海角视频

Europe鈥檚 building stock is vast, predominantly old and in urgent need of transformation.

With about , most of them residential and many constructed before modern energy standards, the EU faces both a significant challenge and a major opportunity in upgrading existing structures for the low-carbon future set out in the European Climate Law. Large portions of these buildings still perform poorly on energy efficiency, and renovation rates remain far below what is needed to meet climate targets. Research by the Buildings Performance Institute Europe (BPIE) suggests that about of EU building stock must be updated to comply with the EU鈥檚 target of climate neutrality by 2050.

The challenges of transforming existing buildings are manifold, but it also holds many advantages. We asked 海角视频 experts to talk about their experiences.

Benefits of transforming existing buildings

Transforming existing buildings brings a wide range of ecological, economic, social and cultural benefits. Reusing structural elements reduces material consumption, lowers embodied carbon and supports circularity, while energy retrofits can further improve environmental performance. Sensitively upgrading buildings can also strengthen social cohesion by preserving neighbourhoods, supporting affordability and enabling community participation. At the same time, the careful renewal of historic or architecturally distinctive structures enriches cultural identity and opens up new design potential by integrating old and new.

Challenge 1: Existing structural elements and static limitations

Despite its advantages, working with existing buildings presents challenges. Comprehensive surveys are essential to reveal structural issues, moisture damage, contaminants or loadbearing limitations. Structural adjustments are often required for extensions or conversions. A precise analysis of the structural integrity is essential, especially when planned work could affect loadbearing elements. Buildings with incomplete documentation require particularly thorough investigations.

Paul Roberts, structural engineer and Director at our Copenhagen office, explains that the biggest challenge is finding the right information about an existing building. Drawings, calculations, revisions, and documentation are often inconsistent or incomplete. This makes establishing a reliable baseline time-consuming.

He also highlights the challenge of convincing clients that working with existing buildings is the right path. Many clients perceive existing structures as limiting. Retaining existing fabric is often seen as too expensive and demolition as the more cost-effective option. However, Paul believes these constraints often lead to creative, unique solutions.

Exploring options using rapid prototyping

To support well-informed decision-making, Paul鈥檚 team has developed rapid prototyping for transformation. Using a suite of digital tools, the method analyses different scenarios – thermal upgrades, structural strengthening, extensions, renewable energy integration – and provides both qualitative and quantitative results. These insights help clients assess carbon savings, added emissions, energy performance and feasibility.

The team is also exploring AI-based tools to manage large volumes of existing building documentation. The aim is to extract drawings to help reorder and classify files, cutting through a mass of disorganised document histories and providing a much stronger basis for design work.

Paul highlights the ongoing Krulli Kasvuhoone project in Tallinn, Estonia, where a cluster of former steel fabrication warehouses is being transformed into a creative innovation hub. The project involves a thoughtful mix of reuse, retention and refurbishment, supported by new low-carbon timber structures. Some of the buildings鈥� historical facades are protected and cannot be altered, which required the team to use passive comfort strategies to overcome thermal constraints. The project showcases how inventive design solutions can emerge when existing structures guide the process rather than restrict it.

Challenge 2: Dealing with existing materials and circular potential

More than two thirds of the buildings that will still be in use in 2050 already exist today. Transforming the existing building stock is therefore a crucial lever for climate mitigation and climate adaptation. While new buildings are typically constructed to meet modern and often ambitious sustainability standards, existing buildings largely reflect the construction methods and energy performance of their time. At the same time, they offer enormous potential for CO鈧� reduction, resource conservation and climate resilient, urban renewal.

Sustainability Consultants Felicitas Leithner and Mariya Pichurina know that working with existing buildings differs fundamentally from designing new build projects and that achieving climate aligned development comes with its own particularly challenges.

