Title: Arh.Emil Lekov speaking for www.
Date: 10-05-2010

Description: 1.Architect Lekov, you work on building projects. Do the requirements for insulation differ according to the type of building and the external environment?

Of course, each project has to be considered separately. Factors to be considered are the client’s preferences and financial considerations; the purpose to which the building will be put; and the construction and overall design and appearance of the building. There is no given formula for arriving at such choices.

Every type of insulation has its advantages and disadvantages. To give an example, Expandiran Polystyrol (EPS) is recommended for external insulation of facades. It allows for the wall to ‘breathe’, and so prevents the appearance of mold and condensation. This makes it very suitable for renovating old buildings. This material also increases the strength of the façade, and increases its resistance to shocks and atmospheric conditions. However, it must be well hydro-insulated, because of its open-cell structure. Expandiran Polystyrol (EPS) is thermal insulation material, and it does not absorb water; it has a high load resistance factor, which makes it suitable for use in places such as the plinth, under the foundation slab, wet premises, and terraces; that is to say all the places where there is a high load factor and damp. The rock wool combines a low coefficient of thermal conductivity, a high level of sound insulation and it is fire-resistant with a high melting point.

2.What are your personal preferences for the type of insulation materials for use in your projects?

A. Each project is different, unique, as I already said. Everything depends on what the investor’s preferences are. Recently, we had a client whose special requirement for the house we designed was that it should use a technology that is relatively new to Bulgaria: the use of thermal insulation panels with shuttering elements which are left after the building work has ended. In this way, the whole building is thermally insulated as an integral part of the building process. The panels themselves are made of integrated thermal insulation material and, because of that, the energy efficiency of the building is really high, close to hermetic. So, we needed to build in conformity with the client’s instructions and to accommodate this technology from the design stage. In general, investors have paid more attention in recent years to the buildings being well-insulated.

3.What measures would you recommend for the best thermal and hydro-insulation?

A. For the thermal and hydro-insulation to be most effective, it has to be installed throughout the building. This insulation is, perhaps, the most important element in ensuring that your house is properly protected from external conditions. Another, not less important, factor is the use of high quality materials, such as rock wool, which, if properly installed, makes the building last ‘forever’. It is also essential to follow the manufacturer’s guidelines. Unless all the above is complied with and followed, the result might still be unsatisfactory even if the best quality materials are used. If proper account is taken of these matters, then the house will retain heat in the winter and remain cool in the summer, so also optimizing the use of energy and minimizing the cost.

Another goal is better energy efficiency of the heating systems, cooling and lighting, as well as the use of renewable energy sources, such as geothermal and solar energy. These latter reduce the energy required from external sources, and are to be found in unlimited supply in nature.

Thermal insulation is part of one system, each element of which must be of high quality for energy efficiency to be obtained.

4.Energy efficient architecture is very modern today. What other architectural methods will increase energy efficiency apart from good quality insulation?

The main method used by architects is to orientate the building having regard to the landscape and the geographical location. In our location, the goal is to achieve the maximum exposure of the building to the sun. Another important method is to consider the situation of the building with respect to the inclination of the land and how the rooms are oriented vis-à-vis this inclination. You must also consider the wind patterns in the region and their negative impact on the building’s heating. To summarise, the other method for promoting energy efficiency in urban developments, apart from good quality insulation, is the optimum situation of the buildings taking into consideration the natural characteristics of each region.

A study is made of all elements in the landscape which absorb or emit heat in different ways.

Methods of a purely architectural nature include the choices for covering the building according to whether it has a sloping or a flat roof, and the materials for external cladding and roof construction. We, at Ivis Project and Design, aim at achieving the best solutions for every new project.

5.Price is the defining factor for many people. What is the difference in the cost of energy efficient projects and similar projects without the good energy practices?

There is a big difference, but only if looked at from a short-term cash flow perspective. If you analyse the project from the point of view of the initial investment, the energy efficient project is more expensive. However, matters are not so simple. Each building has an exploitation cost, and, for projects which do not benefit from energy efficient materials and methods, this cost goes up every year. Energy efficient projects reduce the annual energy costs amortizing in effect the initial investment over a certain time, and thereafter even make money for the client.

6.The state of buildings throughout Bulgaria is poor. What is your opinion, as a specialist, on how to improve it? How do you evaluate the role of quality thermal insulation in this?

As a whole, we have to work towards a culture of energy efficiency. We live in times when conventional fuel is a finite resource. It is therefore extremely important to use the remaining energy sources rationally and economically. Quality thermal insulation is one of the most important factors for achieving this. In general, buildings in this country need improvement and the re-evaluation of energy efficiency. This is equally valid for urban apartment complexes and for individual houses in the smaller villages. We have to hope the state will take on a bigger role in promoting energy efficiency, because improving separate households is not sufficient. Many people try to do the improvement themselves without involving experts, and this is often done with low quality materials and shoddy workmanship. Another negative tendency is the work carried out is often mismatched in terms of colour and other ways, and makes the whole ugly. The decision as to how this is to be carried out should be taken at state or municipal level, as it is in Pernik.

7.Is there a universal way for the clients to distinguish between good and bad architectural projects when they are choosing a home?

I will not say there are universal criteria, but there are ways to do this. Amongst these are: access to the apartment – that is to say the vertical and horizontal connections of the building; the functionality of the apartment – the clear separation of the day and night quarters and their access to the sanitary facilities; how the surface of the different rooms allows for their furnishing – if they offer the necessary comfort and possibilities for this; the flexibility of the rooms – that is to say if the construction allows for internal rearrangement of space without the destruction of load-bearing walls; the orientation of the rooms as a function of their intended use; and other details such as light and proportion. These are the main criteria for good architecture. People have to pay attention to these matters from the moment they step into the building.
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