Conservation Langley Case Study: Conversion and Renewal

A Case of Langley

Protecting the Future. Preserving the Past

The

A CASE STUDY

Conversion and Renewal at The Langley, a stunning 5-star Hotel, Spa and Conference Resort

FROM HERITAGE HUNTING LODGE TO 5 STAR* LUXE HOTEL

BACKGROUND

Built in 1755, Grade II* Langley Park House and Estate, the former hunting lodge of the third Duke of Marlborough, has been over 12 years in the making - a culmination of conservation, restoration and conversion by a team of leading experts, including ByrneLooby, Multiplex Global, Gibberd Architects and numerous restoration and stonework specialists. The project team converted and restored the house and estate, designed by architect Stiff Leadbetter, transforming it into a luxury 5-star hotel, featuring spa, indoor and outdoor pool and conference centre.

The attention to detail within this project is breathtaking: from the restoration of twenty 250-year old fireplaces to the miniature books for the listed shelves (or ‘Invisible Library’ as it was called back in the 1800s), to the dramatic doubleentrance stairs in honeyed Bath Stone to provide guest accessibility

(which required extensive earthworks), the restoration of the curved wings, towers and stone niches, to the addition of new spa and pool below ground. All are highlighted by tasteful lighting, which showcases the architectural splendour at night.

A HERITAGE ASSET IN DECLINE

Since 2003, Langley had deteriorated, its previous use as an office for British Plasterboard and a decade without a tenant had taken its toll with significant rot and water ingress setting into the two-century-old buildings. The local council (South Bucks District County Council, SBDC) held the freehold for the estate, and sold the leasehold to Arab Investments for £2.4 million. In 2009, Khalid Affara of Arab Investments commissioned Gibberd Architects, ByrneLooby and Multiplex Global to assess the feasibility of a conversion and development scheme to deliver a luxury hotel.

Project: Langley House

Location: Buckinghamshire

Country: UK

Client: Arab Investments

Operator: Marriott

Cost £30m

Date: October 2009 - present

Our Role: Full Civil/Structural Engineering, Conservation, Feasibility Studies

PROJECT TEAM

Architect Gibberd Architects

Contractor: Multiplex Global

GEOTECHNICS

Specialist: Oxley Conservation

Client Advisors: Brett Lawrence

Project Manager: BTP Group

Planning: RSP Group

Plasterer: George Jackson Ltd

Stonework: Szerelmey

Landscape: Colvin and Moggridge

Interior Design: Dennis Irvine Studio

Miniature Books: Original Book Works Company

Sinclair Johnston CONSULTANT/PROJECT DIRECTOR

This project has been a decade-long passion for our London team, particularly Sinclair Johnston, who has worked on this project since 2009 and has been key to the thorough understanding of the spirit of the site, its unique history and the client’s aspirations for its future. Following several planning applications over four years from 20092013, the project received the green light, and Multiplex Global commenced the construction. From the beginning, the brief faced considerable challenges and required the sensitive participation of multiple stakeholders, including the South Bucks District County Council, Historic England, Conservation Officer and existing tenants living on the estate. However, the aligned teamwork and collaboration from the entire project team, combined with the unwavering leadership of the client were hugely instrumental in the project’s successful and on-time delivery.

STAKEHOLDER AND ENGAGEMENT MAP

Our collaborative approach helped guide the project – we used a stakeholder map to develop the brief, which outlined any risks and constraints to inform the design, costs, and investment decisions. A Stakeholder Engagement Plan was applied, identifying and prioritising stakeholders for collaboration, information and inclusion. This process continued throughout the design development and construction.

DESIGN APPROACH: The conversion and renewal scheme included the Grade II* Listed Langley Park Mansion, with Victorian wings at the front, the Winter Garden at the rear, a Grade II stand-alone Clock Tower Building, and a new underground development spa and extensive landscaping. The Grade II* Listed mansion house and Grade II Clock House were guided by SPAB principles (Society for the Protection of Ancient Buildings). This approach advises retaining the existing structures as much as possible, using careful repairs and sympathetic additions only where appropriate. Layers of historical development were teased apart to assess site significance, and sensitive tree protection and ecological considerations were evaluated alongside the exacting requirements of a five-star hotel operator. ByrneLooby aims always to respect the delicate balance between the historic fabric and commercial viability. As the estate is located within the Green Belt, it was necessary to define the ‘Very Special Circumstances’ in reusing this vacant but sensitive property.

