Crawford Partnership have won planning permission for a new three storey eco friendly house on a site flanking a railway embankment in North LondonLocated on a backlands plot occupied by a semi derelict two storey brick building formerly housing a joinery shop, the sole access is via a narrow 'undercroft' passage between the neighbouring houses.The extreme constraints of the site have meant that internal planning has focused on minimising issues of overlooking of adjacent homes and noise from the railway. In order to maximise the available built space, the house occupies the entire site with an internal covered access 'gallery' that is top lit. This elongated access approach leads to the main body of the house which is entirely open plan at ground floor and with full height continuous windows on the south aspect looking out across the heavily treelined undergrowth on the elevated railway embankment that provides natural shading.From the street the scheme presents a subtle and sympathetic frontage, with the only indication of the contemporary design within being the new opaque toughened glass door etched to interpret the panelled doors of neighbouring properties in a contemporary style.The house incorporates south facing triple glazed soundproof full height windows allow plentiful light into the interior. External copper mesh shutters control solar gain. A green 'sedum' roof reduces water run off while improving insulation values and a grey water recycling system reduces water use. A ground source heat pump provides much of the energy for the heating system with high efficiency under floor heating utilised throughout combined with solar hot water heating.This is one of several new houses Crawford Partnership are working on that exploits the possibilities of derelict and back lands development plots, where individually crafted, contemporary and sustainable designs have been achieved.