Homes in Hameln modernised following the Energiesprong approach In Hameln (Lower Saxony), the first building in Germany was serially retrofitted following the Energiesprong approach. Energiesprong is a new method for net zero energy renovation: using prefabricated roof and façade elements, as well as prefabricated building technology, buildings can be modernised quickly and in a climate-friendly manner. The innovative construction process brought the Hameln building up to the climate-friendly NetZero standard. The German Energy Agency (dena) is responsible for launching serial renovations in Germany on behalf of the Federal Ministry for Economic Affairs and Energy (BMWi) and supports companies in planning and implementing pilot projects. The 1930s Hameln apartment block, consisting of three building sections with two floors each, was previously in great need of renovation. Almost all of the twelve apartments in the apartment building are now rented. Since the renovation, the building has achieved the climate-neutral NetZero standard: a photovoltaic system on the roof generates as much energy over the year as is required for heating, hot water and electricity. Over 500 sensors installed in the house evaluate the consumption data and help to optimally-control the heating supply and ventilation of the building. A heat pump and a heat recovery ventilation system complete the innovative building technology. Now the serially-renovated building can prove itself in operation and show that the Net-Zero standard works. Ecoworks GmbH, provider of CO2-neutral and serial renovation in Germany, coordinated the implementation as a total solution provider. A prefabricated construction company from Brandenburg prefabricated the façade elements. Windows, ventilation, power cables, fiberglass insulation and coatings were already integrated into the elements. They were installed on site as a new shell on the house. The house is owned by the Arsago Group. Thomas Bareiß, Parliamentary State Secretary in the Federal Ministry of Economics said: “Around 35% of Germany’s total final energy is currently consumed in buildings, especially for heating and hot water. A lot of energy can be saved by renovating the energy efficiency of buildings. The Federal Ministry of Economics already supports renovation measures for buildings with a large number of funding measures. In 2020, we made 8.5 billion Euros available, triggering an estimated investment of 83 billion Euros through KfW’s support measures alone. Serial renovation is a new component in this package. It enables buildings to be quickly renovated using prefabricated elements. This is attractive for the real estate industry, for owners and also for tenants”. Andreas Kuhlmann, Chairman of dena management said: “The pilot in Hameln is a milestone in the market development of serial renovation solutions. A house in great need of renovation has become an affordable, climate-friendly and high-quality home. The pilot makes it clear that innovation in the construction sector pays off. The experience gained here can be used to gradually improve technologies and processes. Scaling and innovation will keep costs down. This is how we get step-by-step from the pilot phase to serial production. A future-oriented and profitable market is currently emerging for companies in the construction industry. After the upheavals in mobility and renewable energies, the construction industry must now deliver the next major climate protection innovation”. Florian Schrage from Arsago said: “As owners, we are very satisfied that we have actually succeeded in implementing the first project of this kind in Germany. I am also particularly pleased that we were able to set an example for energy transition here in Kuckuck, Hameln with its eventful history. This pilot project was the much-cited "great challenge" as anticipated, but in my opinion we have achieved a convincing result both technically and creatively, which I hope will be followed by many people”. Emanuel Heisenberg from Ecoworks said: “We are proud to have implemented the first serial renovation in Germany and to have renovated three comfortable, CO2-neutral buildings for the owner and the tenant. Now it is time for us to use the experience and data to further develop the serial solution”. About Energiesprong In Germany, Energiesprong is coordinated by the Deutsche Energie-Agentur GmbH (dena). In close cooperation with the construction and housing industry, dena develops the redevelopment concept for the German market, brings companies together and advocates optimal framework conditions. The project is financed by the Federal Ministry for Economic Affairs and Energy (BMWi) and supported by the GdW Federal Association of German Housing and Real Estate Companies. Implementation of the first pilot projects is funded by the EU INTERREG NWE programme as part of the “MUSTBE0” project. This also includes the project in Hameln. Dena estimates the potential number of small to medium-sized apartment buildings from the 1950s to 1970s in Germany to be around 300,000 buildings. Further pilot projects will be implemented in 2021.

