Historical Solutions in Buildings in the Context of Current Problems of Green Architecture

The 19th century saw an important breakthrough in green thinking, when the issues of the thermal comfort and health of the users of architectural facilities started to be taken into account. However, the architecture was not devoid of green features before. The applied solutions were based on intuition, experience and creative thinking of the architects of those times [6]. Without modern technologies, they strived for the protection of a building interior against external environmental factors and for the preservation of relatively stable temperature, irrespective of weather conditions. The used heating systems were imperfect and not very efficient. Moreover, architects did not have an important tool that we use today: they erected their buildings without knowing the building physics, which was established in the 20^th century. There were also no standards regulating thermal conditions in buildings. Only stylistic canons and experiences of architects passed from generation to generation were available. Architectural examples show that they were familiar with the problems of thermal comfort. Historical green solutions prove that they were treated as equally important to architectural styles or structures.

From the standpoint of contemporary technical knowledge, very important was the favourable orientation of facilities towards the sun and wind direction. Churches are situated in such a way that the chancel faces the East. The use of massive bodies and architectural structures implies the intention to stabilize the temperature of the interior, which is currently referred to as thermal inertia or thermal stability of an object. The first church facilities on the Polish land – rotundas were central buildings, particularly favourable in terms of the protection against external environmental factors. A castle chapel of the 11th century – St. Nicolas rotunda in Cieszyn has a cylindrical nave and a semi-circular apse with massive stone walls (Fig. 1).

Figure 1.

The walls, made of lime cut stones with the use of “opus emplectum” method, are 1.25 m thick and are characterised by high thermal capacity. Both in religious and secular facilities, buildings were “cut off” on the north by the proper distribution of functions, small windows, the use of buffering elements or relevant solutions for roofs and elevations. An interesting example is a type of wooden church used on the Polish land, which did not change from the Middle Ages to the 19^th century. St. Michael the Archangel Church of the 15^th century in Dębno, containing a number of architectural elements indicating a deliberate development of energy-efficient architecture (Fig. 2).

Figure 2.

It mainly consists of a firm body surrounded by buffering elements – timbered arcades, called in Poland “Szalowane soboty”, which served as a kind of a waiting room for the faithful waiting for religious ceremonies. Wooden churches had a uniform functional arrangement, in which the entrance was placed to the west and north, the sacristy was available only from the chancel, without the possibility of entering the northern part. There were no window openings in the northern wall, the interiors were lit by windows cut exclusively to the south and in the closure to the east. It was associated with a belief, common in the Middle Ages, that the northern side is a zone of evil and its power [7]. In medieval wooden churches, people consciously protected structural elements against damp by means of appropriate materials and design solutions, such as the above-mentioned arcades. In wooden churches, they were one-storey, low column structures covered with a mono-pitched roof, surrounding the church around the entire perimeter or a part of it. They formed an external structure typical for Poland, whose main purpose was to protect the lower parts of the walls against damp, whereas a shelter for the faithful was their secondary function [8]. In the closed (timbered) form, they provided protection not only against the rain, but also against low temperatures or heat. Wooden facilities were erected on Polish lands mainly with the use of a log structure. Corner beam connections prevented the lengthwise movement of beams and served as a kind of a “freeze barrier”, using the physical properties of wood. As we know, cold penetration along wood fibres is twice higher than crosswise. Churches erected with the use of this technique provided, apart from considerable durability, sufficient protection against cold, heat and precipitation [9]. This aspect is particularly interesting in the context of contemporary principles of sustainable construction. It should therefore be pointed out that the use and arrangement of construction materials in partitions used their best qualities and physical properties. In brick architecture, one can observe a tendency to improve the insulation of partitions by the use of layered partitions and buffering spaces in walls and roof finials. Even in the Roman times walls were built in such a way that wall faces were carefully made of cut stones or bricks, whereas the interior was filled with debris or crushed stone and poured with lime mortar. The porous structure of the internal side of the wall provided good thermal insulation. A similar principle was applied for domes, and sometimes the structural layers were separated by an air gap. In order to protect interiors against external environmental factors, parts of the facility were often hidden under the ground. Storied arrangements were also used in buildings or their parts. Some medieval churches had all these elements. Saint Cross Church in Wrocław has two sacred storeys, both of which are used for the purposes of liturgy (Fig. 3).

Figure 3.

The lower church is partially sunk into the ground, and the sacristy has two storeys. The body of the church is firm, with beautiful Gothic forms, showing energy-efficiency properties. Location was an important element of historic architecture. Apart from the orientation, the location of churches in microclimatic conditions, favourable in terms of energy-efficiency, was also important. Cistercians built their monasteries in the vicinity of water: rivers and water bodies. The proximity of water areas is an important factor influencing the stability of the ambient temperature [10]. Water bodies are kinds of heat accumulators and they reduce temperature fluctuation in adjacent areas [11]. In the history of architecture there are also consciously used architectural and natural elements that protect against the wind. This function was provided in churches by wooden towers. They covered the nave to the west, that is, the dominant wind direction in Poland, and protected it against the rain. Greenery was also an important accompanying element. It is hard to prove that it was used deliberately in order to reduce energy loss in buildings, but it must be mentioned that there existed a number of palace and park complexes, where deliberately shaped plants formed urban and landscape arrangements and contributed to the creation of specific microclimatic conditions. Groups of trees served as windbreaks, as they are currently used for this purpose [11].

