A Chartered team for listed building retention
The retention, repair and protection of historic buildings is crucial for future generations to be able to benefit from them. Work with Richard Herrmann Associates Ltd to make these tasks achievable for clients across the UK from our offices in Cambridgeshire
Respectfully preserving listed buildings
Listed and historic buildings represent the architectural and cultural legacy of our past, and they require a delicate approach when it comes to their preservation and modernisation. Richard Herrmann Associates Ltd tackle these sensitive design alterations and structural improvements with the care and respect they deserve, working with stakeholders across the UK to breathe new life into tired yet treasured spaces and enabling them to meet the practical needs of today.
Collaboration is essential in these projects, and we work closely with architects, conservation officers, and heritage consultants to ensure that every element of the design is sympathetic to the building’s history. Our team also liaises with local planning authorities to navigate the regulatory landscape, ensuring that all interventions meet the strict guidelines governing listed buildings in the UK.
Understanding the intricacies of building restoration
Given the nature of these projects, it’s imperative that we understand the materials employed during the original construction and the methods suitable for repair in current times. Our goal is always to preserve as much of the original fabric of the building as possible, whilst making necessary interventions that enhance its structural stability. This can look differently from project to project, from reinforcing ageing foundations, upgrading to modern materials where appropriate, or addressing environmental issues such as damp or subsidence. Whatever the circumstances, we can ensure that every modification is in keeping with the building’s historical significance.
Modernisation without compromising historic beauty
Listed and historic buildings often need to be adapted to serve contemporary purposes, whether that’s transforming an old manor into a hotel or converting a historic warehouse into modern office space. Our designs seamlessly integrate today’s functionality with the building’s existing features, ensuring that new additions or refurbishments respect the character of the original structure. We work to maintain the aesthetic integrity of the building while providing the structural support needed to meet modern standards of safety, accessibility, and comfort.
37
Years Est.
6,500+
Clients
100+
Years' Experience
Words from our clients
Case Study: Inspection and Preservation of Historic Posts in East Anglia
As part of a routine maintenance program for structures of historic importance, a series of historic posts were inspected in East Anglia. These posts are not only structural artifacts but also serve as silent markers of the dramatic environmental changes caused by human intervention over centuries.
The inspections revealed an astonishing finding: timber piles beneath one of the posts, in place since 1848, remained in remarkably good condition. This case study highlights the technical investigation process, the significance of the findings, and the insights they provide into both structural longevity and the environmental changes in the fen peatlands.
Project Background
The posts, believed to date back to the mid-19th century, were originally installed as part of a structural or boundary system. Over time, changes in the surrounding environment have dramatically altered their visibility and the ground conditions. Key findings included:
-
Ground Level Changes: The visible portion of the posts today demonstrates the extent to which the fen peat levels in East Anglia have receded due to man-made drainage and agricultural activity. Originally flush with the ground, the posts now stand partially exposed, providing a stark visual record of historic environmental transformation.
-
Structural Integrity: Despite their prolonged exposure to natural elements and their long burial in peat, the underlying timber piles were found to be in good condition, a testament to both the quality of the timber and the unique preservative properties of peat soils.
Engineering and Environmental Challenges - the inspection and preservation of these posts posed several considerations for the engineers and conservation specialists:
1. Understanding Historic Ground Movement:
​
-
Fen peat in East Anglia has been subject to significant degradation and subsidence due to drainage activities beginning in the 17th century, primarily for agricultural purposes. This process has led to a marked lowering of ground levels, exposing formerly buried structures.
-
Understanding the rate and extent of this subsidence is crucial for documenting the environmental impact of human activity over time.
2. Structural Investigation of Timber Piles:
-
The inspection required non-destructive or minimally invasive methods to assess the condition of timber piles that had been underground for over 170 years.
-
Timber structures buried in peat are often well-preserved due to the anaerobic (oxygen-free) conditions, but this required confirmation to ensure ongoing structural stability.
3. Balancing Preservation with Conservation Goals:
-
As historic structures, the posts hold both structural and cultural significance. Any intervention needed to align with conservation principles, ensuring the posts remain undisturbed while being properly monitored and maintained.
