Experience from Best Practice – With a Focus on Renovation Norwegian Best Practice – Poland, February 2015 Experience from Best Practice – With a Focus on Renovation 2006 2011 Michael Klinski, Research Scientist, Architect

SINTEF Byggforsk/ Building and Infrastructure

Norway: Mild coast and cold inland Oslo Bergen

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

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

Pilot project „NorONE“ Passive House Wood fibreboards 35 mm Cellulose insulation 241 mm OSB 15 mm Cellulose insulation 140 mm Completed 2008 Wall/window

NorONE: Energy use 2008-2011 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

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

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

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 2011-2012: No indications for increased mold potential

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

7 apartment blocks – Myhrerenga First renovation with Passive House components 2011 168 flats, built 1968-70, 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

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

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

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)

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

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

… 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

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

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)

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