Energy jump

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Energiesprong (Dutch [enɛrʒi sprɔŋ] for energy jump) is a concept for the energetic renovation of residential buildings that promises quick implementation, cost reduction, sustainability and tenant-friendliness. Energiesprong relies on industrial prefabrication of facade and roof elements (serial renovation) and the use of renewable energies in order to achieve the so-called NetZero standard (corresponds to the zero-energy house ). The aim is to enable an attractive renovation for everyone involved. This is aimed at, among other things, by significantly shortening assembly times and refinancing that does not affect heating rents. The cost reductions required for this are achieved in serial refurbishment through automation in production and economies of scale in mass production .

In the country of origin, the Netherlands , several thousand terraced houses have already been renovated with Energiesprong. These are predominantly single-family houses with a similar geometry. The system technology typically consists of a photovoltaic system and a technology module that houses an air-water heat pump , a heat storage unit, hot water preparation and a ventilation system. There are efforts in France, Great Britain and Germany to copy the concept. The German Energy Agency (dena) has started a program to adapt Energiesprong to German regulations and to transfer it to apartment buildings. The first pilot projects in Germany are to be completed in 2020. Dena networks and promotes construction companies and the housing industry and was able to announce commitments to commission more than 17,000 residential units over the next four years.

background

Climate protection in the German building sector

The German federal government has set itself the goal of reducing greenhouse gases by 55 percent compared to 1990 levels by 2030 and by at least 80 percent by 2050.

The building sector has a significant share in this. It represents 36 percent of final energy consumption and 13 percent of CO2 emissions in Germany. Since fossil fuels and uninsulated building shells are almost characteristic of existing buildings in Germany today, this creates an immense task that must be accomplished in order to be able to achieve the general reduction targets. This modernization is summarized under the term heat transition . The following sector-specific goals have been formulated:

  • Reduction of GHG emissions by 66% by 2030 compared to 1990
  • climate-neutral building stock by 2050
  • Reduction of the primary energy demand by 80% by 2050

This means that through energy efficiency, renovation, thermal insulation and conversion to renewable energies, the entire inventory must be modernized within the next 30 years. The size of this task can be seen from the following indicators: In Germany there are 21.7 million buildings. Of these, 15.7 million are single and two-family houses, 3.2 million are multi-family houses and 2.7 million are non-residential buildings. Residential buildings account for 64 percent of the energy consumption. It should be emphasized here that 12 million of the residential buildings are older than the first thermal insulation ordinance (1979) and therefore have particularly high consumption values. In accordance with the goals mentioned above, this requires a renovation rate of 1.4% per year to 2% per year, depending on the source. However, the actual renovation rate in the past few years was only 0.8% to 1% per year.

The challenges in the building stock

A number of challenges arise from the objectives described above and the status quo. The necessary increase in the renovation rate is limited by the capacities of the construction industry. In addition to thermal insulation, energy supply plays a key role. The goal of climate neutrality requires the abandonment of fossil fuels, but the switch to renewable heat supply is often technically demanding and costly. The German Energy Agency (dena) looked at various technology paths in its 2017 building study. The concentration on electric heat pumps or a technology mix that integrates synthetic fuels has great potential. Regardless of the technological solution, an immense investment volume is required for the heating transition.

The costs of a deep energy-efficient renovation are often as high as those for demolition and new construction. Since a comparatively high proportion of people rented 55 percent in Germany, another problem arises; that of the social consequences. Allocating modernization costs to rents has the potential to undermine the legitimacy of the heating transition in a similar way to the way that the social consequences of the EEG surcharge endanger the (electrical) energy transition. In the case of condominiums and houses owned by the resident, investments in the property are understood as upgrading the property. The owner himself benefits from a higher quality of living, increases the value of the property and can possibly benefit from subsidy programs. In a tenancy, a number of problems and conflicts can arise from a renovation project. In times of tense housing markets, there is also the fact that the landlord is secure in income even without high standards. These circumstances often make redevelopment unattractive for one or both sides, which is known as the tenant-landlord dilemma. Against this background, the renovation of the existing multi-family houses is a particular challenge, as these represent the typical tenement house in Germany.