Technical Inspection and Findings
1. Structural Assessment
​
The condition of the posts and underlying timber piles was evaluated through a detailed structural inspection. Key steps included:
​
-
Visual Inspection: The above-ground portions of the posts were inspected for signs of weathering, splitting, and decay. The visible length of the posts provided critical evidence of historic ground subsidence.
-
Timber Pile Evaluation: To assess the buried portions of the posts:
-
Probe Testing: Carefully controlled probing confirmed the presence and depth of the buried timber piles.
-
Core Sampling: Small samples of the timber were extracted to assess their internal condition and identify any degradation.
-
2. Preservation of Timber Piles
​
The inspection revealed that the timber piles, buried since 1848, were remarkably well-preserved. This finding was attributed to:
​
-
Anaerobic Peat Conditions: Peat soils are rich in organic material and low in oxygen, which slows the biological processes that typically cause timber to decay.
-
Quality of Timber: The timber used in 19th-century construction was often high-quality, dense hardwood, which further contributed to its durability.
3. Environmental Insights
​
The posts serve as important historical markers, highlighting the extent of ground subsidence in the fenlands:
​
-
At the time of installation, the top of the posts was at ground level. The exposed sections today clearly show the vertical loss of peat, illustrating the impact of centuries of drainage and agricultural practices.
-
The findings emphasise the fragility of peatland environments and the long-term consequences of human intervention in natural systems.
Significance of the Findings
The inspection and analysis of these historic posts provided valuable insights:
1. Preservation of Heritage Structures:
The good condition of the timber piles, despite being underground for over 170 years, showcases the resilience of traditional construction methods and materials. The posts remain structurally stable, demonstrating the preservative qualities of peat soils.
2. Environmental History:
The posts serve as tangible records of the dramatic environmental changes in the East Anglian fens. The visible ground level reduction provides a compelling narrative of human activity—particularly the drainage of fenlands for agriculture—and its impact on the landscape.
2. Informing Future Conservation:
​
By assessing the structural integrity of the posts and understanding the conditions that contributed to their preservation, engineers and conservationists can develop long-term monitoring and maintenance plans. This ensures that these structures, and the stories they tell, are preserved for future generations.
Conclusion
The inspection of the historic posts in East Anglia highlights the intersection of structural engineering, material preservation, and environmental history. The remarkable condition of the timber piles, buried since 1848, demonstrates the enduring legacy of traditional craftsmanship and the unique preservative properties of fen peat.
​
Beyond their structural significance, the posts offer an enduring visual reminder of the human-driven changes to East Anglia’s fenlands. They stand as both engineering artifacts and environmental markers, bridging the gap between history, heritage, and science.
​
This case study underscores the importance of ongoing inspection and maintenance programs for historic structures, ensuring their longevity while preserving their cultural and environmental narratives.
Case Study: Structural Repair and Reinforcement of a Listed Building Following Vehicle Impact
In a rare and unfortunate incident, the front elevation of a historic, Listed building was struck by a 4x4 vehicle, causing extensive structural damage. The force of the impact severely affected the portico, the external elevation wall, and an internal partition wall. This case study details the engineering response, which involved immediate structural safety measures, detailed remedial works, and close collaboration with the project architect, all within the constraints of the building’s Conservation zone status.
Project Background
The building in question, a Grade II Listed structure, forms an integral part of the local historic fabric, located within a sensitive Conservation zone. The vehicle strike caused significant damage to the facade and internal structures, including:
​
-
Portico Damage: The decorative entrance portico, a key feature of the building’s front elevation, was severely damaged, with structural elements displaced.
-
External Wall Damage: The external elevation wall sustained cracks and deformation from the impact, threatening the structural stability of the building.
-
Internal Partition Wall: The internal partition wall was compromised, with cracks appearing due to the transferred forces from the impact.
Immediate Response and Safety Measures
Given the extent of the damage, immediate safety assessments and actions were required:
1. Evacuation Advice
​
-
The structural integrity of the affected areas was evaluated to ensure the safety of the building’s occupants. The immediate evacuation of parts of the building was advised to prevent injury in the event of further structural collapse.
