A client’s desire to build a carbon negative house, incorporating a blend of innovative design and technology solutions, led to the design and build of Tump Barn, a residential property in Herefordshire.

EDGE were commissioned to satisfy the project’s design and environmental objectives in accordance with relevant planning policy. Taking an integrated ‘whole-building’ design approach, EDGE ensured that the maximum use of energy efficient measures were built into the design at the very start, in order to achieve :

  • an efficient and sensitive renovation of a detached, steel frame semi-submerged barn,
  • planning permission for a carbon negative build requiring exceptional design and located in open countryside,
  • conversion to a single residence,
  • high insulation levels and air-tightness,
  • utilisation of air source heat pump and photovoltiac cells technology,
  • installation of low energy appliances and
  • reduced water consumption.

The resulting design addressed the inadequacies of the client’s existing house, with EDGE providing a client-specific, site-specific solution which not only delivered on a carbon negative footprint, but responded to a strict internal design brief requiring:

  • separation of ancillary and living spaces,
  • open plan living area,
  • centralised entertaining spaces and
  • privacy.

Environmental Specification for Planning

  • Design Air Test Value: Design permeability 2. m³/hm².

  • Floor: U-value floor 0.1 W/m²K 13.

  • Walls: U-value walls 0.11 W/m²K.

  • Roof: U-value roof 0.11 W/m²K – to be calculated in detail.

  • Windows: Windows WER ‘A‘ Transmittance 0.41 U-value 1.4 W/m²K.

  • Heating Systems: Air Source Heat Pump and biomass boiler.

  • Photovoltaic: To reduce the reliance on mains electrical connection a solar photovoltaic array will be located adjacent to the house.

  • Battery Storage: Tesla Powerwall 2 (or similar) will provide storage of on-site generated electricity through the photovoltaic array.

  • Lighting: 100% low energy fittings.

  • Thermal Bridging: Accredited Construction Details were adopted.

  • Water Consumption: Design water consumption less than 125 litres per person per day.

  • Water Treatment: Klargester BA BioDisc sewage treatment plant using rotating biological contactor (or similar) to produce wastewater qualities of better than 15mg/l BOD*, 25mg/l SS and 3.8mg/l ammonia.