Case Studies

Renovation of an apartment in a multi-family build

Cholargos, Greece

Code: CS3

View from the outside
© HPHI

Original situation

A 1980s multifamily house with a treated floor area of 1500m2, a lightly insulated brick façade, 150m of balconies, a flat, uninsulated roof and a floor slab that is 2.4m above ground. The windows are double-glazed with aluminium frames that are not thermally broken. The building is quite leaky with an airtightness level of n50 = 8 ACH (as compared to 0.6 ACH for the Passive House Standard).

Renovation approach

Under construction:

At the moment, the external insulation needs and the roller blinds need to be installed. The last one out of the 3 ventilation system needs to be installed. A blowerdoor airtightness test and ventilation protocol are also in the works. The postmonitoring is being set up at the moment as well.

Modernisation proposal

EnerPHit Energy Demand Method. This means that we will achieve EnerPHit level energy demand (25 kWh/m2a) certification by insulating the entire envelope, minimsing existing themal bridges, replacing windows,  improving airtightness and installing mechanical ventilation with heat recovery.

This project will be carried out as a step by step renovation.

Efficiency improvement

Renovation will reduce the heating demand by factor of 17.5 and the cooling demand by a factor 3.5.

PHPP verification sheet before retrofit

TFA existing treated floor area (usable floor space)

140,0 m2

Space heating Heating demand

210,0 kWh/(m2a)

Heating load

93,0  W/m2

Space cooling Cooling & dehum. demand

41,0 kWh/(m2a)

Cooling load

41,0 W/m2

Frequency of overheating (> 25 °C)

– %

Frequency of excessively high humidity (> 12 g/kg)

91,0 %

Airtightness Pressurization test result n50

1,0 /h

Non-renewable Primary Energy (PE) PE demand

591,0 kWh/(m2a)

Generation of renewable energy (in relation to projected building footprint area)

352,0 kWh/(m2a)

PHPP verification sheet after retrofit

TFA existing treated floor area (usable floor space)

140,0 m2

Space heating Heating demand

12,0 kWh/(m2a)

Heating load

10,0  W/m2

Space cooling Cooling & dehum. demand

12,0 kWh/(m2a)

Cooling load

10,0 W/m2

Frequency of overheating (> 25 °C)

– %

Frequency of excessively high humidity (> 12 g/kg)

3,0 %

Airtightness Pressurization test result n50

1,0 /h

Non-renewable Primary Energy (PE) PE demand

89,0 kWh/(m2a)

Generation of renewable energy (in relation to projected building footprint area)

43,0 kWh/(m2a)

Video

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Key facts

Building typology

Multi family dwelling

Existing treated floor area (usable floor space)

140 m2

Building owner

12 owners

Consulting outphit partner

Hellenic Passive House Institute (HPHI)

Project status

Planning phase

Overall budget

38 000 €

Contact

Dimitris Pallantzas
Hellenic Passive House Institute (HPHI)
Téléphone: +30 211 4081109
E-Mail: info@eipak.org