-
Risk Assessment: A detailed risk assessment was conducted, identifying which areas of the building were most vulnerable to collapse.
2. Temporary Propping and Support
​
Temporary Propping: In order to prevent further damage and ensure the stability of the building during repairs, temporary propping was introduced. The portico and affected external and internal walls were propped up with strong, non-invasive support structures.
Engineering Monitoring: The temporary propping system was monitored regularly to ensure its effectiveness, especially during the ongoing assessment of the building’s structural condition.
Remedial Works
The repairs to the historic building required careful planning and execution to restore the structure’s safety and integrity while preserving its historical value. Key elements of the remedial works included:
1. Careful Rebuilding of the Portico and Walls
​
-
Restoration of the Portico: The portico, an architectural feature of significant historical importance, was carefully rebuilt using matching materials to maintain its original appearance and structural function. The rebuilding process required detailed structural analysis to ensure the new work aligned seamlessly with the original structure.
-
Rebuilding the External Elevation Wall: The external wall required substantial repairs. Cracks and distortions caused by the impact were addressed by carefully matching the existing materials, including brick and mortar, to ensure that the restored section blended with the unaltered parts of the building.
-
Internal Wall Stabilisation: The internal partition wall was rebuilt to restore structural integrity, while ensuring that the restoration adhered to building preservation guidelines for Listed structures.
2. Additional Horizontal Restraint Ties
​
-
Horizontal Restraint Ties: To strengthen the overall structure and prevent any future movement, additional horizontal restraint ties were incorporated into both the external and internal walls. These ties ensured that the walls were better secured against lateral forces, such as those that could arise from future impact events or environmental factors. -
Minimising Disruption to Historic Fabric: The installation of restraint ties was carried out with meticulous care to avoid disturbing or compromising the building’s historic fabric. The work was designed to blend with the original structure and maintain the aesthetic integrity of the building.
Challenges and Considerations
Several challenges were encountered throughout the repair process, particularly in working with a Listed building within a Conservation zone:
1. Preservation of Historic Features
-
The building’s Listed status meant that the repairs needed to be carried out in strict accordance with conservation guidelines to preserve the historical and architectural integrity of the structure.
-
The work was carefully monitored and designed to ensure that any interventions, such as the addition of restraint ties or the rebuilding of the portico, were sympathetic to the building’s original design and materials.
-
Regular consultations with heritage specialists and the Architect were essential to ensure that every step of the remedial work complied with conservation standards.
​
2. Liaison with the Architect
Close coordination with the Architect was required to ensure that the repairs preserved the building’s historical significance while meeting modern structural safety standards.
The architect was involved in choosing the materials for rebuilding and in ensuring that the design of the temporary and permanent supports respected the original aesthetics.
​
3. Integration of Modern Engineering Techniques with Traditional Methods
​
​The repair solutions incorporated both modern engineering techniques, such as horizontal restraint ties, and traditional building methods to ensure the work was as inconspicuous as possible. This integration allowed for a secure and durable repair while respecting the building’s original craftsmanship.
Results and Impact
​
1. Restored Structural Integrity
The remedial works successfully restored the structural integrity of the building, ensuring that it was safe for continued use. The portico, external walls, and internal partition were all repaired and stabilized to their original design, with additional resilience against future damage.
2. Preservation of Historical Value
The restoration work preserved the architectural and historical value of the building. The carefully rebuilt portico and external wall now blend seamlessly with the rest of the structure, maintaining its Listed status and aesthetic appeal.
3. Enhanced Safety
The addition of horizontal restraint ties strengthened the structure against future lateral forces, improving its safety for both occupants and passers by. The building now meets modern safety standards while respecting its historical context.
4. Compliance with Conservation Requirements
The close collaboration with the Architect and conservation specialists ensured that all work was in line with the required conservation standards, helping the building retain its status within the Conservation zone.
Conclusion
The damage caused by the vehicle impact provided an opportunity to reinforce and restore a historically significant structure while ensuring its continued safety. Through careful planning, collaboration, and the use of both modern engineering techniques and traditional methods, the building was successfully repaired to its former glory.
