Welbeck Street

Luxury residential development renovation

Slim Sliding Doors to a Marylebone Renovation in the Harley Street Conservation Area 

Welbeck Street is a sensitive residential conversion within the Harley Street Conservation Area in central London. The sixstorey, turnofthecentury building was previously used as offices and has now been carefully redeveloped into four luxury apartments. Designed by Morrow + Lorraine Architects for The Howard de Walden Estate, the project required a contemporary glazing strategy that could transform internal light levels and spatial quality while respecting the historic context. IQ Glass was appointed to design, supply and install a comprehensive architectural glazing package, with slim sliding doors to the Marylebone renovation forming a defining architectural feature across multiple levels of the building. 

 

Project Partners

Architect: Morrow + Lorraine Architects                  

Photographer: Simon C Maxwell

Location

London

Conservation Context and Conversion Challenges 

The building occupies a prominent position within the Harley Street Conservation Area, an area characterised by historic façades and tightly controlled planning constraints. While the front elevation required preservation, the rear of the building presented an opportunity to introduce a modern intervention that could support contemporary residential use. A previous 1970s rear extension was largely demolished, although the existing substructure and original spiral staircase were retained and adapted to suit the new copperclad rear elevation. 

The design introduced a central internal courtyard to bring daylight deep into the building. This courtyard needed to function as both a lightwell and a private external space, meaning the glazing surrounding it had to provide maximum transparency, seamless access and high thermal performance without overwhelming the existing structure. 

ThreeSided Sliding Glass Façade to the Internal Courtyard 

IQ Glass engineered and installed a threesided, Ushaped sliding glass door façade to the groundfloor apartment, enclosing the internal courtyard. Each elevation of the courtyard was formed using a slim framed, thermally broken sliding door system, configured as threetrack, threepanel arrangements with one fixed and two sliding panels per elevation. Two of the elevations meet on an opening glass corner, while the third forms a fixed corner, creating a fully glazed enclosure around the courtyard. 

These slim sliding doors to the Marylebone renovation allow the groundfloor living space to open completely to the courtyard when required, while maintaining a clean, minimal appearance when closed. Flush base tracks were integrated to ensure level transitions between the internal and external floor finishes, reinforcing the sense of continuous living space. 

UpperFloor Glazing and Rooflight Integration 

Across the upper floors of the building, IQ Glass installed a series of slim sliding glass doors, frameless structural glass windows and sliding glass windows to maximise daylight penetration throughout the apartments. These openings were detailed as floortoceiling elements, maintaining consistency with the glazed courtyard façade below and enhancing vertical light distribution. 

Frameless structural glass rooflights were installed at roof level to bring additional daylight into the topfloor apartments. These rooflights soften the boundary between interior and exterior, allowing natural light and sky views to animate the living spaces below. In one location, a walkon structural glass floor was introduced to transmit light between levels while maintaining usable floor space above. 

Light, Privacy and Material Contrast 

The glazed courtyard acts as a central organising element within the building, drawing light into every apartment and creating a private external space that contrasts with the dense urban setting of Marylebone. The combination of copper cladding, warm timber finishes and expansive glazing gives the rear elevation a distinctly contemporary character while remaining visually recessive from surrounding properties. 

Selected glazing units incorporated switchable privacy glass where overlooking was a concern, allowing residents to control visibility without the need for blinds or curtains. Together, the architectural glazing elements support both privacy and openness, demonstrating how carefully specified glazing can enhance liveability within conservationarea developments. 

Technical Details 

  • Residential conversion of a sixstorey building within the Harley Street Conservation Area 
  • Threesided, Ushaped slim sliding glass door façade enclosing an internal courtyard measuring approximately 3.7m x 3.9m 
  • Sliding doors to courtyard configured as threetrack, threepanel systems with two sliding and one fixed panel per elevation 
  • Sliding door height approximately 2.4m 
  • Twotrack, twopanel slim sliding glass doors installed to upper floors, measuring approximately 2.4m wide x 2.4m tall 
  • Frameless structural glass windows to upper floors measuring approximately 1.2m x 2.3m and 0.6m x 2.3m 
  • Slim sliding glass windows installed as floortoceiling openings with bespoke external pressings acting as window cills 
  • Frameless structural glass rooflights measuring approximately 2.3m x 1.0m installed at roof level 
  • Walkon structural glass floor measuring approximately 2.4m x 1.0m 
  • All sliding systems thermally broken with doubleglazed units incorporating lowe coatings 
  • Selected glazing units incorporating switchable privacy glass 

Begin Your Slim Sliding Doors to Marylebone Renovation Project 

For architects, developers and clients planning a Marylebone renovation using slim sliding doors, Welbeck Street demonstrates how contemporary glazing can be successfully integrated within conservationarea developments to enhance light, space and usability. IQ Glass provides technical design input, bespoke engineering and specialist installation for complex residential conversions across central London. Contact our team to discuss your project requirements.