Facilitator: Kleopatra Theologidou,
Architect, MA Conservation Studies
City of Veria, Greece
The workshop started with a short introduction about the importance of protecting and enhancing the historic centres of the cities, where historic and traditional buildings hold a central role to their image and identity. It was pointed out the importance of keeping these buildings alive and to achieve this, the only way is to ensure their continuous and proper use, which means that they should respond to current needs, namely alterations. A major theme under discussion nowadays is energy efficiency. Till recently, however, heritage was out of this discussion at a European level as dealing with certificates and standards, because the improvement of the energy efficiency of historic buildings means alterations which seem to influence the integrity and the historic values of the buildings.
The introduction was further referred to the different thermal behaviour historic and traditional buildings have in comparison to modern constructions and the different values these buildings possess which poses the question how realistic it is to talk about standards and certificates, as it seems that there are not “one-size-fits-all” solutions.
Finally, the need for an integrated approach was stressed, an issue widely discussed during URBACT Conference, as the only way cities can tackle effectively the different economic, environmental, climate and social challenges they face. Energy efficiency of historic buildings meets all these challenges and therefore cities need to adopt integrated strategies so that they are effective to their policies and get funds in the new programming period 2014-2020[1].
The discussion of the Heritage table[2] was focused mainly on the following questions:
1. Heritage versus energy efficiency: still a conflict?
- What initiatives can cities take to succeed a common base of acceptable actions and methodologies among different authorities?
- Is there a case that energy standards for historic buildings could be adopted at a European, National or Local level?
2. What short of support (financial, technical and administrative) can cities offer to the owners and tenants in order to respond to the additional demands deriving from the specific character of historic buildings?
The different backgrounds of the participants during the 2 days workshop and their strong interest and participation gave the opportunity for an interdisciplinary approach where very interesting opinions and knowledge were put on the table. The limited time for discussion, however, did not permit to deepen on specific matters. In brief, discussion, opinions and questions were as follows:
General matters
What is the difference between historic and traditional buildings?
- Historic buildings are buildings which are protected (listed). Any intervention on them should follow strict preservation rules. At the moment these buildings are excluded from the energy efficiency certificates
- Traditional buildings are old buildings, built in traditional methods and materials, which are not protected but they are in a protected area. In these buildings the possibilities for alterations are increased.
- When we are referred to historic buildings and energy efficiency, we do not mean monuments of high importance.
It is very encouraging that in many cities, like in Delft, there is a tendency among residents to come back to the historic centre. This makes the need to take action more urgent, so that different problems are solved.
We cannot talk only for energy and historic buildings, but we should approach it in a broader context where social problems have a major role.
Knowledge
How can we face the challenge between conservation of the “integrity of historic buildings” versus improved energy efficiency standards?
Or
Buildings versus building: Connection for improving novel efficiency methodologies
Historic and traditional buildings have a different thermal behaviour in comparison to modern constructions, due to their building technology, their form and architecture. Even among them there are a great many differences depending on the time period and place of construction. Additionally, values differ from building to building resulting to the different degree of alterations to be permitted. As a result, there are no “one-size-fits-all” solutions; is it realistic to talk about standards and certificates?
Knowledge about the energy performance of traditional buildings has not yet been fully established. Especially in the case of composite building elements, like stone walls, further research is needed. In general, the methods applied to improve the energy performance of these buildings are borrowed from the methods applied to modern constructions, where different building materials are used. In addition, restrictions derived from the historic character of the buildings, like the retention of the facades, guide to the application of insulation methods which could not be characterised ideal. For example, the use of insulation on the internal part of the wall raises several questions. On the other hand, are we sure that we need additional insulation, especially in the case of mass walls?
However, it seems that there are methods to improve the energy performance of different building elements, such as windows, roofs and floors, which could have a general approval.
In general, at a European level, the idea of collecting cases of cost effective solutions on historic buildings was stressed, as well as the idea of analysing buildings of similar periods and architecture across Europe to find similar barriers and solutions. At a local level, the need for additional knowledge appeared in many cases to be necessary, as well as the need to connect energy demands to type of uses.
Standardization
Is there a case that energy standards for historic buildings could be adopted at a European, National or Local level?