​
This case study highlights the importance of maintaining a balance between structural safety and historical preservation in Listed buildings. The expertise of structural engineers and architects, along with the involvement of heritage professionals, was key to ensuring that the repairs were executed in a way that protected both the building’s integrity and its historical value.
Case Study: Restoration and Repair of a Historic Boundary Wall Following Storm Damage
Following a storm event, a historic boundary wall suffered a partial collapse, highlighting the vulnerability of the structure to environmental factors and past maintenance issues. The wall, which forms an integral part of a Listed property and is located within a Conservation zone, required careful inspection and restoration to preserve its historical value while addressing the underlying structural issues. This case study explores the engineering approach to restoring the wall, the challenges of working within a sensitive conservation area, and the collaborative efforts between engineers and the conservation architect to retain as much of the original fabric as possible.
Project Background
The boundary wall in question was an important feature of the historic property, acting as both a structural element and a boundary marker. However, the wall had been compromised by several factors:
​
-
Storm Damage: The wall suffered a partial collapse during a severe storm, which triggered a thorough investigation into the cause of the failure.
-
Water Ingress: Water ingress, exacerbated by the storm, was found to have played a significant role in the collapse. The water had infiltrated the wall through cracks, compromising the integrity of the structure.
-
Vegetation Growth: Overgrown vegetation on the wall further contributed to the structural weakening. The roots of the plants had grown into the masonry, creating additional pathways for water to penetrate and cause further damage.
-
Poor Past Repairs: The wall had also been poorly repaired in the past, with non-traditional materials and methods that were incompatible with the original structure, further exacerbating its vulnerability.
Inspection and Diagnosis
A thorough inspection of the collapsed section and the surrounding wall was carried out to determine the full extent of the damage and identify the causes:
1. Structural Assessment:
The collapsed portion of the wall was carefully assessed to understand the type of failure, which was attributed to a combination of water damage and the mechanical stresses caused by vegetation growth.
2. Water Damage Investigation:
Water had infiltrated the masonry, eroding the mortar and weakening the stones. This issue was particularly pronounced in areas where vegetation had taken root, allowing water to collect and spread through the wall structure.
3. Vegetation Assessment:
The overgrown vegetation, while attractive from an aesthetic standpoint, had caused physical damage to the wall’s surface. Roots had penetrated the joints and mortar, further increasing water retention and the risk of damage.
Repair Scheme Development
Given the historic nature of the wall, the repair strategy focused on preserving as much of the original fabric as possible while addressing the underlying structural issues. Key aspects of the repair plan included:
1. Retaining Existing Materials:
The goal was to retain as much of the original masonry as possible. Only the damaged sections, which could not be salvaged, would be replaced with matching materials.
The existing stones were carefully cleaned and repointed where necessary to restore the wall’s integrity while preserving its historic appearance.
​
2. Waterproofing and Drainage Solutions:
A drainage system was introduced behind the wall to divert water away from the structure, preventing future water ingress.
Waterproofing agents were applied to the mortar and stones to improve the wall's resistance to moisture penetration.
​
3. Vegetation Removal and Control:
All vegetation was carefully removed, and the roots were treated to prevent further growth. This step was essential to eliminate the long-term source of water penetration and prevent damage caused by plant roots.
A long-term maintenance plan was developed to monitor vegetation growth and ensure that the wall remained free of plant material in the future.
4. Use of Traditional Materials:
To respect the historic character of the wall, traditional building materials—such as lime mortar—were used in the repair process. These materials were chosen for their compatibility with the original construction and their ability to breathe, preventing trapped moisture within the masonry
Challenges and Considerations
​
1. Preservation of Historical Integrity
Given that the wall is located within a Conservation zone, the restoration had to comply with strict heritage and conservation guidelines. The challenge was to ensure that the repairs were both structurally sound and in keeping with the original design.
​
-
Close consultation with the conservation architect ensured that the repair methods respected the historical value of the wall.
-
The use of traditional techniques and materials was essential to maintaining the wall’s Listed status and avoiding any modifications that could alter its appearance.
