The calculations were made with the dynamic simulation program DYNBIL of the Passive House Institute. Comparisons between DYNBIL simulations and analysis of existing buildings show very good accordance.
For the thermal insulation following solutions have been analysed:
Insulation materials produced with Neopor® (expandable EPS containing infrared-absorbers) by BASF for the walls.
Styrodur® C (XPS) by BASF for perimeter and floor slab insulation.
Spray foam system or sandwich elements with Elastopor® H (polyurethane) by Elastogran for the roof insulation.
The simulation case is based on an end-of-terrace house with massive construction having two floors and a living area of 120 m2. For the simulations south of the Alps the roof is massive and the windows have shutters. North of the Alps the roof is considered to be a lightweight construction.
Building characteristics in Warsaw, Frankfurt, London and Paris.
Insulation: no insulation
Double glazing, U ≈ 2,8 W/(m²K), g ≈ 0,76
68 mm wood window profiles
Air tightness: n50 = 6 h-1 Natural ventilation (windows)
Insulation: roof 10 cm, wall 8 cm, perimeter and floor slab 4 cm
Double low–e glazing with gas filling, U ≈ 1,2 W/(m²K), g ≈ 0,53
68 mm wood window profiles
Air tightness: n50 = 4 h-1
Exhaust air plant
Insulation: roof 15 cm, wall 15 cm, perimeter and floor slab 8 cm
Double low–e glazing with gas filling, U ≈ 1,2 W/(m²K), g ≈ 0,53
68 mm wood window profiles
Air tightness: n50 = 1,5 h-1
Exhaust air plant
Insulation: roof 30 cm, wall 30 cm, perimeter and floor slab 20 cm
Triple low–e glazing with gas filling, U ≈ 0,51 W/(m²K), g ≈ 0,52
Passive house window profiles
Air tightness: n50 = 0,5 h-1
Ventilation system with 85% heat recovery
U values of the building components:
U value
roof
W/(m2K)
U value
wall
W/(m2K)
U value
floor slab
W/(m2K)
U value
perimeter
W/(m2K)
minimal
0,839
1,158
4,0
4,0
moderate
0,181
0,297
0,694
0,699
good
0,13
0,18
0,4
0,4
very good
0,07
0,098
0,19
0,19
Building characteristics in Rome and Sevilla.
Insulation: no insulation
Double glazing, U ≈ 5,7 W/(m²K), g ≈ 0,85
45 mm wood window profiles
Air tightness: n50 = 6 h-1 Natural ventilation (windows)
Insulation: roof 4 cm, wall 4 cm, perimeter 2 cm, floor slab 0 cm
Normal glazing, U ≈ 5,7 W/(m²K), g ≈ 0,85
45 mm wood window profiles
Air tightness: n50 = 4 h-1
Exhaust air system
Insulation: roof 8 cm, wall 10 cm, perimeter 4 cm, floor slab 0 cm
Double glazing, U ≈ 2,8 W/(m²K), g ≈ 0,76
68 mm wood window profiles
Air tightness: n50 = 1,5 h-1
Exhaust air system
Insulation: roof 15 cm, wall 15 cm, perimeter 6 cm, floor slab 0 cm
Double low–e glazing with gas filling, U ≈ 1,2 W/(m²K), g ≈ 0,53
68 mm wood window profiles
Air tightness: n50 = 0,5 h-1
Ventilation system with 85% heat recovery (if cooling foreseen)
U values of the building components:
U value
roof
W/(m2K)
U value
wall
W/(m2K)
U value
floor slab
W/(m2K)
U value
perimeter
W/(m2K)
minimal
1,019
1,158
4,0
4,0
moderate
0,368
0,473
4,0
1,139
good
0,224
0,251
4,0
0,699
very good
0,133
0,18
4,0
0,496
Notes to the savings and pay back time calculations
Savings after the pay back time are referred to a standard life cycle of the insulation measure (50 years).
For the development of energy prices two scenarios have been considered:
Scenario 1: moderate real price increase. Average during life cycle: heat energy 0,061 €/kWh, electricity: 0.17 €/kWh
Scenario 2: price increase 3,5% per year. Averages: heat energy 0,17 €/kWh, electricity: 0,268 €/kWh
The calculation shows only the economic effectiveness of the insulation measure. Additional costs in case of renovation (such as, e.g., scaffolding or façade painting) have not been considered since they occur anyway both in a new building and in a renovation measure.
