The COP2 1 Paris Agreement recognises the role of cities and calls on local authorities to introduce policies to rapidly reduce greenhouse gas emissions and foster adaptation to climate change. According to Smart Cities and Communities - European Innovation Partnership ‘Cities are becoming more and more a focal point for our economies and societies at large, particularly because of on-going urbanization and the trend towards increasing knowledge-intensive economies as well as a growing share of resource consumption and emissions. To meet public policy objectives under these circumstances, cities need to change and develop, but in times of tight budgets, this change needs to be achieved in a smart way: our cities need to become smart cities’ (UN 2013: 3).
The building sector is one of the key consumers of energy in every continent and Europe is no exception. Over a number of years, the EU has enacted several directives dealing with energy efficiency in buildings with the aim of reducing their energy use. Unfortunately, these mainly concern modern stock, whereas buildings representative of the Architectural Heritage have to be treated with special care during each design process. Countries adapt their own rules, which often differ from region to region. Furthermore, the legislation forming the European Union Treaty does not cover Cultural Heritage, which would allow the bridging of the gap between historic buildings and energy as well as sustainable issues within retrofit processes. The former has by now become an element deeply integrated in everyday design. With the development of a modern designer’s workshop, we now have to include various interdisciplinary solutions (Dalla Mora et al. 2015). Currently, when civilisation is confronted with a barrier of resource scarcity, a shrinking level of not just fossil energy sources but of other resources as well, there is a need to remodel the curricula of design education and move first from linear autonomous solutions to interdisciplinary and then circular ones (Ryńska 2016). This different approach to the design process should include the use of external environmental parameters specific to each given location. It is also strongly connected with the emerging theme of the circular economy. Nevertheless, a deeper analysis distinguishes certain characteristics (Ryńska, Koźmińska & Rucińska 2018). First, the development of societies and urbanisation should be consistent on a level deeper than it currently is, and should be included within the design process, organisation and planning, as well as the modernisation and redevelopment procedures of the existing urban tissue. Second, the urbanisation process should be perceived holistically as an interaction and harmonious development of both natural and manmade environments, with solutions based on the best technical and technological standards available as well as choices consistent with the circular economy. Lastly - the ideas described are only achievable if we incorporate continuous cooperation between urban planners, architects, specialist consultants, as well as energy effective interdisciplinary solutions to achieve energy efficiency measures. One of the thresholds is circular economic feasibility; the other is the health and wellbeing of the users whose needs should always be discussed as a priority over any other solutions. Social and educational issues may also form important barriers.
Sustainable conditions for the design and construction of buildings directly involve the implementation of particular design procedures and management methods together with specifications for environmentally friendly building materials. Designers participating in building design represent a group of professionals who have a direct influence on the process whereby the building materials become part of a circular closed-loop economy. Such an approach reduces the dependence of further economic development on the finite supply of natural resources. The choice process and the management system used are part of a complicated procedure in which each phase of the building’s life is analysed - it includes the production process, building techniques and technologies used, and the expected end of life of the building and it should include the initial re-use of either the materials or the structural elements incorporated in the building (Koźmińska & Ryńska 2018).
Complex relationship between Cultural Heritage and circular economy issues
The EC introduced its Circular Economy Package in 2015. This contained the basic definition of the circular economy as an approach where economic value and the path to the further economic development of a low-carbon society are united in a single policy approach. Adoption of necessary policies also means a more sustainable footing and transformation towards more efficient and circular business (Pomponi & Moncaster 2016; EC 2018). This in turn requires radical change compared to green-field projects, which are the usual choice of investors (Sanchez & Haas 2018). The new principles include product recovery, management, life cycle assessment (LCA), design for disassembly sequence planning, adaptability, closed material loops and deconstruction. These very general indicators do not include any particular technologies when choosing between green field construction and adaptive reuse (Sanchez & Haas 2018), and between optimisation of adaptive reuse or complete reuse of existing structures. It is even more difficult when considering buildings which are part of the Cultural Heritage and which do not have an economic value – but rather draw attention to cultural, aesthetic, social and historical issues (Rypkema 2008).
