LIVE PROJECT

HALSWELL HOUSE

Grade I Mansion House and Estate, Somerset


for Private Client

“the most important house of its date in the county” Pevsner on Halswell

This Grade I Listed property is fronted by a 1689 Mansion House, built by Sir Halswell Tynte, behind which sits a series of earlier phases of construction, thought to date from 1536. The buildings and surrounding landscape form a property of significant size and immense architectural interest. Our work is as Architects and Lead Consultant, working with a diverse team of specialists, supporting the client and contractors on site on this extensive and fascinating restoration project.

The property has been used for a variety of purposes under previous ownerships, including a private home, PoW Camp, school, wedding venue and a series of apartments. However, in 1999 Halswell was considered in such a state of disrepair that English Heritage (now Historic England) listed it on the Buildings at Risk Register. The buildings’ fortunes improved with a partial restoration by the previous owner, but the property was finally left vacant in 2013 with water penetrating the structure and with its C18th Landscape and many associated outbuildings in different ownership.

Working closely with Corbel Conservation and the owner, Thread’s work was initially focused on opening up works which were needed to assess the condition and extent of repairs required – prior to progressing the significant repair and restoration. Due to the special interest of the property, all works are being undertaken in close consultation with Historic England, Somerset County Archaeologists, local and County Conservation Officers, Structural Engineers and Archaeologists.

In tandem with the opening up and investigation works, works to secure the envelope of the building were undertaken to prevent further deterioration. The complete re-roofing of the Tudor Range was completed in July 2016. This work was completed under licence from Natural England and with constant collaboration with our ecologist and the ever-vigilant Paul Carpenter Associates as Structural Engineers – and a little help from the local bee-keeper. The structural repairs, whole roof ventilation strategy and insulation proposals, were all subject to the usual permissions required for a building of this caliber and were designed to respond to the many different scenarios around the house, including areas of completely modern roof structure, historic C16th trusses, modern plasterboard, historic reed and also lath and plaster ceilings. There were also issues of flashing, structural repair and stabilisation of the gables and tying together the roof structure and external masonry walls.

Another early element of work was to address the rampant dry rot, which had been enjoying the damp and warm internal environment – due largely to areas of failing flashings, incomplete work by the previous owners and poor detailing. Although significant in area, this work was completed without the loss of any historic fabric and with chemicals and processes approved for areas in close contact with wildlife.

The next phase of work was to focus on the repair and consolidation of the external walls to the southern ranges; including the removal of C20th chimney stacks and cement pointing, stone repairs, replacement render, restoration of windows, replacement of decorative lead gutters and bespoke hand-carved stone finials. Great attention to detail was given to every aspect of the work to ensure the most sympathetic results including mortar pointing and render trials which were conducted on site to assess the most appropriate mix, texture and application. Included within these samples were hot lime mixes and designed mortars to replicate the presence of lump lime in bedding mortar.

Claire is also working with Bath University on a project to investigate the possibilities of using lump lime in the original areas of mortar for carbon dating. This is an experimental procedure and samples for dating are being processed by Dr. Giovanni Pesce in a laboratory in Italy. The South and West Elevations were completed and scaffolding taken down to reveal this work in November 2017.

The next phase of work, to be undertaken in 2018, is focussed on Knot House, a building to the rear of the mansion house, and the associated Knot Garden within the southern courtyard. Works to Knot House include external repairs to the masonry walls; replacement of C20th steel windows with hand-carved stone mullion windows and leaded lights; and the complete reinstatement of a habitable interior. The proposed removal of unsympathetic C20th alterations and reinstatement of an interior sympathetic to its C17th origins, includes a limecrete ground floor (incorporating underfloor heating) and the reinstatement of the C18th Ornamental Dairy (which will also conceal a functioning kitchen). Every detail is being considered to ensure the integrity of the reinstatement, including the careful re-appropriation of historical joinery and finishes details discovered in other parts of the property. To ensure the comfortable and sustainable use of the building into the future, new services throughout will include air-source hot water and underfloor heating throughout, upgrading of thermal elements using limecrete, hemp lime renders and plasters, and insulating wood wool boards and lime plaster finishes.

Corbel Conservation, The Halswell Park Trust and Thread conduct tours and visits to the property by interested parties. Visitors so far include Bath University, U3A, Civic Societies, Garden Groups, Preservation trusts, the Local Conservation Officers Group, and members of the community.

For more information on this project please refer to the owner’s blog for regular updates – https://halswellpark.wordpress.com