Quadriga was appointed to undertake the careful restoration of the building’s original cast iron windows, as part of a significant programme of works which had been several years in the planning.

With the school remaining operational throughout the project, the works were carefully programmed around school holidays to minimise disruption to pupils and staff.

Restoring the Original Cast Iron Windows

The historic windows required extensive refurbishment to address years of deterioration while retaining as much of the original fabric as possible.

Each cast iron window was carefully removed from its opening and deglazed before the frames were sent away for specialist sand blasting and powder coating. This removed accumulated corrosion and failing coatings before providing the cast iron with a durable new protective finish.

While the frames were off site, Quadriga carried out localised repairs to the surrounding stonework and redecorated the interfaces between the cast iron frames and masonry.

Internally, traditional limewash was reapplied where required, helping to maintain the character and breathability of the historic building.

The distinctive diamond-pattern opening casements, many of which had seized and could no longer be operated, were also overhauled as part of the works. Following restoration, the casements were returned to full working order, retaining both the appearance and functionality of the original windows.

Preserving More Than the Building Fabric

One particularly important aspect of the project demonstrated how conservation can extend beyond simply repairing the physical fabric of a building.

Over many years, generations of pupils had scratched their names and initials into some of the small diamond-shaped panes of glass.

Although these markings could easily have been viewed as defects, they had become part of the story of a school which has educated children for more than 400 years.

Before any glazing was removed, every inscribed pane was carefully recorded and its precise location documented. This allowed the individual pieces of historic glass to be reinstated in exactly the same positions when the restored frames returned to site.

By taking this approach, an informal record left by generations of former pupils was retained as part of the building’s continuing history.

Improving Performance While Protecting Historic Character

Alongside the restoration of the original windows, secondary glazing was installed internally as part of the wider project.

This provides improved thermal performance and helps create a warmer, more energy-efficient learning environment without altering the appearance or significance of the historic external windows.

The completed project has transformed the condition and performance of the windows while retaining the details that make Burnsall Primary School such a distinctive historic building.

For Quadriga, the project is a good example of the principles at the heart of successful building conservation: repair rather than unnecessary replacement, retain as much original fabric as possible and understand that sometimes the smallest details can carry the greatest historical significance.

Works included:

• Careful removal and deglazing of the original cast iron windows
• Specialist sand blasting of cast iron frames
• Protective powder coating and redecoration
• Overhaul and reinstatement of diamond-pattern opening casements
• Careful recording and reinstatement of historic glass panes
• Preservation of panes inscribed by former pupils
• Localised stone repairs around window openings
• Redecoration of cast iron and stonework interfaces
• Application of traditional limewash internally
• Reinstallation and commissioning of the restored windows
• Secondary glazing installed internally as part of the wider improvement works

The project required a conservation-led approach to repair extensive timber decay whilst preserving the character and significance of the historic building. Working closely with the design team, Quadriga delivered a comprehensive programme of structural timber repairs, decorative joinery restoration, window conservation and traditional building repairs, ensuring the maximum retention of original historic fabric.

The Challenge

A detailed condition survey identified extensive deterioration throughout the timber-framed façade. Previous repairs using resin and filler systems had trapped moisture within the timber, accelerating decay and concealing significant structural defects.

Areas requiring specialist intervention included:

• Structural timber framing
• Principal corner posts and wall plates
• Decorative carved gable features
• Roof finial and supporting structure
• Timber-framed windows and stained glass
• Corbels and moulded joinery
• Traditional lath and lime plaster panels

Each repair required careful investigation to determine whether the original timber could be retained or whether selective replacement was necessary.

Our Approach

Following detailed investigation, a programme of conservation-led repairs was developed to preserve as much historic fabric as possible while restoring the building’s structural integrity.

The works included:

• Removal of failed historic repairs and concealed decayed timber
• Traditional oak splice repairs to structural framing
• Manufacture of replacement oak sections to replicate original profiles
• Reconstruction of the principal corner post and wall plate assembly
• Conservation and reinstatement of the original roof finial using stainless steel reinforcement
• Restoration of decorative carved gable features using surviving sections as templates
• Repairs to corbels, mouldings and balcony structures
• Traditional lath and multi-coat lime plaster repairs
• Conservation of historic timber windows and stained-glass panels

Throughout the project, traditional materials and construction techniques were combined with modern engineering solutions where appropriate to achieve long-term durability whilst respecting the building’s heritage significance.

