1. Experience from Best Practice – With a Focus on Renovation
Norwegian Best Practice – Poland, February 2015
Experience from Best Practice – With a Focus on Renovation
Michael Klinski, Research Scientist, Architect

2. SINTEF Byggforsk/ Building and Infrastructure

3. Norway: Mild coast and cold inland
Oslo
Bergen

4. Large spatial and topographical difference
Climate change will increase impact and challenges
Needed: More directed requirements, Increased holistic and interdisciplinary approaches
Energy requirements were always stronger than in Central Europe >>> More experience!
Step by step tightening announced

5. Passive measures first!
… and materials! - ZEB
Passive Active

6. Pilot project „NorONE“ Passive House
Wood fibreboards 35 mm
Cellulose insulation mm
OSB 15 mm
Cellulose insulation mm
Completed 2008
Wall/window

7. NorONE: Energy use
Energy gains by solar collectors and grey water heat exchanger continuously increasing over the years, but
Heat pump works not efficiently (remaining heat demand very low)
Too many active components to be cost-efficient and controllable
Electricity and space heating energy consumption continuously decreasing over the years
Space heating consumption only a bit higher than calculated
Higher room temperatures; open bedroom window in the annex
Bathroom floor heating switched on longer than needed

8. Pilot project Løvåshagen, PH and LE
52 low energy and 28 Passive House dwellings, 2008
Overall energy demand in PH block not as low as calculated
Probable cause: Failure in active components (water based heating, solar collectors)
Detailed monitoring ongoing
Good score in dweller survey

9. Two similar dwellings as PH and LE
2 nearly identical structures, same building envelope
Building B: natural ventilation
2011/12 additional energy consumption: 24 kWh/m²
Corresponds to additional heat losses due to natural ventilation
Building A: Genuine Passive House with balanced ventilation and high efficient heat recovery
Better air quality, more consistent indoor air temperature
Occupants tend to be more satisfied
Indications to assume that one radiator per story + bath room floor heating may be not sufficient in all situations

10. Passive House school in Drammen
1. PH school, completed 2010
Load-bearing concrete structure + timber frame panel walls
Moisture and temperature measuring at crucial positions :
No indications for increased mold potential

11. Existing building stock
But: No fundamental energy saving without existing buildings
New
Existing building stock

12. 7 apartment blocks – Myhrerenga
First renovation with Passive House components 2011
168 flats, built , façade renovation needed
Added insulation in cellar ceiling, walls and roof
Increased air tightness and reduction of thermal bridges
Passive House windows and doors
Highly efficient balanced ventilation
Upgraded boiler house connected to air to water heat pumps and solar collectors
Reuse of existing heat distribution system

13. PH-window and vapor permeable wall
Existing construction
OSB-boards and 20 cm unbroken insulation on the existing 10 cm stud wall
+ new facade lining
Air tightness: adhesive tape
Arkitektskap AS

14. Roof and balcony Insulation blown in Air tightness measures:
Air tightening OSB – frame and between stories
Roof and balcony
Existing construction

15. Energy supply
Only one radiator in the living room (1-1,5 kW) + existing radiator in the bathroom
4 air-to-water heat pumps
Cover 60 % of the heat demand
44 vacuum solar collectors on the nearest block roof
Cover 10 % of the heat demand
1 electric boiler kept (peak load)
Reuse of existing heat distribution system
Individual energy accounting (heat and electricity)

16. Calculated energy demand
Energy Demand [kWh/m²a]
Before renovation (measured)* delivered e.
After renovation** (simulated)
Net energy demand
Delivered energy
Space Heating
195 – 220 25 15
DHW 30
Fans and pumps 10
Electricity use (lighting and appliances) 40
Sum
275 – 300
105 80
- 88 %
- 72 %
* Varying from year to year
** To be measured after renovation

17. Increased investment cost for PH-retrofit, in addition to façade renovation – but ...
Project cost million NOK
Cost NOK/m²
Cost EUR/m²
Overall construction cost
70.0
6430
800
Design + construction supervision
4.5
410 50
Overall investment cost PH-retrofit
74.5
6840
850
Conventional façade renovation
53.8
4940
615
Gross additional cost PH-retrofit
(38 %) 20.7
1900
235
Allowances from Enova
6.4
590 75
Net additional cost PH-retrofit
(26 %) 14.3
1310
160
Included larger balconies, new drainage and VAT

18. … lower cost per month ...
Total monthly cost (capital, energy, association fees)
One-bedroom apartment
Two-bedroom apartment
Total monthly cost conventional façade renovation [NOK]
3510
4390
Total monthly cost Passive House retrofit [NOK]
3190
3990
Savings NOK/month
320
400
Savings EUR/month 40 50
PH-retrofit without allowances [NOK]
3330
4160
Without allowances + ordinary bank loan
3490
4380
4,7 % interest rate for PH-retrofit (Norwegian State Housing Bank), 5,7 % for façade renovation (ordinary bank), 30 years, energy price 0,1 Euro/kWh 18

19. Myhrerenga in practice
From very leaky to very airtight
Air change rate 0.64 was reached
Residents are satisfied with the results and proud of the new appearance
Good air quality, low need for heating, but:
Technical installations did not work optimally

20. Myhrerenga: Final heat energy, week 1-48 2012
Nearly as calculated
Unexpected summer consumption
Problems with solar collectors and heat pumps?
Additional consumption due to bath floor heating?
Metered Calculated* Ø Outdoor temperature (* temp.adjusted)

21. Conclusion
Passive solutions are a robust basis for zero energy, plus energy or zero emission buildings
Good experience in Norway
Ambitious concept with optimal building envelope works in practice
Technical installations: Adjustment is essential and often required once again after some time in operation >>> better planning and execution is required
Acceptable additional cost for ambitious level
New buildings: Difference between current requirements and PH is less than in other countries
Existing buildings: Funding of basic major renovation is crucial