The renovation Zöld Liget Kindergarten, in the first phase of the StepUP project – step by step

The Municipality of the 18th District of Budapest Capital participates in the StepUP project as a demonstration site to integrate the technologies developed in the project in a public building in need of energy modernization, as well as test their effectiveness.

Out of the entire public building stock, the Zöld Liget Kindergarten in Pestszentimre met all the criteriaAn initial evaluation concluded that the building’s walls and flat roof were not thermally insulated, although the doors and windows had been replaced earlier. 

The open-burner, an atmospheric hot water boiler providing central heating was outdated and its operation was not reliable, as well as the cast-iron radiators and steel sheet pipe network installed approximately 60 years ago. Room-by-room temperature control was also not possible.

Figure 1. Status of the Zöld Liget kindergarten before the deep renovation.

To prepare for the renovation process, Eurecat Technology Centre deployed an energy and comfort monitoring system installation, IES prepared the calibrated simulation model of the building, and ABUD conducted an occupant comfort survey with the kindergarten employees.

In June 2020, a deep survey of the current state of the building was made, followed by the development of the first detailed designs. The selected renovation measures included the insulation of the envelope via the installation of the P&P facade modules as facade insulation, the performance of roof insulation with traditional technologies, the renovation of the heating system and the installation of PV panels on the roof for the generation of renewable energy.

The design of the renovation was thought to be implemented in two stages, a first phase for the installation of the plug & play envelope system and the installation of the heating and cooling system in the second stage.

The assessment and planning process – taking place in 2020-2021 – was slowed down by the multiple lockdowns ordered due to Covid-19, and the available budget also had to be renegotiated in 2022, due to the significantly increased construction industry prices.

During summer 2022, the public procurement process for the thermal insulation of the facade and the roof could finally begin. Finally, based on the contract signed with the winning contractor in  January 2023, the work area was handed over.

After several preparatory works, the first step was to measure the location of the panel fixing brackets on the facade and then fix them. During the planning phase, the experts carried out several measurements to verify the load-bearing capacity of the walls built in the 1960s.

The prefabricated sandwich panels were made in Italy by MANNI Group and were delivered to Hungary on three trucks. Each panel weighs around 300 kg, with an average surface area of 6 m2.

Figure 2. Arrival of the P&P panels in Budapest.

The P&P modules were assembled early 2023. The assembly steps are briefly the following, and are illustrated in the following video:

  1. Assemble the anchor bracket
  2. Adjust and align the anchor brackets positioning
  3. Install the brackets to the wall
  4. Hang the module to the lifting tools through the proper linchpin
  5. Bring the P&P module to a height and install the module.
  6. Fix the module to the existing wall thanks to the brackets
  7. Adjust the position of the module thanks to the proper pin

To eliminate thermal bridges, the contractor closed the door and window junctions with additional mineral wool insulation and then with HPL plates. The windows were given uniform metal windowsills.

In addition to the usual foreman from the detailed designer – as usual for large-scale construction projects -, this time representatives MANNI Group, the company producing the thermal insulation panels, also regularly visited the work site and helped with the installation of the experimental technology with training and on-site consultations. Different members of the StepUP consortium with a diverse professional background also actively followed up the process.

Figure 3. Assembly planning meeting with StepUP consortium members (left), installation training during February 2023.

A total of 973 m2 surface was thermally insulated on the Zöld Liget Kindergarten building. The task of the construction company was complicated by several factors, such as the frequent and heavy rain, the soggy ground, and leaking issues. Due to this, the panels could not be moved with the forklifts as planned, and a special lifting structure had to be built on the roof.

It was also a challenge that the almost 100 children attending the institution could not be directed to another kindergarten, so the construction took place in an operating kindergarten. Therefore it was necessary to ensure that the working area was constantly closed from children, and their afternoon rest could not be disturbed by the works.

Figure 4. View of the current state of the building with the P&P modules installed..

This is the first phase of the renovation, which, thanks to the thermal insulation, passively contributes to the reduction of the building’s energy consumption and, of course, to the visual experience. According to calculations, the building’s heating energy demand is reduced by 32% only by the thermal insulation.

In the second phase, planned for early 2024, the entire mechanical engineering of the building will be renewed. This installation will include the renovation of the heating and cooling system for a thermal battery storing and flexibly consuming cooling or heating energy. Part of the electricity demand of the planned heat pumps will be provided by the solar panels installed on the roof.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 847053.

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