To reach these ambitious goals, all districts of the city need to get involved. Now is a crucial moment of opportunity: the City of Amsterdam is working out the ambitions of the Sustainable Heritage Implementation Agenda, and one of the intentions is to relax policies around monuments and protected cityscapes. Owners of historic buildings in Amsterdam will receive assistance and can insulate their homes or restaurants more easily by, for example, replacing the glass in their windows. If all historic buildings in Amsterdam’s Centrum would be carefully retrofitted, the city could cut 8% of the total CO2 emissions from all buildings in Amsterdam. These changes can significantly reduce emissions and energy costs, without requiring changes to the external façade of most buildings.
Monumental values
Parts of the City's historic center, some of which date back to the early 17th century, are listed as a UNESCO World Heritage site. The monumental facades of these properties are valuable, and renovations or other modifications require great care. Real estate in this area is also the most expensive in the country, after Amsterdam Zuid, and is highly valuable for residents and local stakeholders. Partly due to the monumental character of Amsterdam Centrum, current sustainable heating plans aim to keep the district connected to the gas grid, aiming for a 70% reduction in natural gas usage by 2040. The remaining demand plans to be met with biogas, hydrogen and hybrid solutions.
However, the availability of these sources is currently very limited, and their production is not always as environmentally friendly as perceived: using hydrogen for heating is economically and environmentally unfavorable compared to heat pumps and district heating, studies suggest. Additionally, most buildings are protected and often insufficiently insulated, leading to increased energy use and poor thermal comfort. Given these complexities, other policies (such as the Isolatieoffensief 2024-2026) and the presence of the city’s district heating network in the city’s suburbs, the city's transition programs planned to start with other districts such as Noord, Zuid-Oost, and Nieuw-West. According to Transitie Visie Warmte 2020, Amsterdam Centrum would transition last.
“When talking about energy transition one mostly refers to large-scale repetitive housing types such as rowhouses, tenement flats and gallery flats, the seemingly low-hanging fruit. Monuments and other old buildings may be more complicated — the high-hanging fruit — but the improvement potential often is much greater. And we can do much more about them than people often think. Therefore, this study explored the energy renovation opportunities of the historical inner city of Amsterdam”
Andy van den Dobbelsteen
Professor & AMS PI
The ways to achieve energy efficiency with heritage conservation
The four-year AMS Institute and TU Delft (Architecture Faculty, Climate Design & Sustainability), research program, Reaching the High-Hanging Fruit, explores alternative strategies for Amsterdam's historic heart to gradually transition away from natural gas.1 In this research, retrofitting refers to ‘changes at the building level that reduce space heating needs’, thereby making it possible to heat buildings with lower temperature heat sources. Houses can then be heated via heat pumps using other heat sources. This means that, in the future, heat may be obtained from multiple (hyper)local sources such as outside air, canal water, the soil, or waste heat.
The results indicate that retrofitting only non-protected buildings could lead to an 4% reduction in space heating demand, saving 6 kilotons of operational CO2. If buildings that are 'order 2' and 'order 3' (i.e. not listed but representing heritage values) are also renovated, the reduction could reach 23%. Expanding retrofitting efforts to all buildings in the city center could lead to a 59% total decrease in space heating demand and a reduction of 90 kilotons operational CO2, representing an 8% decrease in the total CO2 emissions from all buildings in Amsterdam.
“We're gaining valuable insights into the varying potential for energy reduction across different neighborhoods in the city center. The research shows the impact targeted retrofitting can have, even in areas that might not seem obvious. For example, retrofitting buildings in the seventeenth-century canal ring area, a UNESCO World Heritage Site, is especially impactful, contributing nearly a quarter of the total potential reduction in space heating within the city center. Monuments can play a pivotal role in the heat transition, and world heritage can evolve to meet the demands of our time, which today also includes addressing climate change”
Maéva Dang
Research Fellow
To achieve the modeled results, increased flexibility in permitting would be needed for insulated glazing and double wall construction in heritage buildings. For instance, permitting the use of vacuum glass in older apartment buildings can lead to an additional 33% reduction in space heating demand. Fortunately, this is in line with the recently published executive agenda, Duurzaam Erfgoed, from the Municipality of Amsterdam.
The research finds that changes to the exterior facade would not be necessary to transition away from natural gas, except for corner-type buildings, which could only shift to a hybrid system. Key measures for residential and non-residential buildings would include:
- Insulation of the interior wall (maximum 5 cm to avoid condensation risks);
- Use of vacuum glass (vacuum glass is expensive, but the use of HR++ glass as back glass is a practical alternative to preserve the authenticity of the facade while meeting energy efficiency targets);
- Insulation of the ground floor and roof;
- Sealing of gaps combined with effective ventilation.
“Monuments and other historic buildings can also be future-proofed without compromising their values. Scientific research provides new insights to make these properties sustainably future-proof. The research program of TU Delft and AMS Institute is therefore valuable. We include the advice in our communication to owners and users of monumental buildings to take the necessary steps for a sustainable heat transition. Of course, the approach remains customized.”
Annette ten Doeschate, Advisor and Project Leader Sustainable Heritage, Monuments and Archaeology at the City of Amsterdam.
The results also show that special attention should be given to non-residential, large buildings which account for 54% of the heating demand of Amsterdam Centrum. For hospitality buildings (restaurants, cafés, hotels), investing in heat recovery ventilation can save between 30 and 50% in heating demand. Given their higher natural gas usage for cooking, transitioning to electric cooking is also a must-have.
The top two images explore the potential reduction in space heating demand in all neighborhoods. Compared to now, providing the entire city center with space heating would be possible using low-temperature heating networks (right). The bottom three images explore the potential reduction after insulation within regulations and under different renovation scenarios in all neighborhoods of the Amsterdam city center, from insulating only the non-protected buildings (left) to all buildings except orde 1 buildings (right).
A call to homeowners: insulate and ventilate now!
The parametric approach in the study, due to its versatility, can help quickly identify and prioritize impactful measures, in line with your values, allowing for back-and-forth explorations to create step-by-step retrofitting plans. This would enable citizen groups to select a building or an area and apply various hypothetical scenarios. Citizens could see which energy improvements offer the greatest value for their investment, and how close it could bring them to achieving carbon neutrality. Ultimately, city officials could apply different policies to entire neighborhoods and simulate the potential impact.
To ensure a sustainable future for these buildings and the City of Amsterdam, while also cutting costs for homeowners, finding smart retrofitting solutions is crucial. Traditional methods have clear limitations but this research pinpoint innovative approaches to balance energy efficiency with historical preservation that can begin now.
At the end of this year, a new paper will be published about this research: Integrated Energy Planning for Historic City Centers in the Netherlands.