The Energiesprong renovation concept

The Energiesprong concept is a new type of renovation concept that originated in the Netherlands. The motivation is to make the far-reaching energetic renovation of residential buildings, which focuses on energy efficiency and energy supply, more attractive. Energiesprong aims to carry out the energetic renovation of existing residential buildings through a holistic approach, standardization of processes in planning, production and implementation, as well as the use of modern digital technology and serial production technology, faster, cheaper and with less work on site than conventional approaches. In addition to the serial production of the facade elements, which is inspired by the prefabricated construction industry, the conversion of the energy supply according to sustainability aspects is characteristic. The goal is an energy-efficient house with the so-called NetZero standard, which describes a balanced annual balance of energy generation and consumption in the property. This is mainly implemented technically through the use of PV modules , heat pumps and heat recovery in air conditioning. In addition to questions of technological and economic optimization, it should be ensured that social interests are taken into account. If it is possible to prove the attractiveness of the Energiesprong renovation for all stakeholders , there will be great potential in the German building stock. Scalability is thus both a means and an inherent condition for the profitability of individual projects as well as a political goal in the debate about the implementation of climate protection under economically and socially acceptable conditions.

In addition to Energiesprong, there are other conceptual approaches for the introduction of serial or industrial renovation in the construction industry. There are already completed prototypes and pilot projects across Europe. The Energiesprong concept developed in the Netherlands stands out because 5,000 houses in the Netherlands have already been renovated with Energiesprong, a few more in France and Great Britain. These are mostly row houses, but apartment buildings have also been renovated in this way.

The term Energiesprong means energy jump and was coined by a non-profit organization in the Netherlands, which today bears the name Stroomversnelling. In the spring of 2020, there are not yet any completed Energiesprong projects in Germany. The German Energy Agency (dena) has set itself the goal of promoting Energiesprong in this country, pushing the expansion to multi-family houses and achieving a high level of attractiveness for players in the construction industry in the medium term. In addition, there are numerous activities and events to adapt Energiesprong to German regulations, to initiate the development of products and services in companies, to bring demand from owners to a critical mass and to network companies from the construction and housing sectors.

The process steps in the Energiesprong process

The innovative approach of the Energiesprong concept aims at unification, standardization and scaling in several respects. Modern, digital technologies are integrated and enable serial prefabrication with the necessary flexibility for specific adaptations. Holistic service models that monitor function and operation over the long term or integrate contracting round off the concept. The following process steps are of particular interest:

Digital measurement

The use of modern measurement technology in the form of 3D laser scan technology forms the basis for standardizing the work steps. A digital image of the building to be refurbished is necessary in order to enable standardization in production with simultaneously individually adapted dimensions. Since there is seldom comprehensive documentation for existing buildings, data recording is necessary. Measurement methods such as terrestrial laser scanning (TLS) are used for this purpose. Modern 3D scan devices make it possible to measure interiors and entire buildings with high resolution and comparatively little time. The scanner projects laser or other light beams onto the object and calculates the position of individual points on the object based on the reflection. In this way, several hundred thousand points are measured per second, which in the digital output result in a three-dimensional model of position points, a so-called point cloud. Depending on the technology, an accuracy in the millimeter range and beyond can be achieved. In post-processing, the point clouds are processed using specific software. First, all scans are semi-automatically converted into a point cloud of the entire object and then into a CAD- compatible model. 3D scanners with integrated cameras make it possible to create colored point clouds. If necessary, aerial scans can be performed with drones. In the case of an apartment building of typical size, the costs for such a measurement and model creation are in the four-digit range.

Digital planning

Using the technology described above, it is also possible to create digital models with high accuracy when working with existing objects. These form the basis for planning. These models are absolutely necessary for a serial renovation. Only in this way can the elements for the building envelope be adapted to the object with millimeter precision. This is also a prerequisite for prefabrication in highly automated factories. In addition, the standardized procedures in digital planning enable considerable time savings in the preparation of offers and draft planning based on a certain basis for similar projects.

The idea of ​​digital optimization of processes in the construction industry did not first come about through serial renovation. The concept of the digital revolution in the construction industry operates under the term Building Information Modeling (BIM) . Here, too, standardization, unification and integration play decisive roles; The aim is for all actors in all phases of the building's life to use the same model in which all information is gathered. The use of BIM in the Energiesprong process is only logical, given the inherent application of digital innovations. With RenoBIM, there is already a BIM-compatible software that focuses on renovation projects.

