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No other European city has more buildings constructed in line with passive house standards (PHS) than Frankfurt am Main (Stadt Frankfurt am Main – Department for Environment and Health NA), which is owed substantially to city regulations stipulating that new public buildings must meet passive house requirements (heating energy demand ≤15 kWh/m2/year) if possible. Thus, legislation especially guides the local construction sector as it encourages them to further develop PHS technologies and skills. One very successful example is the refurbishment of the Riedberg School resulting in annual energy savings of €67,000/yr (i.e. €8,000 instead of €75,000). While overall construction costs were €16.7 million, the additional costs for meeting the PHS were only about €900,000 (Passivhaus Institut 2007).
In 2007, the City of Frankfurt am Main established the Passive House Standard for Municipally Owned and Municipally Used Buildings. This means that the passive house (PH) construction method is the standard construction method for the municipality. The PH Standard is defined by a maximum of 15 kWh/m2/yr of heating energy demand (equivalent to 1.5 l of oil or 1.5 m3 gas) (IG-Passivhaus 2006).
This shall be achieved through legal requirements e.g. the obligation for municipally used and owned buildings to be constructed in accordance with the Passive House Standard (PHS). The obligation is also valid for private investors buying municipal property as a construction site. If, for whatever reason, it is not possible to construct a PHS building, the energy efficiency requirement still obliges developers to stay 30% below the national building energy performance standard (Energieeinsparverordnung EnEV – Energy Saving Ordinance). Through the introduction of this self-obligation, the municipality seeks to lead by example i.e. the aim of the policy is to raise public awareness of the PH concept, demonstrate to investors its economic viability and other benefits (e.g. improved working and living conditions due to better indoor climate), and also – by way of increasing the demand for passive houses – incentivise the construction industry to further advance their PH construction skills and technologies.
The policy is one measure within the „Klimaschutzkonzept“ (Climate Protection Concept) of Frankfurt, which includes a wide variety of initiatives in order to promote energy efficiency and climate protection measures. The policy is designed by the Department of Energy (Energiereferat) of the City of Frankfurt and is implemented by the City of Frankfurt’s Construction Office (Hochbauamt).
There are several example buildings where the energy consumption has been drastically reduced compared to the EnEV e.g. the school Riedberg-Schule has achieved savings in energy costs of €67,000/yr (€8,000 instead of €75,000). The energy savings relating to heating oil have been 8.5 litres/m2/yr or 85 % (consumption of 1.5l/m2/yr compared to 10l/m2/yr if built in accordance with EnEV). The higher investment costs for construction are paid back after only a few years, due to the reduced energy costs, tax benefits and lower interest rates.
Main factors allowing the city’s Passive house policy to be successfully implemented were:
In New York City public buildings, whose estimated costs for construction orrefurbishment exceeds $2 million must meet LEED’s silver certification standard (Local Law 86), which is a green building standard. While non-municipal buildings that receive at least 50% of the expenses from the municipality must also be in line with silver certification, there are no requirements for public buildings that cost less than $2 million.
More information available on:
(in-depth information including completed projects etc.)
In 1990, Frankfurt joined the “Climate-Alliance of European Cities” and developed an energy concept focused on energy efficient buildings and cogeneration of heat and power. Even if living space (by 15%) and office space (by 80%) have increased, CO2 emissions were still reduced by 10% between 1990 and 2008. In addition to the support for cogeneration of heat and power (CHP), the city focuses on the dissemination of the Passive House Standard.
The aim of the policy is to promote the Passive House Standard as the new building standard in Frankfurt am Main. This is to be achieved through the obligation that buildings built by the municipality or for its use have to be built in Passive House Standard. Also the ABG Frankfurt Holding - a city owned real estate company - is supporting this measure for its own housing stock. Additionally, the City promotes the standard via contracts: whenever municipal property is sold to a private person as a construction site, the buyer has to build with PHS.
If PHS is not possible (a justification is required in that case), the energy consumption of the building has to be 30% below the national MEPS (EnEV 2009).
Through the introduction of this self-obligation for the public sector, the City of Frankfurt is leading the way and setting a good example in terms of ultra-low energy buildings. Therefore, the aim of the policy is ultimately to induce replication in the private sector by raising public awareness of the PH concept, demonstrating to investors its economic viability and other benefits (e.g. improved working conditions due to better indoor climate), and also – by way of increasing the demand for passive houses – incentivising the construction industry to further advance their PH construction skills and technologies.
The policy is implemented on a local level.
The sectoral focus is the residential and public sector (in the case of municipal property sold to private investors possibly also commercial sector)
The targets are the promotion of the PH Standard and the use of CHP. This is to be achieved through information campaigns and legal requirements. The City is therefore obliged to build in PH standard, and if this is not possible, the new building has to be at least 30% below EnEV. Also, citizens should be made aware of the opportunities of the PH Standard, its economic feasibility and the benefits offered by passive houses, such as energy cost savings and increased comfort levels.
Furthermore, a Department for Energy Management has been set up within the City Construction Office. The department provides a number of services (e.g. energy controlling, automated consumption monitoring, optimised building operation, etc.) in order to minimise the energy and water consumption in municipal buildings. Between 1990 and 2009, net savings of € 83.4 million have been achieved through energy management ().
The policy includes innovative instruments/elements and combines them in an innovative package:
In order to be ahead of schedule, Frankfurt promotes the EU guideline for Nearly Zero Energy Buildings to come in 2020 at a very early stage and is creating a building stock that is not only more energy- and resource-efficient, but also performs well economically.
Since municipalities in Germany cannot mandate stricter general energy efficiency standards for buildings than the national law, the City uses the two options it has available: mandating the strict PHS for its own buildings, and for buildings constructed on land that the City sells, via the sales contracts. This works well as land is scarce in the Frankfurt area.
