1377388). She was both an architect and an artist and exhibited work for the Ipswich Art Club.


A house in the International Style, dating to 1933 and designed by Hilda Mason ARIBA as her own residence.

MATERIALS: the building is rendered brick, some at least in triple terracotta blocks, with a felt covered flat roof. The windows are set in timber frames, with a few metal framed units remaining.

PLAN: the building has a butterfly plan, with a later sun room built in the southern flank, and a later guest annex to the north-west corner. A further single-storey extension has been added to the north-east wing of the building.

DESCRIPTION: the house is two main storeys with a partial third floor in the centre of the building. The entrance is to the north in a diminutive single leaf door below a small canopy which has a later art deco decorative panel above. The sweep of the elevation contains strip windows and other irregular fenestration. There is a large garage to the left. The later extension rises to the right. There is an overhanging eave between the first and second floors. The eave line has been cut back from its original extent by the removal of the integral gutter and replacement with fascia and plastic guttering. One original down pipe survives which drops straight through the soffit. To the far right is the later guest suite which is on the first floor and is not of special interest*.

The south elevation faces towards the river valley. The floors step back between the first and second floor and are delineated by the overhanging eaves of the flat roofs. There is a formal terrace with a pond towards the left. In the centre of the elevation on the ground floor is a fully glazed sun room* which was constructed later and is not of special interest. To the left is a balcony on the first floor with original tubular railings. To the right is a projecting bay window with a replacement single leaf door which is part of the NE extension to the building. There is a further smaller bay window above. There are now enclosed loggias on the second floor with a blocked opening in the centre of the elevation.

INTERIOR: the interior is plainly detailed and unadorned and has been modernised in its decor. The original plan form is discernible throughout although there have been alterations. The drawing room and dining room are the principal rooms on the ground floor and both face towards the river view to the south. The kitchen was formerly three rooms but the partitions have been removed and the fittings are from the late C20. Also on the ground floor is a workroom which has a small brick-lined wine cellar below it, within the later extension. There is a large garage which formerly had a sliding timber door which has been replaced with a metal tilting secure unit; part of the garage has been incorporated into the work room. The original staircase remains and has plain newel posts topped with ball finials. It is unclear if the panels are original or cover balusters. Some original doors remain in situ. There are ten doors on the first floor with the angled corridor reflecting the butterfly plan. The upper-most storey is reached by a very narrow ladder staircase. The upper space is painted brick, including the terracotta triple bricks. It now contains water tanks. The sun rooms are now enclosed. There is a blocked window which looks out to the north.

* Pursuant to s1 (5A) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (‘the Act’), it is declared that these aforementioned features are not of special architectural or historic interest.

This list entry was subject to a minor enhancement on 12 November 2019.


Books and journals
Bettley, J, Pevsner, N, The Buildings of England: Suffolk: East, (2015), 603
Sandon, E (Author), Suffolk House: A Study of Domestic Architecture, (1977), 332-333
Celebrating Women Architects, accessed 30 May 2019 from
King's Knoll, Development Appraisal, 2019, Cowper Griffith


This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

End of official listing

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