Contrary to the conventional approach, Energiesprong does not provide for a component-oriented tender, but for tenders according to certain quality and service criteria. The idea behind this should enable the manufacturer to freely choose which technical solution will meet the specifications given by the planner.

Modular prefabrication

The core idea of ​​the serial renovation is the industrial prefabrication of modules that only need to be assembled on the construction site. Knowledge of the prefabricated house industry is used here. In addition to the facade and roof elements for the building envelope, the modular and thus serial production of the energy supply systems is also desirable. Thanks to digital measurement and planning, the so-called Industry 4.0 or an appropriately equipped factory can play out its innovations and produce the individual elements in a highly automated manner and still produce them according to individual dimensions and requirements. This individualized mass production has given rise to the term series-of-one . The automation and scaling achieved in this way should enable considerable cost savings. Such a factory of the future is being developed as part of the EU research program Interreg North Sea Region in the Indu-Zero project. It should be able to produce 500 facade elements a day. Today, serial production is still largely conventional production: partially automated using CNC machines with a comparatively high workload and is comparable to the production of prefabricated houses or prefabricated bathrooms. In the Bouwgroep Dijkstra Draisma BV (BGDD) plant, individual work steps are already carried out by robots.

In addition to the cost advantage through reduced use of personnel, it is expected that factory production with quality controls can reduce construction costs based on personnel and material errors. It is estimated that planning and installation errors account for 20 percent of global construction costs. Further advantages of prefabrication are reduced waste and less noise and dust on the construction site. The properties of the modular elements are discussed in more detail below.

Construction and assembly

The high degree of prefabrication in the case of serial renovations enables greatly reduced assembly times. The roof and facade elements are brought into position using a construction crane and assembled there by workers. The attachment is z. B. via brackets that are introduced into the facade at the level of the floor slabs. Support on concrete foundations is also possible. This assembly reduces the construction times on the property considerably and has a positive effect on labor costs and the negative impact on tenants. If the system technology and wiring within the apartments do not need to be converted, the renovation can even be carried out in a continuously inhabited state. The preparatory and accompanying measures for the building envelope are manageable: scaffolding the building, attaching the brackets, removing the windows and external doors, exposing the roof structure, perimeter insulation and insulation of the basement ceiling. It gets more complicated with the system technology, which is discussed in the section below.

Research projects have shown that serial renovation has the potential to significantly reduce construction times. For example, one hour can be calculated for the assembly time of a facade module with three fitters. In this way, single-family houses can be renovated within one to two days. Overall, the construction time can be shortened by 18 to 44 percent compared to conventional energetic renovation. In the case of multi-family houses, the expected effort is heavily dependent on the type of stock and the scope of the measures.

business

The Energiesprong concept includes the guarantee of the NetZero standard. As a result, the providers of Energiesprong renovations mainly offer service contracts that include long-term maintenance and repair, monitoring and energy management. In addition, there are contracting models. In this way, part of the financing can also be provided by the general contractor and refinanced in the long term via heat and electricity supply contracts.

Building envelope and insulation

A central component of the Energiesprong refurbishment is the reduction of energy consumption. The greatest potential lies in the area of ​​heating energy demand. Typical terraced and multi-family houses from the 1950s to 1980s usually have no external insulation and have requirements of 100 - 130 kWh / m² / a or more. Common renovation measures such as the insulation of facades, basement ceilings and roofs, as well as window replacement make it possible to reduce heat losses and thus the heat requirement to a fraction. These measures are also part of the renovation at Energiesprong. After implementation, the heating requirement should be 30 to 40 kWh / m² / a and the requirements of the Efficiency House 55 of the KfW Bank should be met. The Energiesprong concept also stands out in terms of implementation through the standardization of processes and work steps. Instead of implementing the renovation measures on site as usual, elements are prefabricated. These are custom-made based on digital measurements and planning. For the new building envelope, the facade and roof are prefabricated in modules. The elements are based on wooden or steel frame constructions, have the height of one storey, a width of 7 meters, for example, and include the insulation layer, new doors and windows and the new facade surface. In addition, some manufacturers are planning to integrate roller shutters, ventilation systems and / or supply lines into the facade elements.

