Mezzanine Refurbishment with ASHP | Architects in Hackney

Our latest Stoke Newington townhouse refurbishment makes some smart moves as well as a dramatic one. The existing rear extension, built a decade ago, was perfectly good-so rather than knocking it down and starting again, we worked with it. The dramatic intervention was removal of the first floor room for a  new timber mezzanine added above the new rear lounge. A modest single-storey space is transfixed into a generous double-height room. The exposed timber structure sits in a dynamic diagonal providing a fine aspect from the new mezzanine office space.

The ground floor plan has been completely reorganised around how the family actually lives. The kitchen now sits at the centre of the plan-for day to day living-while the dining room moves to the front bay window, overlooking the street. It is an arrangement that feels both practical and sociable. To open the ground floor up fully, a residential sprinkler system was installed throughout the ground and first floor mezzanine level. This allowed the stairwell walls to be removed entirely, connecting kitchen, dining and living into one bright and airy space.

Heating the house without gas was a core ambition from the start. An Air Source Heat Pump now serves as the primary heat source, extracting warmth from outside air to heat the home and its hot water. The existing walls have been insulated to help the system run as efficiently as possible. A DEFRA-approved wood-burning stove provides a focal point to the new lounge and a different kind of warmth on the coldest evenings-not replacing the heat pump, but complementing it. With rising summer temperatures making comfort cooling increasingly necessary, air conditioning has also been added.

A south-facing aspect is a genuine asset for the energy efficiency of the house, though it does need managing solar gain; a number of shading measures have been incorporated in the form of awnings and electrical window roller blinds.

A brand new whole basement, has been added below the existing footprint.  Finished in a striking bright orange rubber flooring it provides a dedicated gym and climbing wall. The challenge here was however significant: the main sewer connection ran directly beneath the building, which could have ruled the whole idea out. Instead, the sewer was redirected to ensure the basement remained fully useable.

The basement also provided essential space for the ASHP and solar panel and  battery storage apparatus. The solar panels sit on the existing dormer roof, generating electricity that feeds back into running the heat pump and charging the battery store. Energy captured during the day is not wasted when the sun goes down. It is a system that rewards the investment over time and reduces the household’s reliance on the grid in a meaningful way.