This report is the first report of the ‘Energy Savings 2030’-project which seeks to help the Coalition for Energy Savings to produce a robust and timely input to the 2030 policy discussion. It brings together and summarises recent empirical evidence on costs and benefits of energy efficiency measures. The evidence gap in terms of reliable ex-post data is well known. In the majority of cases results from ex-ante modelling studies inform the debate. The research carried out for this report confirms the persistent gap in publicly available ex-post evaluations of energy efficiency programmes.

Global warming and environment problems caused by the excessive emission of greenhouse gases (GHGs), along with rapid economic development has attracted the attention of many countries and regions of the world. Reducing GHG emissions is essential to mitigate the threat of global warming. Household carbon (dioxide) emissions have been recognized as one of the most important contributors to climate change, with a significant impact on both the local and global environment, and various policy instruments have been implemented by governments to bring about the reduction.

Contemporary societies are facing a broad range of challenges, from pressures on human health and well-being to natural capital depletion, and the security of food, water and energy. These challenges are deeply intertwined with global processes, such as climate change and with local events such as natural disasters. The EU's research & innovation (R&I) policy is now seeking to address these challenges from a new perspective, with Nature-Based Solutions, and turn them into innovation opportunities that optimise the synergies between nature, society and the economy.

Pursuing economic targets of job creation, growth, and innovation while tackling global environmental challenges, has long been seen as impossible. However, any long-term economic competitiveness and security depends on the extent to which natural resources are used sustainably. Therefore, the European Union is investing in nature-based solutions to achieve this double goal. The difference between the prevailing economic model and a sustainable resource use has long seemed insurmountable.

Nature has provided humankind with food, fuel, and shelter throughout evolutionary history. However, in contemporary cities, many natural landscapes have become degraded and replaced with impermeable hard surfaces (e.g., roads, paving, car parks and buildings). The reversal of this trend is dynamic, complex and still in its infancy. There are many facets of urban greening initiatives involving multiple benefits, sensitivities and limitations.

Nature-based solutions (NBS) are increasingly applied to guide the design of resilient landscapes and cities to enable them to reach economic development goals with beneficial outcomes for the environment and society. The NBS concept is closely related to other concepts including sustainability, resilience, ecosystem services, coupled human and environment, and green (blue) infrastructure; however, NBS represent a more efficient and cost-effective approach to development than traditional approaches.

Increasing urbanisation, changing disease scenarios, and current predictions of climate change impacts require innovative strategies for providing healthy and sustainable cities, now and in the future. The recently coined concept, Nature-based solutions (NBS), is one such strategy referring to actions that are inspired by, supported by, or copied from nature, designed to address a range of environmental challenges.

We report on an original systematic review of 165 empirical, ex post studies examining policies that promote the development and use of low-carbon technologies. Policy is defined broadly to include diverse instruments (e.g., eco-labels, voluntary agreements, emission credits, and taxes), developed, administered, and promoted by state and non-state actors (e.g., cities, states, corporations, business associations, and non-governmental organizations) that are relevant to climate change.

This paper contrasts two perspectives on energy efficient home renovations from applied behavioural research on energy efficiency and from sociological research on homes and domestic life. Applied behavioural research characterises drivers and barriers to cost-effective renovations, and identifies personal and contextual influences on homeowners’ renovation decisions. Research findings inform policies to promote energy efficiency by removing barriers or strengthening decision influences.