Nearly 70 percent of the city’s total carbon emissions come from buildings. A project to retrofit nine buildings with green technology is pioneering a new solution. Casa Pasiva was the brainchild of the architect Chris Benedict, a longtime partner on passive house projects with RiseBoro. She drew inspiration from  Energiesprong , a Dutch process that uses standardized, premade building panels with built-in heating and cooling systems to upgrade older buildings. In the United States, and New York in particular, the wide variety of housing types, as well as differing climates, makes the standardized Dutch approach unfeasible. Read the whole article here >>

An ambitious project: The complete renovation of an outdated Intervam flat on the Camera Obscuradreef in Utrecht, the Netherlands.   After a successful pilot with 8 homes that were made net zero in 10 weeks, construction company VIOS refurbished a total of 252 apartments and 15 new homes in the same neighbourhood to net zero energy homes. This was just the starting point for the Housing Organisation Mitros. Goals: Extend lifespan by 50 years High energy measures Design, completion, management and maintenance on the one hand, and agreement on the other Multi-year maintenance plans € 1,350 including VAT per home per year Resident satisfaction > 8 In addition, all homes also included a new kitchen, bathroom and toilet. New stucco, interior paintwork, interior doors, H&S work, switchgear, and new interior installations throughout. Asbestos must be remediated and we completed 15 new homes. The successful project has received a lot of media attention and, at the end of 2019, it received an award at the prestigious  Green Solutions Awards  in the Sustainable Renovation category. Technical specifications: Performance guarantee: 10 years Energy use  before  the renovation: 225 kWh/m2 per year Energy use  after  the renovation: 50 kWh/m2 per year Divided over energy use: Heating: 10,9 kWh/m2 (including ventilation) Warm Water: 14,2 kWh/m2 Cooling: 0 kWh/m2 Household consumption: 24,8 kWh/m2 Energy  savings : 175 kWh/m2 per year Production of energy through solar panels to achieve net zero energy: around 50 kWh/m2 per year Most important elements: Ventilation by means of balanced ventilation with a Heat Recovery Unit CO2 controlled (system D) Air-water heat pump PV (solar panel) Insulation Entire shell thermally insulated:roof: Rc= 6closed façade: Rc = 4,5open façade, triple glas: U-value = 0,5ground floor: Rc = 4,5cold bridges removed by local insulation and thermal breaks Cooperation: Design, Build & Maintain with Mitros Woningcorporatie Chain cooperation with chain partners VIOS Bouw  Click  here  for the complete photoalbum

Energiesprong UK has announced that its deep retrofit innovation partnership is live and open to bids.This ground breaking approach to procuring and developing Energiesprong deep retrofit solutions aims to unlock up to £10bn of market potential and kickstart large-scale, whole-house retrofit for homes across the country.  The innovation partnership brings together housing providers and suppliers to help transform the approach to retrofitting the UK’s aging, inefficient housing, creating desirable, warm, affordable homes at scale.

The German housing company LEG has commissioned three construction companies to develop serial retrofitting processes that can be used in parallel, based on the Energiesprong approach, and to modernise residential buildings to the net zero standard. The goal is scalable and more cost-effective. “The process technologies to be tested only hold promise in terms of generating the necessary cost advantages if they are scalable, which is why we, together with Dena, have made the findings transparent (similar to the open source concept in software development), in order to be able to scale up more quickly"Dr. Volker Wiegel, COO of LEG The housing company LEG based in Düsseldorf is launching a real-life laboratory in Mönchengladbach for serial renovation based on the Energiesprong approach. Three construction companies were commissioned to develop a serial usable renovation process based on the Energiesprong approach for a third of the buildings each, and to modernise these buildings to Net-Zero standard. The buildings, built in 1956, each have two floors, four to six apartments and a high energy consumption level, with an H energy performance certificate. LEG would like to make climate-neutral living possible in these buildings without the rents having to increase significantly. The three companies commissioned: B&O from Bad Aibling, Fischbach from Essen and Renolution from Haaksbergen in the Netherlands are all members of the  NetZeroNow network . Energiesprong supports companies in this network to plan and implement initial serial retrofitting projects. Each company will use different technologies and approaches to modernise the buildings. The aim is to test how the renovation concepts can be applied and improved under real conditions. LEG aims to deliberately encourage the exchange of information and ideas between the project participants. According to LEG, the aim of the real-world laboratory is: "to develop renovation concepts that are scalable, which thus become more cost-effective and help to accelerate the energy transition". “This project is very demanding and exciting from a purely technical point of view. The buildings are captured using 3D scans and the façades and solar roof elements are prefabricated with millimetre precision. This includes the windows, the insulation and the external cladding. The finished elements are then installed on the building. An energy module is also preassembled, which contains all the technology for the entire building, e.g. a heat pump that replaces the old heating system, a hot water storage tank, a ventilation system with heat recovery and the electronics for the photovoltaic system and the monitoring system. The complete module is delivered to the construction site and then only has to be connected on site”, says Uwe Bigalke, Team Leader for energy-efficient buildings at Dena.

