1. Click to edit Master title style Estonian cost optimal calculation and implementation in the code 14.03.2013 CA-EPBD III Madrid Jarek Kurnitski Professor, Tallinn University of Technology Vice-president REHVA jarek.kurnitski@ttu.ee www.nzeb.ee

2. Presentation outline Estonian cost optimal calculations: conducted as a financial calculation in 2011 Implementation into building code: cost optimal energy performance minimum reqs. for new buildings and major renovations apply from Jan 9, 2013

3. Federation of European Heating, Ventilation and Air-conditioning Associations Situation with energy frames In most of countries, on site renewable energy production is subtracted from delivered energy (must for Cost Optimal) Differences in energy frames: –primary energy not yet used in all countries (must for Cost Optimal) –Some countries (Germany, France) use reference building method, fixed values in other countries –Both simulation (Estonia, Finland) and monthly methods (Germany, Denmark) used Inclusion of energy flows depends on country: –Germany/residential – heating energy only (space heating, DHW and heating of ventilation air) –Germany/non-residential – cooling and lighting also included (appliances not) –Denmark – appliances and in residential also lighting not included –Sweden – appliances and user’s lighting not included (facility lighting incl.) –Estonia, Finland, Norway – appliances and lighting included (all inclusive)

4. Federation of European Heating, Ventilation and Air-conditioning Associations Energy frames, exported energy Exported electricity can be taken into account on annual basis (full utilization), monthly bases (limited to the amount of the delivered electricity each month and the rest of exported is not accounted) or is not taken into account Full utilization (annual bases) (must for Cost Optimal?): –Denmark, Estonia, net plus energy program in Germany Monthly bases: –Germany, Sweden? (not decided) Not accounted –Finland, Norway, Italy Most of energy frames not yet ready to support exported energy

5. Estonian Cost Optimal: Seven step systematic procedure (Kurnitski et al. Energy and Buildings 43 (2011) 1.selection of the reference building/buildings 2.definition of construction concepts based on building envelope optimization for fixed specific heat loss levels (from business as usual construction to highly insulated building envelope in 4 steps) 3.specification of building technical systems 4.energy calculations for specified construction concepts 5.post processing of energy results to calculate delivered, exported and primary energy 6.economic calculations for construction cost and net present value of operating cost 7.sensitivity analyses (discount rate, escalation of energy prices and other parameters) All this steps are independent, iterative approach not needed for residential buildings, because of the specific heat loss method used Worked well for residential, non-residential buildings less predictable

6. Reference buildings – proposed by the society of Estonian architects, 3 out of 6 buildings shown 9.11.20 11 Jarek Kurnitski

7. Pre-optimized building envelope The specific heat loss coefficient includes transmission and infiltration losses through the building envelope and is calculated per heated net floor area:

9. Energy simulations Results of the detached house as a function of insulation level (construction concepts) and heat source From left to right from passive house building envelope to BAU

10. Energy cost data used (2011 data) Electricity 0.0983 €/kWh + VAT (20%) Natural gas0.0395 €/kWh + VAT (20%) (consumption over 750 m 3 /year) Pellet0.033 €/kWh + VAT (20%) Heating oil0.0717 €/kWh + VAT (20%) District heating0.0569 €/kWh + VAT (20%) (Tallinn, natural gas boiler) Escalation 2% (in base case) Discount rate 3% (in base case) In sensitivity analyses:  Escalation 3% and discount rate 3%  Escalation 1% and discount rate 3%

11. Incremental cost calculation Construction cost calculation for energy performance related works and components included:  thermal insulation  windows  air handling units (without ductwork)  heat supply solutions (boilers, heat pumps etc.) Labour costs, material costs, overheads, the share of project management and design costs, connection fees, and VAT were included in the energy performance related construction cost Global energy performance related cost was calculated as a sum of the energy performance related construction cost and discounted energy costs for 30/20 years (res./non-res.), including all electrical and heating energy use As the total construction cost was not calculated, the global incremental cost was used (relative to the business as usual construction):

12. Global incremental cost calculation: “Gas boiler” cases The global cost included, first divided by net heated floor area of 171 m 2 The values of the reference building (DH 0.96) subtracted

13. Example of cost optimal: Estonian detached house 3% discount rate and 2% escalation (Kurnitski et al. Energy and Buildings 43 (2011)) AWHP – air to water heat pump, GSHP – ground source heat pump, DH – district heating W/o PV, 4 insulation levels from left to right: 0,42, 0,58, 0,76 ja 0,96 specific heat loss H/A H/A 0,42 ja 0,58 are calculated with solar collectors nZEB +239 €/m 2 construction cost (PE = 40 ), W/o PV +93 €/m 2 (PE = 80) nZEB Cost optimal Min.req.

