CS15 Single family home, Tournon sur Rhône

Current status: 
Building Owner: 
Family André
Consulting EuroPHit Partner: 

LaMP - Contact person Simon Camal

Existing treated floor area (usable floor space): 
155.00 m²
Original situation: 

The building, erected in 1985, follows the terrain slope with stepwise floors in contact with a non-heated basement. The existing walls are made of concrete hollow bricks with a 6 cm interior insulation of extruded polystyrene (XPS). The slabs are based on a concrete beam and block structure, partially interior insulated by a 6 cm XPS layer where an electric floor heating system has been installed. The roofs are made of a traditional wooden frame, partially insulated with mineral wool and XPS.

Airtightness is poor as accounted by the owners. Windows are composed of double glazing 4-6-4 without filling gas and 48 mm wooden frames not insulated.

A Mechanical Ventilation with Heat Recovery has been installed in the 80’s, but is not functioning anymore and shall be replaced.

Heating demand is covered by the afore-mentioned electric floor heating plus a wood stove. Domestic Hot Water demand is covered by an electric storage hot water heater of 300 L.

Electricity meter indicates an average yearly consumption of 17 000 kWh.

The key challenge here is to reach the EnerPHit standard, given the scarce solar resource in winter and the various complex eave situations for airtightness.

Modernisation proposal: 

The expected optimization procedure for diminishing the heating demand aims at the performance of the following building envelope elements:

Step 1 :

- Insulation and airtightness of staircase basement walls and slab, including passive house quality door to access unheated basement.

Thermal bridge at staircase slab is minimized by injecting PU foam into first range of concrete hollow blocks.

- Projected insulation on slabs over basement to reach a U-value of 0.16 W/(m.K)

Step 2 :

- Rooftop sarking insulation to reach a U-value of 0,10 W/(m².K)

- MVHR with a minimum 88% effective heat recovery assessed following Passivhaus Institut method.

Step 3 :

- airtightness layer on existing wall render + Exterior insulation of walls to reach a U-value of 0,12 W/(m².K)

- Passive house quality (phA) windows

Step 4 :

- Renewal of electric hot water storage tank

- Install PV panels on south roof, 8 kWp


Efficiency improvement: 
PHPP verification sheet before retrofit: 
after retrofit: 
Current situation: 

Basement staircase refurbished.Offers received for roof retrofit, the owner looks for an optimal balance between performance and cost.

Challenges of the project: 
The main challenge here is to deal with protruding roof wooden beams penetrating the airtightness layer of the wall. A wooden balcony will also have to be modified due to the ETICS applied on the wall. Another challenge was to find an easy solution for the retrofit of the basement, given geometrical constraints.
Construction photos (click to view gallery): 
07300 Tournon