ACE-Retrofitting: Accelerating Condominium Energy Retrofitting

Project Summary

A majority of buildings in North-West Europe are still energy-inefficient and in need of deep renovation. 

Even though local governments are tackling climate change, the building sector remains a weak point. If action in this field is not reinforced, local governments will be locked in a high carbon future. Condominiums (tenements and flatted buildings) are an important area. By directing efforts towards co-owned residential buildings, a large number of private owners at once can benefit from more energy efficient homes, reduced energy bills and carbon footprint (50-70%).

Through the ACE Retrofitting project local governments learn to act as facilitators between co-owners and building experts.

Energy Cities, the European city network, along with six local authorities from five different countries design a method and governance framework that will help overcome the legal, human and financial barriers that are currently hindering energy retrofitting of condominiums.

Inspired by...  

CoachCopro, a free, online collaborative tool developed by the Paris Climate Agency (Agence Parisienne du Climat), is central to this strategy and will be improved and adapted to be used in other parts of Europe.

In France, this web-based platform has already successfully assisted condominium owners (demand) and building professionals (supply) through an iterative process which cultivates trust relationships and generates direct and indirect jobs (potentially 19 net jobs created per €1M investment). More in "Resources".

It's all about collective power 

Annemarie Van Zeijl works at the Sustainability Institute of Maastricht University. She knows a lot about stakeholder processes, especially when it comes to energy retrofitting in condominiums. A project run by several co-owners can be fun. At the same time, it is also a challenge to bring different interests together. Annemarie explains how co-owners can collectively make their building more energy efficient.

The Step-by-Step tool developed in the framework of the ACE-Retrofitting project is an important help in this process.


For any query or suggestion regarding condominium stories, please contact our communications expert Miriam Eisermann.

Contact us


NWE making an impact!

04-12-2019 - 05-12-2019, Tourcoing (Lille agglomeration), France

The Interreg North-West Europe (NWE) programme is pleased to announce its first impact event on 4 and 5 December 2019, which will take place in Tourcoing (Lille agglomeration, Haut... Read more

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New tender on video production!

Posted on 31-07-2019

The object of this tender is to hire a service provider for all programmes managed by GEIE-GECOTTI, including Interreg NWE. Check the documents. Read more

REGIOSTARS awards 2019: support our finalists!

Posted on 24-07-2019

Do you believe in the impact that our projects make in your region? Then give us a hand and vote for your favourite among our two finalists: CAN and eMEN! Read more

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This project is also supported by the French Energy Management Agency - ADEME.

Project Partners

Lead partner

Organisation Contact name Address Email Website
Energy Cities Ian Turner 2 Chemin de Palente
Name Contact Name Email Country
Ville de Liège Marc Schlitz Belgium
Agence Parisienne du Climat Béatrice Bienenfeld France
Universiteit Maastricht Annemarie Van Zeijl-Rozema Netherlands
Aberdeen City Council Maizatul Afzan Muhammad United Kingdom
Stadt Frankfurt am Main Energiereferat Jonas Geissler Germany
Gemeente Maastricht Rianne Van Der Krogt Netherlands
Autonoom Gemeentebedrijf Energiebesparingsfonds Antwerpen Jan Meuleman Belgium
Changeworks Resources for Life Ltd. Ian Smith United Kingdom


Frankfurt: A web platform to support citizens in condominium energy renovation throughout Germany

Posted on

The German city of Frankfurt am Main recently launched an online platform for the renovation of condominiums as part of the Interreg-NWE ACE-Retrofitting project. The platform is strongly inspired by the successful collaborative web tool CoachCopro developed by the Paris Climate Agency in 2005. Thanks to this new platform, about 200 000 residents could benefit from an energy retrofit in their condominiums! Read More

Understanding owners’ motivations to support renovation of condominiums: What research and experimentation tell us

Posted on

With 12,000 households living in condominiums in Maastricht and among them 7,000 with a G energy label, the energy retrofitting of these buildings is a major challenge for the municipality. The workshop and site visit organised on 16 November in Maastricht - as part of the Interreg North-West Europe ACE-Retrofitting project, aimed to better understand owners’ barriers to taking action in their buildings thanks to feedback from academic research and project experience. Read More

ACE Retrofitting in Frankfurt – We need to reduce the energy consumption of our buildings by 70% by 2050!

