Across Europe, renovating post-war apartment buildings presents a major challenge. Many residential buildings built in the ’60s using standardised systems are nearing the end of their original design life, and their energy performance, accessibility, and living environments often no longer meet residents’ current expectations and needs. The scale of the challenge makes conventional, building-by-building renovation slow and difficult to replicate. That’s why SOFTacademy is testing a different approach through a neighbourhood-based renovation in Mustamäe, a modernist residential district of Tallinn. Its objective is to develop and test a collaborative renovation model that combines energy-efficient building improvements, prefabricated construction technology and resident participation.
Renovating beyond the façade
The project’s innovation goes beyond simply applying an innovative renovation technology with prefabricated façade panels. Rather, it brings together several elements that are often addressed separately: the simultaneous renovation of multiple buildings and the installation of elevators to improve accessibility (both a premiere in Estonia), the integration of industrialised construction methods, the involvement of residents in renovation solution, including architectural designs, and the improvement of the spaces between buildings. The aim is to develop an approach that can be replicated in other neighbourhoods containing similar housing stock.
The building renovation uses prefabricated timber-frame elements to improve the building envelope and potentially integrate additional systems, including windows, ventilation, roof elements and façade finishes. Depending on the building and the housing association’s decisions, the renovation also includes balconies, solar panels, and elevators. The wider project addresses the quality of courtyards and public space, reflecting the principle that successful neighbourhood regeneration must improve both buildings and their surroundings (learn more about this in the previous articles here). This approach aligns with the New European Bauhaus principles of sustainability, inclusion and quality of the built environment. It also addresses a practical question facing many European cities: how can the renovation of a large building stock be accelerated without reducing each project to a standard technical intervention?
Pilot building before renovation. Credits: Municipality of Tallinn
The design process is central to answering this question. SOFTacademy has had to reconcile residents’ aspirations, architectural quality, energy performance, affordability, existing building conditions, industrial production requirements and public procurement procedures. Its experience shows that prefabrication can accelerate on-site construction, but realising that potential requires substantial preparation and careful coordination before production begins.
From residents’ aspirations to a design ready for procurement
Co-designing with the residents
SOFTacademy revolves around the concept that renovation choices affect residents differently. Improvements such as larger balconies, elevators and higher energy performance bring benefits but also increase costs, requiring housing associations to balance residents’ priorities against their financial capacity. The project team therefore established a structured process for comparing renovation options before finalising a design, organised in several co-design sessions with inhabitants. The design team developed a system of spatial components, including façade elements, balconies and windows, based on a consistent architectural logic. These components could be combined in different ways while maintaining coherence across the four buildings. This framework let residents explore alternatives without relying solely on conventional architectural drawings, leaving detailed technical decisions for a later stage.
The workshops used 3D models and virtual reality (VR) to help residents compare an ambitious renovation scenario with a more affordable alternative. Their priorities differed: two housing associations favoured elevators despite the additional costs, while two prioritised affordability. Visualisation also prompted discussions about materials and aesthetics, illustrating how design representations influence participants’ expectations and decisions.
Co-design sessions with residents. Credits: Municipality of Tallinn
The pilot’s experience showed that this kind of involvement is laborious: in addition to creating solutions, the process must be structured, tools must be developed and used, and communication with residents must be maintained. On average, six people participated in the workshops per building, a small fraction of the 80 apartments. Therefore, the workshop results had to be further refined and presented to the entire apartment association for validation.
The solutions developed in the workshops were an input for the decision-making process of apartment associations as well as for architects to further detail the design, which supported the renovation funding application and subsequent design-and-build tender. However, translating co-created ambitions into binding procurement documents proved difficult. The draft project illustrated the intended design, while the technical specification governed implementation, without clearly distinguishing binding architectural decisions from elements open to interpretation. Some details affecting spatial and visual quality were insufficiently specified or linked to explicit budgets. Consequently, procurement did not fully secure residents’ choices, exposing the risk that co-created architectural ambitions could be diluted during implementation.