14. Results without solar collectors With or w/o solar collectors? Calculate both with and without solar collectors! Cost optimality depended on energy source: with reasonably cheap gas, it was optimal to increase the insulation thickness by one step instead of solar collectors

15. Breakdown of the global cost components Extra global cost < extra investment cost Extra global cost is less than extra investment cost, because of reduced energy use Improvement from DH 0.76 to DH 0.42 means extra investment cost of 15 943 € corresponding to 6757 € NPV in GSHP case

16. Apartment building

17. Apartment building 3% discount rate and 2% escalation

18. Office building

19. Office building 3% discount rate and 2% escalation

20. Distance from cost optimal to nZEB Investments needed for nZEB in the reference detached house: +16 000 € investment in GSHP case led to 75 kWh/(m 2 a) primary energy + 5 kW solar PV installation with about 25 000 € investment (2011 data) Results in about nZEB=40 kWh/(m 2 a) primary energy Distance to nZEB the reference detached house : 41 000 € extra construction cost 239 €/m 2 extra construction cost – (2011 data) (W/o PV +93 €/m 2 ) In the reference apartment and office buildings: 80-90 €/m 2 extra construction cost (2011 data)

21. Cost optimal solutions – main principles Building envelope: -External wall U=0.14…0.17 (small/large building) -Window U=0.8 -Roof and external floor U=0.09…0.14 Technical systems: -Specific fan power of ventilation SFP=1.7…2.0 -Heat recovery  80% (possible also with exhaust air heat pump/ventilation radiators) -Lighting <12 W/m 2 -Hydronic heating (electrical not possible) -Free cooling loop in the cooling system Architectural preconditions: -Reasonable compactness -Solar shading -Controlled window to wall ratio (“glass building” needs double skin)

22. Implementation into the regulation Energy frame based on primary energy Exported energy in the energy frame Lighting&Appliances included, i.e. calculated ≈ measured Dynamic simulation required for non-residential Implementation was possible by just adjusting primary energy requirements, given for 9 building types Primary energy reqs. improved by about 20-40% depending on building type and energy source (some adjustments in the standard use of buildings and PE factor of electricity) Safety margin of 10 to 15% was generally applied to cost optimal primary energy Cost optimal regulation in force since Jan 9, 2013 both for new buildings and major renovation

23. Estonian system boundaries

24. Federation of European Heating, Ventilation and Air-conditioning Associations REHVA system boundaries

25. Estonian regulation VV No 68: 2012 implemented nZEB and cost optimal Primary energy requirements for 9 building types (apply from Jan 9, 2013) nZEB and low energy requirements officially given together with cost optimal minimum reqs (not yet mandatory) Conversion factors: –Electricity 2.0 –Fossil fuels 1.0 –District heat 0.9 –Renewable fuels 0.75

26. Estonian regulation VV No 68: 2012 – Minimum requirements for energy performance MKM No 63: 2012 – Energy calculation methodology Compliance assessment:  For all buildings equipped with cooling, energy performance calculation shall be based on dynamic building simulation  Requirements are specified for simulation tools, which refer to relevant European, ISO, ASHRAE or CIBSE standards, IEA BESTEST or other equivalent generally accepted method.  For residential buildings without cooling, monthly energy calculation methods may be also used.  An exception is for detached houses, which have an alternative compliance assessment method based on tabulated specific heat loss values Summer thermal comfort:  If no cooling installed, a dynamic temperature simulation in critical rooms required in order to comply with summer temperature requirements (25°C + 100 °Ch in non-residential and 27°C + 150 °Ch in residential buildings during three summer months simulated with TRY)  An exception is for detached house, there the compliance may be alternatively shown with tabulated values for solar protection, window sizes and window airing

27. How to compare min. requirements? Detached house (1/2013 data) Recalculation from primary energy to delivered energy needed, which can be compared in all countries 150 m 2 detached house considered Degree-day correction (base 17°C) to Copenhagen, energy use for hot water heating 25 kWh/(m 2 a) The figure shows maximum allowed delivered energy without household electricity (i.e. delivered energy to heating, hot water and ventilation systems) in each country for fossil fuel or electrical heating

28. Apartment and office buildings with district heating (1/2013 data) Maximum allowed delivered energy for heating, hot water and ventilation systems in apartment buildings and for office buildings (lighting included) with district heating