The aim of the MustBe0 Design Competition,  launched last November  by Energiesprong UK, was to develop new approaches for high-performance, scalable and cost-effective net zero retrofit solutions focused on apartment blocks. The Design Competition has been a fruitful process and shows fantastic progress, resulting in 6 winning teams who presented their concept designs at  Futurebuild in London , March 2020.  During this event, our partner IET (who were keen to document the whole process through video) interviewed presenters to learn more about the aims of the competition, the purpose, challenges and intentions. They also had the opportunity to speak with 5 of the 6 consortia winners. Click  here  to meet the winners and hear about their inspiring ideas! The concept designs and solutions you’ll hear about in the videos are divided into the 3 categories which the Design Competition focussed on: Build Up, which includes adding a layer of new dwellings on top of existing flats while ensuring whole building net zero energy, Net zero energy for low rise apartments (< 4 stories) and billing, metering and monitoring. The Design Competition doesn’t stop there. Energiesprong UK continues to support the winners in developing the market in a way which allows their great ideas to become reality. IET will continue to film the whole process so keep an eye out for the more in-depth documentary! Emily Braham from Energiesprong UK says “It was fantastic to see these top players develop themselves and their ideas in this competition. They all had to deal with specific challenges, and I’m really excited by the innovative ideas they have come up with. I have confidence that we will see some of the designs put into practice.” The Design Competition is supported by the European project NWE834 MustBe0, Multi Storey Building Energy = 0, funded by the Interreg NWE Programme through the European Regional Development Fund.

RetrofitNY has made a Pledge. The purpose of this pledge is to mobilise the market to enable building owners to retrofit their buildings to net-zero energy (NZE) performance in a cost-effective way, significantly improving their building’s value and reducing its construction period and operating expenses, while improving residents’ quality of life. NYCHA, which has a total of 169,820 dwelling units in its portfolio, signed the RetrofitNY Pledge and has therefore committed to drastically reduce its GHG emissions by implementing deep energy and net zero retrofits. To date 15 additional social housing owners have signed on, totalling over 280,000 units aggregated under the RetrofitNY Pledge.  Climate Mobilization Act As New York City has now passed the Climate Mobilization Act (CMA), in a few short years, the business landscape is going to be very different for building owners compared to what it is today, and owners need to be prepared for these changes now. The Climate Mobilization Act (CMA) includes legislation requiring owners of buildings over 25,000 square feet to substantially reduce their greenhouse gas emissions over time enabling the City to meet its targets of 40% by 2030 and 80% by 2050. The CMA would affect 50,000 buildings in the City. This law also requires the study of a citywide emissions trading scheme for carbon credits which, if enacted, may lead to an increase in value and revenue potential for NZE buildings whose performance would meet or exceed the mandated levels. Similar high-performance standards are pending or being implemented in Massachusetts, California, Vancouver and in many other municipalities. The Pledge New retrofit solutions must be made available in order to give building owners a viable way to comply with new laws, prepare for imminent changes in the market and reduce risk in their building portfolios, while enhancing the performance and value of their building assets. The RetrofitNY Pledge will allow building owners to use their collective buying power to compel manufacturers to introduce new retrofit solutions into the market at no risk to themselves. As proven by the success of similar programmes throughout Europe, Energiesprong for example, building owners’ signatures on this pledge will help to dramatically increase the availability of affordable high performance retrofit solutions from which they and the entire market will directly benefit. Additional RetrofitNY programme information and resources are available at https://www.nyserda.ny.gov/RetrofitNY .

