Energy use of 3,453 kWhrs per year: a sixth of that allowable under Passivhaus Standard. Energy generation of 3,338 kWhrs per year. Energy usage from April 2014 to April 2015 was just under 3000 kWhrs (see Ecotricity letter above).
In addition, the house meets carbon zero by some measurement, although in reality it just has very low carbon emissions resulting in about 11 Kg of CO2 being produced per year when all the offsets are taken into account.
No overheating occurred in summer due to the thermal mass, the deep reveals and overhanging eaves, the stack effect of the stair void and the efficient ventilation system.
No cold bridging occurred, no draughts were discerned by the users and high levels of comfort were sustained throughout the year.
Natural light floods the rooms during the day, with the centre of the house being lit from the roof windows above the stair. Throughout the house LED downlighters are used to provide high quality utility lighting and wall light, but these are only required the hours of darkness. A small number of low energy feature pendant lights augment the ultra low energy LEDs.