The European Standardisation Committee (CEN) has just set up a new Workgroup CEN TC 346/WG8 “Energy efficiency of historic buildings” with the aim to develop harmonised European standards to deal with the unsolved problem of energy upgrade in historic buildings.
Historic buildings and renewables
The use of renewables on historic buildings is very sensitive matter. Different opinions were expressed and different information was brought on the table. In most cases, the use of renewables and especially photovoltaic on historic buildings, like in UK or in Belgium is strictly forbidden for obvious reasons. However, in other areas, like in Denmark, it is permitted. In this case, they should be hidden, that means be located in areas that will not affect the landscape. In Delft also, a partner city in LINKs project, the use of photovoltaic on the roof of historic buildings is permitted on condition that they are not visible and the intervention is reversible[3].
In general, there has been a big concern among the participants of the roundtable whether to use or not photovoltaic on historic buildings, while the same possibility for traditional buildings seemed to be more acceptable, under the condition that it is not disturbing the image of the historic centre.
Other ideas were also expressed like in the case of Tailin, where sea water was used for heating the Estonian Maritime museum, built in 1914[4].
A practice applied in Spain is biomechanical energy, meaning the use of piezoelectric floor in buildings where human traffic is of a high level[5].
Other ideas like common heating system among a group of historic and traditional buildings could also be a solution. In this case, renewables, such as photovoltaic or geothermy could be used at a distance from the buildings.
What short of support (financial, technical and administrative) can cities offer to the owners and tenants?
Raise Awareness
Raising awareness is a major theme. In order to succeed, it is necessary to keep telling the story again and again. It can be:
By implementing pilot projects to help people see the benefits from retrofitting historic buildings. Knowledge on how much you save by energy improvement is crucial.
Encourage community leaders to implement policies which will help raising awareness about the importance of energy saving and business opportunities
Organize different activities, like in the case of Bayonne city, coordinator of LINKs network (Old European cities as a key for sustainability), which organises “the night of Thermography” open to the citizens, which help them see with the help of thermo cameras, the thermal emissions of traditional buildings.[6]
Dissemination of knowledge
The need for spread knowledge is crucial. People interested in restoring their buildings need to know what is permitted to do and what should be avoided.
In many cases knowledge is there but it is not diffused. A lot of work on heritage and energy performance has been done in many countries, like in UK (English Heritage, Edinburgh World Heritage trust), Ireland, Nederlands and France. Cities can help by organising seminars workshops, exhibitions, meetings etc. The city of Bayonne has organised the “boutique de restauration”, a permanent place with a small exhibition of materials and techniques, where different workshops are taking place addressed to different groups of stakeholders.
Cities can also organise training sessions.
The project ENERGY VILLAGES in Denmark focuses among others on knowledge sharing and best practice. One of them, Herringløse, is focused on heritage buildings.
At a national level, a platform with guidelines and technical aspects can be developed to help owners, technicians and different stakeholders. In Denmark a site has been organised with information on how to restore historic buildings.[7]
Administrative and financial support
Cities can provide assistance by promoting an office advisor who could help tenants with approval procedures, agreements, funding possibilities and knowledge.
Cities can also financially support privates in order to fill the gap of additional expenditures derived from the restrictions for the preservation of the historic character of the buildings.
Help in different ways examining the possibility to use cheaper materials, so that the cost for retrofitting is reduced.
Examine and stress the possibility of investing on historic buildings and under which circumstances.
Social aspects
The social factor was stressed by the coordinator of CASH network (Cities Action for Sustainable Housing), with emphasis to low income families and measures were proposed for renovating historic buildings without rent increase, like involving stakeholders and tenants from the beginning, creating a financial platform and providing training and qualified workforce[8].
[1] European Commission, Cohesion Policy, Integrated Sustainable Urban Development
[2] Reporter of the first day workshop was Mrs. Sara Van Rompaey, architect, expert in heritage and energy efficiency, to whom I am mostly grateful for her involvement and support.
[4] EU pilot project Tallinn: Restoration of seaplane harbour – Estonian Maritime museum: produce energy with a heath pump using sea water. The large harbour hangar is heated energy-efficiently by an underfloor heating system on a 6,300 m2 of area. The heat supply utilises a source next to the harbour: the sea, Katrin Savomagi, www.meremuuseum.ee
http://www.youtube.com/watch?v=y0L_mHfdO7A
Building Energy Efficiency in European Cities 