16.05.2011
We Build Local Communities One of Norway s leading concerns in entrepreneuring and property development 1.000 employees Revenue appr. 2,3 billion NOK in 2010 Earnings before tax appr. 90 mill NOK Development and construction of commercial and private property 11 companies from Trondheim and further south Equity appr. 500 mill. NOK Owned by the Backe family 2
Company Structure 3
Market Area BERGEN Backer Entreprenør ELVERUM Martin M. Bakken BAS Maskinutleie GJØVIK Miljøbygg BAS Maskinutleie RUDSHØGDA Mjøsen Murmesterforretning KLØFTA Agathon Borgen OSLO AS Backe Ing. Gunnar M. Backe Backe Entreprenør Backe Eiendom LINDEBERG BAS Maskinutleie KONGSBERG Bøhmer Entreprenør REVETAL VåleBygg HOF BAS Maskinutleie SKIEN Buer Entreprenør GRÅLUM BAS Maskinutleie FREDRIKSTAD Backe Østfold SANDNES Backe Bygg TRONDHEIM Aasen Bygg 4
Myhrerenga Housing Cooperative. Norway s first Rehabilitation of Apartment Buildings to Passive House Standard Det første blokkprosjektet i Norge som rehabiliteres til passivhusstandard. Mål om 90% reduksjon av oppvarmingskostnader! 5
Myhrerenga before Rehabilitation 168 apartments in 7 houses Built in 1968-1970 Bad indoor air quality, draft, cold floors Exhaust ventilation Annual energy consumption 275kWh/m2 6
Myhrerenga before Rehabilitation Cracks, damages Thermal damages!!! Thermal insulation in walls and roofs 5-10 cm Great need of rehabilitation 7
Choice of Solution The cost of a traditional rehabilitation of the facade was estimated to appr. 35 million NOK, a rehabilitation to passive house standard would cost about 70 million NOK. SINTEF Byggforsk calculated that rehabilitation to passive house standard would be cheaper when considering the cost of heating Passive house rehabilitation was chosen. 8
Contributors in the Process Project Management: Architect: Consultant engineering: Consultant HVAC and plumbing: General contractor: Boligbyggelaget Usbl Arkitektskap AS Norconsult, SINTEF Byggforsk Norconsult, SINTEF Byggforsk Agathon Borgen AS 9
Cost Estimate Passive House Rehabiliation : Monthly Costs in NOK 1bedr. apart. 2-bedr. Apart. Fixed costs (maintenance, taxes, CE, etc)* 1290 1560 Energy costs (heating and electricity)** 370 470 Borrowing costs (interest rate, installments)*** 1760 2250 Total montly costs 3420 4280 Tax credit (loan interest rate)**** 230 290 Net monthly costs incl. tax credit 3190 3990 Traditional Facade Rehabilitation: Monthly Costs in NOK 1 bedr. apart. 2 bedr. apart Fixed costs (maintenance, taxes, CE, etc)* 1290 1560 Energy costs (heating and electricity)** 890 1130 Borrowing costs (interest rate, installments)*** 1560 1990 Total monthly costs 3740 4680 Tax credit (loan interest rate)**** 230 290 Net monthly costs incl. tax credit 3510 4390 10
Measures taken: Additional insulation in all facades and roofs The building is made airtight New windows and doors with very low U-value Balanced ventilation that reuses heat Solar thermal collectors and heat pumps are installed New and effective convector radiators 11
Walls and Windows 12
Window Window is mounted with brackets on OSB All joints are taped 13
Wall with Rockwool Flex System Flex is technically approved for outdoor use without exterior wind barrier Requires accurate mounting 14
Roof Insulation was blown into the wooden roof Moisture damages? 15
Airtightness became a challenge Measured airtightness in the whole building: 0,7!! Big amounts of tape 16
Balanced ventilation Separate systems in each stairwell Uses old garbage shaft as air duct Recycles heat with effect of 80 % SFP = 1,5 17
Simple air duct construction Involves little construction work indoors 18
Renewable energy 3 heat pumps 44 vacuum solar thermal collectors on the roof 19
Challenges Airtightness Cold weather 25 days per building without central heating One entire outdoor wall and balconies had to be replaced, also in minus 20 degrees!! Unsimilar interior in apartments as suspended ceiling Planned solutions had to be altered 20
Reasons for success in the contrcution process Details well planned before startup Construction inside the apartments planned in detail. Limit the time inside the apartments. STICK WITH THE PLAN! Good information given to residents early. Residents will accept much when informed. Tidy workers!!!!! Good and safe access to site 21
End result From 275 kwh/m2 to appr. 90 kwh/m2 22