New European directives on energy efficiency, targeting a 55% reduction in greenhouse gas (GHG) emissions to be achieved by 2023, are triggering deep renovation building projects, which are largely responsible for these emissions. This high demand for the transformation of the existing building stock makes us consider the need to execute this type of renovation projects in the shortest period of time. Furthermore, it is important to offer an adequate cost/benefit balance for the proposed interventions.
And in this process of transition towards climate-neutral buildings, how can the use of new technologies and the application of methodologies such as Building Information Modelling (BIM) help in the implementation of deep renovation projects? The adoption of BIM models, traditionally used for new buildings, can provide important decision support when selecting solutions to be implemented in renovation projects. This was one of the main objectives of the H2020 BIM-SPEED Project, to improve deep renovation projects of residential buildings, reducing the time and costs associated with them, and promoting the use of BIM among the different stakeholders involved. To this end, standardised processes, with the creation of Use Cases, and different BIM‑based tools were developed as part of the BIM‑SPEED web platform ecosystem, as well as training materials on how to use these services1. To address interoperability issues, different ETLs (Extract, Transform and Load) and BIM connectors were implemented.
Interoperability framework between BIM tools and the BIM-SPEED web platform, showing the connection to the implemented ETLs and BIM Connectors. To ensure the reliability of the data, different Checker tools were applied
It was also possible to see how beneficial the combination of Machine Learning techniques with BIM models is for decision making in deep renovation projects, allowing the automatic selection of the most appropriate renovation option. This selection is based on national building envelope regulations, and also takes into consideration a number of user-defined input parameters on the limitations of its application2. The combination of the Scan to BIM process with the automatic creation of walls in BIM, using point clouds as input data, was also of great interest to end users3.
And now, what else?
The possibilities of using BIM models do not end with the renovation phase of the building. These models can also play a key role in the Operation and Maintenance phase. The development of Digital Building Twins based on BIM models can help in the optimisation and control of buildings to improve their energy performance. In line with this, projects such as BuildON, coordinated by CARTIF, and SMARTeeSTORY, the latter focused on monitoring and optimisation of the energy performance of non-residential historical buildings, are starting. We will keep you updated on further developments in future posts.
2 Mulero-Palencia, S.; Álvarez-Díaz, S.; Andrés-Chicote, M. Machine Learning for the Improvement of Deep Renovation Building Projects Using As-Built BIM Models. Sustainability2021, 13, 6576. https://doi.org/10.3390/su13126576
3 Álvarez-Díaz, S.; Román-Cembranos, J.; Lukaszewska, A.; Dymarski, P. 3D Modelling of Existing Asset Based on Point Clouds: A Comparison of Scan2BIM Approaches. In 2022 IEEE International Workshop on Metrology for Living Environment (MetroLivEn); IEEE, 2022; pp 274–279. https://doi.org/10.1109/MetroLivEnv54405.2022.9826964
The BIM approach (Building Information Modelling) is all around Architecture, Engineering and Construction professionals, but when it comes down, very few companies are founding their daily work on this paradigm and applications are really far from being homogeneous. BIM is many times (let’s say “usually”) incorrectly identified as a specific software package or a type of 3D digital model. However, BIM is much more than a newer version of CAD or a 3D visualisation tool.
The BIM approach provides a digital featuring of a building or infrastructure throughout its whole life-cycle, adding extra information to help making better and more-timely decisions upon a 3D model that allows a multidimensional analysis: 4D (evolution); 5D (costs); 6D (sustainability -including energy efficiency-); 7D (maintenance).
Although there is still a lack of knowledge on how BIM and associated digital innovations are applied across European countries, the European Directive 2014/24/EU imposes BIM Level 2 for government centrally procured projects. Level 2 refers a collaborative process of producing federated discipline specific models, consisting of 3D graphical data (those visually represented) and semantic data (those significant additions) as well as associated documentation (for instance: master plans). Information is exchanged using non-proprietary formats, such as Industry Foundation Classes (IFC).
Consequently the built heritage is subject to BIM for the purposes of documentation, conservation and dissemination, but the distinctiveness and sensitivity to meet heritage demands requires technological and methodological particularizations leading to the concept of Heritage-BIM (H-BIM). The purpose of H-BIM is to provide a 3D parametric model as a “container” of information generated all over time by different procedures, by different people, and from different sources (hw & sw). The model would capture the multidisciplinary nature of Heritage, far away from the simplicity and modularity of conventional construction, and would be very useful to study, evaluate the state of conservation and plan interventions on the assets in a profitable way. It is quite a challenge for a sector where digitization is a pending issue.