Posted on

The second project meeting of ACE-Retrofitting - Interreg North-West Europe, was hosted by the City of Frankfurt from 12 to14 June, including a half-day conference which gathered ACE partners and German stakeholders involved in the energy retrofitting of condominiums. A great opportunity to better understand the challenges that the cities face to retrofit their condominiums. Read More


ACE-Retrofitting Webinar: From concept to realisation – A step-by-step tool that helps co-owners accelerate retrofitting in condos

, (online)

14:00-15:00 CET Partners in the ACE-Retrofitting project are seeking to support municipalities in launching energy retrofitting strategies for condominiums. They developed a range of tools that notably help municipalities make the link between the demand side (co-owners, trustees, etc.) and the supply side (professionals). The “Step-by-Step” toolkit provides 17 specific soft and hard tools to accompany co-owners on the road to condominium energy retrofitting. It is divided into three main complementary phases: 1. The “first step” allows the co-owners to explore the idea of leading an energy retrofit in their building. 2. The “taking-off step” deals with the activities to be developed until the vote for retrofitting. 3. The “real thing step” is related to the start of the energy retrofitting work itself.
Read More

Low Carbon City Forum

, Paris, France

It will include a number of panel discussions, talks, film projections, exhibitions, workshops for both children and adults, group meals, evening activities, and an eco-friendly market. The Low Carbon City Forum will offer everyone the chance to come together to imagine and subsequently build sustainable, people-centric cities. The event is free and open to all!
Read More

It takes some courage for condominium co-owners to plan or carry out an energy retrofitting in their building.
The ACE step-by-step tool is there to make things easier.

If you are from a public authority, wishing to support co-owners in their endeavour, do not hesitate to spread the guide amongst your city's condominiums. 

The guide is divided into three big phases: “First steps”, “Taking-off” and “The real thing”. All together, the guide counts 17 helpful items for soft and hard measures:

  • 14 documents are ready-to-use 
  • 3 documents are designed in a way as to be adapted by a public body, esp. regarding legal and financial issues, according to the local and national context. 

Keep in mind that there is no unique starting point or strict order to use the items. However, it makes sense for co-owners to define at what stage of the building retrofitting process their project is before going to a specific section of the guide.

You can start with the summary (PPT) which links you to the various items that are available (in Word and Excel). 

🏡 Step-by-Step tool in English

This tool shall help condominium co-owners getting an insight into all steps that are necessary to make an energy retrofitting project come true.


Why and how to start or further an energy retrofitting project?

These tools will help you:

  • Inspire condominium co-owners
  • Assess the existing and required resources
  • Mobilize co-owners around the retrofitting

📥 PPT Introduction to the step-by-step tool

📥 Convince your condo 

📥 Determine your capacity

📥 Energy audit -Quickscan


How to get insight into all the relevant matters to be ready for an energy retrofitting project?

These tools will help you:

  • Design a retrofitting roadmap
  • Get legal, financial and technical information from experts
  • Learn about governance and communication schemes

📥 Communicate with neighbours

📥 Masterplan

📥 Project team mandate

📥 Tips for voting

📥 Assessing financial solutions



What, when and how will be done in the energy retrofitting project?

This tool provides you with: 

  • A specific project management plan
  • A planned timetable
  • Transparent communication among the all stakeholders

📥 Project management plan

🏡 Step-by-step tool auf Deutsch

Das Step-by-Step Tool soll Wohneigentümergemeinschaften bei der Planung und Durchführung von Sanierungsarbeiten helfen.


Wieso und wie sollte ein energetisches Sanierungsprojekt (weiter) auf den Weg gebracht werden?

Vier Hilfsmittel, um:

  • die Mitglieder einer Wohnungseigentümergemeinschaft zu inspirieren
  • vorhandene und benötigte Ressourcen innerhalb der Wohnungseigentümer zu ermitteln
  • Mitglieder der Wohnungseigentümergemeinschaft für das Sanierungsprojekt zu gewinnen

📥 PPT Einführung zum Step-by-Step Tool

📥 Eigentümer überzeugen

📥 Gebäudeaudit- Quickscan

📥 Kapazitäten bestimmen



Wie erhält man einen Überblick über alle relevanten Fragen für die Vorbereitung auf ein energetisches Sanierungsprojekt?

