What is retrofit?
Both climate change and fuel poverty can be combatted by improving the energy efficiency of our buildings. It is approximated that 17% of the UK’s total carbon footprint can be attributed to heating within domestic properties alone. Statistics such as this, combined with national carbon commitments and an increased public awareness of both the cost of living and the climate crisis, have resulted in recent changes to the way in which construction works must be undertaken. In 2021, consultation on the long-awaited ‘Future Buildings Standard’ was concluded. This consultation was primarily focused on changes to Part L (conservation of fuel and power), Part F (ventilation) and Part O (overheating) of The Building Regulations 2010.
The first stage of the changes, which came into force in June 2022, aims to facilitate a pathway to highly efficient buildings which are zero carbon ready. For example, Part L now requires new homes to produce almost a third less carbon. With additional changes expected over the next two years, the target is for new homes built from 2025 to produce 75-80% less carbon emissions than required under current regulations. In line with the Sixth Carbon Budget recommendation, the result means that in the longer term, as the electricity grid continues to decarbonise, future homes should require no further retrofit work to enable them to operate on a zero carbon basis.
These changes to the Building Regulations are a step in the right direction. After 2025, the UK will no longer be building new homes that will be unable to operate on a net zero basis by the year 2050. The fundamental problem, however, is that 80% of the buildings that will be in existence in 2050 have already been built today. This means that the core issue sits with the existing UK building stock. It is for this reason, that ‘retrofit’ is highlighted as one of the “essential planks, that we can be confident net zero will depend on”, within the UK government’s ‘Net Zero Strategy: Build Back Greener’.
Retrofit can be defined as the upgrading of a building to enable it to respond to climate change. The London Energy Transformation Initiative (LETI) was originally established in 2017, to support London’s transition to meet Net Zero Carbon. In October 2021, LETI released their ‘Climate Emergency Retrofit Guide’, within which it is stated that “retrofit may involve the repair, renovation, refurbishment and/or restoration of the building. The aim is to both mitigate against climate change and ensure the building is well adapted for our changing climate”. In addition to mitigating emissions and reducing fuel poverty, retrofit works can have wider benefits. These include improvements in health, wellbeing, and household disposable income, and reductions in anti-social behaviour and national unemployment.
Retrofit works can be undertaken to varied levels of depth. For example, a limited or ‘shallow’ retrofit might focus on performance optimisation, with only basic remodelling, replacement, or adaptation of existing building elements. Shallow retrofits tend to focus on a single aspect or feature (lighting upgrades, optimisation of building controls and operation, etc). A fully specified or ‘deep’ retrofit might allow for fully extensive wall, floor and roof insulation to the entirety of the property, with improved doors and windows and a new air source heat pump system, in lieu of a gas-fired boiler.
It is stated within the PAS 2035 specification (see next article) ‘Retrofitting dwellings for improved energy efficiency’ that retrofit works can range from the single improvement measures, such as replacement windows, “to whole-house projects involving the installation of multiple measures”. When considering the scope of retrofit works, both ‘deep’ and ‘shallow’ projects should be contextualised alongside the UK’s target of ‘near zero’ emissions from buildings by 2050. It is widely acknowledged that isolated single improvement measures or ‘shallow retrofits’ do not result in the required carbon reductions, which are typically between 80%-100% for dwellings and 60%-100% for domestic properties. Additionally, shallow retrofits are identified as one of the fundamental problems, when considering the widespread uptake of retrofit across the UK. This is because the single measures are often undertaken at the wrong time and place, with an insufficient understanding of thermal bridging, ventilation and potential defects.
It must, however, be acknowledged that budget is often a determining factor when it comes to the level of retrofit works undertaken. A lack of funding often results in shallow retrofit. It is for this reason that leaders in retrofit guidance recommend that ‘Medium Term Improvement Plans’ (MTIPs, or similar) should be put in place for every property, with deep retrofit as the end-goal. MTIPs make it possible to reach this end goal by undertaking limited improvements in the short term, whilst identifying further improvements for implementation over a 20 or 30 year period. MTIPs essentially identify an appropriate order for undertaking single improvement measures, so that the homeowner or developer has a high quality, cost effective route to deep retrofit in the future. This process is referred to as “step-by-step retrofit” within the Plentific report ‘Retrofitting the Property Sector’.
If you are planning on undertaking energy efficiency improvements to your property, it is vital that you are aware of the associated risks. These can materialise in the form of defective building fabric, under performance, financial liability and adverse health implications. At Develeco, we are aware of these risks and we are able to implement clear and cost effective retrofit strategies, in accordance with the PAS2035 framework.