Much of the built fabric is shaped by historic construction methods, meaning design flexibility is often limited and engineers must work around established structures, materials and spatial constraints. This makes it essential to balance the preservation of architectural identity with the need to improve energy efficiency, resilience and occupant comfort. They point out that existing buildings were rarely designed for today鈥檚 environmental stresses, for instance, intensifying heat, heavier rainfall and prolonged dry periods, which leaves them without sufficient thermal protection or ways to manage water.

Circularity poses a further challenge: large volumes of gypsum-based material produced during refurbishment often end up in landfill due to limited regional recycling options, disrupting material cycles and inhibiting the wider shift towards circular construction.

Kitty Walker, Senior Facade Engineer at our Berlin office, highlighted warranties as the biggest challenge for her discipline of fa莽ade engineering, particularly for reused elements such as fire doors. Building control authorities, especially in the European Union, are often hesitant to certify reused components, even when they remain in good condition. Clients and designers also fear the 鈥渦nknown unknowns鈥� associated with older structures. Logistical issues such as finding space to store and refurbish materials in dense cities like London or Berlin add to the difficulty.

海角视频 played a key role in the transformation of The Whiteley, an iconic historic London landmark, a former department store from the early 20^th century, by prioritising the retention, restoration and adaptive reuse of the existing Grade II鈥憀isted structure, preserving the building鈥檚 embodied carbon and architectural character. Detailed structural and heritage surveys informed decisions on which elements could be retained, conserved or carefully adapted, including the historic Portland stone fa莽ade, the central staircase, courtyard and glass dome. Original features were restored where possible, while new interventions were designed to integrate sensitively with the existing fabric, such as authentic replicas of the original steel storefront windows, upgraded to meet modern energy, acoustic and safety standards.

Challenge 3: Adapting existing buildings to the climate

Sustainable transformation requires a holistic rethinking of existing buildings and their surrounding spaces, integrating future鈥憄roof systems rather than isolated measures. Early, interdisciplinary collaboration is critical to address the challenges of climate adaptation effectively, particularly in the existing building stock, where interventions must often align with refurbishment cycles, regulatory frameworks and limited available data.

In dense urban environments, sealed surfaces such as concrete, asphalt and stone store significant heat during summer months, while shading, vegetation and cooling through evaporation are often lacking. At the same time, climate adaptation is still less embedded in decision鈥憁aking than climate mitigation. While issues such as energy efficiency and operational emissions are now widely addressed, the risks associated with overheating, heavy rainfall, storm events and long鈥憈erm climate resilience are frequently underestimated or deprioritised, particularly where their impacts are not immediately visible or easily quantified.

Jill Theobald, who works closely on climate adaptation on existing buildings, agrees that challenges arise from structural limitations, incomplete knowledge of building condition and concerns around potential risks. Measures such as fa莽ade or roof greening, for example, depend on structural capacity and reliable data, which is often unavailable for older buildings. This uncertainty can lead to hesitation, despite the fact that such measures offer substantial resilience benefits when carefully designed and integrated. Where heritage regulations apply, these are increasingly less of a barrier than commonly assumed, with many authorities now actively supporting solutions that safeguard both cultural value and long鈥憈erm climate resilience.

Depending on the regulatory context and structural condition of a building, integrated rainwater management strategies, including green roofs and de鈥憇ealing of hard surfaces, can significantly enhance both building鈥憇cale and urban resilience. Climate adaptation can be further strengthened through fa莽ade and roof greening, which improve the microclimate by acting as a natural form of air conditioning. They contributing to thermal comfort not only outdoors but also indoors, particularly in office environments where overheating can directly affect occupant wellbeing and productivity.

Beyond thermal regulation, climbing plants and vegetated fa莽ades help filter fine particulate matter by trapping pollutants on leaf surfaces, contributing to improved air quality in dense urban areas. They also create valuable habitats within sealed cityscapes, supporting biodiversity by providing shelter, nesting opportunities and food sources for insects and birds. In this way, individual buildings can function as small biotopes that connect existing green infrastructure and positively influence the wider neighbourhood.