The modern circular economy is based on overwhelmingly saturated markets, not scarcity (Baker-Brown 2017). The industrial revolution initiated in the 18th Century, was based on linearity and a certain type of efficiency allowing the production of more and of better quality goods. Some research studies imply a direct connection between metabolism and circulation (Heynen, Kaika & Swyngedouw 2006), but it should be noted that this assumption is mainly based on the circulation of capital as value in motion perceived from the social angle. Nevertheless, the idea that urbanisation is not only a technical issue, but is to a large extent based on policies similar to social processes, is a correct one (Cook & Swyngedouw 2012). Prevailing contemporary social expectations, which in major part support unlimited consumption, are responsible for the most visible outcomes of civilisation including large volumes of non-used waste often collected as landfill and overconsumption of natural resources. Regardless of whether the idea of a circular economy is perceived from a social or technical angle, it should be noted that the transformation from a linear to a circular development is not an easy process and only limited progress has been accomplished so far. This is largely due to low consumer interest and awareness (Kirchherr et al. 2018).
Issues that are included in the transition zone leading towards a circular economy may be allocated into phases starting with the useful application of materials, continuing with extending the lifespan of products and parts, and concluding with smarter use and manufacture of products (Ellen MacArthur Foundation 2016; World Economic Forum 2018) The idea of re-using goods, components and materials with the prime aim of preserving the value of the existing building stock and their aesthetics can be traced in sub-areas such as (World Economic Forum 2018: 7):
- recycling - where the materials are processed to obtain the same or lower quality products;
- repurposing – where discarded products or parts may be used in a new product with a different function;
- refurbishment – where old products are restored and brought up to date;
- repair – concerned with the repair and maintenance of defective products, to be used for its original function;
- reuse - where another consumer may reuse a discarded product, which is still in good condition and fulfils its original function.
These sub-areas are quite evident when applied to modernisation and preservation procedures in the building stock. There are already many examples of deep retrofit procedures which preserve the existing building materials while also achieving energy-efficient solutions. The Kjorbe building in Norway may be highlighted as a good example of best practice, where great emphasis was given to the choice of environmentally responsible building materials including the re-use of elements of the former external façade as internal office partitions (Klimowicz 2018). This is an example confirming that in the construction business, the circular economy manages and reuses manufactured capital, multiplying the length of service of goods and lowering the volume of waste (Baker-Brown 2017). Hence, the contemporary building industry faces a triple challenge: the development of efficient and waste free construction methods, designing buildings to achieve a minimum consumption of resources during operation and maintenance, as well as developing methods to permit their deconstruction while preserving the highest value (Baker-Brown 2017). It should be noted that the issue of circular economics used in retrofitting historic buildings is rare in most papers so far published. Even the IDSA Principles of Design appear to miss this area, except maybe with regard to a point concerning the use of recycled materials.
Since historic buildings constitute at least 25% of the European built environment, they have a major role to play in delivering CO2 emission-reduction targets along with the rest of the domestic stock of which more than 50% is more than 50 years old (Moran, Sukumar & Nikolopoulou 2012; Moran et al. 2014; Ginks & Painter 2017). Current EU projects often include criteria inapplicable to historic buildings. This situation has arisen because of the already-mentioned status quo where the regulations concerning the preservation of architectural heritage and the rational use of energy are not linked, and also due to the fact that there is a lack of a standard for energy retrofitting intended for use in historic buildings (Litti, Audenaert & Braet 2013). In some countries, research organisations have been developing strategies aimed at evaluating energy efficiency solutions in historic buildings and offering a set of guidelines. Such examples may be found in Italy (Di Ruocco, Sicignano & Sessa 2016), where the guidelines show a range of architectural restoration projects involving the use of innovative, less invasive more efficient building materials adaptable to the historic content (Battisti 2016).
Historic buildings have significant cultural value and were built with technologies and materials that promote fabric breathability and may be perceived as part of an approach based on a circular economy. This is especially the case when the strategies used, allow to maintain their location or re-use historic building materials and structural elements in other cultural heritage buildings when upgrading their fabric (Ryńska 2008; Roberti et al. 2016). Some decisions have an impact on both the existing fabric and aesthetics, therefore prior to any design process which deals with such cases, there should be a requirement to perform a cultural diagnosis of each particular site in order to establish the sequence of procedures. It should be noted that this approach is an emerging one that is being used at the same time as an increasing attention on preserving the architectural heritage where typical invasive retrofit interventions are not applicable. The need for a replicable methodology to improve the sustainability of historic buildings is based on the integration of energy efficiency solutions with renewable technologies (Pisello et al. 2015; Rodrigues & Freire 2017; Webb 2017). In addition the introduction of circular economic loops is one of the major subjects which should be considered. In view of this background brief, it should be noted that the urbanisation process and the impacts of climate change are pressing cities to prepare new development procedures. One of those paths is the circular economy (Kalmykova & Rosado 2015; Prendeville, Cherim & Bocken 2018) with the idea of the re-circulation of resources through economies for consecutive re-use. Whereas this concept is currently at an experimental level, in many ways it can be applied to the cultural heritage stock with the condition that circular issues are merged with the cultural appraisal. Since there is a lack of consensus on what a circular city should constitute, this proposition might be one of the possible choices.