Sechs Hilfsmittel, um:

  • einen Sanierungsfahrplan zu erstellen
  • Rechtliches, finanzielles und technisches Expertenwissen zu erlangen
  • Verwaltungs- und Kommunikationsmodelle zu kennen

📥 Mit den Nachbarn kommunizieren

📥 Projektteam Mandat

📥 Tipps zur Abstimmung

📥 Masterplan

📥 Auswahl der richtigen Finanzierungsmöglichkeiten



Was wird wann und wie im Rahmen des energetischen Sanierungsprojekts gemacht?

Ein Hilfsmittel, um

  • Einen spezifischer Projektplan zu erstellen
  • Einen Zeitplan zu erstellen
  • Transparente Kommunikation zwischen allen Beteiligten

📥 Projektmanagementplan

🏡 Step-by-Step Tool en nederlands

Eerste Stap

Waarom en hoe een energierenovatieproject starten of uitbreiden?

Te verwachten resultaten na gebruik van deze 4 hulpmiddelen:

  •  Mede-eigenaars van flatgebouwen inspireren
  • De bestaande en benodigde middelen beoordelen
  • Mede-eigenaars warm maken om te renoveren

📥 PPT Inleiding stapsgewijze tool

📥 Appartamentencomplex overtuigen

📥 Inovatievermogen-Tool

📥 Quickscan



Hoe krijg je inzicht in alle belangrijke zaken die nodig zijn om een energierenovatie te starten?

Te verwachten resultaten na gebruik van deze 5 hulpmiddelen:

  • Een renovatie stappenplan
  • Wettelijke, financiële en technische informatie door experten
  • Bestuurs- en communicatieprogramma's

📥 Communiceer buren

📥 Masterplan

📥 Beschikbare financieringsmogelijkheden

📥 Projectteam mandaat

📥 Tips voor het stemmen


Het echte werk

Wat moet wanneer en hoe gebeuren in het energierenovatieproject?

Te verwachten resultaten na gebruik van dit hulpmiddel:

  • Een specifiek projectmanagementplan
  • Een gedetailleerd tijdsschema
  • Transparante communicatie tussen alle belanghebbenden


🏡 Outil step-by-step en français

Cet outil est censé aider les copropriétés à planifier et mettre en oeuvre leur projet de rénovation énergétique.


Pourquoi et comment lancer ou poursuivre un projet de rénovation énergétique ?

Les outils vous permettent de:

  • Intéresser les copropriétaires
  • Évaluer les ressources existantes et requises
  • Mobiliser les copropriétaires autour de la rénovation

📥 PPT Introduction outils Step-by-Step

📥 Convaincre sa copro

📥 Déterminer ses capacités et ressources

📥 Audit du bâtiment - Quickscan_FR


Comment connaître tous les aspects pertinents pour préparer un projet de rénovation énergétique ?

Les outils vous permettent de:

  • Une feuille de route pour la rénovation
  • Des informations juridiques, financières et techniques d'experts
  • Des systèmes de gouvernance et de communication

📥 Communiquer avec les voisins

📥 Conseil pour le vote

📥 Mandat équipe de projet

📥 Options de financement

📥 Plan directeur


Quand et comment le projet de rénovation énergétique sera-t-il réalisé, avec quel contenu ?

Cet outil vous permet de:

  • Un planning de gestion de projet précis
  • Un calendrier prévisionnel
  • Une communication transparente entre toutes les parties prenantes

📥 Planning de gestion de projet

In addition to the very practical step-by-step tool, you can find inspirational material to boost energy retrofitting of condominiums in your area.

🏡 Case studies 

Guidance and match-making through an interactive platform: Paris, France

Béatrice Bienenfeld works at the Paris Climate Agency (APC). The APC has developed a tool called CoachCopro that facilitates energy retrofit projects. In this video (in French), Béatrice explains how this tool and platform brings homeowners and professionals together. The Step-by-Step tool developed in the framework of the ACE-Retrofitting project has been inspired by the CoachCopro and is an important help in such an endeavour.