Additional benefits include noise attenuation along busy streets and enhanced protection of the building envelope from weathering, intense solar radiation and moisture. Over time, these measures can help preserve asset value by reducing climate鈥憆elated damage and improving the attractiveness and usability of buildings. When viewed through a long鈥憈erm lens, climate adaptation is therefore not only an environmental necessity, but a strategic investment in resilience, user wellbeing and the sustained performance of the built environment.

Karlsg盲rten Berlin: where principles meet practice

The CA Immo Karlsg盲rten project in Berlin is an extensive transformation of an office building. It demonstrates how these principles interact in practice. The project prioritises the consistent use of circular opportunities: the loadbearing structure, one of the main drivers of embodied emissions in newbuild construction, is retained and extended. The original natural stone fa莽ade was dismantled, refurbished and stored so it can be reinstalled after the building envelope is upgraded, reducing embodied emissions while preserving architectural identity.

An integrated rainwater management system uses green roofs with retention layers, infiltration trenches and permeable surfaces in the redesigned courtyard. This is complemented by provisions for mobile flood protection to safeguard against extreme weather. The extension of the existing structure uses a timber hybrid construction that reduces loads, enables prefabrication and minimises additional emissions. Green roofs and photovoltaic panels further support biodiversity, climate adaptation and onsite energy generation.

A lightweight timber structure with integrated balconies forms the courtyard facing extension. These projections create fa莽ade depth and overhangs that provide natural, passive solar shading. The future ready energy concept combines efficient building services with renewable energy sources. Continuous energy monitoring enables long-term optimisation of consumption and reduces operating costs.

Karlsg盲rten thus exemplifies the potential of holistic existing building transformation: through smart concepts, circular thinking and interdisciplinary planning, existing structures can evolve into resource efficient, resilient architecture. The project demonstrates that climate mitigation and climate adaptation in the existing stock are not only achievable but laying the foundation for a built environment that preserves resources and actively shapes resilient urban development.

Challenge 4: Reducing CO₂ emissions and increasing energy efficiency

Lucien Engels, Associate Director for MEP and energy at our office in Rotterdam, identifies the central challenge as deceptively simple: the building already exists. Unlike new鈥慴uild projects, where systems can be planned freely, the structure of an existing building sets firm boundaries, making opportunities to improve daylighting or add insulation are extremely limited.

He adds, older buildings respond differently to modern systems. Without a detailed understanding of materials and moisture behaviour, new interventions can lead to condensation, thermal bridges or even long-term damage. Heating and cooling present further complications. Many existing buildings rely on high temperature heating systems. Without significant insulation upgrades, these systems cannot deliver comfortable indoor climates, making performance gaps likely unless the envelope is carefully improved.

Nevertheless, effective solutions exist, provided they are tailored to the building. Decentralised ventilation or climate systems, for example, can avoid the need for large ductwork that a structure cannot accommodate. Where appropriate, natural ventilation strategies can also reduce invasive interventions.Improving insulation is essential, not only for energy performance but to enable low-temperature heating and cooling systems to operate effectively.

One project that exemplifies the realities of transforming existing buildings is Public Library Rotterdam, where 海角视频 is supporting architecture firm Powerhouse Company and Atelier Oslo/LundHagem to facilitate significant internal functional changes. Although the fa莽ade is being fully replaced, the internal systems remain governed by the original spatial and structural constraints.

Transformation: Challenge and opportunity

The transformation of existing buildings is the future. In the face of the climate crisis, reusing what already exists is no longer optional. It is a necessity.

Beyond environmental performance, working with existing structures brings originality, uniqueness, and a stronger sense of place. The imperfections and constraints of longstanding buildings can inspire higher quality, contextually rich design that contributes meaningfully to cities. Working with existing buildings demands resourcefulness, patience and a willingness to question assumptions, but in return, it offers design possibilities that new construction often cannot match. The buildings we already have are not relics of the past. They are the foundations of a more responsible, characterful and sustainable future.