2. Environmental Considerations
​
The storm event highlighted the vulnerability of the wall to weathering and natural forces. The repair plan not only addressed immediate damage but also implemented long-term solutions to prevent future damage.
-
The drainage system and waterproofing measures were essential to addressing the root cause of the damage—water ingress.
-
Careful consideration was given to the sustainability of the wall and its ability to withstand future environmental stresses, including storm damage and water exposure.
​
3. Liaison with the Conservation Architect
Throughout the repair process, there was close liaison with the conservation architect to ensure that every step of the project met the necessary conservation standards. This collaboration was critical in balancing the need for structural integrity with the goal of preserving the historic character of the wall.
Results and Impact
1, Restored Structural Stability
The repairs successfully restored the wall’s structural stability, with the added waterproofing and drainage measures preventing further water ingress. The wall now stands secure against future storms and environmental stressors.
2. Preservation of Historic Fabric
By retaining as much of the original masonry as possible, the repairs ensured that the historic appearance of the wall was preserved. The use of traditional materials and techniques meant that the wall’s authenticity remained intact.
3. Enhanced Durability and Resilience
With the introduction of proper drainage systems and waterproofing solutions, the wall is now more resilient to moisture damage. Additionally, the vegetation control plan ensures that plant growth will no longer pose a risk to the structure.
4. Compliance with Conservation Guidelines
The project adhered to all relevant Conservation zone regulations, ensuring that the historic value of the wall was maintained while also addressing modern structural requirements.
Conclusion
This case study highlights the successful restoration of a historic boundary wall following storm damage. By carefully balancing modern engineering techniques with traditional preservation methods, the wall was repaired to its former strength while retaining its historic value. The collaborative effort between structural engineers, conservation specialists, and the conservation architect ensured that the repairs were both structurally sound and aesthetically appropriate.
​
The project not only restored the wall but also enhanced its ability to withstand future environmental challenges, preserving an important piece of the local heritage for generations to come.
Case Study: Restoration and Repair of Corroded Embedded Metalwork in a Historic Building
A historic building in Peterborough was found to be suffering from significant structural issues related to the corrosion of embedded metalwork in both its stone and brickwork external elevations. The metal elements, which had been part of the original construction, had deteriorated over time, leading to structural instability and aesthetic damage. This case study outlines the process of diagnosing the problem, designing a detailed repair scheme, and implementing the restoration of the building’s external elevations to preserve its historical integrity.
Project Background
The building in question, a Listed structure, forms part of the architectural heritage in Peterborough. Over time, the presence of embedded metalwork, such as iron ties, brackets, and other support elements, caused issues when the metal began to corrode, expanding and exerting pressure on the surrounding stone and brickwork. This corrosion resulted in several issues:
​
-
Cracking and Spalling of Stonework: The expansion of corroded metal elements led to cracking, spalling, and loosening of stonework.
-
Instability of Brickwork: In some areas, the corrosion of embedded metalwork within the brick masonry created a threat to the structural integrity of the wall, which could potentially compromise the building’s safety.
-
Aesthetic Degradation: The corrosion and resulting damage were visible on the external elevations, detracting from the building’s historical and architectural value.
Inspection and Diagnosis
1. Corrosion of Embedded Metalwork:
​
-
Iron Elements: Iron ties and other metal elements embedded within the stone and brickwork had corroded due to long-term exposure to moisture and oxygen. The corrosion had caused these metals to expand, creating internal stresses that were visible on the surface.
-
Localised Damage: The corrosion was most pronounced in specific sections where water had penetrated over the years, leading to more localized areas of cracking and material failure. ability to breathe, preventing trapped moisture within the masonry.
​
2. Damage to Stone and Brickwork:
​​
The corrosion of metal elements had caused spalling (fragmentation of stone surfaces) in several locations, particularly near window frames and structural joints.
Cracks were observed in both the stone and brickwork, particularly where the metal elements had exerted pressure from within.
​
2. Risk of Further Deterioration:
The ongoing corrosion posed a risk of further deterioration, potentially destabilising parts of the external elevations if not addressed.