Conservation Principles

The project demonstrates Quadriga’s commitment to repairing rather than replacing historic timber wherever practicable.

By removing only defective material and introducing carefully detailed splice repairs and replacement sections, significant quantities of original timber were retained. New oak elements were manufactured to match the existing species, profiles and detailing, ensuring repairs remained sympathetic to the character of the listed building while improving its long-term structural performance.

The Result

The completed conservation programme restored one of Chester’s most recognisable historic façades, addressing long-standing structural defects while preserving its architectural character and craftsmanship.

Through careful investigation, conservation-led design and skilled workmanship, the project successfully secured the future of this important heritage asset, demonstrating how historic timber structures can be sympathetically repaired and conserved for future generations.

Scope of Works

• Timber condition surveys
• Structural timber repairs
• Oak splice repairs
• Replacement timber framing
• Decorative timber carving restoration
• Roof finial conservation
• Corbel and moulding repairs
• Corner post reconstruction
• Traditional lath and lime plaster repairs
• Historic timber window restoration
• Stained glass conservation
• Listed building conservation works

To facilitate the operation, a scaffold structure incorporating a lifting beam was erected directly above the monument. The existing stone section was carefully supported using lifting straps before precision cuts were made to separate the damaged element from the structure. The upper and lower sections were then safely removed using chain blocks, allowing the defective central section to be extracted without disturbing adjacent masonry.

Following removal, the remaining original stonework was drilled and prepared to receive a replacement section. The removed stone was used as a template to produce an accurate replica, ensuring the new work matched the original profile and detailing.

Once the replacement stone had been manufactured, it was returned to site and dry-fitted to verify dimensional accuracy. The monument was then reassembled using stainless steel dowels bonded with two-part epoxy resin, providing a secure structural connection between the existing and replacement elements. The upper section of the monument was carefully lowered into position using chain blocks, with epoxy resin introduced into the dowel sockets to achieve a permanent bond.

The completed works restored the structural integrity of the memorial while preserving its historic appearance and significance.

Historical Significance

The memorial commemorates the officers and men of the 7th Battalion, Manchester Regiment who lost their lives during the First World War. As part of the 42nd (East Lancashire) Division, the battalion served in several major campaigns, including Gallipoli, Egypt and the Western Front.

Unveiled in 1933, the monument serves as a lasting tribute to those who made the ultimate sacrifice and remains an important part of Manchester’s military and civic heritage. Through careful conservation and repair, the memorial has been preserved to ensure it continues to fulfil its commemorative purpose for future generations.

Quadriga was appointed to undertake critical conservation works to arrest deterioration and stabilise the building, ensuring its long-term survival and enabling future restoration for       community use.

• Full access scaffold design for façade, roof and chimney works
• Specialist DOFF cleaning of all elevation
• Remove vegetation and de-vegetate masonry. Vegetation removal and careful de-vegetation of masonry
• Extensive lime-based repointing and mortar repairs
• Targeted brick replacement and stone repair across all elevations
• Reconstruction of south elevation gable
• Stone repairs to all elevations.
• Timber window repairs and frame sealing
• Structural timber frame repairs, including installation of new oak elements
• Lime render infill panels and internal lime plastering
• Installation of leadwork detailing to improve weathering performance
• Crack stabilization using Helibar reinforcement
• Removal of inappropriate modern materials
• Introduction of discreet structural steel support where required

Delivery Approach

By the time of intervention, the building was suffering from;

Structural movement and cracking across masonry elevations
Deterioration of timber frame and infill panels
Water ingress due to defective roof and rainwater goods
Vegetation growth accelerating decay of historic fabric

Working on a Grade II* listed building demanded a methodical and conservation-led methodology

Quadriga’s approach included:

• Early-stage condition surveys and make-safe works to mitigate immediate risks
• Controlled dismantling of unstable elements, followed by careful reconstruction using traditional materials
• Close collaboration with the design team to ensure historical accuracy and compliance
• Robust quality assurance, including: Photographic recording throughout, inspection and test plans and structured snagging and defect tracking.

