We used EnerPHit, Passivhaus standards for this rear extension and interior refurbishment for a family house in Barnes, Richmond, Greater London, London, UK. We maximised the exposure to natural light throughout the day, catching the sunset light by means of a pitch roof that in turn reflects the light to the entire open plan areas. The exterior and interior space boundary is blurred by means of a terrace with the same floor level as the interior flooring, large format sliding doors and an extended pergola aligned with the indoor ceiling level.