Case Studies of Low and Zero Carbon homes
The following section illustrates a number of examples of dwellings built to the standards for low carbon retrofit and new build. These projects typically have delivered energy and CO2 performance, well in advance of what has been required by building regulations. These examples include a range of approaches adopted, and are intended to illustrate the differing of approaches that have been adopted to reducing energy and CO2 from domestic buildings.
Code for Sustainable homes level 5 – Parkfield, Thurlestone, Devon, UK
Figure 1 Code 5 passive social housing development -Thurlestone South Devon (SDC, 2014)
The project included a requirement to achieve CfSH level 5, meaning zero CO2 emissions from regulated emissions (heating lighting, hot water, pumps and ventilation). This also included requirements to reduce water usage to 80l per person; via rainwater harvesting, along with a range of other exemplar sustainable features. The project was for a small housing association social housing client.
The project includes 4 dwellings in the form of 2 pairs of semi- detached dwellings, each 3 bed/ 5 person. The build uses a modular timber frame system, manufactured offsite under factory conditions in Ireland. This way of building allows a rapid and efficient build process, reducing waste and enabling foundations and frame to be built simultaneously.
The aim of the project was to demonstrate the potential for exemplary sustainable housing to be delivered for affordable and social tenants in a rural location, typically with no gas grid connection. The approach adopted Passivhaus principles and specification, although did not pursue Passivhaus certification, due to the costs of some passivhaus certified components, the costs of certification and the constraints it places on the buildings orientation and layout (SDC, 2014) Performance/U-valueDetailDate Completed Spring 2014Description4, 3 bed properties (92m2)Social housing for subsidised rentClient/DeveloperSDRHA – Housing AssociationSmall rurally focused HAConstructionTimber FrameLightweight, offsite manufacturedDwelling Emission Rate DER ≤ -5.57 kgCO2/m2<ZERO CO2 from heating, lighting, hot water and fansWalls0.12 W/m2k300mm recycled cellulose newspaper insulationRoof 0.11 W/m2k400mm recycled cellulose newspaper insulationWindows0.86 W/m2kTriple glazed passivhaus certifiedFloor0.10 W/m2kPassive slab eliminates wall-floor thermal bridgeHeating SystemElectric air in MVHR DuctRemoves need for central heatingVentilationMVHR – 95% heat recovery, Fan power 0.4W/l/sImprove air quality and heat retentionSolar thermal16 evacuated tubesReduced CO2 and 60-70% hot waterPV panels15 panels -3.975 kW – 3204 kWh approx.Reduced CO2 and free electricityCode For Sustainable Homes88 points from 107 – Level 5Demonstrating exemplar sustainability across the 9 categoriesBudget (92m2 house)£132,500 per propertyTurnkey £1,440/m2 including feesFigure 2 technical specification for CfSH level 5project, Parkfield Thurlestone (SDC, 2014)
SDC. 2014. 14-17, Parkfield, Thurlestone, Code 5, Social housing project [Online]. Sustainable Design Collective. Available: https://www.sustainabledesigncollective.co.uk/portfolio/parkfield-thurlestone/ [Accessed].