Case Studies

Résidence Colbert

Colombes, France

Code: OP08

© Avant

© Aprés + Vekemans

© Aprés + Vekemans


1970 built residential uilding in the dense centre of Colombes, a western suburb of Paris.

Original situation

The retrofitting process started in 2013, and the project consists of three buildings using the same construction methods (A: 2529 m², B: 1523 m², C: 1768 m²). All three buildings were retroffitted together. The buildings were using approximately 250 kWh/m² of oil heating.

Renovation approach

The main retrofit steps were finished in 2020 after a 2-year delay. Some finishing touches are still being undertaken in 2022, but now in 2023 the project is completely finished and the residents are in.

Renovation approach document

Modernisation proposal

Global prefabricated retrofit set to reach the EnerPHit standard. The facade uses the "Panobloc" pre-fab facade system.

Efficiency improvement

After the renovation measures, this social housing made of 3 buildings in total, saved approx. 700 tonnes CO² annually and used wood pellet heating.


PHPP verification sheet after retrofit

TFA existing treated floor area (usable floor space)

5820.0 m2

Space heating Heating demand

20.0 kWh/(m2a)

Heating load

12.0  W/m2

Space cooling Cooling & dehum. demand

0.0 kWh/(m2a)

Cooling load

0.0 W/m2

Frequency of overheating (> 25 °C)

8.0 %

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

0.0 %

Airtightness Pressurization test result n50

0.6 /h

Non-renewable Primary Energy (PE) PE demand

117.0 kWh/(m2a)

Primary Energy Renewable (PER) PER demand

152.0 kWh/(m2a)

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

– kWh/(m2a)

EnerPHit classic


Key facts

Building typology

Urban settlement | housing colony

Existing treated floor area (usable floor space)

5820 m2

Building owner


Consulting outphit partner


Project status



Etienne Vekemans
Phone: 0145081335