The policy is part of a wide range of energy efficiency improvement measures for buildings promoted in the City of Frankfurt.
In countries where local authorities have the legal possibility to do so, the policy can be optimised by setting the Passive House Standard as standard for all new buildings, municipal or private.
Before the policy was implemented, evaluations of the energy performance and the lifecycle costs of existing passive houses were made or considered with the result, that the investment will be paid back after a maximum of 30 years from saved heating costs, and that over 50 years costs of over €75,000 could be saved in PH homes.
Agencies or other actors responsible for implementation
The City’s Energy Department was instrumental in collecting this evidence and drafting the policy. City of Frankfurt’s Construction Office has the task to implement it for the municipal buildings.
The promotional bank of the Federal Republic of Germany (KfW) provides soft loans for passive houses.
In the beginning of the 1990s, Frankfurt started to build public buildings like kindergartens and housing estates with heating energy demand parameters of 75 kWh/m2/yr but soon improved this standard to PHS with heating energy demand parameters below 15 kWh/m2/yr. In 1998/1999, the first single family houses were constructed with PHS and another important project was the construction of 19 housing units with PHS realised through the FAAG corporation, which is a subsidiary company of ABG Frankfurt Holding. This project was the activator for ABG’s decision to construct new buildings in PHS only. So far 800 dwellings have been constructed, are under construction or planned. In 2004 and 2007, new schools in PHS design were constructed, belonging to the first ones in Germany.
In 2007, this resulted in the enactment by the City Council (Parliament) that all new municipal buildings have to be designed and built in accordance with the PHS. This requirement was justified through better indoor air quality and cost-effectiveness over the life cycle. Investors who buy municipal property are also obliged to build in PHS wherever possible, otherwise 30% below the EnEV. Frankfurt’s declared aim is to become “Passivhaus-Bundeshauptstadt” (Federal Capital of Passive Houses) and therefore it has established the PHS as its standard construction method.
The City of Frankfurt Construction Office was assigned the task of implementing the standard in new municipal buildings.
Costs for passive houses have been assessed in already built dwellings and it has been discovered, that due to yearly energy savings, tax advantages and better interest rates with the KfW, passive houses are the cost effective option in the long run.
The target is for the ABG Frankfurt Holding to have realised the construction of 1,300 new PHS apartments by 2013.
Actors responsible for design
Energiereferat der Stadt Frankfurt am Main (Department of Energy of the City of Frankfurt)
Actors responsible for the implementation
Hochbauamt Frankfurt (City of Frankfurt Construction Office)
There is a monitoring system in place tracking data necessary for evaluation, such as capital, operating and environmental follow-up costs.
There is no evaluation available for the policy as a whole. However, some example buildings have been evaluated.
With the PHS, co-benefits like fresh air without open windows can be achieved. In schools this is good for the learning atmosphere, because outside noise is mostly eliminated and it can be good for allergic persons too. The ventilation system filters the fresh air and therefore pollen and dust have hardly any chance of getting into the building.
No information on the overall energy savings expected from the City’s PH standard is available.
An example house of 162 m2 is expected to achieve end-use energy savings (heating and warm water) of approximately 11,000 kWh/yr compared to a house built with EnEV 2009 Standard (Stadt Frankfurt am Main 2011, p. 4).
According to the Füßler Survey, the primary energy demand for the 162 m2 example PH is around 9.000 kWh/yr lower than in the EnEV house (6.626 vs. 15.698) (Füßler 2010). This corresponds to 27.7 compared to 73.7 kWh/m2/yr. The end-use energy demand is almost 11,000 kWh lower than in a comparable EnEV house.
No information on the overall energy savings achieved by the City’s PH standard is available.
However, the Riedberg school is saving 8.5 litres of heating oil per m2 and year (1.5 instead of 10 l) (Stadt Frankfurt am Main 2009, p. 10).
For the example house of 162 m2, the construction costs are assessed at €1,914 per m2 compared to €1,784 per m2 for a standard EnEV 2009 house. This translates to additional costs of approx. € 21,000 for the whole house i.e. an incremental construction cost of 6.71%. The interest rate for the PH was 3.05 over a 10 year period (KfW preferential loan), not available for EnEV (Stadt Frankfurt am Main 2011, p. 4).
The Riedbergschule equated to a total project cost of €16.7 million and to €1,110/m2. The additional costs compared to EnEV 2004 -30% were 5.3%.
According to the exemplary comparison assessment of an EnEV 2009 and a PHS dwelling of 162 m2, the cost savings total € 75.000over 50 years (Stadt Frankfurt am Main 2011, p. 5).
The total costs (capital and operation/energy) for the PHS-School in Riedberg can be reduced from €1.43 to €1.32 million/yr. Heating costs can be reduced by €67,000 from €75,000 to €8,000/yr compared to a usual EnEV building (Table 2).
The Grundschule Preungesheim (Elementary School Preungesheim) can reduce its annual costs compared to EnEV Standard building from €1.71 to €1.63 million. The reduction in heating costs only are €83,000/yr. A table for an overview of total costs is attached (next table).
The example house of 162 m2 is supposed to save more than €75,000 over a 50 year period and is therefore cost effective (Stadt Frankfurt am Main 2011, p. 5).
The Grundschule Preungesheim saves annually €88,000 by being built in PHS compared to EnEV. The higher investment costs will pay back after 14.8 years (see the first table).
The Riedberg school saves €108,000 annually with the PHS compared to EnEV and the additional costs will pay back after 4.3 years.
Official document establishing the policy:
§ 2443: Resolution of the 15th meeting of the City Council (Parliament) on 9/6/2007
§ 2443 Beschlussausfertigung aus der 15. Sitzung der Stadtverordnetenversammlung am 06.09.2007