Every approach to the retrofit design process is faced with a decision making process attributed to the selection of best cases depending on the goals initially set (Kašs et al. 2016). Therefore, the development of evaluation criteria should be anticipated, which will form a set of red flag choices, filed down to the case of a specific building. In the case of historic buildings, the procedure is often very complex and therefore there is a requirement to form a net of procedures where recycling, repurposing, refurbishment, and repair and reuse will form a basic pattern of choices from which further choices and possible procedures can be undertaken. This net of procedures should be also supported by the city’s policies and social requirements. Other researchers have also followed this line of thought, where a scientific approach will also include a variety of framework conditions (Kašs et al. 2016).
This paper presents a possible approach to the cultural heritage forming part of the city’s urban tissue when the main aim is not only historic diagnosis of the most valuable building elements, but also re-use of existing valuable materials either in-situ or as part of other renovated buildings dating back to the same period. This is in line with the idea of circular cities introduced by the EU in 2015. This paper contains the outcomes of a cultural and historic appraisal based on a number of analyses, but due to limited space, only a single case study is shown as an example. This building is located in a city centre with the Client’s initial brief indicating case studies of the best energy efficiency solutions. This particular case is presented as the authors were personally involved in the design development process, as well being a typical example of the complex issues which can be found in many other historic Polish buildings.
Case study – housing in Mokotów District
In 1897, a German investor Georg von Narbut, bought a large parcel of land located just outside the Warsaw city limits and started to divide it into smaller plots and streets. A large market square was planned half way down the main street. The study building, although not listed for its special architectural interest (Fig. 1.), is located in an area currently under historic urban preservation. This zone is subject to restrictions as to street layout and some of the buildings are listed in the Register of Historic Monuments. Most of the buildings in this area were built in the middle of the 20th Century. Since a number of documents were lost during the WWII, the official data that existed placed the construction date in the early 1950s, in a style described as early Modernism, with a simple plain façade devoid of ornament. This was the information given to the new owner of the estate, who approached a design team to prepare a proposal. According to the Client’s Brief, the proposed works were to be divided into two categories:
- recovery and rehabilitation, which included upwards extension of the building by two floors; providing adequate insulation and waterproofing, introduction of new technical systems; achievement of a class B energy certificate, removal of all internal finishing details and partition walls;
- aesthetics, which included redevelopment of the façade including provision of larger window openings (as the level of daylight in some of the rooms did not meet current requirements); modernisation of the balcony balustrades and introduction of new features which included new external cladding elements and a new colour scheme.
This initial brief was consulted with representatives of the Warsaw Department for the Preservation of the Historic Heritage, who objected to some of the plans and requested the preparation of a cultural and of the site with the main aim being to discover the original colour of the building’s façade, which in general was to be off-white. Research was conducted in two areas. The first one consisted of archival research. This permitted the definition of the primary architectural solutions and, later on, making site openings and sample cut-outs in characteristic areas. Samples were taken on-site as cross cuts containing stratigraphic layers of the previous internal and external finishes. Apart from the original colours and the finish materials of the façades, research included investigating the primary design features used in the main entrance area, which included loggias on the first and second floor levels, as well as confirmation of the initial form of the historic portal. Other secondary themes included an analysis and the obtaining of samples of those areas which have an impact on the building’s cultural value. These included the main entrance hall and staircase, ceramic tiles dating back to the beginning of the 20th Century, and the window frames. The outcomes of this appraisal proved that the history and value of the building were different from the initial assumptions, as it was in fact constructed in 1934. There is no name of the designer mentioned in any of the documents found, but the historic details are more appropriate to an earlier period (1925-27) when the oldest building in the vicinity was built. Possibly, this unusually long pre-development period caused the mix of two different architectonic styles – Historic and Modern. The exposed corner site was flanked with a large balcony off the south-western façade, and an open loggia facing the square off North-East. The assumption was that one of the floors was to remain in the owner’s hands, whereas the remaining apartments were intended to be let. There was a small retail use in the semi-basement area.
