In addition to efficiency and consistency, sufficiency measures are needed to achieve climate neutrality. This means moving away from "more is more" and towards a moderate, i.e. sufficient use of resources.
With the help of the "Sufficiency evaluation matrix for residential buildings", you can determine and optimise the key sufficiency properties during the planning process. The free download comprises seven subject areas with 23 criteria and 58 indicators. It is supplemented by an overview, which is also available free of charge.
When developing the set of criteria, the focus was on making the assessment and quantification as objective and manageable as possible during the planning process, which is why existing assessment methods from the DGNB and NaWoh certification systems are used in many places. The overview and matrix were created as part of a master's thesis on "Assessability and life cycle assessment influence of sufficiency in building areas", submitted by Patrick Zimmermann at the Technical University of Munich, 2018.
The pressure to act in the building sector to achieve climate neutrality and other sustainability goals is enormous. So far, efforts in politics, research and practice have focussed on better thermal insulation (efficiency) and the use of renewable energies and renewable raw materials (consistency). However, these purely technical strategies are not enough.
Rebound effects are one of the factors that reduce the effectiveness of technical strategies. For example, per capita living space [1] has been increasing for decades due to smaller households, more property ownership and the empty nest effect. As the graph below shows, the increased space requirement offsets the savings achieved through efficiency and consistency [2].
In addition, the two technical solution strategies are not being implemented ambitiously enough and the time to massively reduce greenhouse gas emissions is now so pressing that all options must be exhausted.
Sufficiency comes into play as a complementary addition to technical strategies. It focuses on behavioural changes "that help to stay within the Earth's ecological carrying capacity, while changing the utility aspects of consumption" [3]. The aim is to absolutely minimise the ecological impact while maintaining an appropriate quality of life.
Purely technical energy-saving strategies are not enough. We have to adapt our demands and our behaviour. And use resources with moderation. The good news: anyone can achieve sufficiency!
For the building sector, "this means above all an appreciative, needs-orientated and environmentally friendly approach to what is available, i.e. space, material and natural resources and existing building fabric" [4].
"This means that there must be a cascade of decisions. In the first stage, this involves maintaining and renewing existing buildings. Only when the objectively proven functional, energy and design requirements can no longer be met in the renovated existing building will it be possible to expand the existing building in a second stage. And only if an extension of the existing building is also unable to fulfil the aforementioned requirements can a new building be the "ultima ratio" in a third stage in the future" [5].
Even if the technical approaches to efficiency and consistency were consistently utilised: This alone will not achieve climate neutrality in the construction sector. It will not be possible without a change in expectations and a greater appreciation of what already exists. Sufficiency does not mean a loss of quality of life, but a change in priorities.