Barratt Developments, the UK’s largest housebuilder, has built a unique flagship zero carbon home concept called the Zed House that will be occupied and monitored to assess its performance. It is the first new home in the country built by a major housebuilder to go beyond the new Future Homes Standard  by delivering a carbon reduction of 125% . Last year Barratt Developments announced that all of its new homes will be zero carbon by 2030 and this flagship concept is the first step in achieving that.
Darren Evans partnered with Barratt Developments on the project to carry out SAP calculations on all variants of the building covering building materials, air permeability, heating, water, PV and renewables. These calculations enable accurate forecasting of carbon reductions, performance relating to the Building Regulations and the Future Homes Standard and what this actually means in financial terms. Once the costing analysis was complete and specification of the Z House was finalised, the data was compared to a house built to 2013 standards and a typical Victorian build, to give a percentage improvement is 127%, and a SAP rating of 109. A SAP rating of 100 is equal to 100% regulated emissions. So, roughly this means that the PV system coupled with the battery storage system will generate more electrical energy than is consumed by the heating, hot water, lighting, and ventilation system.
This energy production is enough, that it is estimated to produce 1521 kWh/yr excess towards the unregulated energy of the home (SAP estimated at 3555/annum). Meaning the remaining electrical consumption is estimated at 2043kWh/yr @ £0.15/kWh = total resident bill of £305/yr + about £90 in standing charges. Bills = £30 a month roughly.
Brandon Wipperfurth, Senior Sustainability and Energy consultant at Darren Evans explains: “We modelled the Z House in both current and future regulations, and what was needed to achieve regulated operational net zero. The combination of battery storage and PV will keep residents running costs under control, and we have analysed this based on projected electrical consumption. The fabric and heat pump technology controls space heating demand and peak energy demand and makes the property's water consumption much more efficient all year-round. We also value engineered different approaches and options with Barratts so they could see the different approaches available in the marketplace and understand fully what their options were.”
The Zed House has been developed as an industry showcase home to demonstrate what is achievable, particularly from a mainstream, volume housebuilder. The new home was built with over 40 leading industry partners from across the housebuilding, sustainability, and technology sectors, all helping to broaden knowledge in zero carbon living with the lessons learnt from the construction being shared across the industry. Partners included Darren Evans, the University of Salford, GTC, British Gypsum, Octopus, Nissan and Mitsubishi, plus a host of other important suppliers.
The new house features cutting edge technology such as overhead infrared panels that provide instant zero carbon heat, new air powered showers that will save families hundreds of pounds per year in water and heating bills, plaster which eliminates pollutants giving cleaner, healthier air, a fridge which keeps the right humidity resulting in 60% less food wastage, and innovative heated skirting boards delivering 10% more heat than traditional radiators whilst also saving space.
The Zed House was constructed using the latest building methods incorporating Modern Methods of Construction (MMC) such as closed panel timber frames with highly insulated cladding, factory fitted windows and offsite panelised masonry ground floor wall panels, reducing the need for bricklayers and the time it takes to build by half. And it includes the most modern sustainable housing technology such as an air source heat pump, EV charging points, PV solar panels and battery storage.
The move to achieve net zero in construction is a once-in-a-lifetime opportunity. Creating more energy-efficient and sustainable buildings does not need to cost the earth. By changing how we think about building specifications, we see time and time again how it’s possible to exceed energy and sustainability targets without excessive costs.
To find out more about net zero carbon and the benefits of sustainability modelling for your development, contact us to start a conversation today!