The production takes place externally in the factory similar to the prefabricated construction industry. The exact digital recording of the existing property enables planning and production to the millimeter, which corresponds to the individual circumstances. The innovations of the so-called Industry 4.0 can show their strengths here: standardized and thus scaled production with individually adaptable products. The product are facade and roof elements that can be assembled according to the modular principle and wrap around the building like a second shell. The appearance of the facade is quite freely configurable, which enables aesthetics and an individual look. The new windows are integrated into the facade elements and are true to scale to the old windows. However, since they are presented and the old windows are removed, the window reveal on the inside becomes deeper and there is a little more space. When integrating a decentralized ventilation system, the installation of mechanical window fans, which are integrated into the facade, is recommended. Balconies present a challenge. In some cases, dismantling with, if necessary, a new construction using a stud balcony is preferred.

Plant technology and energy concept

Refurbishing the building envelope is not enough to meet the Energiesprong criteria. On the technical side, compliance with the so-called NetZero standard is also planned.

NetZero

The so-called NetZero standard describes a building standard with an energetically balanced annual balance and thus corresponds to the German term zero energy house . The target in this balance includes all final energy consumption based on the supply of heating, hot water, ventilation and household electricity. These can be offset on the credit side by on-site regeneratively generated energy, e.g. B. through the operation of photovoltaic systems. The NetZero standard therefore does not provide for an independent energy supply. Solar-generated electricity is credited to the balance, regardless of the ratio of self-consumption to grid feed-in. Furthermore, no distinction is made between thermal and electrical energy in the calculation. The majority of Energiesprong projects work with photovoltaics to generate energy. The use of other sustainable technologies, such as solar thermal energy , pellet boilers or CHP units , has hardly been considered at Energiesprong so far.

The integration of the photovoltaic system can take place as a roof-top or in-roof model. In addition to the usual parameters such as the available roof area, the design is based primarily on the calculations in accordance with NetZero specifications. The expected amount of yield must outweigh the calculated energy consumption. In the constellation of a PV system with a heat pump for heat supply, the assumed annual performance factor (JAZ) of the heat pump is of decisive importance. It describes how many thermal kilowatt hours are generated per electrical kilowatt hour used.

A JAZ of 3.0 is assumed in a document from the German Energy Agency (dena). This means that the calculation is based on an average performance figure, the COP (Coefficient of Performance) of 3.0. Such a value is controversial in the professional world. In the case of air-water heat pumps in particular, the efficiency COP is heavily dependent on the temperature difference and thus on the outside temperature. Studies show: In reality, the JAZ is often well below 3. For the calculation of the NetZero energy balance , an JAZ of 3 means that the annual PV yield meets the criteria as soon as the annual electricity consumption and a third of the heat requirement are exceeded.

Plant engineering

The principles of modularity and prefabrication also apply to the system technology. As part of Energiesprong and other serial renovations in the Netherlands, energy modules have already been developed and installed for single-family and terraced houses. These contain e.g. B. PV converter, ventilation system, hot water preparation and a heat generator (heat pump or gas boiler) and are designed for installation next to the building or in the roof structure. New connection and connection systems were developed, which made it possible to reduce the installation time of the system technology to up to two hours per unit. The costs of the energy modules have already been reduced and should be further reduced through scaling.

Similarly, there are concepts for apartment buildings. These are based, for example, on a container that collects all building services and can be placed in the basement, in the attic or next to the building. Buildings that are already supplied via central heating and hot water systems can easily be supplied with such concepts. It becomes more complicated with decentralized heat supply, since in these cases there are no distribution systems that can be used or converted. There are approaches here that provide for the installation of decentralized energy modules in the apartments, similar to those of the terraced house concepts. Alternatively, there are concepts for facade elements that accommodate the distribution lines. This can enable the switch from decentralized to centralized supply or avoid pipeline rehabilitation in the case of ailing plant systems. For economic reasons, it makes sense to continue to use existing distribution lines. Thanks to the reduced heating requirement, lower flow temperatures are sufficient compared to the status quo , which is why a switch from combustion-based to electrical heat generation can be successful. With central concepts, a hot water flow temperature of 60 ° C is required for reasons of hygiene . This can pose a problem in conjunction with air-water heat pumps, as these deliver poor efficiencies at high temperature differences. A reduction in the hot water temperature is possible through the use of ultrafiltration . This is z. B. planned by Ecoworks GmbH.