The Reframed Initiative is calling on European industry partners to participate in a six-month exploratory design process to develop next-generation refurbishment concepts with the mission to transform existing housing into high energy efficiency buildings. ( click here to subscribe) Taking inspiration from the Energiesprong approach to retrofitting residential buildings in Europe, the Reframed Initiative in British Columbia (B.C.), Canada is working with designers, builders, owners, financiers, and policymakers to scale up deep retrofits. The initiative is a partnership between the Pembina Institute, a non-profit think-tank that advocates for strong, effective policies to support Canada’s clean energy transition, the BC Non-Profit Housing Association, and the City of Vancouver. Their goal is to work together to address the climate emergency in Canada by preserving and upgrading existing residential buildings that provide affordable housing in a market with high rents and low vacancy rates. Deep retrofit designs wanted Encouraged by Energiesprong’s success in implementing its revolutionary, whole house refurbishment approach in Europe, the Reframed Initiative is teaming up with BC Housing, a crown corporation accountable to the provincial government that develops, manages and administers housing in the province, to commission deep retrofit designs for up to five multi-unit residential buildings. The target archetype is typical to B.C., low-rise (less than four storeys), wood-frame building with 11-50 residential units.  This programme aims to demonstrate advanced innovation in building retrofits that make buildings more energy-efficient, less polluting, and more resilient to earthquakes and extreme weather. Looking for integrated technologies Reframed is particularly interested in retrofit solutions that integrate technologies such as pre-fabricated exterior wall and roof panels, high-efficiency and low-carbon mechanical systems, roofing solutions that integrate on-site renewable electricity, storage and/or thermal generation, seismic upgrades and climate adaptation measures. To facilitate early integration of innovative solutions, design teams will be multi-disciplinary and include practitioners such as architects, contractors, manufacturers, suppliers, modellers, performance monitoring specialists, among others. Energiesprong’s European partners and solution providers would be welcome to partner on a design team! Next generation solutions in six-months Selected teams will participate in an exciting new exploration lab, called the Reframed Lab , which will bring them together in a six-month exploratory design process where they will share retrofit ideas and learn from experts on technical innovations, resilience, embodied carbon, and health. The aim of this collaborative design process is to demonstrate next-generation solutions that integrate health, seismic and fire safety and climate adaptation measures with envelope and mechanical upgrades to improve the energy efficiency of old buildings and cut carbon pollution while minimizing tenant disruption. Each design team will design a retrofit specific to one building and consider how the solution could be applied to the other buildings. Design teams will determine the appropriate combination of interventions to balance the needs of the building, owner and occupants with respect to costs, performance targets, and health and safety requirements. Being near a fault line, seismic safety is a priority in British Columbia. Each building will be assigned a project technologist by BC Housing to work with the team of experts. The teams will then come together to share their expertise and provide feedback on the different retrofit designs for each building. The designs will be evaluated by a jury of experts and Reframed partners who will recommend a preferred design for the design and construction phase of the projects. Sanne de Wit, Head of Ideas at Energiesprong Foundation, said, “We are really happy to see that the Canadians are moving forward in terms of reducing the energy needs of old buildings. We love the idea of the Reframed Lab, launched by our Canadian counterparts. Pembina and the other partner organisations involved in the initiative really are frontrunners when it comes to energy transition. I can’t wait to see the outcomes of their design process. I can imagine that many of our European contacts and partners will be interested in joining this initiative.” To find out more about the Reframed Initiative and to register your interest, visit: reframedinitiative.org/lab The primary consultant leading the design team must be an engineering professional licensed to practice in B.C.

A refurbished and improved building stock will help pave the way for a decarbonised and clean energy system, as the building sector is responsible for more than one third of the EU's emissions. Renovation of all buildings has been singled out in the  European Green Deal   to drive energy efficiency in the sector.  The upcoming renovation wave strategy will need to address many issues for transforming the existing building stock to net zero standards. Since most of today’s buildings will still be standing in 2050, this is a big challenge. However, construction does not materialise overnight, and that is why timing, and early deployment require working examples for replication. Factory Zero in Tiel, the Netherlands, is one such working example. It was built as an answer to the lack of prefabricated, integrated components for the renovation of existing buildings. To illustrate this, on Tuesday 29 th September, a webinar and virtual tour through Factory Zero took place. Before the visit to the factory, there was a presentation on the importance of low temperature heating and heat pumps and why countries (and the European institutions) should fully focus on this approach in the renovation wave and all the innovation programmes. The tour of Factory Zero explained how the integration of components and industrialisation can create better options for consumers and enable us to meet our carbon targets at the same time. Over 200 people connected. The overall impression was that they loved the informative, but also livelier format adapted for these changed and online times. We invite you to watch the (edited) recording of this event, which took place last week, here:  https://vimeo.com/464213810