This technologically means facing many challenges, starting with the minimum amount of graphical and semantic data that would be adequate to support the activities of the sector. Two of the most important are:
The combination of 3D data with different types of images (thermography, high resolution photographs or multispectral recordings) to produce a really useful H-BIM model for exhaustive assessment.
The photorealistic texturing of 3D models for a rigorous representation of reality.
Both aspects are being worked by CARTIF to decisively help companies, managers and public administrations in the digitization of Cultural Heritage.
Beneath the vaults of a Gothic church, within the thick walls of a Cistercian monastery, in the stucco of a Renaissance palace or the rammed earth and timber frames of a traditional house, a single truth emerges: built heritage is an essential part of our history and collective identity. It is a physical legacy made of stone, wood, lime, brick or raw earth, conceived with construction wisdom adapted to its time.
Today, however, many of these buildings are deteriorating, left empty, and, far too often, disappearing without ever having been given a second chance. The lack of contemporary use, societal passivity, the absence of maintenance plans, the associated costs and, above all, something rarely discussed or deliberately overlooked: a technical misunderstanding of how they were built, are accelerating their loss.
Lifecycle of the Monastery of Nuestra Señora del Prado (Valladolid), pilot building of the INHERIT project. Source: own elaboration
How can we preserve what we don´t understand? How can we maintain with sound judgement if we ignore how something was built, why specific materials were used, or what structural logic underlies it? Preventive conservation is not a trend, it is an urgent necesssity if we want to safeguard our cultural heritage with rigour and responsibility.
At CARTIF, we believe it is essential to research and develop technical, innovative, yet realistic and implementable solutions that address this challenge through knowledge and respect for what has already been built. We aim to contribute to asmarter, more useful conservation approach, one that avoids improvisation and standard formulas, and instead promotes a deep understanding of how things were constructed, in order to care for them better. We are convinced that heritage conservation is a collective process: a way of valuing what connects us, engaging citizens, and reinforcing our bond with the built environment.
Projects we have been involved in, such as INHERIT andiPhotoCult, support this vision and underscore the need for a new technological perspective on heritage conservation. We already explored this line of thought in our blog post “A proper approach to inspecting historic buildings”; if you’re interested in digging deeper, we recommend giving it a read.
Why can´t we apply the same criteria userd for contemporary buildings?
Historic buildings do not follow the rules of modern construction. Their materials, lime, brick, stone, wood, earth, are porous, natural, and adapted to local climates and contexts. Their construction systems, load-bearing walls, vaults, timber roof frames, obey a different logic. Assessing them using the same technical criteria as reinforced concrete or steel buildings is not only incorrect, it’s unjust.
We need tools that speak the language of built heritage. A specific approach that values their unique technical nature, because constructive diversity is not a problem, it’s a valuable asset.
A technical proposal for knowledge-based conservation
Today, many diagnostic inspections still rely almost exclusively on the expertise of the technician conducting them. While that professional judgement is valuable, even essential, it becomes insufficient if the data gathered is not structured in a consistent, traceable and useful way for follow-up actions such as maintenance planning, rehabilitation, or risk assessment.
Workflow towards preventive maintenance based on HBIM: from data collection to knowledge. Source: own elaboration
That’s why we believe it is crucial to open the debate and move towards the development of a methodological proposal that addresses the specific needs of this field, through clear technical criteria and a systematic approach that enables us to:
Identify and evaluate historical construction systems according to their own internal logic.
Detect and structure deterioration symptoms by technical domain (foundations, structure, façades, roofs, interior partitions and finishes, metalwork and joinery, accessibility, installations and smart systems).
Assess associated risks, whether physical, functional or environmental.
Generate structured, reusable data that can be connected to digital tools such as H-BIM models or maintenance platforms.
This approach does not aim to simplify through standardisation, but to intelligently unify technical criteria through consensus among professionals, adapting to different contexts and typologies while respecting the architectural and cultural diversity of the built heritage. It remains fully aligned with current regulatory frameworks, such as the UNE 41805 standard for building diagnostics, and takes as a reference the National Preventive Conservation Plan of Spain’s Institute of Cultural Heritage (IPCE).
What are the benefits of a well-designed technical tool?
Adopting a technical methodology adapted to heritage buildings offers tangible benefits for technicians, companies and public administrations alike:
Reduced medium- and long-term costs by avoiding emergency interventions.