The building itself was build using pre-purchased building elements (there was evidence that the existing window frames were marked with the date 1932). In 1945, the building was burned out during the wartime siege, but the external façade, staircase and some of the
internal fittings remained. It was re-built in 1945-47 by the owners, but some of the works were still being carried out in the 1950s. As with many other estates, the building was taken over by the State Treasury in 1955, which was further confirmed by the entry in the Land Register in 1956. The building became part of the communal property stock, which meant that it was very badly maintained. Even after many years of misuse, some of the original features remain – such as conch shaped niches for tiled stoves in the dining rooms, an elliptical entrance hall leading into the staircase area still clad in the original terrazzo, and original early 20th Century ceramic floor tiles in some of the rooms (Fig. 2.). The historic analysis that was prepared leads one to the conclusion that the main historic and cultural value is the volume of the tenement building – with a height lower than other typical modernistic buildings that were built later, but similar to the no 50 plot where a historic Neo-renaissance building designed by arch. T. Zieliński remained intact.
The early 1960s brought new investments throughout Warsaw, and the adjacent plots were developed with a building that was located right against the balcony wall on the North side, and a building off the gable wall on the East side completing the façade of the square. This solution created a new situation where the building had only two external walls, whereas the remaining (reduced ones) became walls facing an internal courtyard that was entered through a gate opening accessed off a main street. The study building remained a tenement building throughout this time and some of the apartments were divided up into smaller flats.
The next 40 years brought no change in the approach to the maintenance procedures. The building was in low technical condition and the city authorities did not invest in its upgrade. New approach was introduced with the first Energy Directive which brought changes throughout Polish cities starting from 1997. Many of the buildings were given a permit to provide external insulation in order to achieve better energy efficiency, including the building under consideration, which was given such a permit in 2000. The works were carried out in 2005. As all the façades currently have external Styrofoam panels (8 cm thick), it was impossible to conduct a complete assessment.
Nevertheless, it can be stated that the form of the façade was subjected to the rhythm and logic characteristic of the Historicism tradition (Neo-classical style) while presenting features of historic modernism. The authors were unable to find any evidence of photographic documentation showing how the building looked prior to modernisation – even though such evidence should form a part of the design of the thick layer of insulation. Warsaw state archives included an accepted version of the new façades, but the research team found differences between the accepted form and colour of the façades and the ones that were actually built. The documents describing the provision of the insulation works indicate that any architectural articulations (including those more than 3.0 cm deep) had to be covered in layers of Styrofoam in order to produce a flat surface on the façade. In the areas where historic steel balcony balustrades’ were embedded in the external walls, the contractors were requested to cut off side flower baskets, destroying the original design. Analysis of samples of the plaster layers and a thorough search of the colours used for Warsaw’s tenement buildings at the time showed that the original main colour of the façade was light salmon pink stucco. The building’s socle was rather high (140 cm), constructed from an off-white terrazzo slab protruding from the surface of the elevation. According to the technical description of the façade, when covering with the insulation panels, the condition of the existing plaster was very bad, blackened from the fire and with an uneven often-loosened surface. Hence, after applying a thick layer of insulation the original plaster was destroyed beyond recovery. Even if the insulation cladding were to be removed, the reconstruction of a new plaster layer would have to include materials and techniques not accessible on the contemporary building market.
The main problem with the insulation works is that they have destroyed the main architectonic, urban and cultural values of a building located in a very visible location. Sample cut-outs, as well as research on buildings built in Warsaw during the corresponding period, allowed the researchers to prepare a proposal for restoring the original frontage facing the square (Fig. 3.).
The circular economy and Cultural Heritage proposals
In the contemporary world, the attitude of developers, when embarking on a development, which includes historic buildings, is to find the least troublesome solution. In most cases, this means dismantling the fabric of the existing building and creating a new one in its place. If pressed towards choices consistent with a circular economy, the easiest choice will be recycling the existing fabric with the aim of using the products on different sites. Therefore, there appears to be a requirement for additional reference documents specifying what are the best circular choices to be used as there is no obvious indication when and which buildings should be dismantled or treated with different procedures. In the case of buildings located in cultural heritage zones, cultural diagnosis might prove to be the major issue. The second, more advanced choices are repurpose and refurbish, where discarded elements may be used in new buildings with a different function, or in the case of a historic building - relocated within the building in order to enhance the most valuable features. Again, circular economy procedures do not refer to any additional documentation on the basis of which decisions could be made. As to which parts can be repaired, removed and relocated while still maintaining both heritage and circular values – there is also no indication as to how to proceed. The final possibility is the use of discarded historic building elements on a different site. The authors assume that in this case a cultural diagnosis should indicate where those elements should be reused in order to enhance their value.
