7 months ago

Insulate Magazine Issue 14 - January 2018

Featuring exclusive articles, standing out from the crowd, NIA conference review, keeping everything moving and Review, Reflect and Reset the new year edition of insulation provides a kick start to 2018...

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The only independent insulation industry trade magazine Insulate Columnist Decarbonisation and Building Regulations Compliance By Anthony Dale, Energy Assessor, Darren Evans Assessments This year saw Britain have its first ever day without coal power since the industrial revolution; a significant milestone in our march towards ambitious climate change targets and reducing greenhouse gas emissions. As we decommission coal-fired power stations and remove coal from our energy mix - in favour of renewables - the emissions associated with electricity generation are decreasing. This has a knock-on effect when assessing compliance with building regulations as fixed values are used for electrical emissions. The growing disparity between the real world and this fixed value will lead to a greater disparity between effective design for real world conditions and design for building regulation compliance. The higher proportion of renewables on the grid and a lower proportion of carbon intensive coal generation will bring down the amount of CO2 produced per kWh of electricity generation (emission factor). This will have an effect on the emissions associated with our built environment. All new buildings in the UK have to comply with Part L of Building Regulations and the estimated emissions of these buildings are a key aspect of compliance. If a building uses grid electricity then its’ emissions will, in part, depend on the energy mix of the UK’s national grid. Any benefits from offsetting electricity use (eg. Solar photovoltaics) will also be determined against this grid electricity emission factor. The current compliance tools for both residential and commercial buildings use the same emission factor of 0.519 kgCO2/kWh, taken from SAP 2012, to determine the CO2 produced from grid electricity. This is a fixed value used to determine compliance with Part L. As the grid moves towards a higher proportion of renewable energy the actual emission factor will move away from this value used in compliance tools to a lower figure. A building that uses, for instance, an Air Source Heat Pump, which utilises grid electricity, will therefore have lower emissions in reality than the compliance tool will suggest. A combined Heat and Power unit will have the reverse affect as it generates its own electricity, normally from gas, instead of importing grid electricity. The emissions from gas will be constant, but as the grid becomes ‘greener’ there will be less-and-less benefit, in terms of emissions, from on-site generation as the emission factors of both forms of generation move closer to each other. This would increase the emissions of buildings using CHP in the future relative to those built today. There is also the topic of regional emission factors. An area such as North West Scotland, with large amounts of renewables on the grid, but a relatively low demand, will have a very different regional emission factor than some of the large urban centres of southern England where demand is high and renewables comparatively low. This difference between emissions estimated in compliance tools and emissions in reality pose difficulties for stakeholders, specifiers, energy assessors and end clients. The current emission factor used in compliance software is due to be updated for the newest version of the methodology next year. However, compliance tools need to use a fixed value to ensure comparable assessments, but the energy mix is changing so fast and the uptake of renewables is becoming so rapid that the emission factor for grid electricity is going to continuously fall year-on-year for the foreseeable future. A greater emphasis therefore needs to be placed within, and outside, the industry to highlight the difference between an effective assessment for compliance with building regulations and the sustainable design for the lifecycle of a building. 32

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