ZERO CARBON | ILKE HOMES ILKE HOMES FIVE STEPS TO ZERO COST 1. Design for ease of manufacture modules are designed for speed and ease of assembly on its factory production lines. It has subsequently cooking and to power devices such as televisions. Ilke Homes use of an ASHP reduces the cost of energy by eliminating the need for a gas connection and its associated standing charge. It also enables ASHP to charge the hot-water cylinder at times when electricity tariffs are lower, which also helps to minimise costs. However, to get to zero, Banks says additional PVs are required as is electric battery storage. The battery enables occupiers to avoid buying electricity when it is expensive and to sell excess power generated by the PVs back to the grid at the most profitable time. Our modelling has shown that to get to zero energy bills you need: smart controls to take advantage of variable electricity tariffs; more solar PV to increase electricity generated; and battery storage to [enable occupiers to] maximise the self-use of PV-generated power, Banks explains. And, when you are exporting, the battery enables you to export at those times that will give you a higher export tariff. Banks says the housebuilder has a range of sites in the pipeline containing large numbers of zero carbon homes. These will enable the firm to optimise the use of PVs, battery storage and their controls in time for 2030. As the costs of energy change, our zero bills target may get harder or easier to achieve, although as the output from solar PV technology gets better and ASHP performance improves that should make the journey easier. Embodied energy Along with targeting zero carbon and zero bills, ilke Homes is also looking to future-proof its buildings by targeting embodied carbon too. Our embodied technology. This includes the addition of a hot-water cylinder, resized pipe bend radii to limit pump losses. 2. Materials the cost of solar panels has dropped considerably. Today a solar panel costs the same as a high-quality roof tile. By integrating the panels, ilke Homes can omit the cost of the equivalent area of roof tiles. 3. Labour unlike traditional housebuilders that use subcontract labour layers of overhead and margins and means workers have a better focus on the product, design and, critically, processes and quality standards. 4. Processes according to Banks, the construction industry has seen the lowest rise in productivity of any sector in the UK whereas, in assembled in a modern manufacturing environment. Working in a warm, dry factory with the right tools, following the right processes, transforms 5. Continuous improvement ilke Homes has a team of manufacturing improve quality, performance and productivity, and to lower costs. carbon figure is lower than that of a traditionally constructed home, he says. Cradle-to-handover emissions are currently 261kgCO2.m-2 per year, which is already below the RIBA 2030 target and LETI stretch goal for residential buildings, says Banks. Were targeting a 75% reduction in the whole-life carbon emissions of our homes by 2030. Perhaps the biggest challenge ilke has in delivering its zero goals is to do so at zero additional cost. Zero cost means no additional build costs compared with traditional construction, says Banks. To achieve this, it is bringing the productivity, efficiencies and continuous improvements in manufacturing to its housebuilding facility. It aims to exploit advances in manufacturing processes to improve its efficiencies combined with an increase in its use of robotics. This, combined with expected reductions in the cost of key components such as solar panels and batteries, should help ilke move ahead on its journey to achieving its zero additional cost target. CJ 46 September 2021 www.cibsejournal.com CIBSE Sep 21 pp44-46 ilke homes.indd 46 27/08/2021 10:17