External environmental factors have a considerable influence on the development of the microclimate of interiors in historic buildings. The structure of historic buildings usually includes partitions with poor thermal insulation, which sometimes causes that the conditions inside them are tightly related to external environmental factors. External environmental factors are understood as environmental and natural issues associated with the location, season or even time of the day. They have a direct influence on the temperature inside buildings as well as other physical qualities related to the properties of a building [6]. Most of the above-mentioned phenomena are induced by sunlight. Solar absorption makes it possible to acquire energy through the appropriate shaping of bodies and elevations of buildings, architectural details and urban interiors as well as the use of appropriate construction materials. The lack of thermal insulation, understood as a layer made of an insulation material of very low thermal conductivity, causes that the thermal circulation in partitions is not reduced drastically. This, in turn, enables the acquisition of external heat to construction elements as well as its storage and distribution in the building interior. It also provides the possibility of acquiring heat from the atmosphere by means of appropriate construction materials and partition structures. Materials of high thermal capacity fulfilled, in this case, the role of heat stores. Other important heat sources in historic buildings include the use of heat emitted by people present in a building. It is particularly useful for religious buildings, which can house a large number of people. Heating systems have existed since the ancient times. As Palladio writes: “even the ancients placed fireplaces with columns and brackets supporting the architrave and the eaves through which smoke was discharged in the middle of their rooms. When they did not want to build a fireplace, they made channels in the walls through which the heat of the fire set under habitable rooms got inside” [12]. They were gradually modified and improved, sometimes taking the form of very complex heating systems. They were based on the principle of acquiring, storing (thermal capacity) and distributing heat energy. Interesting examples include the central heating system built before 1340 in a medieval castle in Malbork (Fig. 4).

Figure 4.

Here smoke conducts are separated from channels distributing hot air. The fire from heaters warmed up huge stones, which served as heat stores. Once they were warmed up, the chimney draught was blocked and, after extinguishing the fire, the second hot air cycle was opened and the hot air was let into the rooms through special openings (Fig. 5). The system heated the Great Refectory in the Middle Castle in Malbork, but the entire concept included more than ten heaters [13, 14].

Figure 5.

A later, but also interesting heating system was used in the Cistercian monastery in Lubiąż. During the reconstruction of the facility in the 17^th century, a central heating system made of air channels distributing heat to the rooms of the building was established. It forms a system connected to numerous chimneys and smoke channels leading to them, which is difficult to figure out nowadays due to its present condition [6, 15].

In the past, ventilation was used in two ways, both for air exchange in interiors and for cooling. The appearance of ventilation using the phenomenon of chimney draught is most probably related to the development of heating systems, as the use of smoke conduits forced air exchange even outside the heating season. Apart from the basic ventilation function, that is, ensuring air supply and exchange, it had also a positive influence on the condition of building structures. The lack of air exchange caused the occurrence of damp on the foundations, walls or vaults. We currently know that damp on construction partitions is caused by the worsening of their insulation parameters. It was also related to other issues, such as the microclimate of interiors, that is, broadly defined users’ comfort. There are interesting historical solutions implying that these issues have been important since the ancient times. Interesting examples include openings in vaults, which have existed since the ancient times, through the Middle Ages, to the modern times. They are present in vaults of some Gothic churches in Silesia. Churches in Wrocław have open keystones in the form of oculi. Their main function is to support the structure and to distribute the load of the vault to the ribs. However, very characteristic is the fact that only 2 or 3 out of tens of ogival vaults have the open form, enabling gravitational airflow. Other vaults have traditional keystones. The oculi are distributed intentionally in a way to ensure the possibility of ventilating the most important area of a building. They usually include: the nave, the chancel and sometimes the transept. As it was not possible to open windows in these facilities, ventilation through keystones was the only air exchange measure. What is important, it could be adjusted seasonally by covering the opening with boards. The above-mentioned Saint Cross Church in Wrocław is a perfect example (Fig. 6).

Figure 6.

We do not know whether the solutions of the Middle Ages were modelled on the example of ancient Rome. The temple of the Pantheon is described by Andrea Palladio in his “Four Books on Architecture”. The inspiration is visible in “Villa Rotonda” near Vicenza, where such oculus modelled on the one from the Pantheon was used, but it was closed with a lantern. Many years later, in 18^th century, this ventilation method started to be used mainly for the sake of users, in order to ensure quick air exchange in auditoria in theatres and operas.