Greater transparency and traceability through structured, comparable data across buildings.
Enhanced appreciation of traditional technical knowledge, acknowledging the logic and effectiveness of historic systems and materials, while also addressing professional niches that currently lack recognition.
Real support for decision-making without replacing professional judgement.
Seamless integration with digital models and H-BIM platforms to plan maintenance, evaluate deterioration risks, monitor material ageing or assess energy performance (when appropriate).
These tools are key to achieving a more useful and proactive form of management, enabling better planning, fewer interventions, and more effective conservation, helping us move towards sustainable, resilient, resource-efficient and ultimately cost-effective heritage.
Looking ahead: meaningful digitalisation
The potential of this approach does not end with inspection or diagnostics. It opens the door to digital tools capable of integrating 3D models, geolocated imagery, environmental or structural sensors, and lesion monitoring systems, or even AI-based tools capable of predicting deterioration patterns.
Workflow applied to the former collegiate church of Nuestra Señora de la Asunción in Roa (iPhotoCult project), with data acquisition using a ground-based robotic platforma (UGV). Source: own elaboration
But none of this will be useful without a solid foundation: reliable, technically sound and well-structured data. Because technology alone doesn’t preserve buildings. It’s people, with sound judgement, supported by tools that respect and understand what has been built.
Built heritage is not merely a collection of old stones. It is a living expression of our identity, our way of inhabiting space, our craftsmanship, our decisions and our memory. And today, more than ever, preserving it is a way of taking care of ourselves as a society.
In a world where sustainability is increasingly at the forefront of our concerns, the need for innovative solutions to transform our built environment is more pressing than ever. The current state of the EU building stock presents a significant challenge, acting as one of the largest energy consumers in Europe and responsible for over one third of the EU’s emissions.
Recognizing the urgency of the situation, the European Commission unveiled a new strategy in October 2020: “A Renovation Wave for Europe – Greening our buildings, creating jobs, improving lives.” This strategy represents a crucial step forward, aiming to incentivize investments in renovation and support the implementation of efficient methods and technologies.
Despite these efforts, the reality remains stark – over 75% of the EU building stock is not energy-efficient, and the annual renovation rate languishes at a mere 1%. The strategy emphasizes the need for deep renovations, those achieving over 60% reduction in energy consumption, as a top priority. The overarching goal? To double annual energy renovation rates over the next decade, not only to reduce emissions but also to enhance the quality of life for building occupants and create green jobs in the construction sector.
To achieve the depth and volume of renovation required, a strong and competitive construction sector is essential. Embracing innovation and sustainability is paramount to increasing quality and reducing production and installation costs. The Built4People European Partnership highlights three pillars crucial to this endeavour:
Industrialized Technological Solutions: Embracing advanced technologies to streamline construction processes.
Digitalization of the Construction Industry: Leveraging digital tools such as Building Information Modelling (BIM) to improve transparency and efficiency.
Integration of Circularity Principles: Incorporating circular economy principles across the entire value chain, from materials sourcing to waste management.
In the midst of this pressing need for renovation innovation, REHOUSEemerges as a beacon of hope. Coordinated by CARTIF and under the Horizon Europe program, REHOUSE is poised to lead the charge in innovation within the construction sector. With a laser focus on deep renovations and circularity principles, REHOUSE aims to develop and demonstrate eight renovation packages incorporating promising technology innovations up to TRL7 (Integrated pilot system demonstrated).
These renovation packages are meticulously designed to overcome the main barriers that impede current EU renovation ratios. Through the integration of active/passive elements, prefabrication, and off-site construction, REHOUSE seeks to deliver affordable and sustainable renovation solutions with the flexibility to address nearly 100% of building renovation challenges at the EU level.
But what truly sets REHOUSE apart is its people-centric approach. By actively engaging residents and building owners throughout the renovation process, the project ensures that solutions are not only sustainable but also affordable, satisfactory, and attractive.
REHOUSE is now at its halfway point, demonstrating remarkable progress and achievements. The project has already established the basis for the social innovation strategy, detailed the specifications of innovative solutions, and produced digital versions of the Renovation Packages. Additionally, an innovative evaluation framework and technical building diagnosis of the demo-sites have been completed. The validation of the Renovation Packages (RPs) is underway to achieve TRL6 (Prototype system verified), accompanied by the development of guidelines for their industrialization. Furthermore, the project is actively defining specifications for the Digital Building Logbook, designing and preparing the groundwork for the later construction of the demo-sites, and outlining the pathway towards market achievement after the project concludes. These efforts mark the beginning of our journey to revolutionize renovation processes, driven by innovation and collaboration.
