Heritage Inspection at Strathearn Villa
Project Overview
- Project: Strathearn Villa, Lansdowne Campus (Bournemouth and Poole College)
- Client: Kier Construction Southern
- Building Status: Grade II Listed
Strathearn Villa 2
Overview
Strathearn Villa is a Grade II listed, three-storey building located within the Lansdowne campus. As with many historic structures constructed from clay brick, the building requires careful maintenance to support its ongoing preservation.
Graham Garner and Partners Limited (GGP) were appointed to provide a structural perspective on the condition of the external brickwork. The challenge was to assess the structural integrity of the facade—which showed signs of previous repairs and alterations—while avoiding invasive testing on the historic fabric.
Our Approach
Our team conducted a non-intrusive, visual inspection of the North, East, and Western elevations.
To inform our understanding of the underlying wall construction without conducting new invasive works, we inspected pre-existing pockets that had been removed from the brickwork by others. This allowed us to gauge the cavity width and wall tie condition while keeping our own survey strictly visual and non-destructive.
Key Findings
By combining our visual survey of the external facade with observations from the pre-existing openings, we identified several critical issues:
- Wall Tie Condition: Through the existing pockets in the masonry, we observed that wall ties were of varying types and conditions. In several locations, ties appeared loose or capable of being moved by hand, indicating a potential compromise in the connection between the inner and outer leaves.
- Incompatible Mortar: We noted that the original lime-based mortar had been repointed in areas with a hard sand and cement mortar. We highlighted this as a risk to the fabric, as inflexible cement on breathable lime mortar walls can accelerate deterioration in heritage brickwork.
- Structural Distortion (Western Inset): We identified a specific defect at the ground floor of the Western Inset Elevation, where a timber lintel over a window had rotted, leading to distortion in the masonry directly above.
- Moisture Ingress: Our inspection highlighted that various external windowsill details appeared to allow water ingress into the wall cavity.
The Solution
Based on our visual assessment, GGP provided a series of technical recommendations designed to respect the building’s heritage:
- Restorative Repointing: We advised removing the incompatible sand and cement pointing and replacing it with a lime-based mortar to re-establish the breathability of the walls.
- Retrofit Stabilisation: To address the loose wall ties observed in the exposed cavities, we recommended installing a retrofit wall tie system to stabilise the connection between the leaves.
- Targeted Repairs: For the Western elevation, we advised immediate temporary propping and localised rebuilding of the outer leaf including the installation of a replacement lintel.
- Investigative Next Steps: While cracking over rendered lintels appeared superficial, we recommended removing render in specific high-stress areas to further verify the brickwork condition beneath.
The Outcome
Our recommendations provided the client with a pragmatic path to support the preservation of the Grade II listed villa for the future.
Strathearn Villa 4
Disclaimer: The information provided in these articles is for general interest and educational purposes only and does not constitute professional structural engineering advice. Every project is unique. You should always consult a qualified Structural Engineer for site-specific advice before undertaking any construction work.
