A school focused on energy savings and renewable energy sources
The subject of the activity of this COPaG high school in Prague is a comprehensive educational offer at a high professional level. The school provides a wide range of opportunities to gain qualifications within secondary education as well as adult education. In recent years, modern teaching spaces, workshops, classrooms and laboratories equipped with top teaching aids and measuring and diagnostic technology were built here. In 2011, the Center for Environmental Education was opened here, focused on the popularization of energy savings and energy renewable sources. It is primarily intended for teachers and pupils of primary and secondary schools, but also serves the professional and lay public.
Need for revitalization
The original school building dates from the 1970s and its extension from the 1990s. It was built in the Kord system, which was used for these buildings at the time. Its disadvantage was that it contained a large amount of asbestos, which today is included in the group of proven carcinogens. So the building needed to go through a special decontamination process. In addition, it was very energy inefficient and damaged in many places. The layout and equipment of the school no longer corresponded to the requirements of the 21st century. Client, the Prague city municipality, thus announced a project for the revitalization and reconstruction of this building.
Cooperation with academia
The goal was to transform the school building into an intelligent, sustainable, energy- and carbon-positive building. Long-term sustainable low-energy materials, low-energy operation and user comfort of the building were required in the project specification. A gentle school reconstruction project applying the principles of indoor environment quality was selected, which was implemented in cooperation with ČVUT - UCEEB (Czech Technical University in Prague - University Center for Energy Efficient Buildings).
The public administration thus collaborated with the academic sphere on this project. The know-how and technology tested in the experimental environment were successfully transferred to the pilot project in practice. The author and general designer was Ing. Jiří Tencar, Ph.D. from ECOTEN company and the general contractor was Subterra a.s. the construction company.
Principles of sustainability applied to the project
The following features of the building were emphasized in the design:
- energy efficiency,
- water management,
- healthy indoor environment – acoustics, light, air, thermal comfort, well-being,
- gentle/sustainable materials.
Already at the beginning of the project, everyone focused on sustainability, and the design was prepared in accordance with the SBTool CZ certification tool. This is a building comprehensive quality assessment methodology developed by Czech Technical University in Prague, which focuses on environmental aspects, socio-cultural aspects and managerial-economic aspects.
Layout solutions and modern technology for a 21st century school
The original layout of the school no longer corresponded to current requirements and trends. Together, the architect and school representatives identified the needs and determined the new layout of the area. A number of modern technologies were also built into the building.
The special ENVILOP envelope made of light wooden panels is the result of Czech applied research at UCEEB and was used for the first time in the Czech Republic right on this building.
The project involved a lot of greenery – the school building is covered by a green roof and part of the facade is surrounded by greenery. Accumulated rainwater is used to water the greenery. Gray water from showers and sinks is also accumulated and used to flush toilets. The well increases the replacement of potable water with utility water.
Geothermal wells and heat pumps provide heating, hot water heating and cooling. Intelligent led lighting cooperates with external lighting, so that the lights are adjusted according to movement and the intensity of daylight and create the most optimal light in the classrooms.
The school has its own photovoltaic power plant with a battery capacity of 300 KWh, which makes its building not only energy self-sufficient, but even energy and carbon positive. In a year, the school therefore produces more electricity than it consumes.
The ventilation system is linked to the school schedule via the information system and before the start of classes it will ventilate itself and ensure a pleasant indoor climate. CO2 sensors are installed here, i.e. when the classrooms are "exhaled", the air conditioning system automatically ensures ventilation.
All systems are managed in such a way that they are economical and used only when necessary. The operating costs of the building are thus extremely low. In addition, the school building was certified with the SBTool CZ gold certificate, which underlines the benefits of the school in terms of impact on the environment and quality of life.
What about good sound?
Acoustics were also considered in the design from the beginning. The building's acoustics required such measures that the individual rooms in the school were soundly separated from each other. From the point of view of room acoustics, emphasis was placed on ensuring the comfort of the rooms themselves.
The acoustic model of the building was developed by EKOLA group ltd. Its goal was to provide an acoustic environment going beyond the scope of the law. The biggest challenge in terms of acoustics was the amount of technology integrated in the building's ceilings.
Requirements for room acoustics parameters
Speech intelligibility is achieved by controlling the reverberation time, which is normatively determined for spaces intended for the education of children and youth in the Czech Republic. Standard ČSN 73 0527 and decree 343/2009 Coll. obligatorily set the following reverberation times as key parameters: tribal classroom: T0 = 0.7 s, language classroom: T0 = 0.45 s.
It was recommended to install Rockfon acoustic solutions in the whole building. In the classrooms, excellent intelligibility had to be achieved, which was ensured by the installation of highly acoustically absorbing Rockfon® Sonar® and Rockfon® Sonar® Bas suspended ceilings and impact-resistant Rockfon® VertiQ® wall panels. In the canteen, it was necessary to reduce noise and ensure a visually aesthetic impression, which was perfectly served by Rockfon® Eclipse™, the white circular acoustic ceiling islands. In the gym, it was necessary to reduce noise and ensure speech intelligibility, for which Rockfon® Samson™ impact-resistant acoustic suspended ceilings were chosen. And also in the corridors, Rockfon® Sonar® tiles were installed to reduce noise.
The author of the design Ing. Jiří Tencar, Ph.D., says: "In all spaces, already in the design phase, emphasis was placed on optimal reverberation time, i.e. the creation of pleasant acoustic comfort. And it was very successful. A regular grid of round acoustic panels was originally designed in the entrance hall and the adjacent canteen and cafe, but due to the need to almost double the area of the acoustic panels, an irregular multi-layered „forest“ was created, which aesthetically looks even better than the original plan."
An experiment for the future
The revitalization of this Prague school incorporated several innovations and essentially became an experiment. Time will test how the solutions work, and the building will thus become a valuable source of information for the future design of similar buildings. This revitalization project will serve as a pilot project for the city municipality, which will test what a 21st century school should look like and what criteria must be assessed when planning investments.