OP20 - House in St Cyr au Mont d'Or

Current status: 
Building Owner: 
Single Family House
Consulting EuroPHit Partner: 

LaMP - Contact person Simon Camal

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

House of 1978 built in cast concrete with interior insulation. Exterior cement render in good state, no craks and leaks, effective as an airtight layer.

Windows with wooden casement and double glazing installed in the insulation layer, with poor energy efficiency.

Partially insulated concrete slab with 60 mm XPS.

Existing 300 mm insulation in unheated attic.

Supply air mechanical unit with convective electric heaters at diffusion terminals.

20 kW installed heating power.

Estimated heating demand with PHPP 110 kWh/(m².a)

Estimated total non renewable primary energy consumption 165 kWh/(m².a)


Modernisation proposal: 

Perimeter insulation 160 mm XPS 0.036 W/m.K buried to the foundation level.

Exterior insulation glued and fixed to the wall via dowels 200 m EPS 0.032 W/m.K. No special works on existing render needed.

Wood/alu Smartwin windows installed on the outer edge of the wall, joining the existing interior insulation layer with complementary interior insulation.

Existing shutterbox filled with mineral insulation and treated with airtightness membrane.

Airtightness membrane under ceiling, fixed with adapted scotch to internal and external walls.

Integration of ventilation unit with heat recovery in the garage, reusing the existing supply air ducts and inserting exhaust ducts with careful penetrations of the airtight layer in the ceiling.

Installation of a wood log stove on the first floor.

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

1st Step completed : Envelope as EnerPHit quality, ventilation with heat recovery, wood stove.

2nd Step foreseen : replace the existing electric domestic hot water supply with an efficient storage tank with solar thermal panels.

Estimated heating demand after 1st step : 25 kWh/(m².a)

Estimated primary energy consumption after 1st step : 119 kWh/(m².a)

Architect : Atelier de Montrottier Loïc Parmentier & Associés

Energy engineering : Bureau d'études Pollet Ingénierie

Construction photos (click to view gallery): 
ETICS and shutter box
Photos by Pollet Ingénierie
Connection details and thermal performance of the building (click to view gallery): 
Detail Slab-Wall
Other downloadable materials: 
69450 St Cyr Au Mont d'Or