A unique opportunity to transition to climate-neutral and energy-generator building.


Buildings in the EU contribute significantly to energy consumption and CO2 emissions, with most of their energy needs being met by fossil fuels. The EU’s Green Deal demonstrates Europe’s commitment to achieving climate neutrality by 2050, making it the first continent to do so. Additionally, construction and demolition waste accounts for a substantial portion of the total waste in the EU, and the Commission is launching a new plan to increase their re-use, recycling, and recovery. These sustainability goals are clearly ambitious and achieving them will require additional measures.

Concept and Innovation

Positive energy buildings (PEBs) are a promising approach to reaching the EU goals. PEBs surpass the established concept of nearly zero-energy buildings (NZEBs) by generating more energy than they consume. The surplus is shared through an intelligent energy distribution network, supporting other buildings needing additional energy. PEBs are now moving toward using renewable energy sources that can significantly reduce the environmental impact of the building complex. They primarily employ NZEB-like technology, but they also incorporate more diverse renewable energy generation technologies into the same structure while maintaining good energy efficiency.

The REN+HOMES project aims to enhance and select affordable key technologies (KTs) while developing highly replicable technology packages (TPs) for PEBs. These advancements will contribute to the widespread of PEBs and support the EU’s sustainability goals.

The REN+HOMES concept comprises three core components:
  1. +1

    Development and/or upgrade of KTs – This involves 16 solutions: 9 Hardware and 7 Software

  2. +2

    National and international methodologies for circular plus energy homes (CPEH) – This includes the 6 national and 1 universal/EU flags.

  3. +3

    Physical demonstration of CPEHs – This aspect focuses on the practical demonstration of circular plus energy homes.


REN+HOMES will deliver 1 international and 6 national (M#1-6) innovative methodologies for the development of CPEH. These methods provide the means to future building scenarios, where renewable energy is generated, delivered, and stored within the space of each construction.

Universal Positive Homes Methodology

The building sector is changing fast to keep up to date with the new energy efficiency policies, users’ interests, and resource scarcity. According to the main certification and standardisation bodies included in REN+HOMES, the current methodologies are not up to date and don’t address “resource scarcity” enough. REN+HOMES will create a new generation of dynamic certificates usable worldwide – they will consider design and operation, as well as water and material scarcity.

M#1, M#2

International PassivHaus methodology: Primary Energy Renewable (PER) update

The PER system generates a model of a region’s future renewable energy sources and allows the optimisation of buildings with 100 % energy from renewable resources. REN+HOMES will develop a new version of the PER system that distinguishes two diverse climates: COLD (continental subarctic climate) and WARM (humid subtropical climate), respectively tested in Austria and Spain.

See this methodology in action:

ROMANIAN GBC methodology: Upgrading nZCB methodology in co-design with residents

REN+HOMES will support the transition of buildings to approved Mc001/2006 Nearly Zero-Energy Buildings (NZEBs) via professional training by NZEB experts and monitoring the support offered to a variety of financial institution partners in the green mortgage programme. REN+HOMES will also implement strategies that improve local readiness.

See this methodology in action:

ESTONIAN GBC methodology: Upgrading PEB regulation from NZEB in co-design with residents

Estonia follows its own regulations for calculating the energy efficiency of buildings, defined by the Estonian Energy Performance of Buildings Directive (EPBD). Currently, EPBDs are not covered by any regulations in Estonia and REN+HOMES will set out the requirements for CPEH.

See this methodology in action:

GREECE PassivHaus methodology: Focus on electrification and energy communities

REN+HOMES will support the design, building, and certification of passive houses in Greece, focusing on plus and premium classes of passive houses that support PEB. The project will enhance the use of renewable energy sources, and implement energy demand-offer coordination, a new business model, and better services for citizens.


FRANCE CERQUAL methodology: Focus on multi-criteria positive home

Current regulations of the High-Quality Environmental (HQE) standards for buildings in France only consider energy consumption. REN+HOMES will test new versions of international HQE standards using a multi-criteria approach that also consider environmental impact, climate resilience, and comfort of inhabitants.


Objectives and Results

The main goal of the REN+HOMES project is to create a universal methodology for designing positive energy homes and residential districts. This approach aims to support the shift towards climate-neutral and energy-positive residential buildings. More specifically the project will seek to:

  • develop a universal methodology for positive energy homes certification to achieve positive energy building in a holistic way, considering embodied emissions, circularity of the materials and reduction of consumption of all the resources

  • upgrade / select affordable key technologies (KTs), building highly-replicable technology packages (TPs), to be applied to renovations or new construction

  • engage residents in decision making process, to raise awareness and influence sustainable behaviours and set up National Advisory Boards of experts to steer and support relevant decisions in each demo-site

  • test the approach in 4 countries (Spain, Romania, Estonia, Austria) both on new construction (Spain and Austria) and renovation (Romania and Estonia) buildings

  • develop the best financial strategies for deploying positive energy & climate neutral buildings and start deploying training courses for skilled workforce as a way to speed up the delivery of cost-effective positive homes

  • influence decision-making for the future of the “positive” residential buildings at EU level, thanks to the liaison with 15 renowned EU expert advisors to the project (International Advisory Board).