The first address for energy-efficient building refurbishment


Anyone who owns a residential building wants to maintain its value and save energy costs. Yet energy-efficient renovation is a complex matter: How do I plan the project? What subsidies are available? Which craftsmen can I trust? In order to implement cost-effective and profitable solutions, you need experience.

We are working on a solution for this: One-Stop-Shops bundle the necessary competences and can help as needed.

What are One-Stop-Shops?

One-Stop-Shops facilitate energy efficiency renovations by being a single point of contact. They are able to fulfil all tasks associated with an energy efficiency renovation or organise that third parties will fulfil these tasks. This should help to simplify an energy-saving renovation of a building.

The One-Stop-Shops’ tasks range from planning and financing over commissioning construction work to supervision. How autonomous it is in these activities will be decided according to the customer’s wishes.

The One-Stop-Shops shall reduce non-financial costs (information and search costs, administrative costs) incurred by building owners. And it shall also increase the quality of energy efficiency renovations. This will be due to the experience and knowledge it has gained from organising a large number of renovations.

Background and Objectives

ProRetro supports owners of residential buildings who want to renovate their house. Within the project One-Stop-Shops are developed and put to test in five German cities and regions.

The German project partners are regional energy agencies and small and medium enterprises. Organisations from other European countries that have experimented with and implemented successful One-Stop-Shop business models support the German project partners. Peer-to-peer learning will ensure the project’s success. The project is coordinated by the Wuppertal Institute.

ProRetro aims to:

  • overcome barriers to residential energy efficiency renovations by offering new One-Stop-Shop services to customers in five German cities/regions
  • conceptualise, plan, implement and monitor and evaluate the new One-Stop-Shops
  • cover the whole customer journey of a building renovation from audit/advice, planning, contracting, implementation and monitoring and approval – and involve respective stakeholders/experts in the service offer
  • prepare their continuation beyond the project lifetime


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Scaffolding around a house to install thermal insulation on the facade

One-Stop-Shop: Guide for Energy Renovations

As part of the steps the European Union (EU) is taking to achieve climate neutrality by 2050, it has agreed on stricter requirements for the energy efficiency of buildings as part of reforming the Energy Performance of Buildings Directive at the end of 2023. Among other policies, the revised directive asks the member states to establish one-stop-shops for energy building renovations.

Renovation of an old half-timbered house

The One-Stop-Shop for Hanover Region

In the Hanover region, the One-Stop-Shop was offered through the Modernisation Partner Network. The local project team, consisting of the Climate Protection Agency of Hanover Region and proKlima – the enercity fund, was able to convince the Modernisation Partner Network of the benefits of the concept.

Aerial view of Bottrop

The One-Stop-Shop for Bottrop

The One-Stop-Shop for Bottrop, which was tested during the implementation phase of ProRetro, was able to build on many years of previous experience. Bottrop was selected as InnovationCity Ruhr in 2010.

Final workshop of ProRetro on 19 October 2023 in Berlin

The final workshop of the ProRetro project took place in Berlin on 19 October 2023. It was organised by the ProRetro team together with ZEBAU, which is a project partner in the One-Stop-Shop project I-HEROS also funded within the Horizon 2020 programme.

Picture of a single family home before and under renovation

A One-Stop-Shop for Wuppertal: Raumfabrik

Within the ProRetro project, Raumfabrik from Wuppertal has expanded its services in the field of energy renovation. The task of the implementation phase was to test the integration of the new services in practice.

A One-Stop-Shop for homeowner associations in Böblingen district

Thanks to the EU funded project ProRetro, Energieagentur Landkreis Böblingen, the energy agency in Böblingen district, now acts as a One-Stop-Shop for homeowner associations. In the case of an energy renovation of a residential building, it serves as a first point of contact and supports the renovation from the initial decision-making process to implementation.

Cityscape of Berlin

The ProRetro-One-Stop-Shop in Berlin – An overview of services

The ProRetro-One-Stop-Shop in Berlin is implemented in cooperation with BAUInfo Berlin. Owners of condominiums and their associations can get free and impartial advice regarding their ideas for an energy renovation.

Looking back at 2022

The year 2022 brought the ProRetro project successes and growing interest in One-Stop-Shops for energy renovation, but also new and unexpected challenges. In this blog post we look back at the previous year. The most significant success is that our implementing...

Speed Meeting in Hanover: For what we intend to do, we must become more

The challenges in the building sector to achieve climate protection goals are immense. In fact, the renovation rate in Hanover Region to make the building stock fit for the future is far below what is needed. A major factor driving this problem is the shortage of...
Renovation and reconstruction of Dutch apartment houses in Amsterdam

Reimarkt: A One-Stop-Shop for the Netherlands

Reimarkt is a One-Stop-Shop for energy efficiency renovations in the east of the Netherlands. The shop was founded in 2014 and has been involved in the renovation of more than 6,000 buildings. Its main specialization is the renovation of buildings owned by social...
Picture of a Swedish house under renovation

Klimatfastigheter: A One-Stop-Shop for Sweden

Klimatfastigheter Småland AB offers energy renovations of single-family houses, by managing the entire process from day one, on homeowners' terms and based on their conditions. With the help of Klimatfastigheter, homeowners lower their operational costs, increase the...
View of Paris

Île-de-France Energies: A One-Stop-Shop for condominiums

Île-de-France region includes Paris city and dense suburbs, rural areas and some other towns within a radius of 60 km around Paris. With 12 million inhabitants on 12 000 km2, it is one of the most densely populated regions in Europe. The Region counts 4.7 million...

