ENV-2D02 ENV-2D02 Energy Energy

ConservationConservation

Building RegulationsBuilding Regulations

Jane Powell (JC)

j.c.powell@uea.ac.uk

What is energy conservation?What is energy conservation?

Supply and DemandSupply and Demand SupplySupply

More efficient productionMore efficient production• CHPCHP

Changing demandChanging demand More appropriate useMore appropriate use

• Fuel switchingFuel switching Use lessUse less

• Demand managementDemand management

• Reduce heat lossReduce heat loss

• Low energy appliancesLow energy appliances

• Behavioural changeBehavioural change

Why is energy conservation important?Why is energy conservation important?

Climate changeClimate change Limits to fossil fuelsLimits to fossil fuels SecuritySecurity Risks Risks Threat to our current way of life Threat to our current way of life Fuel povertyFuel poverty

2030 (EU)

Based on present trends

90% imported oil

80% imported gas

3 million UK households

Observed and simulated change:Observed and simulated change:natural and man-made factorsnatural and man-made factors

Tem

per

atu

re c

han

ge

ºC

1.0

0.5

0.0

-0.51850 1900 1950 2000

observed

model simulation

+

+

Source: Hadley Centre

UK targetsUK targets

Kyoto targetsKyoto targets GHG 12.5% below 1990 levels 2008-2012GHG 12.5% below 1990 levels 2008-2012

• 2002 14.4%; 2003 13.4%; 2004 12.6%2002 14.4%; 2003 13.4%; 2004 12.6%

UK CO2 TargetsUK CO2 Targets• Previous target: 20% below 1990 levels by 2010Previous target: 20% below 1990 levels by 2010

• New target: 60% below 1990 levels by 2050New target: 60% below 1990 levels by 2050

• 50% 2010 target can be achieved by energy efficiency measures50% 2010 target can be achieved by energy efficiency measures

RenewablesRenewables 10% electricity generated by 201010% electricity generated by 2010

• 3.5% 20043.5% 2004

Reduce heat loss & behavioural changeReduce heat loss & behavioural change

Of who?Of who? OccupantsOccupants Developers, planners, Developers, planners,

architectsarchitects

What method?What method? IncentivesIncentives

• SubsidiesSubsidies• Economic instrumentsEconomic instruments

Voluntary initiativesVoluntary initiatives RegulationsRegulations

The Energy Performance of Buildings Directive (EPBD) The Energy Performance of Buildings Directive (EPBD) 2002/91/EC2002/91/EC

40% of final energy consumption in the EC is 40% of final energy consumption in the EC is in the buildings sector. in the buildings sector.

Improving energy efficiency, carbon emissionsImproving energy efficiency, carbon emissions from buildings could be reduced by 22%.from buildings could be reduced by 22%.

Objectives of the Directive:Objectives of the Directive: To promote the improvement of the energy performance of buildings To promote the improvement of the energy performance of buildings

within the EU through cost effective measures; within the EU through cost effective measures; To promote the convergence of building standards towards those of To promote the convergence of building standards towards those of

Member States which already have ambitious levels. Member States which already have ambitious levels.

Measures include:Measures include: Methodology for calculating the energy performance of buildings; Methodology for calculating the energy performance of buildings; Application of performance standards on new and existing buildings; Application of performance standards on new and existing buildings; Certification schemes for all buildings; Certification schemes for all buildings; Regular inspection and assessment of boilers/heating and cooling Regular inspection and assessment of boilers/heating and cooling

installations. installations. Must be implemented by 4 Jan 2006

UK ResponseUK ResponsePart L Building Regulations (2005)Part L Building Regulations (2005)

Comes into force in England and Wales on 6 April Comes into force in England and Wales on 6 April 2006 (Scotland & Ireland to follow)2006 (Scotland & Ireland to follow)

Office of the Deputy Prime Minister (ODPMOffice of the Deputy Prime Minister (ODPM)) Complies with EU legislationComplies with EU legislation Move away from energy conservation to carbon Move away from energy conservation to carbon

emission reductionemission reduction UK National Calculation Methodology (NCM) for UK National Calculation Methodology (NCM) for

energy performance of buildingsenergy performance of buildings

Deficiencies in earlier Building RegulationsDeficiencies in earlier Building Regulations

Before 1994 if double glazing was used Before 1994 if double glazing was used window area could be doubledwindow area could be doubled requirements for walls/roof/floor could be relaxedrequirements for walls/roof/floor could be relaxed if overall loss < = standard house (type 1 trade off)if overall loss < = standard house (type 1 trade off)

From 1995From 1995 Could include incidental gains from appliance use/solar gainsCould include incidental gains from appliance use/solar gains If consumption <= standard house - regulations could be relaxed If consumption <= standard house - regulations could be relaxed

furtherfurther 1994 & 2000 regulations1994 & 2000 regulations

If triple glazing used window area can be increased by 50% (type 2 If triple glazing used window area can be increased by 50% (type 2 trade off)trade off)

If higher insulations for walls used, greater window area permitted If higher insulations for walls used, greater window area permitted provided <= standard house.provided <= standard house.

