Case Studies
The Vauxhall, a semi prefabricated EnerPHit
Bagnères de Bigorre, France
Code: CS7
Original situation
A four storey non-residential building from the 1830s located in the dense city centre of Bagnères de Bigorre in the Pyrenean piedmont (FR-65000).
Originally built as a maison, the building was separated into 5 flats and now, after renovation, it will be used as a hotel.
Renovation approach
Just finished checking structural integrity in preparation for the retrofit; likely finsihed in 2024, started in 2022.
Modernisation proposal
Semi prefabricated complete retrofit to the EnerPHit Standard. The front side will be a traditional retrofit, since the building is listed, with vacuum insulation on the inside of the wall. The back side will be a prefabricated, compressed straw wall (Ecococon Wall). The bottom is being dug out from the inside of the building for a depth of 50cm. The soil will be subsequently replaced with foamglas. New triple glazed windows, heat pumps and ventilation with heat recovery will be added. Also collecting 50% of the heat from grey water.
Efficiency improvement
The planned renovation will bring heating demand down by a factor of more than 20 and also result in an impressive reduction in total primary energy.
PHPP verification sheet before retrofit
| TFA | existing treated floor area (usable floor space) |
250.0 m2 |
|---|---|---|
| Space heating | Heating demand |
354.0 kWh/(m2a) |
| Heating load |
114.0 W/m2 |
|
| Space cooling | Cooling & dehum. demand |
0.0 kWh/(m2a) |
| Cooling load |
0.0 W/m2 |
|
| Frequency of overheating (> 25 °C) |
0.0 % |
|
| Frequency of excessively high humidity (> 12 g/kg) |
1.0 % |
|
| Airtightness | Pressurization test result n50 |
1.0 /h |
| Non-renewable Primary Energy (PE) | PE demand |
455.0 kWh/(m2a) |
| Primary Energy Renewable (PER) | PER demand |
881.0 kWh/(m2a) |
| Generation of renewable energy (in relation to projected building footprint area) |
– kWh/(m2a) |
|
| EnerPHit classic |
no |
PHPP verification sheet after retrofit
| TFA | existing treated floor area (usable floor space) |
250.0 m2 |
|---|---|---|
| Space heating | Heating demand |
15.0 kWh/(m2a) |
| Heating load |
8.0 W/m2 |
|
| Space cooling | Cooling & dehum. demand |
0.0 kWh/(m2a) |
| Cooling load |
0.0 W/m2 |
|
| Frequency of overheating (> 25 °C) |
10.0 % |
|
| Frequency of excessively high humidity (> 12 g/kg) |
5.0 % |
|
| Airtightness | Pressurization test result n50 |
1.0 /h |
| Non-renewable Primary Energy (PE) | PE demand |
26.0 kWh/(m2a) |
| Primary Energy Renewable (PER) | PER demand |
12.0 kWh/(m2a) |
| Generation of renewable energy (in relation to projected building footprint area) |
– kWh/(m2a) |
|
| EnerPHit classic |
no |
Key facts
Building typology
Multi family dwelling
Existing treated floor area (usable floor space)
250 m2
Building owner
Adourable Bagnères SARL
Consulting outphit partner
PROPASSIF
Project status
Construction phase
Overall budget
400 000 €
Contact
Etienne Vekemans
CEO
PROPASSIF
Phone: 0145081335
E-Mail: e.vekemans@propassif.fr