All works were carried out with a deep understanding of the building’s sensitive historic fabric and significance.

Outcome

The project successfully;

Stabilised and secured the structure, making it watertight
Safeguarded the building’s heritage significance
Prevented further deterioration of key historic elements
Created a clear pathway for future restoration and adaptive reuse

The works demonstrate Quadriga’s ability to respond rapidly to heritage at risk, combining traditional craftsmanship with modern structural solutions to delivery sustainable conservation outcomes.

Quadriga was appointed Principal Contractor for the essential repair and conservation of the Medieval Keep at Lancaster Castle — one of England’s most significant historic fortifications and a Grade I listed structure of national and international importance.

Positioned on a hilltop site with origins dating back nearly 1,000 years, the Castle has evolved from a Roman fort into a Norman stronghold, later serving as a court, prison, and symbol of royal authority. At its heart, the Keep — constructed in the 12th century — forms the oldest surviving element of the Castle and historically acted as its final line of defence.

Commissioned by the Duchy of Lancaster, this project represents a key phase in the Castle’s long-term conservation strategy, safeguarding its structural integrity, improving environmental performance, and ensuring continued public accessibility for future generations.

Scope of Works

The project involved comprehensive conservation and specialist restoration of the Keep’s structure, envelope, and internal fabric, including:

• Reordering of the roof structure and installation of a new natural slate roof, sensitively integrating photovoltaic panels
• Manufacture and installation of pure iron handrails and balustrades
• Traditional lime plasterwork
• Masonry repairs, including indents and stone replacement
• Lime pointing throughout
• Manufacture and installation of bespoke oak timber windows
• Hard landscaping using reclaimed York stone flags
• Repair and replacement of rainwater goods
• Lowering and capping of redundant chimneys

All works were carried out using traditional materials and techniques appropriate to the building’s historic significance.

Circular Economy and Sustainability

Circular economy principles were embedded throughout the project, prioritising material retention, reuse, and minimal intervention.

This approach resulted in a measured saving of 2,256.1 kg CO₂e, achieved through the reuse of existing materials, retention of embodied carbon, and minimisation of construction waste.

Challenges and Solutions

The Castle remained open to the public and in active use throughout the works. Quadriga implemented carefully managed logistics, including controlled access routes, noise mitigation strategies, and robust protection measures to ensure zero disruption to visitors and adjacent operations.

Given the archaeological sensitivity of the site, all excavations were undertaken under specialist archaeological supervision. Historic fabric was recorded in situ, with any findings carefully documented prior to reinstatement.

Skills, Heritage, and Community Engagement

Recognising the importance of skills development within the heritage sector, Quadriga used the project as a platform for training and knowledge-sharing.

• The site was opened to heritage apprentices from organisations across the North of England in collaboration with Historic England, providing hands-on experience in traditional conservation techniques
• The team engaged with students at Lancaster and Morecambe College, delivering talks on careers in heritage construction
• Work experience opportunities were offered to support the next generation entering the industry

Outcomes and Impact

The Medieval Keep has been successfully restored to a stable, watertight, and historically authentic condition, securing its future as a landmark of exceptional heritage value.

Through a combination of technical excellence, sensitive conservation, and meaningful community engagement, the project not only preserves an irreplaceable historic asset but also contributes to the ongoing development of traditional skills within the sector.

Working under Listed Building Consent and in close collaboration with stakeholders, the project required a sensitive balance between repair, replacement and conservation to ensure the long-term protection of the building’s historic fabric.

The Challenge

Canada House is a landmark building whose richly detailed terracotta façade is central to its architectural significance. Over time, sections of the façade had suffered from deterioration including cracking, spalling, sulphation and localised loss of decorative detail.

Many of the affected elements were highly decorative and formed part of complex architectural features such as keystones, mullions, capitals and cornices. Repairing these elements required careful assessment to determine where conservation techniques could be applied and where full replacement was necessary.