📥 Read the full case study on the CoachCopro developed by Paris Climate Agency


Energy expert trainings: Tampere, Finland

The City of Tampere has been actively supporting condominiums (limited liability housing companies) with “Energy Expert” training courses since 2000. Between 2015 and 2017, this activity was supported by the Low Carbon Housing Tampere Plus (TARMO+) project. The aim of this project has been to make housing companies in this region think about how to be energy efficient in line with the 2025 city strategy

📥 Read case study


Everything started in one street: Santa Coloma de Gramenet, Spain

The municipality of Santa Coloma de Gramenet near Barcelona has launched an energy retrofitting programme called Renovem Barris in the south and central-south neighbourhoods of the city. This plan is still in deployment and involves a population of approximately 60 000 inhabitants. 

📥 Read case study


🎤 Want to share the ACE Retrofitting concept with others?

Feel free to use parts or the full content of our presentation below:

📥 English  📥 Deutsch 📥 français 📥 Nederlands

ACE is about smoothing energy retrofit projects. But beyond collaborative processes, we also want to achieve impactful results. 

That is why, every six months, the ACE meter reports the results reached by the project partner cities: How many owners and professionals have been coached? How many co-owner groups started retrofitting their building and how much carbon did they save?

Choose your language and check out below where the condominiums in ACE partner cities currently stand.

👍 English

Every six months, the ACE meter reports the results reached by the project partner cities: How many owners and professionals have been coached? How many co-owner groups started retrofitting their building and how much carbon did they save? Last update: Spring 2019




Co-owners coached

Professionals coached

Retrofitting plans voted

Retrofitting in progress: condominiums/flats

Retrofitting finished: condominiums/flats

Annual decrease of CO2 emissions in tonnes
Antwerpen Belgium 9300 368 7    52/2725  2075
Frankfurt Germany 1206 432 2  1/5    
Liège Belgium 1347 49 7  16/620    1240
Maastricht Netherlands 48 7  0      
Paris France 15064 1885 139  108/2543  166/3983  3059










👍 Français

Tous les six mois, le “ACE mètre” reporte les résultats atteints par les villes partenaires du projet: Combien de propriétaires et de professionnels ont été coachés? Combien de copropriétés ont réalisé une rénovation et combien de CO2 ont-ils ainsi économisé? Dernière mise à jour: printemps 2019



Co-propriétaires coachés

Professionnels coachés

Plans de renovation approuvés

Rénovations en cours: copropriétés / appartements

Rénovations finalisées: copropriétés / appartements

Diminution annuelle des émissions de CO2 (en tonnes)
Anvers Belgique 9300 368 7   52/2725 2075
Francfort Allemagne 1206 432 2 1/5    
Liège Belgique 1347 49 7 16/620   1240
Maastricht Pays-Bas 48 7        
Paris France 15064 1885 139 108/2543 166/3983 3059








👍 Deutsch

Der ACE-Zähler liefert alle sechs Monate die Ergebnisse der Projektpartnerstädte. Wieviele Eigentümer und Fachleute wurden geschult? Wieviele Wohneigentümergemeinschaften haben eine Sanierung begonnen und CO2-Einsparungen zu verzeichnen? Letztes Update: Frühjahr 2019



Geschulte Eigentümer

Geschulte Fachleute

Beschlossene Sanierungspläne

Sanierungen in Umsetzung: WEG / Wohneinheiten

Abgeschlossene Sanierungen: WG /Wohneinheiten

Jährliche CO2-Reduktion (in Tonnen)
Antwerpen Belgien 9300 368 7    52/2725  2075
Frankfurt Deutschland 1206 432 2 1/5    
Lüttich Belgien 1347 49 7 16/620    1240
Maastricht Niederlande 48 7        
Paris Frankreich 15064 1885 139  108/2543  166/3983  3059









👍 Nederlands

De ACE-meter presenteert de resultaten die door de partnersteden zijn bereikt op het gebied van gecoachte eigenaren en professionals, gerealiseerde verduurzamingsmaatregelen en CO2-reductie



Gecoachte mede-eigenaren

Gecoachte professionals

Verduurzamingsplannen vastgesteld door ALV

Duurzame renovaties in uitvoering: appartementen/flats

Afgeronde duurzame renovaties: appartementen/flats

Jaarlijkse CO2 reductie (Ton)
Antwerpen België 9300 368 7   52/2725 2075
Frankfurt Duitsland 1206 432 2 1/5    
Luik België 1347 49 7 16/620   1240
Maastricht Nederland 48 7        
Parijs Frankrijk 15064 1885 139 108/2543 166/3983 3059









Photo by Gleren Meneghin on Unsplash

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