Sustainability: Renovation vs newbuild
Sustainability: Renovation vs newbuild
My renovations of old buildings fuelled my interest in interior design eventually leading to my change in career, I also love contemporary architecture and dream of one day designing and building my own home. Research during my BA in Interior Design led me to investigate the sustainability of renovations and how well they actually perform, I have examined the sustainability of renovation versus newbuilds. Some argue that modern construction methods and materials dramatically outperform older buildings and that therefore it is more sustainable to build from scratch, whilst this may be true in some cases, the materials themselves generally have a higher embodied carbon than traditional materials. There are, of course, eco-friendly construction materials, but these are not yet widely available from builders merchants and often come at a premium. My sustainable sourcing directory contains a wealth of research and information on products available.
The vast majority of homes built today do not even attempt to be sustainable and many have a planned obsolescence, there is also a real worth in our historic buildings, which have proved themselves to be extremely flexible ensuring their longevity, the quality of materials and workmanship was often far better with far lower embodied carbon.
The construction of a building accounts for around 50% of a building’s lifetime greenhouse gas emissions, despite this, the UK government are incentivising mass housebuilding rather than the reuse and retrofit of our existing buildings. In a 2017 survey by the Ministry of Housing, Communities and Local Government it was estimated that 1.1 million homes are standing vacant, some of which are buildings of historical importance. Buildings are responsible for around 40% of the UK’s total carbon footprint, the larger percentage of this is through their usage. In addition to this, “the construction industry creates around 100 million tonnes of waste every year with a quarter of this going to landfill” (WRAP).
It is estimated that around 80% of homes in 2050 are already in existence, logically this makes the renovation and retrofitting of our homes far more relevant in reducing our carbon emissions particularly given that “12% of the homes built in 2018 were rated EPC C, whilst 7% were rated D or below” (parliament.uk) largely due to a loophole allowing developers to build to pre-2013 building regulations.
Careful renovation and retrofitting of our existing building stock has the power to dramatically improve a building’s performance without resulting in the embodied carbon of building from scratch. Whilst there are limitations when dealing with an existing structure, particularly in the case of listed buildings, Historic England have found that “eco-renovations can reduce carbon emissions by over 60%”. SPAB point out that “old buildings are often constructed from materials with a lower embodied energy and that they have longer lifespans and are easier to repair”. The natural materials used in old buildings also make them more reusable and recyclable, for instance brickwork using lime mortar can be cleaned and reused unlike one built with a cement based product. Research by SPAB actually shows that old buildings have a natural thermal ability and that they perform dramatically better than the EPC tells us.
Whether building from scratch or renovating an old building materials will be required, but when dealing respectfully with an old building there are limitations if the building structure is to be protected. Old buildings were not designed to be airtight, Victorian solid wall construction was designed to absorb and release moisture, inhibiting this can cause damage to the building. Despite this, the reuse of an existing structure inherently contributes to a reduction in energy, more than this, it preserves our historic buildings.
A full eco-renovation is, in some cases, not possible, where adding insulation, for example, could result in the loss of original cornicing or window surrounds, but there are always improvements that can be made. Simple strategies such as draft stripping windows and installing shutters or heavy curtains can “reduce leakage and drafts by 80%” claims P. J. Godwin. The installation of energy efficient appliances and lighting should be specified as standard, likewise water-saving fittings should be chosen.
Modern technology can further assist energy efficiency, heating controls, such as zoning the system and the use of smart technology can further improve efficiency. Whilst it may not always be allowable to replace original windows with double glazing, secondary glazing can often be added and in recent years English Heritage are far more supportive of the installation of solar panels on listed buildings.
Selection of materials is complex in a sustainable build of any type, there are often trade offs to be made, where a material may have higher embodied energy but perform far better. Green washing is also an issue, most companies make claims about their sustainability but the issue is complex and requires in-depth research to gain a full understanding. The reuse of an old building often supplies the designer with a palette of sustainable materials, already on site. Reuse is perhaps the most important part of sustainability as it results in minimal carbon emissions and reduces waste.
There are a wealth of reclaimed materials, fixtures and fittings available, whilst it would be virtually impossible to avoid sourcing nothing brand new, the majority can be sourced secondhand, often saving money or resulting in the procurement of design classics. It has become easier to source ethically with labelling systems in place measuring the eco credentials of products, but attention still needs to paid to things like transportation, which are difficult to measure due to the project’s location.
Wall finishes need to be chosen carefully, vinyl paint is not only higher in VOC’s but also inhibits the breathability of traditionally constructed walls. Choosing a high quality low VOC paint will ensure good coverage reducing the quantity required and the labour costs in decoration.
Old buildings have been shown to perform better than was previously thought and to be capable of a vast improvement in energy efficiency. Small alterations can make a difference and with a little knowledge of products available can have a minimal effect on the budget. There are of course unforeseen issues when renovating an old building which can have consequences on the budget, but in my experience most of these are visible and generally have an obvious cause, such as a damp patch caused by a leaky gutter.
Interior designers should be taking the lead on eco-renovations, researching and making themselves aware of new technologies and products. I firmly believe that things like heating, ventilation, insulation and windows should be within our scope, we are increasingly concerned with wellbeing and need to apply that to the building fabric rather than just in finishes, fittings and aesthetics.
Wellbeing in interiors is achieved through so much more than biophilic design, starting with a structure built with natural materials that was designed with passive ventilation and breathability improves indoor air quality. Our ancestors had a greater knowledge than we credit them with, using chimneys as much more heating as to extract stale air from the building. Sash windows, for instance were designed to be opened at both the top and the bottom allowing cool air to flow in and the warm air to exit from the top creating air circulation.
Many of the original features still work from a technical point of view and aid the heating, cooling and ventilation of the building. Modern technologies also have a place and can elevate the eco credentials of a building, by combining new and old I believe we have the most sustainable solution to housing, but we must have an understanding of how these buildings work to ensure we don’t damage the structure.
Only a handful of sustainable new buildings are built each year in the UK which are largely self builds, although with our carbon zero targets this is forecast to increase by 60% in the coming years, just like our old buildings, most new builds will require retrofitting to reduce their emissions. Interior designers need to consider future proofing buildings at the very least, even if clients aren’t ready to invest in greener heating systems consideration can be made for this to be easier in the future. By taking small steps now we can aid the transition to carbon zero in the future and improve the wellbeing in homes now. Every project is an opportunity to create a more environmentally responsible building, if we miss these opportunities it is likely that the materials used today will become tomorrow’s landfill.