Another key challenge was ensuring any new terracotta units blended seamlessly with the historic material in both colour and texture.

Our Approach

Quadriga undertook a comprehensive programme of terracotta conservation across the building’s elevations. The works included specialist cleaning to remove carbon staining and reveal the original colour of the masonry, alongside targeted repair of damaged elements.

Where deterioration was minor,  micro repairs and indent techniques were used to restore decorative detailing. Severely deteriorated blocks were replaced with bespoke hand-made terracotta units, manufactured from site-taken moulds and kiln-fired to match the original material.

Lime-based mortars compatible with terracotta were used for repointing, and displaced high-level units were carefully stabilised. Extensive colour matching trials and test panels ensured new units blended naturally with the historic façade.

The Result

The project successfully restored the building’s terracotta façades, safeguarding their structural integrity while preserving the distinctive architectural character of Canada House.

Through careful conservation and specialist craftsmanship, the works have extended the life of the original fabric and ensured the building’s intricate detailing continues to contribute to Manchester’s historic streetscape.

The scheme also demonstrates Quadriga’s expertise in the conservation of complex terracotta façades, combining traditional craft skills with modern conservation techniques to deliver large-scale heritage restoration projects.

Works included:

• Removal of middle and lower windows to facilitate scaffold erection.

• Once the scaffold was erected, the top windows were removed in readiness for decoration.

• Once the top windows are complete they were reinstated and the scaffolding was removed.

• The remaining windows to the middle and lower sections were removed, prepped and decorated.

• Any broken glass was replaced using heritage handblown glass to match the original.

• The gable end of the glasshouse was prepped and decorated.

• The timber panel in the gable end door had rotted and was repaired.

A tap test is an effective method of identifying and locating areas of de-bonded plaster work. This survey was carried out via an access platform and any areas of loose plaster deemed to be at risk were removed to ensure occupier safety. Once the survey was completed, a report was drawn up indicating any areas of defective plaster work along with our proposals to repair them. De-bonding of plaster refers to the separation of the plaster and the surface to which it was originally applied. If this isn’t addressed, further deterioration and structural issues can occur over time. Regular inspections are instrumental in identifying any issues with heritage plaster and carrying out these small repairs in a timely manner can mitigate the need for more extensive and potentially intrusive restoration work.

Quadriga were employed to carry out a sensitive clean to the façade and install new Portland stone cladding. A new shopfront was created which meant that following the introduction of new steel by a specialist firm, we were tasked with sourcing and installing the stone above the window heads.

A super-heated steam clean was used to remove dirt, contamination and biological growth gently but effectively from the stone façade. Super-heated steam is an excellent way to clean historic masonry. Whilst the temperature is high, the pressure is very gentle, and the volume of water is low. The temperature and pressure are carefully controlled to ensure there is no damage or detrimental impact to the masonry. Once the clean was completed, and following approval of the replacement stone by conservation officers, the new Portland stone was installed. This was carried out by our experienced team who have worked on various Portland stone clad buildings previously. The result is an invigorated building which looks as it would have done upon opening in 1936!

Our first task was to assess the damage and determine how much of the original brick and stone could be salvaged, restored and reinstated and what needed replacing. Unfortunately, due to the nature of the impact, the spherical stone caps needed to be replaced. We sourced suitable stone from our extensive library and this was carved and installed by our talented masons to ensure the replacement caps were a perfect match to the original. Replacement bricks were specially made by The Bulmer Brick and Tile Company, an organisation dedicated to preserving the traditions of brickmaking. They also matched the existing bricks, ensuring a seamless blend of old and new.

Works included:

• Glazing replacement works to roof lanterns.
• Application of liquid coatings to lanterns.
• Lead works and flashings to lanterns.
• Cleaning of existing roof finish.
• Installation of liquid strip to dome glazing.

Works included:

• New liquid roofing system
• New lead gutters to the front elevation
• Partial replacement and restoration of the terracotta balustrade
• Re-pointing to all elevations..
• Repairs to sandstone plinths
• Repairs to the parapet
• Superheated steam clean and restoration of portico stone
• Replacement of ceiling tiles internally and re-decoration of stained areas