The need for us to find new, more sustainable ways of designing, building, and renovating our homes is undeniable. Adopting circular economy principles can help us achieve this goal.
At present, the construction sector is responsible for 32% of all waste generation in the EU. This is a truly staggering statistic, especially when compared to the household sector, which produces only 8% of waste, and even the manufacturing sector, which is responsible for only 11%.
At the same time, the built environment accounts for about 50% of all raw materials and resources used each year in the EU. The exploitation of these (often finite) raw materials can be extremely detrimental to the climate. For example, the production of concrete, the main material used in construction throughout most of Europe, accounts for around 8% of annual greenhouse gas emissions in the EU.
Circularity means avoiding the extraction of new raw materials, and instead finding ways to extend the life of existing products and materials, as well as repurposing them, upcycling them, or recycling them. In essence, it is about avoiding the generation of waste of any kind. In the built environment, this also includes avoiding, as much as possible, the use of heating and electricity, which are too often related to the use of finite and carbon-intensive fossil fuels. This can be achieved by the use of so-called “passive” design solutions.
In recent years, Housing Europe has actively begun promoting the use of circular principles. In this regard, our work on the DRIVE 0 and HOUSEFUL projects has helped to expand our knowledge on this topic, which in turn helps us to inform our membership. Of course, social housing providers from around Europe are not simply standing still, and there are already many examples of innovation in the use of circular solutions from our members that we can point to.
The award-winning ‘Life Reusing Posidonia‘ project from the Balearic Institute for Housing (IBAVI), which shows what can be achieved by focusing on the use of reused and bio-sourced materials, as well as the recent ‘Circulair Bouwen‘ project from Dutch social provider De Woonplats, which made use of a number of circular housing solutions, are just two of the many examples of exemplary projects in our sector.
The HOUSEFUL project is an EU HORIZON 2020 funded initiative. Its core aim is to “develop and demonstrate an integrated systemic service (HOUSEFUL Service) composed of 11 circular solutions”. In simple terms, the project has developed, implemented, and is currently testing a highly-circular system for building renovation. This includes practical solutions to reduce the use of new raw materials, plan for the future deconstruction of buildings (in order to reduce waste at the end-of-life phase), collect, treat, and reuse rainwater and wastewater, convert bio-waste into bio-gas, make the most of nature-based solutions (NBS), and renovate buildings to be as efficient as possible, by using passive standards and techniques. Renewable energy generation is also key to the success of the HOUSEFUL Service.
The package of circular measures developed in HOUSEFUL will have the expected result of reducing the amount of construction waste destined for landfills from 40%, to 10%. It will allow for the recovery and reuse of over 95% of organic food-waste from homes, as well as the capture, treatment and reuse of over 90% of rain, grey, and black water. Non-renewable-based primary energy consumption will also fall by at least 50%, which will result in a reduction of CO2 emissions produced by the homes by roughly 60%.
Turning to DRIVE 0, the focus is on developing circular deep renovation solutions and supporting consumer centred business models for 7 specific study and demonstration cases as real environments. The solutions include innovative technical products and construction processes, combined with process optimisation and digitalisation (with BIM as a main carrier), and innovative business models.
The selected cases are already being prepared, with each of them having a specific local driver for the need of a holistic and circular deep renovation, which is translated in case specific challenges and tasks and case-specific key performance indicators.
The results of the project are expected to trigger an average of 75% of energy savings from deep renovation (a total of 0,645 GWh/year) and a reduction in greenhouse gas emissions (total 20868,3 tCO2-eq/year). All renovated buildings in the pilots are renovated to a level of NZE or ‘zero on the meter’. However, the DRIVE 0 holistic circular renovation strategy will lead to a total high performance of the renovated buildings, including energy, indoor environmental quality and wellbeing.
DRIVE 0 will also allow to reduce the on-site time requirements for renovation works by 20% compared to current national standard practice. The use of prefabrication and plug & play smart connectors can lead to an important cost/output optimisation, leading to an improvement of over 35% compared to the traditional renovation process. Prefabrication can lead to an enhanced quality control of the automated BIM controlled production process, which drives a reduction of construction failure costs to less than 5% compared to the traditional 15 to 20%. The application of prefabricated components reduces the number of stakeholders involved in the deep renovation process (e.g., the replacement of the traditional contractor by a direct application by subcontractors) leading to possible cost savings of 10%.
However, the success of the HOUSEFUL and DRIVE 0 projects will be measured in terms of how successful they are in inspiring others to take up their mantle, and to replicate their techniques. However, in order to maximise this, it is important for project leaders to understand what the main opportunities and constraints are for replication in the different countries of Europe.
At the recent International Social Housing Festival in Helsinki, a workshop was organised by Housing Europe, HOUSEFUL and DRIVE 0, in order to present the work of the projects, better understand the needs of different European regions in terms of renovation and the sustainability of buildings, and finally to see which of the circular products and solutions that have been developed by the two projects could be of use in each local context.
The workshop divided participants into regional groupings, where factors related to climate, energy use, and available resources were more closely aligned. Participants were asked to review the current needs in their region. They were then introduced to the different circular solutions currently on the market. In the final step, participants chose which solutions could be best adapted to their context. It was interesting to see the different outcomes arrived at by the different groups, based on where they saw the challenges and opportunities to be.
One of the main takeaways from the session was that, while interest in circularity and climate sustainability is high, knowledge of the actual ways to achieve good outcomes in that regard is relatively low. The “circular economy” is therefore something that is often discussed by the likes of EU officials, but what that means in real terms and how we take practical steps to realise the stated ambition is still unclear, even for those who work in the housing sector.
However, the workshop also showed that the aforementioned “interest” can be effectively harnessed and converted into the motivation required to achieve tangible action on the part of building owners and developers. In this regard, information is key.
One of the main tasks for both HOUSEFUL and DRIVE 0 over the coming months will be the topic of replication. We need to make sure that the knowledge we have accumulated, and the products and techniques we have developed, help to bring about a real change in the way we plan and execute building development and renovation projects.
To download the full report: Report_Circular renovatoin workshop_DRIVE0_HOUSEFUL_Final.
(This article was written by Dara Turnbull and Clara Mafé Cortés from Housing Europe. The original version is available at this link).