On 4 th July 2019, in the presence of Emmanuelle Wargon, the current Ministre Déléguée au Logement (French Government Minister Delegate for Housing), the Energiesprong France team launched their first innovation competition, with support from the Union Sociale pour Habitat and co-financed by the Interreg NWE project MustBe0, the GRDF and the EEC Energiesprong France programme. The aim is to encourage multi-disciplinary teams to develop innovative, integrated, and cheaper solutions in terms of overall costs in order democratise access to guaranteed zero energy retrofits. “The key is to show entrepreneurs the way forward in terms of the types of solutions needed to achieve Energiesprong retrofits. The faster these high-quality, less expensive solutions are manufactured, the faster ambitious retrofits will multiply. This competition should raise awareness that some high-quality solutions already exist, and that new ones need to be developed. The support of professionals in the process towards industrialising their business activities also appears as a key factor of success. The selected teams received remuneration and were supported in the process to develop their prototypes, in cooperation with their future clients”, said Sébastien Delpont, Director of the Energiesprong France programme. Innovation Competition After assessing the 78 entries, 24 groups of finalists were chosen in September 2019 to work on technical solutions corresponding to the three key modules of Energiesprong zero energy retrofits: Several months later, the teams of finalists were finally able to present and exhibit the prototypes of their innovative solutions at the Energiesprong Innovation Forum. This event, that took place on September 3, concluded with the awarding of prizes to the winners, during which Emmanuelle Wargon, Ministre Déléguée au Logement, gave a new message of encouragement to congratulate the participants and their partners. To find out more about all the winners and for further information on the competition, please do not hesitate to read the press kit. You can also find the specifications for the different categories, as well as the technical descriptions, videos and photos of all the solutions developed by the entrants on the page dedicated to the innovation competition  (see the paragraph entitled “ Pour aller plus loin ”). Forum Innovation The day was devoted to exchanging and sharing knowledge through several round table discussions and activities. It provided an opportunity for those involved in the energy retrofitting sector to find out more about the Energiesprong approach and to benefit from the lessons learned by pioneers who have already embarked on the process. They also had the chance to reflect on the possible future for operators involved in energy efficient retrofits, to identify the potential of the market for this type of retrofitting in France, and to discover the new methods of cooperation created by the approach. Last but not least, participants also learnt about the impressive example of the large-scale territorial approach in the Pays-de-la-Loire during the Innovation Forum.  The event also provided the occasion for the Enedis – Energiesprong agreement to be signed which aims to facilitate the deployment of zero energy retrofits in the region. You can watch the whole of the conference as well as the prize giving ceremony here.