Join us on this transformative journey as we pave the way for a brighter, greener tomorrow with REHOUSE. Together, we can reshape our built environment, create sustainable spaces, and preserve our planet for generations to come.
This project has received funding from the European Union´s Horizon Europe research and innovation programme under grant agreement No 101079951.
Decarbonization is the “trending topic” of terms related to sustainability, energy and the environment. It is the process of reducing the amount of carbon dioxide (CO2) released into the atmosphere. Decarbonization means reducing climate change and dependence on fossil fuels, which are precisely those that emit CO2 when burned (clear examples are fuel-oil and coal). Decarbonization implies the use of cleaner energy sources, but also the adoption of technologies and methods to protect the environment and to reduce these emissions (the so-called “carbon footprint”).
However, what does this have to do with Cultural Heritage? Well, you will be surprised for sure, but it turns out that Heritage contribuyes many important things to decarbonization: the preservation of historical buildings, the reuse of spaces, the promotion of sustainable mobility, the promotion of cultural tourism and technological innovation in the assessment and the conservation of historical assets. In other words, it turns out that offers an environmentally friendly approach to urban planning and rural development.
If we go into a little more detail, you will see that Cultural Heritage can play a significant role in decarbonization and the fight against climate change. Here we provide you five ways to do so, but I´m quite sure your are able to think of some more (please tell us):
Technological innovation applied to conservation1 of historic buildings (where CARTIF has a lot to say): here the sensitivity required by historic buildings implies the development of specific techniques and technologies, which have broader applications in reducing carbon emissions in other fields of construction and environmental management. The digitally based technical inspection, the preventive conservation and the intervention involving H-BIM avoid both ruin and/or demolition, as well as new alternative constructions, which significantly reduces the material and energy resources to be used for these purposes. Furthermore, and this is worthy of remark, the old buildings were designed and built up with techniques and materials that are inherently sustainable, taking advantage of aspects that we are “rediscovering” right now such as orientation, natural ventilation and the use of native materials.
Reuse of spaces: Historical sites and buildings can be suitable adapted for new uses and transformed into living or working spaces with a level of comfort appropriate to the 21st century, which in the medium-long term saves resources compared to the construction of new substitute structures. This reuse contributes to greater energy efficiency and the reduction of carbon emissions.
Adaptation and transcription of ancient professional techniques: historic places are examples of how antique societies adapted to environmental challenges (which have always existed) and how lessons learned in the past can be adopted today through proper understanding and technological shift of traditional techniques and uses (both materials and methods).
Promotion of sustainable mobility: The preservation of historic centres in cities increasingly promotes sustainable mobility. In fact, they were desgined to move on foot, on horseback or in wagons and carriages. Therefore, they absolutely favour pedestrian accesibility and the use of public transport instead of private vehicles. This reduces dependence on fossil fuels and decreases greenhouse gas emissions.
Development of sustainable cultural tourism: it is more than proven that sustainable cultural tourism can play an important role in the local economy and even in the region, encouraging more environmentally friendly practices such as waste management, conservation of biodiversity and the promotion of quality agri-food and crafts.
But, does Cultural Heritage really do that much? Obviously yes. Indeed, a lot. In line with the priorities of the European Green Deal and the EU´s climate ambition for 2030 and 2050, the European Cultural Heritage Green Paper emerged in 2021, where indeed it is already considered a driver of decarbonization and mirror upon which citizens see themselves as key actors in the actions needed on this regard.
Historic building and decarbonization is a bionmial over which the Cultural Heritage & Regeneration Committee of the European Construction Technology Platform has been working for years (CARTIF takes part of the Executive Board). Its latest strategic research agenda for the period 2021-2027, promptly refers to this. And it is an issue that has been deepen into recent plenary assemblies. It is no wonder when 24% of the residential buildings in Europe date back to before 1945, nearly half of them have historical value, and of this latter, 73% are located in cities, which is precisely where the alrgest carbon footprint is made.
From now on, will you see Heritage with an additional view further than cultural, religious and tourist ones? Another thing for you to know.
1 In line with UNESCO and ICOMOS usage related to tangible heritage, conservation is considered as the umbrella term to cover a range of preservation, conservation, restoration, (re)use, interpretation and management activities.
