Enerphit + 4×30
Energy retrofit and much more
The European Green Deal is a strategy of the European Union to achieve climate neutrality by 2050.
The goal is to transform the European economy into a green, circular, and sustainable economy that ensures the health and well-being of citizens and the planet.
As part of its objectives, a clear ambition to reduce CO2 emissions can be found:
– Achieve climate neutrality in the European Union by 2050, reducing greenhouse gas emissions by at least 55% by 2030 compared to 1990 levels.
– Drive the energy transition by increasing the share of renewable energy in final energy consumption by at least 32% by 2030 and improving energy efficiency by at least 32.5%.
– Promote a circular economy by reducing waste generation and encouraging recycling and reuse of materials.
The construction industry is responsible for approximately 40% of global GHG emissions, due to both the energy consumption of buildings during their use and emissions released during the manufacturing of construction materials and their installation on-site.
Addressing existing building stock emerges as the most effective strategy to achieve the three Green Deal objectives outlined above:
1. Retrofitting existing buildings, incorporating passive measures such as increased insulation, solar control, etc. Additionally, by using more efficient HVAC systems powered by renewable energy, energy consumption, and consequently, CO2 emissions will be reduced.
2. This rehabilitation leverages elements of the building with higher embedded CO2 emissions, such as the structure and envelope, avoiding new emissions if these elements were to be rebuilt.
3. Retrofitting, reusing, and implementing new uses in existing buildings reduce the need for new resources, promoting a circular economy. Moreover, these buildings are located in consolidated urban areas, connected to existing urban services, avoiding the need to build new service networks and thus reducing CO2 emissions and resource use.
The new directive on energy efficiency in buildings (EPBD), which the EU is finalizing and is likely to be in force in the coming months, envisions that all buildings receive an energy rating of A or B by 2040 and must be operationally zero-emission by 2050.
It also establishes the requirement to measure the carbon footprint throughout the building’s life cycle, applying a “whole life carbon” approach to all buildings from 2030.
To achieve both objectives we propose an ambitious and effective intervention strategy in existing buildings:
1. Energy retrofitting of the existing building stock using materials and solutions with low embodied carbon, with the selection of insulating materials being particularly relevant.
2. Technically, urbanistically, and financially studying the intensification of the existing building, for example, by extending the building with the construction of new floors, using materials like timber with low embodied carbon and that, due to their reduced weight, have a lesser impact on the existing structure.
3. For vacant buildings, studying the implementation of new uses that fit with the current economic and social context.
Focusing on point 1, energy rehabilitation, we believe that the EnerPHit standard from Passivhaus could be a very useful tool.
Achieving the Passive House standard in the refurbishment of existing buildings is not always a realistic goal. For these buildings, the Passivhaus Institute has developed EnerPHit for certified energy renovations with Passive House components.
This requires compliance with the corresponding requirements for the climatic zone regarding heating and cooling demand, in the case of Spain, corresponding to the warm-temperate and warm climatic zones, as per the following table:
These demand data would be obtained through energy modeling with the specific Passivhaus tool, PHPP.
The standard establishes an alternative method based on meeting minimum criteria for the various building elements used in rehabilitation.
Regardless of the method followed (demand limitation or selection of building elements), it is also necessary to meet criteria regarding achieved airtightness, as well as demand and generation of renewable energy.
On the other hand, the EnerPHit standard introduces the concept of a retrofit plan. Many of the buildings to be energy retrofitted remain in use during the rehabilitation process, so it must be carried out in phases. This can also be due to financial reasons that prevent tackling the entire scope at once.
EnerPHit integrates procedures to schedule this phased intervention efficiently and helps prevent risks or pathologies in intermediate phases, for example, condensation problems in situations where the envelope has been insulated but windows have not been changed or airtightness has increased without installing ventilation systems.
This aspect of phased energy rehabilitation aligns well with the concept of the “building renovation passport” included in the new EPBD and will be mandatory from late 2025. It consists of a roadmap to plan the energy rehabilitation of the building in several stages, allowing owners to meet the objectives set in the directive sustainably from a financial and practical perspective.
Finally, this massive energy rehabilitation process of existing building stock, instigated by new regulations and subsidized in many cases with European funds, can be an opportunity to implement other sustainability strategies that incorporate a holistic approach:
– Creating healthy and comfortable spaces.
– Flexible and resilient spaces that can adapt to new uses and potential threats such as climate change.
– With low CO2 emissions throughout the life cycle.
– With reduced use of resources, including water.
– With waste management that allows the implementation of a circular economy.
To achieve these objectives, we can use frameworks such as Level(s), DGNB, BREEAM, etc., which provide valid methodologies to incorporate these goals during the design of rehabilitation projects, regardless of pursuing certification.
At 4×30, we advocate for combining the best of existing sustainability frameworks to design specific strategies based on the level of ambition pursued, the nature of the project, its scale, or the financial capacity of its owners.
If you want to learn more about EnerPHit, follow this link.
