In various areas HafenCity is making big contributions to sustainability
Halting global warming, protecting biodiversity and tackling a host of other ecological challenges will only succeed if households and companies are in a position to shape lifestyles and commercial patterns in a sustainable way by creating suitable economic parameters and appropriate infrastructure. The development of cities is of particular importance in this context, as 77 percent of the population living in Germany is concentrated in conurbations. Since a large part of our cities has already been built and the existing stock can only adapt gradually, the importance of neighborhoods that are at the planning stage or under construction is that much higher.
It is not only urban development and infrastructure that contribute to the sustainability of HafenCity, but also each individual building. The financial amount of approximately €10 billion invested by developers alone, as opposed to approximately €3 billion spent by the public sector, demonstrates the crucial importance of the properties being built in terms of the ecological quality of the district, but also its social and cultural quality. Since an intelligent, advance purchase strategy for existing properties meant most of the land in the HafenCity area was owned by the city at the start of development, it has since been possible to use the allocation of land to developers as a central control mechanism via the process for awarding planning options and via concept tenders. This approach provides, among other things, for high architectural quality in HafenCity, street level space for retail and cultural uses, diversified housing offers with price differentiation, communal areas and the financial costs of neighborhood management. In the following, the focus will be on environmental sustainability aspects. These include the high building standard of the HafenCity Ecolabel in use since 2007, pilot projects that go beyond it, the building certificate launched June 2023, the DGNB special award Ecolabel, sustainable heating supply, and the smart mobility concept.
Sustainable building: HafenCity Ecolabel and the DGNB special award Ecolabel
The buildings certified with the HafenCity Ecolabel are models and pioneers of the transformation to sustainable building. They are setting standards and today are already providing answers to important future issues. The sustainable buildings have, for example, lower operating and maintenance costs due to their high energy efficiency and thus offer advantages when it comes to renting and selling. Certification makes these advantages visible for all players, i.e. owners, tenants and users.
Since 2007, HafenCity Hamburg GmbH has been awarding an independent certificate for sustainable building, the HafenCity Ecolabel. Certification was made a condition for the award of planning options on building plots in 2010, and since 2017, with Version 3.0 of the Ecolabel, the highest platinum standard has been obligatory for all new buildings in HafenCity. Thus HafenCity Hamburg GmbH was a very early supporter of the development of innovative, climate-friendly building solutions. Hence it has played a key role in anchoring sustainability ideas in the real estate industry and raising sustainability standards to an ever-higher level.
Over the years HafenCity has become a test bed for sustainable building. From a timber-built high-rise to the zero-emissions house, many forward-looking projects are bringing new methods and materials into construction practice and thus generating important impetus in the whole real estate sector. Based on the sustainability requirements of the HafenCity Ecolabel that apply to all projects, many of the flagship projects aim to focus more on a life-cycle approach and concentrate on reducing gray energy. Emitted during a building’s construction, this gray energy comprises the energy expended for material extraction, the manufacture of components, the transport of machines, components and materials to the construction site, and their incorporation. The use of regenerative raw materials such as timber and clay, carbon-reduced steel, recycled building materials and modular or reduced-concrete construction methods all contribute to reducing gray energy. Documentation of the materials used and their separability during deconstruction makes it easier for the materials of the new buildings themselves to be recycled and reused later. Additionally, elements such as photovoltaic systems and new options for digital energy metering have a positive impact on economical building operation. Greened roofs and facades are also increasing being used, making an important contribution to the microclimate and biodiversity in HafenCity. Flagship projects in HafenCity provide tangible best practice examples and thus play a pioneering role when it comes to a comprehensive understanding of sustainability in urban development.
This success story is being continued with the building certification jointly developed by HafenCity Hamburg GmbH and DGNB (German Sustainable Building Council) and launched June 2023. The DGNB special award Ecolabel was designed specifically for the four inner-city zones of HafenCity, Billebogen, Grasbrook and Science City Hamburg Bahrenfeld and gathers together the sustainability requirements for new projects in the areas developed by HafenCity Hamburg GmbH and its subsidiaries. The special award picks up on central aspects of the previous independently-run HafenCity Ecolabel and incorporates them into the DGNB System.