The Energiesprong concept provides for the installation of controlled living space ventilation . This enables the necessary exchange of air to be guaranteed and minimizes the associated heat losses through the use of heat recovery. Most of the existing buildings do not have a ventilation system. Retrofitting a central building ventilation system and distribution lines is very time-consuming, especially in apartment buildings. An alternative are decentralized systems, here a distinction is made between apartment-central and room-central. A central apartment complex requires suspended ceilings to connect all rooms. Another possibility is room-based ventilation, which is integrated in the window sill, for example. The latter can be incorporated into the modular facade elements, which means that, depending on the project, there is no need to intervene in the apartment.

An energy management system regulates the plant system. For example, it is important for economic efficiency to operate the heat pump preferably during times when the PV system is generating electricity in order to reduce the consumption of expensive mains electricity. The heat storage tank serves as a buffer that bridges the time shift in electricity yield and heat demand. A battery can be used as an additional energy storage device if the benefits bear the investment.

In addition, the Energiesprong concept provides for modern monitoring systems to be installed. The digitized real-time recording of all relevant energy consumption serves to optimize, control the goals and provide transparency for users. In addition to modern energy meters and sensors, the system also includes an energy center with a dashboard for every user. In addition, there is the option of stimulating or implementing further energy-saving measures through interaction with the users.

Actors and profitability

The German Energy Agency (dena) emphasizes in its publications that the scaling effects necessary for the success of Energiesprong require high demand. A high level of attractiveness for all stakeholders must be achieved for this. Since the market launch of concepts for serial renovation and the corresponding products in Germany is still being developed in 2020, the economically decisive scaling factors are not yet taking effect. Instead, the prototypes are burdened with development costs. In the Netherlands, notable cost reductions have already been achieved since the renovation of the first row houses in 2014. In Germany, manufacturers have to adapt their products to the different regulations. In addition, the focus is more on apartment buildings. It can therefore be assumed that the pilot projects that are currently being implemented in Germany can only be financed through funding from the EU program Interreg NWE MustBe0 . According to dena, the Energiesprong projects meet the criteria for the KfW Bank's Efficiency House 55 and are therefore qualified for corresponding loan and funding programs . According to a calculation by the Green Alliance, the first British Energiesprong pilot in 2018 cost around £ 75,000 net per row house unit, around 50% more than Dutch renovation projects in 2018, but considerably less than the first pilot projects implemented in the Netherlands in 2010 were. Through further development and scaling, it is expected that a magnitude of 35,000 British pounds will be reached in 2025, assuming a number of projects of 5,000 renovations per year. This order of magnitude would exist in the market even without subsidies.

The Energiesprong concept changes the roles of the actors involved and their weighting. Compared to conventional renovation, industrial production is of greater importance, while manual work on site is becoming less extensive. In the following, the actors relevant for Energiesprong and their role and perspective in serial renovation are described.

The general contractor

The general contractor (GÜ) is a planning company where all threads of a specific Energiesprong project come together. This company is hired by the owner and is responsible for all aspects of the project. It acts as a so-called one-stop shop for the client, which means that it takes over all the renovation services or engages third parties. The owner receives a flat rate, all services from a single source and has only one contact person. The general contractor bundles all the services that the renovation project includes: from architectural planning and TGA planning , through organization, implementation and commissioning, to service and monitoring during operation. It is also possible to integrate financing models such as heat contracting or tenant electricity models . The idea behind it is to offer a holistic product. The owner concludes a construction contract and, if necessary, maintenance and repair contracts and / or a heat supply contract. He receives full services and extensive guarantees from a contractual partner. These include long-term quality guarantees from general contractors and suppliers (10-30 years), which, in addition to the function, guarantee compliance with the NetZero criteria and thus energy cost savings . The latter should be achieved after two years and verified by means of monitoring.

Some of the Energiesprong projects in Germany are being implemented by the general contractor Ecoworks GmbH. In addition to the conclusion of a construction contract with a flat-rate price, Ecoworks provides for heat and electricity supply contracts for 15 years. In this case, the general contractor is also an energy contractor. The Dutch manufacturer renolution BV plans to develop a franchise model to combine planning and production, while assembly and installation are outsourced.

The development of serial renovations results in new business models. Depending on the success of the Energiesprong concept, this could mean some changes in the market for companies in the construction industry.

The housing industry

In Germany, housing companies are the typical owners of the multi-family houses that are eligible for Energiesprong renovation. The Energiesprong concept promises to solve many problems that arise for such companies during renovation. These are above all refinancing, planning expenses and conflicts with tenants due to the allocation of costs to the rent, disruption during implementation, access to apartments for construction work, fear of displacement, etc.

