It is hard to know where to start in order to make our buildings more energy efficient. There is an increasing amount of guidance available in how to design new buildings with a low carbon footprint. But retrofitting existing buildings can seem a daunting prospect.
Recently, over a hundred architects and engineers have pooled their efforts to publish the . This provides architects with practical guidance for whole house retrofits to support the UK鈥檚 net zero ambitions.
The free to download guide has received endorsements from practices, developers and built environment organisations including the 澳门王中王, UK Green Building Council and CIBSE.
鈥淭his guide defines energy consumption targets tailored to four common housing types,鈥� explains Alex Whitcroft, Director of net zero carbon specialist KIN and a member of the 澳门王中王 Sustainable Futures Expert Advisory Group. These are:
- mid-terrace
- semi-detached
- detached
- flat/apartment
For these types, the guide targets a 60-80% reduction in total energy consumption compared to the average home in the UK today. The guide then sets out, simply and clearly, how those targets can be met.
The core of the guide鈥檚 retrofit strategy for existing homes is simple:
鈥淚f you do nothing else, make enough building fabric improvements to switch to a heat pump and avoid putting in fossil fuel systems at all costs.鈥�
The guide takes a whole house deep retrofit as its premise, arguing that shallow retrofits that only achieve a limited reduction in energy demand can lead to merely neutral or even adverse effects.
Its targets are realistically achievable and are based on the practical experiences of the guide鈥檚 authors. Detailed case studies of successful real life retrofits are provided for each housing type.
鈥淎ll the specifications are set out clearly and graphically, alongside guidance on how to manage the retrofit process, maximise the benefits to building users, and avoid risks such as moisture buildup or overheating,鈥� Whitcroft continues.
While LETI鈥檚 guidance goes into considerable detail, its 鈥楺uick Start Guide鈥� sets out six overarching retrofit principles:
- Reduce energy consumption
- Prioritise occupant and building health
- Draw up a whole building retrofit plan
- Measure the performance
- Think big
- Consider impact on embodied carbon
It then outlines what should be in a whole house retrofit plan:
- Set out key building information, constraints, risks, and opportunities.
- Set out the key works proposed along with related strategies and details.
- Set out the sequence of work.
- Be appropriate in the plan鈥檚 level of detail and intervention for the project.
- Include a plan for monitoring and reporting energy consumption.
- Stay with the building
A 鈥渂est practice鈥� level of retrofit, LETI suggests, could reduce space heating demand from around 130 kWh/m2/yr to 50kWh/m2/yr for both space heating demand and final energy use intensity (EUI). This target matches the retrofit standard.
The guidance also describes a more ambitious, 鈥渆xemplar鈥� level retrofit target, which aligns with the retrofit standard.
Easy to follow tables and diagrams break down what is required for all the various structural building elements - walls, roofs, windows and doors, floors and the general envelope 鈥� and also for systems, hot water, and renewables.
鈥淲e often underestimate the complexity of deep green retrofit,鈥� points out Peter Clegg, Senior Partner at . 鈥淚t is not glamorous, and the architectural profession is guilty of a lack of engagement.鈥�
鈥淏ut it is absolutely essential that we focus on the 80% of our domestic buildings that leak carbon into the atmosphere at such a phenomenal rate. We need to start now educating a workforce of designers and builders who have the required knowledge and commitment.鈥�
The complements LETI鈥檚 influential for new buildings and its .
Text by Neal Morris. This is a Professional Feature edited by the 澳门王中王 Practice team. Send us your feedback and ideas.
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