The DGNB special award Ecolabel enables building owners and developers to benefit from the advantages of the established DGNB System in its 2023 version within the location-specific award. Through an integrated verification process based on the criteria of the DGNB System, building owners and developers receive regular DGNB certification in addition to the special award, without any additional effort or costs. They not only benefit from a streamlined process that enables them to fall back on a large pool of skilled expert advisers coupled with established methodological and documentation standards, they also receive an internationally recognized, ambitious certificate that is compatible with national and international funding schemes and regulations such as BEG (federal funding for efficient buildings) or ESG verification within the EU Taxonomy.
The thematic focus of the DGNB special award Ecolabel is on the ecological aspects of building certification. Accordingly, it primarily addresses the active contribution to climate change mitigation and adaptation through the promotion of biodiversity, compatible microclimates and energy generation from renewable sources close to the building, as well as the avoidance of carbon emissions during building construction and operation. A further focus is on conservation of resources and circularity with regard to energy, water, and building materials achieved by circular construction methods. In addition, barrier-free accessibility and socially and environmentally compatible mobility lie at the heart of the special award.
Green heating power
So that the high energy requirements for the buildings can also be met in terms of infrastructure, all the buildings in HafenCity must be connected to two district heating networks operated by private network operators. In western HafenCity, this is the Hamburg district heating network operated by Vattenfall, which is supplemented in HafenCity by solar thermal power (1,800 m² of solar thermal systems are installed on rooftops in western neighborhoods, providing 40 percent of hot water requirements there), as well as other CO2-reducing generating plants (such as the steam turbine in the HafenCity heating plant). Since 2002, this has enabled an efficient energy mix that, with CO2 emissions of 175 g/kWh, clearly outperforms the conventional environmental standards-compliant natural gas-based heat supply whose CO2 emissions average 240 g/kWh.
Thanks to its decentral, modular local heating supply network, eastern HafenCity can boast contractually guaranteed CO2 emission rates of only 70 g/kWh. Actual CO2 emission rates are considerably lower, at approx. 35 g/kWh under current plans. The concept is characterized largely by the use of emission-free industrial waste heat and renewable energy. The proportion of waste heat in consumption is around 90%. A modern combined heat and power plant in Oberhafen, operated with balanced biomethane, covers part of the remaining heat demand in efficient cogeneration - only the peak load is generated by conventional gas-fired boilers. Industrial waste heat comes from the nearby Aurubis copper refinery, where excess heat from gas scrubbing is now no longer discharged unused into the Elbe. A further energy center at Peute with buffer storage tanks and boilers ensures that the highly fluctuating waste heat can be drawn down evenly and securely. The primary energy factor is 0.17. In eastern HafenCity alone, this will save around 12,000 metric tons of CO2 per year compared with a natural gas-based heat supply when complete.
HafenCity’s mobility concept prioritizes walking, cycling and public transport (subway, rapid transit, buses and ferries) not only for ecological reasons but also to enhance the quality of the urban environment. This also includes the goal of substantially reducing car ownership in HafenCity. Firstly, this will reduce the construction costs of large underground garages and the need for parking spaces in public areas. Secondly, people who for various reasons are dependent on a car and own one will then use it for the vast majority of journeys. Since owning a private car entails high fixed costs, the distances traveled in the city do not have a significant cost impact. The purchase of a ticket, on the other hand, is perceived as an additional cost.
The smart mobility concept for eastern HafenCity therefore aims to enable residents and workers to dispense with a private vehicle and weigh up the options of cycling, public transport and car sharing according to the situation. In the underground garages of the private buildings, a cross-district station-based car sharing system is being set up as a dependable service for all residents and workers under the terms of the individual property purchase agreements. The system contributes to reducing both moving and stationary car traffic as well as improving the amenity value of public areas through reducing CO2 emissions and noise pollution.