In contrast to conventional energetic renovation, Energiesprong should achieve refinancing primarily by saving energy and increasing the value of the property. The aim is to only increase the rent excluding heating to the extent that the rent including heating remains constant. The savings can be calculated on the basis of the NetZero calculation. These savings are guaranteed by the general contractor. In the medium term, serial renovation should be cheaper than conventional. Until this is achieved, subsidies for serial renovation are necessary in order to be competitive. In addition, reference is made to the so-called coupling principle: If extensive repairs are already pending on a property, a deep renovation can be represented more economically by offsetting these costs. Serial renovation can minimize tenant disruption and, ideally, no resident has to leave their apartment for the duration of the renovation.

Energiesprong renovation with energy contracting can offer further advantages for housing companies. Financing channels can be opened up via heat supply contracts. The contractor can also implement a tenant electricity model. The housing company then saves effort and risk. In addition, the trade tax privilege for housing companies is at risk if they sell electricity to their tenants and thus deviate legally from pure property management.

The construction industry

Serial renovation results in a relocation of part of the added value from the construction site to the factory. The industry doesn't just manufacture components on the assembly line. Instead, it should offer complete solutions that are modular but ultimately produced as a whole system. In addition to the preparation of digital input data, the development of highly automated productions that can produce modules of individual shapes on the assembly line is necessary for the targeted massive cost reductions. Such a "flexible factory" for serial renovation does not yet exist, but there are research programs and the construction company renolution claims that it is planning to build a factory. In the Netherlands, the construction company Royal BAM Group has carried out some of the previous Energiesprong renovations. In order to develop the facade and system modules, cooperations were concluded with eight partner companies.

The reduction in the workforce required on the construction site could relieve the burden on the sector, which in parts complains about a shortage of skilled workers. However, an increasing renovation rate would prevent this.

The tenants

Energiesprong promises attractive energetic renovation for everyone, including the residents. As a result, the tenant should receive increased living comfort with almost unchanged total costs. These total costs are made up of net rent, operating and heating costs and household electricity. The refinancing of the investment takes place via the increase in the rent excluding heating, which should not be reflected in the rent including heating due to the energy savings.

If no work is necessary in the apartments, there is less tenant interference compared to conventional renovations due to reduced construction and assembly times. The time saved in the facade work is particularly important here.

Society

The German federal government has set ambitious climate protection goals in the building sector. Serial renovation has the potential to increase the renovation rate, which is important in this context, by addressing inhibiting factors such as profitability and a shortage of skilled workers. The Energiesprong concept also includes approaches that reduce the potential for conflict based on social issues. In order to be a success for society as a whole, energy-efficient renovation must not be a luxury. As with the energy transition, the success of the heating transition depends on political decisions, such as the design of funding programs.

There are various technological options for the so-called heat turnaround, the switch from fossil fuels to renewable sources for the provision of heating and hot water, which are described in detail in the dena building study "Scenarios for a market-based climate and resource policy in the building sector in 2050". If society chooses a technology path that relies on electrification in the form of heat pumps, as is the case in the Energiesprong concept, this will have an impact on the electrical energy system and the electrical energy transition. The NetZero standard has to feed a result the corresponding building in the central European summer climate much electricity into the power grid while increasing the demands on the network in electricity and peak load in winter.

Compared to these systemic questions, the discourse about the visual appearance of houses and cities seems to be of secondary importance. However, dena emphasizes this aspect in the Energiesprong concept and even elevates visual attractiveness to one of the basic criteria with which Energiesprong should convince. Industry 4.0 makes it possible to take up the advantages of mass production without renouncing design requirements. The design of the facade elements allows variety, as numerous photos from Energiesprong projects show. The architectural possibilities remain in spite of mass production and in this way sophisticated optics could become more affordable again in the future than new buildings and renovations mean today.

Restrictions in the building selection

Since serial renovation and energy boost are still in the process of being launched on the market and are therefore neither technically fully developed nor can the necessary cost savings be achieved, the general contractor is restricting the buildings in question. The selection is currently limited to buildings with a simple cubature, i.e. H. uncomplicated facade geometry. In order to be able to present the pilot projects more or less economically in spite of their prototype character, a living space of at least 800 m² with heat consumption over 130 kWh / m² / a is assumed. Other conditions are enough space for assembly work and the new building envelope. The height of the individual buildings is limited to four storeys so that there is sufficient roof area for solar power generation in relation to the usable area. For the same reason, there should be no significant shading. In addition, a central heating system, an uninhabited attic and space for a heating container are advantageous.