Hauskunft: The One-Stop-Shop for Vienna

The RenoBooster project, led by the City of Vienna (Department of Technical Urban Renewal, MA 25), aims to increase the overall renovation rate of private housing in Vienna in order to contribute to the achievement of climate targets. It is funded by the EU under the...

Régie du SPEE: A One-Stop-Shop for Northern France

The Regional Public Service for Energy Efficiency of Hauts-de-France («Régie du SPEE») offers a complete service to massively increase energy renovation in private housing. A small revolution in the world of renovation since the offer is based on third-party...

A One-Stop-Shop for Toulouse: The “Maison de L’Énergie” opens its doors

I-HEROS (Integrated Home Energy RenOvation Service) is a project funded in the same Horizon 2020-programme as ProRetro. It develops an entirely integrated home renovation service for homeowners in Toulouse Métropole in the south of France. By increasing the...
A picture of a cityscape in Berlin with the Berlin television tower in sight

A One-Stop-Shop for Berlin

As part of the EU-funded project ProRetro, the Berlin Energy Agency (BEA) is developing a new service for owners of condominiums and their associations in Berlin. The goal is to support them in the energy renovation of their buildings. This will help to fill a gap in Berlin’s existing range of advice services in the future.

Hanover Region: More convenient and faster energy renovations

A large number of public and private advisory services offering support for energy renovations exist in the Hanover Region. The Climate Protection Agency Hanover Region and proKlima – the enercity fund want to bundle these services and make them more well-known. By...

First-hand feedback: Focus groups generate new insights

The ProRetro project team held four focus groups in September and October 2021. Their goal was to discuss the business models that were developed in the first year of the project with potential customers and thereby learn how the concepts are received. The implementing partners invited potential customers to participate in the virtual group interviews. The predominantly positive feedback confirms the project’s approach. However, queries also showed that some questions remain to be addressed. …

Zur Hälfte saniertes Wohngebäude

A One-Stop-Shop for energy efficiency renovations in Bottrop

Building owners in Bottrop wishing to renovate their residential building in terms of energy efficiency can take advantage of the wide range of support services offered by Innovation City Management GmbH (ICM). In particular, these include Energy advice, advice on...

Raumfabrik AG becomes a One-Stop-Shop

From fall 2021 on, Raumfabrik will expand its service "renovation, refurbishment, conversion – from a single source" by a new focus on energy efficiency and sustainable building materials. Thereby, Raumfabrik becomes even closer to an "all-inclusive" one-stop-shop for...

The project’s structure

Progress steps

The partners and their roles

Introducing our partners

Wuppertal Institut

The Wupppertal Institute undertakes research and develops models, strategies and instruments for transitions to a sustainable development at the local, national and international level. Sustainability research at the Wuppertal Institute focuses on resources, climate and energy related challenges and their relation to economy and society.

Country: Germany

Role in project: Overall coordination of ProRetro, Market Analysis, Monitoring & Evaluation


e7 Energie Markt Analyse

e7 is a private research and consulting company working in the fields of energy efficient construction and renovation, energy efficiency services and energy economics. The focus of e7 lies on specific questions and challenges connected with energy efficiency, use of RES and climate protection. 

Country: Austria

Role in project: Lead of Peer Support


Berliner Energieagentur GmbH

The Berliner Energieagentur GmbH (BEA) is an energy service company located in Berlin. As part of its three business divisions Consulting, Contracting and International Know-how Transfer BEA develops and realizes innovative projects that reduce high energy costs as well as CO2 emissions. While rooted in Berlin the BEA launches activities in regional, national and international markets.

Country: Germany

Role in project: Implementing partner


Klimaschutzagentur Region Hannover

The Klimaschutzagentur Region Hannover (Climate Protection Agency Hanover Region, CPAH) consolidates all regional activities concerning climate protection since 2001 and strengthens its role as an economic driving force in the Hanover Region. The non-profit agency informs and consults citizens and businesses on a wide range of topics. Therefore it develops and realizes, together with its partners, information campaigns on the subjects of energy saving, renewable energies and innovative technologies.

Country: Germany

Role in project: Implementing partner



The climate protection fund proKlima operates on the basis of a partnership contract, in which the Capital City of Hannover and the local energy supplier enercity AG play a key role together with five neighbouring municipalities. Since 1998 proKlima has supported more than 32,000 efficiency and climate protection measures with over 64 Mio EUR subsidies. As a result of twenty years of activity the partnership proKlima describes a local success story: 1.6 Mio t of CO2 emissions are avoided.