The Whole House Retrofit (WHR) competition, focused on developing an affordable route to deep retrofit, has announced their winners. Energiesprong UK is one of them, winning projects with both Nottingham (Nottingham City Council and Nottingham City Homes) and Sutton (London Borough of Sutton and Sutton Housing Partnership). The projects entering the WHR competition must consider both process related innovations and material aspects of retrofit, focusing on mass production and large-scale delivery. Approximately £8 million funding has been awarded to 3 organisations to demonstrate a cost reduction trajectory for whole house retrofit. For the winning Energiesprong UK projects Nottingham and Sutton, the combined project budgets are more than £16m with grant of £6.6m. The WHR competition is funded by the Department for Business, Energy and Industrial Strategy’s Energy Innovation Programme. For the housing provider partners, Nottingham City Homes and Sutton Housing Partnership, this means a deep retrofit can take place on homes that aren’t energy efficient to today’s standards, helping to reduce fuel poverty and create warm, affordable desirable homes, fit for 2050 standards. “It’s fantastic that our residents will benefit from lower energy bills, warmer homes and a more sustainable future as a result of this funding. We’re very proud to be working towards a carbon neutral borough and supporting Sutton Council in its ambitious plans to tackle the climate emergency.” Steve Tucker, Managing Director of Sutton Housing Partnership Sutton Housing Partnership The Sutton project aims to retrofit up to 100 homes in the London Borough of Sutton to the net-zero energy Energiesprong standard. Sutton Housing Partnership will manage the project with expertise from Energiesprong UK and Turner & Townsend supported by the Mayor of London’s Retrofit Accelerator programme. A whole house insulated wrap system will be deployed with high performance windows and doors. Other integrated retrofit measures will include an air to water heat pump, solar PV, mechanical ventilation with heat recovery for improved ventilation, and control system. Initial pilots will be delivered for traditional and non-traditional housing types which will then be scaled up to understand suitability for industrialised retrofit in the UK. “I’m delighted that we’ve been successful with this bid in conjunction with Energiesprong UK, we are pleased to be working in partnership to deliver more net zero homes. Through this project, Energiesprong UK is helping us find affordable ways to meet our 2028 goal and become the first carbon neutral city in the UK.” Wayne Bexton, Head of Energy Services, Nottingham City Council Nottingham City Homes Energiesprong is supporting Nottingham with two separate strands within this project to achieve the 2050 standards: Applying learnings from their previous Energiesprong pilot, Nottingham will develop this innovative net zero whole house approach for flats in the Clifton area A new methodology, called Destination Zero, which is being piloted in the Bakersfield area of the city Both of these work streams will use offsite components and are aimed at using industrialisation to drive down cost in line with the project objectives, helping Nottingham understand how to ensure they can improve their homes in the most efficient way, as they are keen to become the first carbon neutral city in 2028. The Energiesprong workstream ‘leaps’ the properties forward in one stage, whilst Destination Zero develops a net zero pathway ensuring that all components fit together and are installed in line with the end goal. Both work streams will use similar components such as wall facades or insulation manufactured into panels off site, and low carbon heating and energy pods. Innovative suppliers, Mauer, Q-bot and Constructive Thinking were partners in the Nottingham bid, and are now delivering the Destination Zero work stream. Energiesprong UK also brought in cost reduction partners, Manufacturing Technology Centre, who are helping to ensure Nottingham meets their cost reduction objectives, both for the project, and beyond. Through the Nottingham project the council and their ALMO, Nottingham City Homes, will improve the homes of 172 tenants and leaseholders, and they will create more than 15 new local employment and training opportunities. Energiesprong UK Energiesprong UK, is proud to be instrumental in supporting these winning projects to flourish and is convinced this will take the movement further in realising better, cheaper and more desirable retrofit solutions, to ensure everyone can live in a home that not only fits our time, but is also ready for our future.

5 March, Berlin: The market development for serial NetZero renovation solutions has entered the next phase: The four construction companies BAM Group, B&O Group, ecoworks and Renolution have developed complete solutions with which they can renovate apartment buildings from the 1950s to the 1970s to a NetZero standard, following the Energiesprong principle. This means that the buildings generate as much annual energy as they need for heating, hot water and electricity. The solutions were presented to a specialist audience on 5 March 2020 at the event “NetZero Now. For climate-friendly and affordable living”. With the addition of the Fischbach Group, another construction company is also now working intensively on the next complete solution. "The high demand from the housing industry naturally gives rise to the development of these future-proof renovation solutions, which already meet the 2050 standard," said Uwe Bigalke, Team Leader for serial renovation Energiesprong at Deutsche Energie-Agentur GmbH (Dena). “We currently have around 17,000 apartments that are to be renovated using the Energiesprong approach over the next four years. That is around 5,000 more than announced in the Volume Deal last November - and there may be more”, he continued. Common development of standards The new renovation solutions were developed as part of the Energiesprong Initiative’s Accelerator Programme, which is coordinated by Dena and supported by the EU-funded Interreg NWE "Mustbe0" project. The construction companies were coached by a market development team and international Energiesprong experts. Through workshops and in close collaboration with housing companies, they have developed their products further into scalable and cost-effective renovation solutions with which apartment buildings can quickly and easily reach a NetZero standard. The exchange with the housing companies will continue beyond the programme in order to develop common standards for the future market of serial renovation. Volume Deal On 26 November 2019, the Volume Deal, a joint declaration of intent by the housing and construction industries, made the first breakthrough in terms of the market development of serial renovation solutions in Germany. In the Deal, 22 housing companies will pool together their demand and provide 11,635 apartments for serial renovation over the next four years. Net Zero Now! Further impressions and information about the event Net Zero Now! can also be found at energiesprong.de . On the site, you can also download the short versions of the NetZero renovation concepts from the construction companies BAM Group, B&O Group, ecoworks, Renolution and further information on what motivates the Fischbach Group.