Make completes largest mixed

Located at 80 Charlotte Street in London's Fitzrovia, the scheme includes social housing, a new public garden and retail space.

An adjacent block of new apartments sits above two floors of office accommodation at Asta House.

The project's island site at Charlotte Street was originally built as a 1960s post office headquarters and was previously occupied by Saatchi & Saatchi. This main block is 90m square and has been combined into one building, its existing fabric stitched into new-build elements.

Varying façade treatments, setbacks and terraces fragments the block externally while retaining large flexible floor plans.

The cores of the existing buildings have been relocated into the centre of the plan so that three atria sits in each corner, bringing in light and ventilation.

Views into these lightwells and framed window bays highlighting the location of the atria are inspired by the scale of surrounding townhouses.

Three floors higher than the original, the new building is 10 storeys high with setback levels helping reduce the mass and providing terraces with views over the surrounding area and out towards the River Thames.

Blending old with new, bespoke shutterboard concrete wraps half the block, framing the windows, which have deep reveals. Red and yellow brick on Whitfield Street is complemented by dark grey long-format Petersen brick fronting Chitty Street and Charlotte Street, with a sculptural weathered steel portico marking the main entrance.

Inside, the atria have exposed concrete with a black concrete floor in the entrance areas. Danish oak timber flooring lines the reception, while an exposed structural steel frame is expressed throughout.

As well as retaining the significant existing façades, the building is all-electric, using renewable electricity sources. The atria also recycle fresh air, which can be combined with openable external windows for a mixed-mode strategy.

The south-eastern part of the building, bounded by Chitty Street and Whitfield Street, accommodates 19 private rented homes, known as Charlotte Apartments, with a café below opening onto Poets’ Park, a new 240m2 public space.

In 2011, the then London Mayor Boris Johnson overturned Camden Council's decision to block the proposed redevelopment. This came after the borough's planning committee rejected the scheme, claiming it was an ‘overdevelopment’ of the site and lacked affordable housing and open space.

However, Johnson took over the application in June and approved the project, claiming the scheme was ’vital to the prosperity of this part of the capital and to London's wider economy’.

The now-completed office space has already been let as headquarters for Boston Consulting Group and Arup, which is also the project's engineer. Nearby Asta House also includes 1,020m2 of refurbished workplace, home to engineering firm Elliott Wood.

This project follows Fletcher Priest's Brunel Building, also for Derwent, which completed in 2019.

Upcoming projects by Derwent include a major office building in Brixton for which Carmody Groarke has been appointed.

Make has been working with Derwent on 80 Charlotte Street for over a decade, and while in that time the economy has changed and the guidelines for offices have changed, the project has remained relevant, with fantastic social spaces, an option for mixed-mode ventilation and a green energy strategy. The design concept for 80 Charlotte Street is an inherently urban response to its Fitzrovia context both in terms of its scale and its character. The breaking-down of the new block's massing achieves this as do set-back spaces, such as the main entrance and pocket garden, that are also important in the way the project responds to the identity of the area and surrounding streetscape.

80 Charlotte Street is inspired by late British Modernism, with an exposed steel frame structure and self-finished materials. Overall, there's real honesty in the structural expression: the steel frame and concrete floor slab are visible throughout.

The building is finely crafted. For example, exposed concrete soffits were cast by extrusion on steel formwork, giving the finished panels a sheen. External shutter-board concrete cladding was cast against rubber moulds produced from timber formwork, with a relatively smooth timber grain finish, chosen to minimise dirt collection and reduce staining. The Danish long-format bricks from Petersen were hand-laid on site to avoid expressed panel joints and to celebrate their hand-made quality. The weathered steel entrance portico was crafted in Italy with minimal joints.

The concrete and steel frame of the building is enhanced by adding special finish elements – bespoke leather seating to reception, timber sunken seating and cabanas to the terraces, and brass bar tops to the ground level cafe. The lifts have three layers of stainless steel mesh to the wall panels and low-level lighting. In this way, the social spaces feel distinct and special, and this continues with feature lighting and varying light levels, more reminiscent of hospitality than commercial office spaces.Jason McColl, lead architect, Make

It was back in 2007 when, through our merger with London Merchant Securities, we acquired their substantial portfolio in central London which included the island site at 80 Charlotte Street Fitzrovia. Then home to Saatchi & Saatchi, the buildings were tired and presented a range of issues including low ceilings. However this 1.4 acre site offered an amazing opportunity for a unique mixed-use scheme in the heart of the West End.

Given the scale and complexity of the project and our long-standing ownership in Fitzrovia, we involved key stakeholders, community groups and individuals early on. We also set up a community engagement programme to support local initiatives, many of which we continue to help through our Community Fund.

Model

After extensive design work with Make, opportunities were explored to retain part of the existing buildings while redeveloping the main elements, which would enable the opportunities of this site to be fully realised. To break down the mass of the building, under Make's direction and using hand-made Petersen Tegl brick, each elevational treatment provides differentiation, responding in a modern way to the legacy of Fitzrovia's fragmented ownerships and their ‘patchwork’ of buildings sitting cheek by jowl. Our focus on materials and artisanship continues internally – from the Cor-ten steel entrance portal to the specialist leather upholstery by Bill Amberg. That we pre-let the building to two major occupiers, Arup and Boston Consulting Group, is testament to the value of our investment into design and detail at every level.

To further enhance the amenity for occupiers and locals alike, a pocket park occupies the south side, inspired by Paley Park in New York and featuring Hugo Dalton's elegant Choreographic Form sculpture. This provides a welcome sanctuary in what we hope will again soon become a bustling central London neighbourhood.Simon Silver, director, Derwent London

Start on site July 2015Completion 2021Gross internal floor area 29,800m2 (office), 4,200m2 (residential)Form of contract Design and BuildConstruction cost UndisclosedArchitect MakeDetail design and delivery Arney Fender KatsalidisClient Derwent LondonStructural engineer ArupM&E consultant ArupQS AecomLandscape consultant Paul GazerwitzAcoustic consultant Clarke SaundersProject manager Avison YoungCDM coordinator Jackson Cole and Multiplex CDMApproved building inspector BRCSMain contractor MultiplexCAD software used Revit

On-site energy generation 2.4%Annual mains water consumption 5.9 m³ per personAirtightness at 50Pa 3m³/h.m2Heating and hot water load 4.95 kWh/m²/yrOverall area-weighted U-value for the façade 1.32 W/m²KSystems design life 25 yearsBuilding design life 60 yearsEmbodied/whole-life carbon 1,562 kgCO2eq/m²Annual CO2 emissions (TM54 regulated and unregulated figures) 25 kgCO2/m²/yr

comment and share

TagsArup Derwent Fitzrovia Make