Co-design sessions with residents. Credits: Municipality of Tallinn
The implications of design-and-build procurement
The design-and-build procurement model placed responsibility for developing the design within the client’s requirements on the contractor, without guaranteeing that the original architect retained control over subsequent decisions. For SOFTacademy, this created a specific challenge: residents co-created preferences for spatial improvements, balconies, windows, and other building elements, but these ambitions were not translated into sufficiently precise, binding tender requirements. The design team also saw the technical specifications as restrictive, leaving little flexibility to adapt solutions as the implications of the prefabricated timber-frame system became clearer. The process therefore faced a dual risk: losing architectural qualities agreed with residents while limiting opportunities for technical optimisation.
SOFTacademy shows that procurement documents must translate co-created design choices into explicit, enforceable requirements. The tender should identify which features—such as balcony dimensions, window configurations and façade appearance—must be preserved, and which technical details the contractor can adapt to accommodate the prefabricated system and actual building conditions. These requirements should be linked to clear budget assumptions and procedures for reviewing design changes with the original architect. This would protect residents’ priorities while allowing technical optimisation during implementation.
Renderings of the pilot buildings, part of the procurement documentation. Credits: TalTech
Prefabricated renovation technology
SOFTacademy tests an alternative to conventional apartment renovation in Estonia, where insulation and rendered façades are typically installed on site, requiring extensive scaffolding and months of construction activity. The project renovates four existing apartment buildings using prefabricated timber-frame façade elements manufactured by Timbeco. The panels include insulation and external finishes and are factory-made before being transported and fixed to the existing structures. Industrialised renovation offers many benefits for residents who experience less noise, dust and disruption, improved energy efficiency and indoor climate; for construction companies and contractors which can rely on faster installation and less work on-site, along reduced dependence on weather conditions; and for cities and the environment, offering greater potential for using bio-based materials, and more sustainable life cycles, with possibilities for disassembly and reuse. Installation rates can reach about 350–400 m² of façade per day, significantly speeding up the renovation process.
Prefabricated panels being installed. Credits: Targo Kalamees
A key lesson is that successful prefabrication starts with accurate knowledge of the existing building. In SOFTacademy, laser scanning captures façade dimensions, while structural assessments and pull-out tests establish whether the existing concrete can support the new elements. This is particularly important for post-war apartment buildings, where decades of alterations and varying conditions create differences even between buildings of the same typology. The four buildings therefore require individually adapted panels rather than identical components. The project illustrates mass customisation rather than identical mass production: standardised manufacturing processes combined with building-specific design. The resulting efficiencies depend on reliable surveys, structural verification and early technical coordination.
The system combines a timber frame, insulation and ventilated external cladding. Compared with conventional rendered insulation, this offers potential advantages in moisture management, maintenance, and replacing external finishes. However, durability depends on appropriate detailing, installation and maintenance, while fire safety, thermal bridges and structural connections require project-specific assessment. The technology cannot simply be transferred unchanged between countries: climate conditions and national regulations influence material choices and façade design.
Integrated façade and roof systems. Credits: Targo Kalamees
The central lesson is that prefabrication shifts work away from the construction site rather than eliminating it. Rapid installation depends on substantial, accurate preparation, including scanning, structural testing, detailed design, manufacturing, and logistics. The approach offers the greatest potential when building conditions are thoroughly assessed, and architectural, technical and production decisions are coordinated early. These requirements are essential to achieving the expected gains in installation speed, quality and reduced disruption.
Challenges and benefits. What the pilot reveals
Faster construction, but a longer preparation phase
Prefabrication reduces on-site disruption, allowing residents to remain in their homes while limiting scaffolding, dust and noise. However, SOFTacademy’s design and permitting phase took approximately 12 months instead of six, with building permits alone taking around six months rather than the planned 65 days. Delays stemmed mainly from administrative and spatial issues, including plot boundaries, vegetation, wider balconies and new stairwells, rather than the panel technology itself. Faster installation does not necessarily guarantee a shorter overall renovation programme and therefore, early design coordination and permitting are essential.
