CURTAIN ROAD – DUGGAN MORRIS ARCHITECTS

architect_ Duggan Morris Architects
structural engineer_ Price & Myers
location_ East London, United Kingdom
construction year_ 2013
total cost_ £3.3M
photography_ Jack Hobhouse
from the architects_

This is a speculative offi ce development generating 20,000sqft (GEA) of retail and work space located at 141-145 Curtain Road, Shoreditch, East London.

The project is located within a conservation area defi ned by Georgian brick buildings and requiring retention of the existing urban block.

The building prior to development was four storeys (G, B+2) in height and is fully remodelled behind a retained brick façade. Above this, three new fl oors of contemporary offi ce space are added, extending the building to 7 storeys in total, almost doubling the usable area.

Planning permission was obtained in September 2011. Construction commenced in November 2012 and completed in October 2013.

 

Introduction

Shoreditch is synonymous with many historical fi gures and events from the emergence of the Tudor Theatre and the plays of William Shakespeare who was a local resident in the 1500s, the textile and furniture industries 1700s-1900s which are now commemorated by the Geffrye Museum, and more recently the emergence of the Tech Hub or Silicon Valley. Gentrifi cation has increased land values over the last 20 years fulfi lling the well know nursery rhyme Oranges and Lemons ‘when I grow rich say the bells of Shoreditch’. Cafes, art galleries and high end apartments now populate the área vastly different from the long gone East end cockney profi le.

The environs around Curtain Road is just one component of this area which has recently been complemented by David Adjaye’s Rivington Place gallery and Theis & Khan’s Batemans Row in close proximity.

The building plot sits within a dense urban block of Georgian properties both commercial and domestic in scale of various widths and heights resulting in a ‘chipped tooth’ silhouette fronting onto the street. Each building block has an individual order of fl oor plates and windows. The unifi ed whole is therefore characterised by a sequence of window rhythms consolidated by brickwork which stitches the entire urban block into one chunk. The local conservation authority were keen to preserve the block in its entirety and therefore in spite of the low grade historic value of the individual plot and the complexity to retain the facade for high end commercial use, the facade had to be retained for the development to be viable.

141-145 is a confi guration of three domestic scale properties which have become conjoined into one demise over time with a shopfront at ground level. The challenge therefore was to retain the domestic scale Windows within a commercial offi ce use as well as to consider the proportional impact and aesthetic quality of the multi Storey addition. The structural complexities required to retain the facade fronting onto the main high street imposed substantial constraints on time and programme.

 

The scheme

To generate the required area of 20,000sqft, a further three storeys were necessary within the permissible building footprint which is defi ned by the alignment of the front facade at street level and the rights of light (RoL) envelope at the rear. There are 7 fl oors in total (B, G 1-5) diminishing is size as you ascend. Logic and effi ciency dictate the plan arrangement. A compact circulation core contains toilets, showers, lift and stair, and is orientated on the tallest side of the building. The offi ces are maximised with external terraces also carved out of the RoL envelope.

The ground and basement are intended for retail use. As such two entrances at ground level occupy either end of the facade – 141 leading to the upper office levels and 145 directly into the retail unit. Ultimately the building is fl exible and can accommodate a single or multi tenant let.

To retain the gravitas and Independence of the urban block, the additional storeys are designed with an ambition to achieve a lightweight object quality restrained from any references to the adjacent heavy masonry structure. Scale references to the adjacent buildings window punctuation are stripped back by reducing the extension to optimum modules horizontally and vertically. The materials are reduced to mesh and glass with minimal panels and visible jointing. The lack of reveals to windows are intended to further communicate the delicate object form by disguising the depth or make-up of the construction.

This object quality is further reinforced by the deep recess to the upper 2 storeys. By revealing a portion of the existing brick fl ank to the adjacent building block (139 Curtain Road) the weight of the existing fabric is further communicated. This obviously reduces nett lettable área but is counterbalanced by a maximised envelope to the rear. Also the precise fi t of the building between party walls without visible overdressing of fl ashings is intended to allow the extension to read as an independant form intended to appear simply resting ‘upon’ the facade below and ‘between’ the adjacent warehouses. A 50mm gap is detailed between the existing masonry and the extension and projecting copings are omitted in lieu of self-draining window sections.

A grid is imposed on the front facade to respond subtlety to the 3 bay house facade below. The plot is trapezoidal in plan and as such a diagonal grid sets up positions of facades and balustrades to the rear. The grid is further enforced at the rear, with smaller staggered terraces, articulating the building where the mass responds to a RoL envelope. Thus a proportional logic of panel size – mesh and glass – is utilised across the facades with the positions of balustrades also defined by the RoL envelope.

 

Materials & color

The visible facade is made up of mesh and large bonded units. The principle behind the entire facade construction is to use a simple curtain walling system where possible, with bespoke inserts to achieve the non standard details. The bonded glazed units are tied back to the main super structure. The mesh is bracketed off the curtain walling to meet the same plain as the bonded units and to achieve the fl ush outer layer. This principle continues around the entire facade front and rear. In order to maintain a reading of the building as a whole the colour palette is carefully calibrated to respond to the masonry tones from grey concrete mortar to mid brown bricks. The refl ectance of the materials increases as you ascend to sky and the textural quality of each material selected is emphasised by various means.

A champagne coloured anodised metal panel is used for the mesh on the upper storeys. This is perforated with small holes achieving 40% free air fl ow and is also calculated to appear almost invisible from the inside to retain views across London. A waved profi le adds another layer of light quality maximising incident sun throughout the day. The anodised Surface is iridescent in sunlight.

The transition from the mesh to the glazed bonded panel is carefully managed by introducing a matching fritt within the double glazed bonded unit. This softens the overall appearance of the glass which would normally be a contrasting frame and fritt colour. Felt curtains have been introduced to the larger windows fronting onto the street to extend the waved mesh detail across the entire facade.

The brick has been lightly cleaned and repointed where spalling with the intention to retain the relic with minimal Surface alteration. All concrete lintels and cills and window frames are painted a matt colour to match the brickwork attempting to simplify the reading of the retained element.

At ground level the shop front is framed in concrete supporting the building mass above. The glass panels within being as large as is permissible with the constraints of the tight street and working zone. Again a fritt has been selected to match the concrete colour to soften the junctions.

The colour treatment stops at the facade. As a rule the entire offi ce units are White including light fi ttings and all exposed services.

Courtesy of Duggan Morris Architects.