Repair Scheme Development
A detailed repair scheme was developed, with a focus on both structural integrity and the preservation of the building’s historic appearance. The strategy was designed to ensure that the repairs were sympathetic to the building's Listed status while addressing the underlying causes of corrosion. Key aspects of the repair plan included:
1. Removal of Corroded Metalwork
-
Assessment of Metal Elements: The corroded metalwork was carefully assessed to determine whether sections could be salvaged or needed to be completely replaced.
-
Removal of Corroded Sections: The corroded metal elements were carefully removed from the stone and brickwork to prevent further damage. In areas where the metal was too damaged to preserve, replacements were designed using compatible materials to maintain the building's historical authenticity.
​
2. Structural Reinforcement
-
Introduction of New Supports: Where necessary, new structural supports were introduced to ensure the stability of the building. This included the installation of reinforced steel ties where metal elements had failed, ensuring that these supports were concealed and did not interfere with the building’s aesthetic.
-
Patching and Rebuilding: The damaged stone and brickwork were repaired using matching materials that were compatible with the original fabric. Traditional techniques were employed to match the mortar and bonding techniques used in the original construction.
3. Waterproofing and Moisture Control
-
Waterproofing: In order to prevent future corrosion, a detailed waterproofing strategy was developed. This involved the application of water-resistant treatments to the stone and brick surfaces to prevent moisture penetration, which had been a significant contributing factor to the corrosion.
-
Drainage Improvements: To address water ingress at the base of the walls, drainage improvements were introduced to divert water away from the external elevations. This was crucial in mitigating the conditions that had led to the original deterioration.
​
4. Preservation of Aesthetic Value
-
Restoration of Stonework: The stonework was carefully restored to its original condition, ensuring that the aesthetic qualities of the building’s facade were preserved. Stone replacements were made with materials that closely matched the original, and repointing was carried out to restore the mortar joints to their original appearance.
-
Brickwork Repair: Similarly, the brickwork was repaired with care, with damaged bricks replaced and new mortar joints made to match the original construction.
Challenges and Considerations
​
1. Preservation of Historic Fabric
-
The repair process had to strike a delicate balance between structural repairs and preserving the historic integrity of the building. All work had to be carried out in accordance with conservation guidelines, ensuring that no irreversible changes were made to the building’s character.
-
Liaison with Conservation Architects: The repair scheme required close consultation with conservation architects to ensure that the work adhered to the building’s Listed status and the requirements of the local Conservation zone.
2. Compatibility of Materials
-
Given the historical significance of the building, careful consideration had to be given to the materials used in the repairs. New materials, such as the replacement metal elements and mortar, had to be compatible with the original construction methods and materials to ensure the building's integrity was maintained.
​
3. Accessibility of Work Areas
-
Due to the nature of the repairs, some sections of the building’s external elevations were difficult to access. Special scaffolding and access equipment were required to reach high and delicate areas without causing further damage to the surrounding fabric of the building.
Results and Impact
1. Restored Structural Integrity
The repairs successfully restored the structural stability of the building, ensuring that the external elevations were secure and safe for continued use. The corrosion was fully addressed, and any failing elements were replaced with new, compatible materials.
2. Preservation of Aesthetic and Historical Value
The building’s aesthetic appeal and historical value were preserved, with the stone and brickwork repairs blending seamlessly with the original structure. The corrosion damage was effectively hidden, ensuring that the visual character of the building remained intact.
3. Improved Long-Term Durability
The introduction of waterproofing and drainage solutions significantly reduced the risk of future corrosion, enhancing the long-term durability of the building's external elevations.
Conclusion
The restoration of this historic building in Peterborough highlights the importance of addressing underlying structural issues in a way that both preserves and strengthens the building for future generations. Through a combination of careful diagnostics, traditional repair methods, and modern engineering solutions, the building’s external elevations were successfully restored while maintaining its historical integrity.
​
This case study underscores the value of working with conservation experts and engineers to navigate the complexities of historic preservation and ensure the long-term survival of important Listed structures.
Work with us to preserve architectural heritage
If you’re planning a project involving a listed or historic building, or have any questions, feel free to all 01480 455179 or complete our online form to share the specifics.