Country: Germany

Role in project: Implementing partner


Raumfabrik Wuppertal

Raumfabrik was founded in 1999 and has been a stock corporation since 2006. For more than 20 years it has been offering craft services “from a single source” in Wuppertal and in the surrounding areas. Raumfabrik coordinates the entire renovation process from planning and implementation support to invoicing. In addition to “classic” refurbishments (e.g. bathroom renovation), in recent years Raumfabrik has specialised in the areas of accessibility refurbishment as well as the use of ecological construction materials.

Country: Germany

Role in project: Implementing partner


Energieagentur Kreis Böblingen (EA-BB)

The EA-BB was founded in 2008 as a non-profit limited company with eight shareholders, the district of Böblingen being the main shareholder. Main tasks of the Agency are

  • Free initial audits and advice to private households, companies and municipalities regarding specific construction and refurbishment actions, their technical potentials for energy savings and integration of renewable energies, as well as financing options for these actions.
  • PR activities to inform the public on the energy-climate nexus and necessary behavioural changes
  • Implementation of own projects for energy savings and renewable energy generation
  • Coordination and facilitation of existing municipal, public and private initiatives for rational energy use and advice

Country: Germany

Role in project: Implementing partner


Innovation City Management (ICM)

ICM is a company for management and consulting in the field of climate-compatible urban redevelopment. ICM was founded by the Initiativkreis Ruhr, the city of Bottrop and others in 2010. The original task is to manage the pilot project in Bottrop. The goal of this project is to reduce the CO2 emissions of a quarter in Bottrop with 70.000 inhabitants and 12.500 residential buildings by 50 percent within ten years (2010–2020). But ICM is busy with projects in other cities, too. ICM wants to spread the experiences from Bottrop all over Germany and beyond.

Country: Germany

Role in project: Implementing partner


Linnaeus University (Linneuniversitetet, LNU)

LNU is one of Sweden’s newest higher education institutions with campuses located in Kalmar and Växjö. The research group on a sustainable built environment (SBER) at the Department of Built Environment and Energy Technology, has been conducting research on energy efficiency in buildings for more than 15 years, especially on issues related to actor perceptions and behaviour, market and policy barriers, and opportunity for OSS business. LNU was one of the first actors to engage in OSS research through the participation in the Nordic research project “SuccessFamilies – Successful sustainable renovation business for single-family houses” (2009–2012). Currently, LNU is involved in the project “Sustainable housing for strong communities – Stronghouse” financed by Interreg North Sea Region (2020-2022), European Union, and Linnaeus University and in the Swedish project “Sectoral readiness for deep renovation of detached households: from research to practice" financed by FORMAS (2019-2021).

Country: Sweden

Role in project: Peer partner


Île-de-France Energies (IDF-E)

Île-de-France Energies is a public-private operator launched in 2013 by the Île-de-France Regional Council. It aims to facilitate the energy renovation of multi-residential buildings, the deployment of renewable energy technologies and the implementation of innovative financing models. This Energy Service Company (ESCO) offers a comprehensive solution to support condominiums during every stage of their renovation project: global audit, technical definition, financial engineering, coordination of works and performance guarantee. This turnkey service adapted to the specificities of every condominium enables to reach ambitious renovation goals, such as targeting the level of performance of the “BBC Effinergie Renovation” label or a reduction by at least 40% of the level of energy consumption after the renovation works.

Country: France

Role in project: Peer partner




Reimarkt ­– The One-Stop-Shop for retrofitting for homeowners, social housing companies and tenants. Retrofitting your house should not be as difficult as it is now with complicated issues as financing, subsidies, quotations, finding out what is possible and what is good. Reimarkt makes retrofitting your house easy and possible for tenants, homeowners and condominiums. With Reimarkt it is easy to get insight in the possibilities, the costs and the savings. Reimarkt’s three step approach enables home-owner to explore what is possible, choose what fits their purse and requirements and order the retrofit directly at Reimarkt.

Country: the Netherlands

Role in project: Peer partner


City of Vienna

Vienna as a historically developed and dense city has to renew and maintain its existing building stock in order to achieve climate and energy goals as well as reach high quality of housing and quality of life. Apart from the public and social housing segments, new approaches for privately owned buildings are needed to raise renovation rates and impacts of renovations. Vienna aims to intensify energy-efficiency and decarbonization strategies for the existing building stock to achieve its Smart City and Climate objectives. For ProRetro, the Department for Technical Urban Renewable will be mainly in charge, plus the Department of Housing Promotion and Energy Planning and will share its experiences from the project RenoBooster.

Country: Austria

Role in project: Peer partner



Regional Public Service for Energy Efficiency (SPEE)

Initiated at the end of 2013 by the former Picardie Regional Council, the Regional Public Service for Energy Efficiency (SPEE) is the first French public operator dedicated to the energy renovation of individual and collective housing in the private residential park. To encourage owners to take action, SPEE sets up a ‘all-inclusive’ service, combining a complete technical support and an adapted financing solution. 100 % public service, the SPEE assumes a position of "trusted third party": simultaneously one-stop-shop for private owners, responsible for the quality of the works implemented and guarantor of the financing of renovation operations.

Country: France

Role in project: Peer partner


The project partners’ links

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