GRADE II* LISTED MANSION HOUSE: In the main house, principal rooms were redecorated rather than structurally altered. The limited headroom of the upper floors presented additional challenges. Working with the design team and conservation officers, several options were explored to maximise the headroom. We carefully detailed

service routes integrating them into the historic structure to meet operational needs without heritage disruption. The enfilade was reinstated and appropriate lavatory accommodations were installed. On the upper floors, en-suite bathrooms were arranged by a simple subdivision of lesser rooms, which are fully reversible if ever needed. Existing concealed plumbing serving the upper floors were re-used and supplemented by defunct chimney flues to ensure minimum disruption to the fabric. All the stonework on the building was cleaned and repaired in situ, with indenting and repointing completed by Szerelmey. Elevations were re-rendered, and a dramatic grand entrance with new front and back steps installed. The balustrades around the house were carefully dismantled and either restored or replaced with new rubbed Clipsham balustrades. The paint was stripped from the barrel-vaulted basement in the main house to expose the original brickwork, and the grand Portland stone fireplace was restored.

WINTER GARDEN: The restoration of the ornate double-height Winter Garden of glass and steel into an elegant function area incorporated a new entrance into the underground Spa. Our Investigations showed significant corrosion in the Winter Garden. The steelwork was taken off-site for repairs and re-erected on-site using a proprietary multicell panel to replace the curved glass (subject to listed building consent). Historic England and the Conservation Officer approved this approach. We incorporated a new entrance to the new basement spa, which needed

Aerial view before works

Aerial view after works

VITOL - AN ENERGY AND COMMODITIES GIANT

significant intervention below the existing steelframed, stone-clad structure, and installed a new stair and lift core. The lake’s proximity was a challenge, and we defined the potential risks for the new and existing buildings. The project team removed the mezzanine floor from the existing Winter Garden to provide a new layout with a gallery, waiter station and kitchen.

TRANSLINK AWARD

DESIGN APPROACH: The conversion and renewal scheme included the Grade II* Listed Langley Park Mansion, with Victorian wings at the front, the Winter Garden at the rear, a Grade II stand-alone Clock Tower Building, and a new underground development spa and extensive landscaping. The Grade II* Listed mansion house and Grade II Clock House were guided by SPAB principles (Society for the Protection of Ancient Buildings). This approach advises retaining the existing structures as much as possible, using careful repairs and sympathetic additions only where appropriate. Layers of historical development were teased apart to assess site significance, and sensitive tree protection and ecological considerations were evaluated alongside the exacting requirements of a five-star hotel operator. ByrneLooby aims always to respect the delicate balance between the historic fabric and commercial viability. As the estate is located within the Green Belt, it was necessary to define the ‘Very Special Circumstances’ in reusing this vacant but sensitive property.

GRADE II* LISTED MANSION HOUSE: In the main house, principal rooms were redecorated rather than structurally altered. The limited headroom of the upper floors presented additional challenges. Working with the design team and conservation officers, several options were explored to maximise the headroom. We carefully detailed service routes integrating them into the historic structure to meet operational needs without heritage disruption. The enfilade was reinstated and appropriate lavatory accommodations were installed. On the upper floors, en-suite bathrooms were arranged by a simple subdivision of lesser rooms, which are fully reversible if ever needed. Existing concealed plumbing serving the upper floors were re-used and supplemented by defunct chimney flues to ensure minimum disruption to the fabric. All the stonework on the building was cleaned and repaired in situ, with indenting and repointing completed by Szerelmey. Elevations were re-rendered, and a dramatic grand entrance with new front and back steps installed. The balustrades around the house were carefully dismantled and either restored or replaced with new rubbed Clipsham balustrades. The paint was stripped from the barrel-vaulted basement in the main house to expose the original brickwork, and the grand Portland stone fireplace was restored.

WINTER GARDEN: The restoration of the ornate double-height Winter Garden of glass and steel into

an elegant function area incorporated a new entrance into the underground Spa. Our Investigations showed significant corrosion in the Winter Garden. The steelwork was taken off-site for repairs and reerected on-site using a proprietary multicell panel to replace the curved glass (subject to listed building consent). Historic England and the Conservation Officer approved this approach. We incorporated a new entrance to the new basement spa, which needed significant intervention below the existing steel-framed, stone-clad structure, and installed a new stair and lift core. The lake’s proximity was a challenge, and we defined the potential risks for the new and existing buildings. The project team removed the mezzanine floor from the existing Winter Garden to provide a new layout with a gallery, waiter station and kitchen below. A separate vertical circulation core serves as the main entrance to the underground Spa and allows access to the changing facilities for the outside pool. The Winter Garden, now an elegant function space, was also cleaned and restored.