Development in Germany

The German Energy Agency (dena) expects the Energiesprong renovation of apartment buildings with a total of around 300 residential units in Germany in 2020. In order to enable profitability through scaling and to generate incentives for the construction industry, dena has brought together companies from the housing industry in a declaration of intent. In the so-called volume deal , housing companies are committed to the Energiesprong concept and promise to order over 17,000 housing units over the next four years. The market potential is great; In Germany, 500,000 multi-family houses or 5 million residential units are classified as technically and economically suitable for Energiesprong renovations.

In the Netherlands, the feasibility and cost-effectiveness of the Energiesprong principle has already been demonstrated in terraced houses. If it is possible to transfer this to multi-family houses, reduce costs as expected and implement the principle of warm rent-neutral renovation into reality, this approach can become a product with resounding success.

Web links

literature

Max Beckmann: Energiesprong - Consideration of the holistic concept for serial renovation under the framework conditions of apartment buildings . TH Köln, student thesis, 2020. URL: https://epb.bibl.th-koeln.de/frontdoor/index/index/docId/1551

Individual evidence

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  6. ↑ a b Christoph Jugel et al .: Final report of the dena project “Urban Energy Transition”. Retrieved April 28, 2020 .
  7. ↑ a b c d e Deutsche Energie-Agentur GmbH (dena): dena building report compact 2019 “Statistics and analyzes on energy efficiency in existing buildings”. Retrieved April 28, 2020 .
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  9. ↑ Foundation Energy & Climate Protection: Infographic: “Heat transition in the 4 walls”. Retrieved April 28, 2020 .
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  12. ↑ a b Martin Kaluza: Serial renovation made to measure. transition - DENA's energy transition magazine, accessed on April 28, 2020 .
  13. ^ The Netherlands - Energiesprong. Retrieved June 16, 2020 .
  14. ↑ a b c Deutsche Energie-Agentur GmbH (dena): The Energiesprong principle. Retrieved April 28, 2020 .
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  16. ↑ Jens Clausen: Industry 4.0 in the context of environmental innovations. Borderstep Institute, accessed April 28, 2020 .
  17. ↑ a b Ulla-Britt Krämer et al .: Presentation: "Indu-Zero - Sanierungsfabrik der Zukunft". Retrieved April 28, 2020 .
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  19. ↑ a b c d Short version of the NetZero restructuring concept of BAM Immobilien-Services GmbH. Retrieved April 28, 2020 .
  20. ↑ a b c d e Brief version of the NetZero restructuring concept of the B&O Group. Retrieved April 28, 2020 .
  21. ↑ a b c d e f Short version of the NetZero redevelopment concept of ecoworks GmbH. Retrieved April 28, 2020 .
  22. ↑ a b Institut Wohnen und Umwelt GmbH: German residential building typology - exemplary measures to improve typical residential buildings. Retrieved April 28, 2020 .
  23. ^ Deutsche Energie-Agentur GmbH (dena): The Energiesprong Principle. Retrieved April 28, 2020 .
  24. ↑ a b c d e Short version of the NetZero renovation concept of renolution BV Accessed on April 28, 2020 .
  25. ^ Energieinstitut Hessen: Heat pump manifesto. Retrieved April 26, 2020 .
  26. ↑ a b Ana Tisov et al .: Sets of deep renovation solutions of Buildings HVAC systems. In: P2Endure Research Project. Retrieved April 28, 2020 .
  27. ↑ a b c Chaitanya Kumar et al .: Reinventing retrofit. Green Alliance, accessed April 28, 2020 .
  28. ↑ Viessmann Deutschland GmbH: Planning manual for heat pumps. Retrieved April 28, 2020 .
  29. ^ A b Reinhard Otter: Netherlands: Zero energy standard for social housing from the kit. Retrieved April 28, 2020 .
  30. ↑ Andreas Enseling et al .: Energy-related building modernization - (how) does it pay off? IWU Schlaglicht 01/2020, accessed on April 28, 2020 .
  31. ↑ Uwe Bigalke: Renovation of the future. Retrieved April 28, 2020 .