Introduction – Critical Details study material

3. Basic requirements for new and significantly renewed buildings

New buildings must fulfil normalized requirements on heating and technological features of constructions and buildings. Normalized requirements must be also fulfilled by the significantly renewed buildings. If it is functional, technically, and economically possible to make, all the building constructions where a significant renovation takes place must fulfill at least the minimum requirements of energy saving buildings. It is therefore necessary to describe the malfunctions and problems for the buildings which are planned to undergo a significant renovation since there is an open call for funding to support the renovation of the buildings where the main criterion is energy saving of at least 30%. The current inflation in energy sector shows that it is necessary to begin the renovation of the existing construction objects and lower their energy consumption demands. There are quite a lot of buildings in this country - schools, kindergartens, public buildings but mainly hospitals. Most of the existing buildings are long overdue their lifespan or are close to its end. It is mostly about low-quality insulation of the building, heating systems, hot water preparation, lighting, ventilation, but also measuring and regulation. These objects and their systems have a significant share on the overall energy consumption. One of the options how to renew these existing and original buildings is use the above-mentioned funding from the Renewal Fund. It is the opportunity of using resources under the law 555/2005 Z. z. to improve the condition for the building constructions but also other places of consumption. Therefore, for the building to use the funding from the Renewal Plan, it is necessary to fulfill certain requirements that need to be proved in the project documentation and project energy rating. It is mostly about reaching a certain level of saving which is ensured by renewing the building envelope by insulating and by changing transparent constructions. This is why the topic is very up-to-date and shows the possible risk that need to be analyzed and avoided directly in the project and realization of the building and building renewal. One of the basic requirements which need to be proved in the project documentation and in the project energy rating is the fulfillment of 30% energy saving for the global indicator, which is the primary energy. The strategic document “Renewal Plan „describes the complex renewal as a renewal where the improvement of heating and technical features of the building envelope are a big part of. The most efficient way to specify the requirement for the complex renovation is through the minimum requirements on the values of energy indicators which influence the heating and technical parameters of the building envelopes. The aim of the requirement is to ensure the agreement with the principle of the energy efficiency priority and make sure that a gas boiler is not installed in a building with high heat losses in the building envelope (e.g., in walls, windows, the roof). The building must fulfill the required level of heating and technical features after the renovation – mainly the requirements for the coefficient of thermal conductivity and the requirements and the requirement to fulfill the energy criterion – measuring need for heating energy. Building constructions must fulfill the requirements for excluding the risk of mold growth on their inner surface (Criterion of hygiene) and on elimination of steam condensation in the building construction or on its inner surface. By fulfilling these criteria, the proof of fulfilling the basic hygiene and health protection is met. The requirements on building constructions and buildings take into consideration various levels of energy efficiency. Minimum requirements (maximum values), normalized (required), recommended and target recommended values of the requirements showing making the thermal and technical features of building constructions for the following levels are as follows:

Energy saving building (minimum requirement),
Low-energy building (required)
Ultra-low-energy building (recommended requirement),
Building with almost zero need of energy (target recommended requirement).

In the revised directive about the energy efficiency of buildings (EPBD) is stated, that all new buildings and renewed buildings built withing the European Union after the year 2020 should reach almost zero need of energy. This means that all new and renewed buildings, if it is technically possible, will have to show very high energy efficiency and their energy needs will be significantly covered by renewable sources. When designing buildings with almost zero need of energy, it is necessary to eliminate all the risks arising at the sole preparation, drawing the project or during realization. The basic concept when designing buildings with zero energy consumption is, besides high-quality thermo-technical characteristics of the building envelope, a correct and efficient heating system, hot water preparation, system of lighting, ventilation with cooling and releasing these individual places of consumption. It is mainly about the right design and the execution of the connection, links of individual technological stages such as connecting the transparent construction to the multi-layer building envelope consisting of the load-bearing construction and the contact insulation system. This system may be contact or ventilated. Regarding the tendencies of changes in climate conditions, it is ideal to start using ecological and accessible materials low carbon footprint in construction. One of these materials is also wood, which is used in CLT construction systems as load bearing constructions of the building envelope. In the given paper, the options of connecting the links in transparent constructions in a family house built with a low carbon footprint and active elements integrated in the building envelope.