In the case of the building discussed, the authors’ proposals are intended to arrive at a balanced solution, which will take account of the existing state of the building and the re-introduction of its historic values based on the refurbishment and repurposing choices. Hence, it is proposed to renovate characteristic pre-war features. These being, the door portal and the composition of the surrounding detail, including loggias, maintaining the original steel balcony balustrades and the original articulation of the façades. It is proposed to reinstate the three dimensional effect of the façade through the application of such details as a socle, pilasters, the crowning cornice and vertical pilaster strips surrounding the portal area. The present Master Plan conditions require that the height of the building should be increased by two floors to the height of the surrounding buildings. Therefore, the conclusions indicated that the cornice crowning the building should act as a visible element – a joining detail between the old building and the new extension. The authors also proposed that, if possible, the open loggia including the balustrades on the Eastern façade should be reinstated, as this feature forms a uniform solution with the main entrance portal – the façade’s main ornamentation – which should be uncovered from the Styrofoam layer and the original grey stucco reintroduced. The research does not prejudge whether the former balustrade can be uncovered from the insulation and then undergo restoration, or if a newer version of the balustrade should be constructed. It may be possible to maintain the newer Warsaw tradition and close the opening in the form of a French window mounted behind the balustrade.
It is also proposed to renovate the original steel balcony balustrades, increasing their height to meet contemporary expectations and introducing flower baskets above the original handrail. It is also suggested that the original set of window roll checkers on the ground and first floors be retained. The original window framework is in a very poor technical condition; therefore, it is proposed to use new framework but to maintain the existing division. The existing ceramic floor tiles dating to prior to 1939 (1st and 3rd floors) should either be kept in situ or relocated to a more exposed area. The main staircase area, including all the original elements – balustrades, terrazzo, and the form of the steps – should be renovated. This solution should also be applied to the reinstatement of the main entrance off the square.
Maintaining the historic location and urban layout of a city is one of the most important features for its cultural identity. A place is only a fragment of cultural space, which is subconsciously given a certain meaning during the course of its creation (Ryńska 2008: 334-335). If the meaning of the place is lost, then the history and identity is also lost, unless it is recovered on the basis of a cultural and historic appraisal of the site. In order to understand the meaning of a site, we have to understand the code of the language presented in material form or space. This code is also part of the cultural background for people belonging to a certain part of civilisation and is a part of their heritage. This principle can also be described as the genius loci – something that in the case of the Mokotów building had been entirely lost. Circular economy procedures are insufficient to proceed beyond a best technical solution for a case. In order to regenerate the identity of the place, the designers used various different features, both where the external façade as well as the internal public areas were concerned. One of the weakest points in contemporary urban fabric is the disappearance of a composition element in modern urban planning and the absence of an acceptance that new solutions – circular economic, sustainable and smart city issues – should form part of the new design. Therefore, in order to achieve harmonious urban composition, the owners and designers should meet more than just the legal requirements and even the newest construction solutions.
Cultural proposals had a major influence on the design originally proposed. Whereas the initial main line of thought was to keep as little as possible of the original substance and exchange it with modern high quality building materials, the request later became to maintain the historic features. In fact this is generally a rare approach, unless the building is subject to strict historic monument regulations. In the case of historic buildings that are located in historic urban areas, but not covered by the historic regulations – developers mostly proceed more in line with financial considerations, not the values which might work to the benefit of the local communities and fulfil the expectations of a circular economy. In this case, the circular economy refurbishment and repurposing were steered by historic and cultural guidelines, which finally proved to be a very effective combination.
This new approach allowed the introduction of certain elements dealing with the circular economy of the building’s management. The form of the building will remain unchanged and most of the structural and building elements either re-used or repurposed. It is planned to reinstate the loggias and use French windows, as well as the original colouring of the façade. The height of the new building will correspond with its surroundings which has a traditional economic value. The existing steel balcony balustrades will be kept in place. The topmost level will be constructed in lightweight elements, mostly a glass façade, in order to achieve different aesthetics from the older part of the buildings. These choices prove that it is possible to introduce circular economy features when modernising historic fabric, allowing one to achieve a synergy of re-use and repair of the existing elements with historic and cultural guidelines.
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