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Scheduled Ancient Monuments

Scheduled Ancient Monuments are buidings or structures which are classified by the 

oldest form of heritage protection dating back to the 1882 Ancient Monuments Protection Act, when a 'Schedule' (hence ‘scheduling’) of almost exclusively prehistoric monuments deserving of state protection was first compiled.

Scheduling applies to sites of national importance, whilst listing is a more recent classification, and can be applied to structures which are only significant locally. Listed buildings have to currently exist in a state similar to their original form. They cannot be completely ruined, or invisible. Scheduled monuments, can however be total ruins, and may even be remains below ground.

Some structures are both Scheduled Monuments and Listed Buildings. Typically, these tend to be intact (or mostly intact) early religious or military structures, such as churches and castles.

The significance and diversity means adoption of pure conservation techniques and can take many forms.

Owlsworth Conservation have worked on some of the most important scheduled ancient monuments in the country. The diversity of the work means each project is approached in a unique way, varying from pure conservation to honest reinstatement.  

Tower of London

West Wycombe Mausoleum

Arborfield Garrison

West wycombe Mausoleum
Arborfield Garrison
Tower of London

The White Tower, built by William the Conqueror and dating from around 1077, is one of Europe’s most important monuments of the period. Its south entrance is raised about 6.4m above ground level and was probably originally accessed by a wooden staircase parallel to the wall as it is today.

Having been unused for 300 years, the south door was returned to service with the building of the previous wooden staircase in 1973. After 40 years, its condition seriously deteriorated, leading to the intial project inception. The design brief from Historic Royal Palaces (HRP) required the new stairs to be built on the same footprint, reusing the old footings and to be as historically authentic a design as possible, to reflect the Norman architecture of the tower itself.

The project was a significant undertaking where everything was considered from trying to remain true to Norman carpentry techniques where possible whilst incorporating a modular construction to allow any future repairs to be undertaken easily. The oak for the project was selected from Mapledurham and Hardwick Estates, Oxfordshire, only a short distance from the yard where it was hewn and framed traditionally.

The project and its story really is quite remarkable with more information available here.

Owlsworth Conservation have a long history of working in the historic village of West Wycombe, having undertaken many projects including West Wycombe Park House, and multiple listed building within the village for the National Trust. Perhaps, however, the most interesting is the extensive works undertaken to the Dashwood Mausoleum.

The imposing Dashwood Mausoleum stands on top of West Wycombe Hill next to the Church of St Lawrence. Owlsworth Conservation were commissioned to undertake a thorough inspection of the scheduled ancient monument with a view to developing a sensitive repair schedule to halt what had become an acceleration in the decline of the structure.

The mausoleum is constructed from portland stone with beautifully knapped and coursed flint work of the highest quality. The structure also includes numerous decorative stone and plaster embellishments including tudor roses, triglyphs, applied pilasters and large stone urns.

Much of the damage had been caused by vegetation taking hold and the roots finding their way in past the flint exterior into the rubble core and causing extensive damage. Furthermore many of the plaster details were beyond repair and required moulds to be taken and new pieces made.


Owlsworth provided a comprehensive solution, producing an accurate scope of work, liaising with relevant authorities regarding methods, techniques and materials, before eventually completing the work within a 10 month period, 2 months ahead of schedule.

Arborfield Infirmary Stables are owned by the Ministry of Defence and have been designated as a

Scheduled Monument since 1979. The stables, which were in a state of disrepair, had been included in Historic England’s Heritage at Risk Register and classified as Category A (highest level of risk).


The early 20th century Horse Infirmary Stables at Arborfield – or rather, what remains of them – constitute a significant survival from an exceptional period of early to mid-20th century warfare. Constructed in circa 1912-1915, the Stables were part of what was originally a much more extensive complex of buildings which functioned as the Arborfield Remount Depot.


The project involved working closely with Historic England and development of a bespoke roofing scheme.  The original roof to both buildings, had failed and was covered in long discontinued asbestos roof tiles. Owlsworth worked with Cembrit, Historic England and the project team to as closely as possible replicate the previous system. This involved cutting down individual tiles, and applying a paint and lacquer system to the underside. All this prior to laying the new bespoke tiles upside down! Trials and negotiation allowed the roof guarantee to remain unaffected.


This attention to detail was present in all aspects of the project including paint analysis in removing the many layers to allow the original scheme to be determined. Then the use of bespoke mixed paints to bring both structures back to their former glory. Even custom made rainwater goods were cast and the concrete hard standing was reinstated.

Arborfield Garrison
Contact us for a full project list and references


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