Technical precision and the limits of standardisation
Laser scanning and structural testing are essential because existing buildings often differ from original drawings and from one another. In SOFTacademy, variations across the four buildings required adaptations to panel dimensions, window openings and connections. This creates a trade-off between standardisation, which improves production efficiency, and customisation, which accommodates actual building conditions. Procuring all four buildings together helped create efficiencies in engineering and production. Nevertheless, the manufacturer estimated that conventional on-site renovation remains at this moment approximately 5% cheaper, showing that prefabrication had not yet achieved a cost advantage in this context.
Prefabricated panel being installed on site. Credits: Timbeco
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Architectural quality, technical and financial constraints
SOFTacademy exposed tensions between architectural ambition, manufacturing requirements and affordability. Resident workshops presented design alternatives alongside estimated costs and energy performance. The architectural choices were further included into procurement documentation. but not all of them were translated into sufficiently precise technical requirements. Roof design illustrates the trade-off: prefabricated roof elements reduced disruption, but conventional roof insulation was identified as a potentially simpler and cheaper alternative. The lesson is that prefabrication need not apply to every building component. Combining prefabricated façades with conventional solutions where appropriate can better balance quality, cost and maintenance. Prefabrication must also be applied to the building’s technical systems and interior finishes.
Accessibility and the integration of elevators
Adding elevators required coordinated changes to staircases, floor levels and external structures. New stairwells extended beyond original building footprints in some locations, creating additional challenges around plot boundaries and permitting. Installation also requires careful sequencing to maintain residents’ access to their homes. The experience shows that accessibility is not an isolated technical intervention; it affects building structure, circulation, architectural design and the surrounding landscape. Differences between the four housing associations also highlighted the importance of co-creation in identifying community priorities and their financial implications.
Circularity and long-term performance
Factory production offers opportunities to reduce waste and improve material efficiency. In SOFTacademy, retaining existing insulation beneath parts of the new façade was estimated to prevent approximately 100–150 m³ of waste across the four buildings. The panel producer wider approach also considers the potential to reuse or repurpose prefabricated elements at the end of their service life. However, circularity depends on the condition of components, material compatibility and the feasibility of disassembly. Reuse must therefore be addressed in the design rather than assumed simply because timber and prefabrication are used.
Institutional learning and replicability
The main contribution of the project is its insight into the organisational conditions for neighbourhood-scale renovation. The project exposed gaps between resident participation, architectural design, procurement, technical coordination and permitting. Its experience with plot boundaries and balconies is particularly relevant to Mustamäe, where the design team identified around 70 buildings with potential boundary issues. The pilot provides a basis for addressing similar challenges in future projects. Replication also depends on clearer procurement requirements, continuity between architectural and technical design, and well-defined responsibilities that preserve co-created design objectives while allowing technical optimisation. Coordinating several buildings within one programme can improve production efficiencies, but requires cooperation between housing associations and municipal authorities across property boundaries and ownership structures.
Conclusion
SOFTacademy shows that prefabricated renovation is not simply a faster way to install insulation. It offers a different way to organise the design and delivery of building renovation, bringing together residents, architects, engineers, manufacturers, contractors, and municipal authorities. The project’s design process began by giving residents structured opportunities to explore alternatives, experience proposed changes and understand their financial consequences. It then exposed the difficulty of translating those choices into binding procurement requirements and a technical design that balances architectural quality with industrial production.
The broader lesson is that industrialised renovation and participatory design must develop together. Residents’ preferences must be translated into clear design priorities; manufacturers need reliable information about existing buildings; and procurement documents must distinguish between essential outcomes and details that remain open to technical development.
One thing is clear: SOFTacademy offers a valuable opportunity to test innovative solutions and to learn for everyone involved. It also serves as a model for other cities interested in neighbourhood-based, prefabricated renovation in their modernist areas. Its contribution lies not only in the panels installed on the buildings, but mostly in the process of discovering how architectural ambition, affordability, technical innovation, and institutional procedures can align to make neighbourhood-scale renovation more feasible.
The author would like to thank the following people for their contribution to this article: Kadri Auväärt (Municipality of Tallinn), Targo Kalamees and Luisa Maria Männilaan (TalTech), Andrus Taliaru and Kadri Reinumägi (Anmeri OÜ) and Tõnis Vaiksaar (Timbeco).
Author Ruxandra Aelenei