Thinking Buildings were the architects for this low energy four bedroom home situated within the open Staffordshire countryside, close to the village of Penkridge. The house replaced an existing cottage, which was demolished to make way for the new development. The original cottage was in very poor condition and, having been extended a number of times during the 20th century, the internal layout was fractured, muddled, and detracted from the original simple form of the cottage. In addition, the cottage was suffering from damp issues, and was generally a cold and unpleasant environment. Due to the number and quality of the various extensions, any renovations and improvements would have been very complicated and expensive.
The client wanted a highly sustainable and low energy building, utilising the principals of the Passivhaus standard. Passivhaus often aims for a very compact building form, to minimise mass to surface area, but due to the local planning policies, the restrictions on the first floor footprint brought its limitations. Thinking Buildings were still able to deliver on the clients aspirations for a home designed and built to the Passivhaus standard.
The house is quite unique in many ways. Using a fabric first approach, the building was designed with a highly insulated and airtight building fabric, achieving U-Values of 0.15 W/m2.K and an air permeability of 0.58 m3/(h.m2) @ 50 Pa, and a Mechanical Ventilation Heat Recovery (MVHR) system, reducing heat loss and minimising the need for space heating and cooling. The main structure is provided by clay blocks, which have a honeycomb style internal structure that makes them very thermally stable, regulating temperature fluctuation in the building in winter and summer. The remaining insulation requirements were provided by wood fibre insulation, a very low carbon embodied material. All the windows on this property are triple glazed, with sliding doors to minimise any thermal bridges in the envelope.
To further reduce the carbon footprint, a roof mounted Solar Photovoltaic-Thermal (PV-T) array meets the electrical demands of the property. Solar panels need to be kept cool to function efficiently, so these were combined with an Energy Earth Bank (EEB) below the footprint of the building, which was used as a heat sink for the solar array. The thermal energy stored within the EEB is later extracted using a Ground Source Heat Pump (GSHP), as and when it is needed, to meet the minimal heating and hot water demands of the house.
Some building features also directly benefit the immediate environment. The main roof of the building is a green roof, which contributes to regulating the internal temperature, and also absorbs rather than radiates solar heat. The species rich mat adds to the local ecology, supporting various fauna wildlife. To reduce any stress on the water network, and minimise flood risk, attenuation tanks are included on the site, to manage the flow of water into the storm drains at peak events.
All these technical aspects join together to form a very environmentally sensitive and efficient building, as well as a beautiful home which functions at the highest level.
Photographs courtesy of Norrsken
