Survey and repair recommendations for the Grade I listed, internationally significant Sheerness Boat Store

Sheerness Boat Store

Sheerness Boat Store, constructed in the late 1860s, is Grade I listed and of international significance owing to its size and innovative structural system: the earliest surviving example of a multi-storey iron-frame and panel structure. The all-metal frame was made rigid by portal bracing and was subsequently adopted by the skyscraper pioneers in Chicago, becoming universal in modern iron-framed buildings.

Having been deemed one of the UK’s top five at risk Victorian structures, our specialist conservation surveyors and architects investigated the condition of the building, then provided recommendations for repairs and a strategy for sustainable future usage to the Boat Store’s owner, local authority, and Historic England.

The timeline was challenging due to the client’s need to use our report to make the case for funding for repairs. We therefore needed to mobilise and arrange site access quickly.

Site access challenges included the location of the Boat Store towards the far end of an active and busy port, adjacent to the Thames Estuary. On the north side of the building, the distance to the water was only ten metres, limiting the use of inspections via an mobile elevated working platform. On the south side was an access road and large amounts of debris and vegetation obscuring the building at low level.

The building itself is in extremely poor condition and internal inspection was severely limited by health and safety risks. The entirety of the north side on levels one, two and three could not be accessed due to the failure of timber floorboards and staircases. The south side levels could be accessed, but not in their entirety.

Drawing on our conservation expertise, we carefully assessed the building’s condition, element by element, and developed reasoned conclusions around realistic, prioritised recommendations for repairs, including estimated costs.

Our measures to safely complete the most comprehensive survey possible began with a desktop review of documentation relating to the building, allowing us to determine which areas of the building could not be surveyed due to the presence of asbestos and the level of deterioration.

We completed a site induction which allowed us to prepare a marked-up plan, with areas of concern noted where access would not be possible, for example, the third-floor office partition where asbestos was present within deteriorating materials, the north side upper floors where water ingress had decayed timber floorboards and stairs, and the central glazed roof atrium where glazing had slipped down and smashed.

Use of a mobile elevated working platform and a drone allowed us to survey areas inaccessible on foot. This gave a unique view of some parts of the building and greatly added to our understanding of the building’s condition and the building’s intended performance, particularly with reference to rainwater disposal.