However, the renaissance architecture developed ventilation systems with air-conditioning systems. Palladio, in “The Four Books on Architecture”, mentions an outstanding solution, probably being one of the first air-conditioning systems for interiors. He writes about “Villa Costoza”, in which cool air from the underground caves located within the estate was used. Several facilities were cooled this way, by supplying them with cool air through vaulted conduits. They could be freely closed and opened in order to cool the rooms more or less, depending on the season [12, 16].

In the medieval and modern times, various solutions based on the thermal stability of the ground and building structures, building so-called ice houses, used to store food. Due to the well thought out location, they maintained a stable, within certain limits, temperature. The ice house in Wawel is one of the examples. It is located under the south-eastern corner of the Renaissance arcaded courtyard. Ice houses and cellars used for food storage usually had proper ventilation, as did the 14^th century castle in Czorsztyn. A ventilation opening is provided in the very thick wall in such a way that the intense sunlight does not reach here (Fig. 7).

Figure 7.

Methods used in the past were improved, developed, but employed intuitively. Physical and chemical started to be taken as late as in the 19^th century. Learning the chemical composition of the air and the development of building physics made it possible to determine the influence of external environmental factors on human health.

In 19th century England, air pollution issues started to be analysed in terms of human health. It was decided that the quality, or rather the chemical composition of the air polluted by the industry, is the source of numerous diseases. They were even called the “bad air ailments”. The recommended solution to these problems provided in the literature of the time was to intensively ventilate habitable rooms. It was believed that a properly dressed and nourished person does not have to be afraid of large amounts of cool or even cold air [17]. Today we know that this method was not entirely right due to the atmospheric pollution caused by the industry of that time. The problem was probably caused by particulate matter and other harmful substances, against which we are currently able to protect ourselves by using filters, ionizers etc. The 20^th century, in turn, saw the problem of excessive insulation of buildings. In 1980’s, glass elevations without the possibility of opening windows started to be used in office buildings. It caused totally new, previously unknown problems like SBS and BRI. It was a very important moment, as scientists realised a number of negative consequences of such a strategy of designing, erecting and using buildings. It made it possible to draw conclusions and adapt certain solutions [18]. Unfortunately, nowadays the problem of excessive insulation of external walls is still present due to the installation of modern, airtight windows valued for energy efficiency and acoustic reasons and by insulating buildings with polystyrene [1, 19]. It seems that the strategy requires looking back and modifying its paradigms as soon as possible.

The historic architecture has numerous interesting solutions that may be analysed, developed and reimplemented in contemporary buildings. Exploring the rich resources of historic facilities may provide an opportunity for the implementation and development of certain solutions. One can use Sustainable Construction Certification Systems for this purpose, in order to implement selected aspects into legislative and normative acts.

Greenery has always been present in architecture, especially as an element of composition, but also served as protection against the wind. Growing freely on elevations, it provided protection against external environmental factors, as does contemporary thermal insulation, yet, it changed with seasons. These properties are used for elevations of currently designed buildings. It prevents interiors from warming up in the summer and provides access to the sunlight in the winter. Greenery used on façades is also a symbol of a return to nature, respect for the environment and a promise of users’ physical health [20, 21]. But it is not all that we can achieve by the use of various types of plants. Greenery is, most of all, a kind of a catalyst reducing CO₂, purifying the atmosphere and generating oxygen. The presence of selected plants in city centres improves the users’ living conditions and health.

Just like in medieval churches, it is not possible to open windows in facilities such as concert halls or hypermarkets, or they sometimes do not have any windows. Ventilation is limited exclusively to mechanical systems. One should, at least partially, reapply old solutions and enable temporary gravitational air exchange, switching off HVAC systems in these periods. It is related to the creation of an adequate, smart control system, which would enable complete air exchange inside, depending on the season, external and internal temperature, humidity or air quality. It had a positive influence on the comfort and health of the users.

In public utility or large format facilities, it would be advisable to create smart, automated internal temperature management systems, which enable the manager to individually control the thermal comfort, but only to a certain, very narrow extent. Such a solution will eliminate situations in which the system is managed by an incompetent person, without even the general knowledge on human thermal comfort. In practice, unfortunately, temperature is managed in the entire facility by a randomly appointed person, selecting an unnaturally low, harmful for user’s temperature. In the proposed solution, it will not be possible, as the system will automatically suggest appropriate temperature, matching external environmental conditions, season (users’ clothing) and other detailed parameters. Facility manager will be able to adjust the internal (equivalent) temperature adequately, but in a very narrow scope.

The last issue that needs attention is related to financial savings of facility managers, which involve temporary switching off of HVAC systems. This leads to situations that are dangerous from the point of view of users’ health and humidity of the building structure. Creating the possibility of the external control of the functioning of HVAC systems would prevent such situations and every user of a building would be sure that the quality of air in the building meets normative parameters. It is possible thanks to the installation of controlling panels connected with external IT systems. Legal and statutory solutions should also be a significant supporting element.