HUT were appointed to retrofit and extend a former six storey (B-5) Victorian building in the heart of Farringdon, within the Hatton Garden jewellery quarter.
The brief was to create high quality office and commercial space by completely rethinking the internal layout of the building and providing bright and airy extensions to both the roof and the rear. The historical building is topped with an impressive penthouse office space with an expressed laminated veneer lumber diagrid structure and its own private roof terrace affording views of Clerkenwell and Farringdon. A new shopfront is framed with folded metal panels, replacing the incongruous existing ground floor and immediately improving the building’s street presence.
Studio Name: HUT Architecture
Design Team: George Jamieson
Area: Central London
Year: 2021
Location: Farringdon, London
Consultants: See below
Photography Credits: Emanuelis Stastaitis
Other Credits: See below
Lead designer
Person responsible for project George Jamieson
Organisation * HUT
Architect (if Lead designer is engineer) or Engineer (if principal designer is architect)
Person responsible for project * Toby Maclean
Organisation * Entuitive
Principal contractor
Person responsible for project * Duncan Taylor
Company: Thirdway Contracts
Other key firms associated with the project
– M&E consultant – Mecserve – This is new for the service
– QS – Stature London
– CDM coordinator – Andrew Goddard Associates
– Approved building inspector – Stroma Building Control
– Main contractor –
– CAD software used – Autodesk Revit 2020
– QS – Stature London
– Other consultants
– Planning Consultant – Savills Planning
– Fire Engineer – Astute Fire Much of the building’s original fabric and structure has been retained, which both adds to the patina and story of the building but also is the most sustainable approach to development.
– Acoustic consultant – Cass Allen
– Project manager – Stature London
The refurbished basement to fourth floors are stripped back to reveal the original building fabric, uncovering the layers of past renovation, repair and rebuilding which tell the historic character of the building.
The building’s core is repositioned to sit asymmetrically within the plan – drastically increasing the efficiency of floorplan arrangement. All services and level access are provided via a new staircase and lift, with opportunities for tenant facilities, tea-points and meeting rooms to be integrated within the core design.
HUT provided the interior design and fit out for the third floor show office which utilises the flexibility afforded by the new core design. The interior design of the space complements the exposed layers of building fabric, pairing soft seating, break out spaces, meeting rooms and task working spaces to enhance the architecture.
The building has hosted a number of consented planning applications, previous extensions and internal reconfigurations, most recently a late 20th century structural repair following a large fire which gutted half of the existing building, leaving only the front façade remaining.
“The diagrid roof and folded metal facade details are inspired by the diamond cutting trade of the area. The heritage of the conservation area is one of high quality and bespoke craftsmanship, something that we wanted to reflect in the quality of the architecture; flowing through to the small details such as the ironmongery and brass rivets.
The faceted steel sheets are folded to frame the glazing overlooking the roof terrace whilst providing passive solar shading during the summer without diminishing the lightness of the extension. The material itself has various perforations to create a tactile surface encouraging the occupiers to interact with the materiality of the building.
Much of the building’s original fabric and structure has been retained, which both adds to the patina and story of the building but also is the most sustainable approach to development.
The new additions have been carefully specified and driven by sustainable principles. The expressed timber structure of the roof is formed from Kerto, an LVL timber system, providing high structural strength with much lower embodied carbon than that of typical construction methods.
This diagrid roof creates a unique architectural feature that nods to the original architectural language of the building referencing the fragments of timber internal details, all of which were lost during the fire.”
Provide a description of your approach to environmental upgrade, including any noteworthy innovations (300 words). Please ensure you include the following…
- Predicted annual CO2 emissions/m2 22.4 kgCO2/m2: (post-retrofit emissions on the basis of NCM, including energy use for equipment, and SAP 10 carbon factors)
- U-values of walls, roof, windows, floor or overall weighted U-value
- Wall U-Value: 0.28w/m2k
roof: 0.18w/m2K
floor: 0.25w/m2K
windows: 1.6w/m2K - Predicted percentage improvement in annual CO2 emissions/m2 (with any emission reductions from renewables indicated) over existing building, if available. A total 55% carbon reduction from baseline carbon emissions (i.e. area-weighted average carbon emissions of existing unrefurbished elements and Part L compliant extension); 23% carbon reduction achieved from Air Source Heat Pumps
- Predicted annual CO2 emissions/m2 for both existing (before retrofit) and after (post retrofit) 49.4 kgCO2/m2 (before retrofit emissions on the basis of NCM, including energy use for equipment, and SAP 10 carbon factors)
- Any relevant figures you have calculated on embodied / whole life carbon savings due to the retrofit of the building compared with new build We have not completed a Life-cycle Carbon Assessment for the scheme, therefore, we cannot provide any carbon figures in terms of embodied carbon emissions associated with the various building elements. However, given that the majority of the substructure and superstructure elements were retained, significant carbon savings have been achieved for the scheme.
