The Ringmer Passivhaus is a new build dwelling, replacing a redundant asbestos dairy barn. Planning approval for the certified Passivhaus scheme was achieved at Planning Committee following an unprecedented Class Q Permitted Development conversion to a larger new build dwelling design.
The three bedroom house is formed from a structurally insulated panel system (SIPS) frame which stands on an insulated raft, ensuring a thermal bridge-free construction. The walls and roof are clad in Siberian Larch, with feature galvanised steel verges and rainwater downpipes completing the detailing. A mechanical ventilation heat recovery (MVHR) system ensures a continuous delivery of room temperature fresh air and the thermal performance is so efficient that the bodies of the occupants deliver 35% of the heating load for the building in the coldest winter months.
What was the brief?
This project started out as a Class Q permitted development to convert an existing asbestos clad equestrian barn into a three bedroom dwelling. The restrictions of the Class Q clause meant that the concrete structure needed to be reclad, but not replaced, which did not meet the client’s high energy efficiency aspirations.
After much research the client decided PassivHaus was the right solution for their lifestyle, both in terms of the energy saving benefits and the client’s comfort as a sufferer of Raynaud’s Phenomenon.
The client therefore searched for a designer and found HMY on the PassivHaus Trust website.
What were the key challenges?
The single biggest challenge presented by the project was the combination of highly shrinkable clay and the wish to incorporate an ISoQuick style raft insulation. Many design solutions were reviewed, with the adopted option being a sacrificial bed of concrete to act as ground improvement on which the IsoQuick was laid. Whilst not the cheapest solution, it proved to be the least risk and least impactful on delivery programme.
What were the solutions?
The Ringmer PassivHaus was the first PH for the client, contractor and structural engineer, with this being the second built and certified PH for HMY and one of many for Enhabit.
What building methods were used?
The project was built using a Structurally Insulated Panel System (SIPS). The coordination of the SIPCO SIP system went well and the structural engineering was carried out with a high level of precision. A high degree of commitment from all team members resulted in a well-coordinated structure and an accurately delivered fabric.
How is the project unique?
This was the first new dwelling to be built based upon a new build permission following a Class Q Permitted Development conversion approval. It was also, to our knowledge, the first planning approval given with a condition for Passivhaus certification, which was agreed at Planning Committee with the client.
What are the sustainability features?
Air tightness was delivered at 0.6 ach @ 50 pascals, primary energy demand is less than 120kWh/m²/year with primary space heating demand below 15 kWh/m²/year, which equates to an energy use less than 10W/m² in peak demand.