GRADE II STAND-ALONE CLOCK TOWER BUILDING: Within the Clock Tower, the extension was designed to sit within the middle of the existing yard to avoid obscuring or damaging the existing Grade II listed courtyard walls, including the dovecote structure, which abuts the eastern flank of the yard. The structure was cleaned and restored internally and externally, and further works were carried out to the brick stable block, which was cleaned and repointed. Sections of defective walls were rebuilt.

THE NEW SPA: The subterranean design of the new spa building beneath the existing car park minimises the impact to the listed buildings and keeps the elysian setting. The structure used new piles and a secant piling wall system that intersects and links to the existing mansion building. The secant piling provides stability for the main building, and the new construction works without significant dewatering. This was a primary consideration to minimise the environmental impact of the works. The requirement for spa privacy is provided by a discrete entrance under the car park and also meant the oak trees remained in-situ and undisturbed. The car park, an essential element of an operational hotel facility, was located above the spa roof. A fire escape from the building was added via a new vertical circulation core to the Winter Garden foyer. Additional plant facilities associated with the new development are discretely housed below ground.

The design and construction sequencing of new structures to the scheme, such as the underground spa and Clock House extension, strived to protect the bat roosting trees, bat foraging areas, and mature oak trees. Repairs and restoration balanced the requirements of a 5-star hotel while respecting the heritage fabric. Sustainability initiatives included recycling materials such as lead and slate in the

GRADE II CLOCK HOUSE

BEFORE: LANGLEY HOUSE ESTATE

AFTER: 5 * LANGLEY

BEFORE: THE WINTER GARDEN

AFTER: THE WINTER GARDEN EVENT & SPA

Unlocking opportunities for VITOL to progress towards a net zero carbon footprint

roofing replacement, repair and replacement of existing structural timbers, replacement roof lights, and roof glazing.

CRAFTSMANSHIP: This project required significant attention to detail and craftsmanship. We worked closely with Oxley Restoration, guided by Historic England conversion requirements. Upon the commencement of restoration, when lifting the tiles in the main reception, an original Victorian Mosaic was discovered underneath. The discovery of words at the centre of the mosaic aptly read: Welcome the coming, speed the departing guest.” Before construction, heritage plasterers - George Jackson Limited was appointed to identify and remove areas of plaster to allow structural repairs. Impressions were taken of decorative features to be replicated, brought to their workshop, where models and moulds of the missing cornices, architraves, pediments and ornaments were manufactured to match the existing. Twenty 250-year-old original fireplaces, marble hearths, decorative frieze details, mantels, cast iron fire baskets and intricate marble figures, cornicing, bookcases and stonework were restored to their original states. Replica miniature books were created for the listed narrow bookshelves called ‘Invisible Libraries’, which were very popular in the grand houses at the time. A small but significant project on the estate was restoring the collapsed structure to the old boathouse. Our team took advantage of the seasonal drop in water levels to rebuild the collapsed wall in matched materials off traditional footings, which was well received by the Conservation Officer.

PUBLIC REALM/ACCESSABILITY: Public amenities such as new passenger lifts, charging points for electric vehicles, wheelchair ramps, and accessible toilets and car parking were added. Mobility scooters and wide ‘wheelchair friendly’ paths were

installed to enable all guests and visitors to enjoy the 150 acres of lush estate parklands by one of England’s most celebrated landscapers - Lancelot ‘Capability’ Brown.

VALUE ADD: Introducing a large below-ground spa complex alongside the listed building in proximity to the lake was technically challenging requiring intricate coordination with our temporary works and geotechnical teams. Thorough investigations enabled a complete picture of parameters through the design and construction phases. This minimised the temporary works, allowing a clearer / safer site and reduced impact on the heritage fabric. This co-ordinated approach was extended through consultation with stakeholders allowing our environmental team to address contamination concerns and our water team to mitigate proximity issues with the lake.

Outputs and Benefits

• Employment and local economic benefits - The Langley supports local employment and ancillary local businesses to grow and develop in the region and beyond.

• Local Area Regeneration: The Langley’s conversion has seen a majestic stately home restored to its former glory, keeping its Grade II-listed status while delivering an opulent country retreat, ensuring this heritage asset and surrounding parklands remains intact for future generations. Local communities can enjoy the landscaped grounds with Serpentine lake and the universal design including wheelchair friendly paths and mobility scooters allows everyone to enjoy this Elysian setting of the British countryside at its best. The 150 acres of parklands provides a welcoming space for villagers, residents, and visitors.

• Awards: In 2019, the hotel received an Ahead Europe Hospitality award, an international renowned hotel award for conversion.