“Electra Metropolis Hotel”. Conversion of an office building into a LEED certified hotel in Athens

Year\2024

The article was originally published on the site here.

It is the reconstruction of the building of the former Ministry of Education at 15 Mitropoleos Street, Voulis Street, Apollo and Penteli Street in Athens into a hotel. The nine-storey building was built in 1959, designed by the architect Patroclus Karantinou, to house the offices of the Ministry of Education. With the transfer of the Ministry to new premises, the building has remained closed since 2006. The reconstruction of the building involves the change of use of the existing building, which was designed for office use, and its conversion into a 5* luxury hotel with 216 fully equipped rooms and suites.
The building consists of an underground level of auxiliary and common areas (hydrotherapy centre – spa), ground floor level (lobby), mezzanine level as office space (in a part of the cover), eight floors consisting of double and triple rooms, suites and conference rooms on the second floor, restaurants, café, swimming pool on the roof, auxiliary and common areas on all levels. The building has a main entrance on Mitropoleos Street and additional exits on Voulis, Penteli and Apollonos Streets.

Strengthening of the supporting structure

The extensive structural reinforcements were applied to the load-bearing structure of the building with absolute application of the regulation on interventions in existing buildings (KAN.EPE), ensuring a level of seismic safety equivalent to that of new buildings and significantly increasing the remaining life of the building. At the same time, all the antiquities found during the execution of the works, which were not reflected in the archaeological reports of the time when the existing building was constructed, were integrated and highlighted in the best possible way, in accordance with the recommendations of the Archaeological Service and the services of the Ministry of Culture. The reconstruction of the building was carried out with full respect for the small royal church of St. Dynamis, which will be immediately restored and restored.

LEED environmental certification criteria

The specifications of the construction materials, its energy study and its operation, as well as its excellent access to public transport, contribute in the best possible way to the comfort of the guest and the achievement of very good environmental performance, resulting in the hotel receiving the LEED (Leadership for Energy and Environmental Design) environmental certification of the US Green Building Council and becoming the first hotel in our country with this international environmental recognition.
Within the framework of the LEED requirements, the energy performance of the building was studied using the energy model simulation method. The energy savings achieved by the building is of 24% (especially for air conditioning or cooling showed an improvement of 35% and for heating 75%) compared to a corresponding conventional building in which no upgraded operating and insulation systems have been used, and this was achieved by using active measures such as: heat recovery from air conditioning for domestic hot water, the simultaneous use of air conditioning for cooling and heating in the intermediate seasons, the use of inverters in pumps, circulators and ventilators and the use of light emitting diodes (LEDs) for all lamps and light strips.

Also, the use of the building as a hotel had the advantage of using digital controllers and a central building management system (BMS), which also helped to save energy. Regarding the shell, the building has double-glazed windows with sound-proofing and low-e technology and an external thermal insulation system with an average thickness of 8 cm was applied to the entire superstructure.
The LEED certification required the implementation of other environmental measures related to the saving in water consumption through appropriate types of percussion and irrigation, the use of local materials (marble, plasterboard, steel, cement, etc.) and the indirect contribution to the reduction of CO2 emissions through the proximity of the building to a multitude of public transport, the availability of bicycle parking spaces and its location in a high density area.