Traditionally framed for minimum compliance rather than actively Traditionally framed for minimum compliance rather than actively promoting energy conservationpromoting energy conservation

Less so by 2000 RegsLess so by 2000 Regs 2005 Regs tightened further2005 Regs tightened further

Comparison of energy consumption for a standard detached house at various ages and improvements (Heat losses in W0C-1)

0

100

200

300

400

500

600

700

800

pre-w ar post-w ar 1960s 1976 1985 1990 1994 2000

unimproved

25mm

50mm

100mm

100+CAV

100+DG

100+DG+CAV

150+DG

200+TG+CAV

250+DG

Effects of built form on energy consumption Effects of built form on energy consumption (Heat (Heat loss Wloss WooCC-1-1))

0

100

200

300

400

500

600

2002

1976

1994 Regulations1994 Regulations Single glazing could no longer be used routinely for domestic Single glazing could no longer be used routinely for domestic

buildingsbuildings Glazed area 22.5% of floor areaGlazed area 22.5% of floor area

50% greater than 1990 regs50% greater than 1990 regs 50% potential saving lost50% potential saving lost

Standard Assessment Procedure Standard Assessment Procedure (SAP) rating for new buildings(SAP) rating for new buildings

0-100 – higher the better0-100 – higher the better No target SAP but requirements relaxed if >60No target SAP but requirements relaxed if >60 SAP 80-84 – Regs automatically satisfiedSAP 80-84 – Regs automatically satisfied Includes energy running costs in calculationIncludes energy running costs in calculation Trade offs permittedTrade offs permitted

Does not specify ventilation rates but advise on estimatingDoes not specify ventilation rates but advise on estimating Make allowance for solar water heatingMake allowance for solar water heating Include hot water requirementsInclude hot water requirements

Building Regulations 2000Building Regulations 2000

Current regulations - implemented April 2002Current regulations - implemented April 2002 Energy rating methodEnergy rating method

SAP replaced by Carbon Index method for complianceSAP replaced by Carbon Index method for compliance SAP ratings still to be calculated and notified to building control bodiesSAP ratings still to be calculated and notified to building control bodies

Requirement of heating & hot water changed to encompass overall Requirement of heating & hot water changed to encompass overall system performance, not just controlssystem performance, not just controls

Boiler seasonal efficiency, inspection & commissioning includedBoiler seasonal efficiency, inspection & commissioning included New requirements for efficient lighting systems & provision of New requirements for efficient lighting systems & provision of

information for householdersinformation for householders Standards of fabric insulation improvedStandards of fabric insulation improved

Lower (better) standards (loft insulation)Lower (better) standards (loft insulation) Reductions in U values (technical limits)Reductions in U values (technical limits) Changed methods for calculating U valuesChanged methods for calculating U values

Lower U values for windowsLower U values for windows Based on sealed double-glazed units with low emissivity panesBased on sealed double-glazed units with low emissivity panes Area of glazing increased to 25% floor areaArea of glazing increased to 25% floor area

Target U-value method retained but provisions for trade-offs Target U-value method retained but provisions for trade-offs improvedimproved..

Compliance procedures 2000 RegulationsCompliance procedures 2000 Regulations

Three methods to demonstrate compliance with Building Three methods to demonstrate compliance with Building Regulations:Regulations:

1.1. Elemental approachElemental approach2.2. Target U-Value methodTarget U-Value method3.3. Carbon IndexCarbon Index

1. Elemental approach – meet specific conditions1. Elemental approach – meet specific conditions Heating must be gas, oil, heat pump, CHP DH, biogas or biomassHeating must be gas, oil, heat pump, CHP DH, biogas or biomass U-values < BR2000 standardsU-values < BR2000 standards Area window, doors, roof lights <=25% floor areaArea window, doors, roof lights <=25% floor area Boiler: SEDBUK efficiency >=78% gas, 80% LPG, 85% oilBoiler: SEDBUK efficiency >=78% gas, 80% LPG, 85% oil

[SEDBUK – Seasonal efficiency of domestic boilers in the UK. The average [SEDBUK – Seasonal efficiency of domestic boilers in the UK. The average annual efficiency achieved in typical domestic conditions.]annual efficiency achieved in typical domestic conditions.]

2. Target U-Value method2. Target U-Value method

Calculate Target U-Value Calculate Target U-Value a function of areas of floor, roof, walls, windows etca function of areas of floor, roof, walls, windows etc

Modify target Modify target gas & oil boilers: gas & oil boilers: actual SEDBUK efficiencyactual SEDBUK efficiency

standard SEDBUK efficiency standard SEDBUK efficiency electric & coal heating: divide by 1.15electric & coal heating: divide by 1.15 No modification for heat pumps, biomass, biogas, CHPNo modification for heat pumps, biomass, biogas, CHP

Modify target if area south facing windows > area north Modify target if area south facing windows > area north facing windowsfacing windows

Calculate weighted average U-value of all external Calculate weighted average U-value of all external surfacessurfaces

Weighted average U-value must be <= Target valueWeighted average U-value must be <= Target value

3. Carbon Index Method3. Carbon Index Method

Most complex methodMost complex method Replaces SAP energy rating as a method of Replaces SAP energy rating as a method of

compliancecompliance Carbon index appears to be 0-10Carbon index appears to be 0-10 Must be >= 8 to complyMust be >= 8 to comply Max carbon index 10 – but actually 17.7!Max carbon index 10 – but actually 17.7!

Reality: 8 out of 17.7 or 4.5 out of 10! Reality: 8 out of 17.7 or 4.5 out of 10!

SAP procedure is followed SAP procedure is followed up to point of introducing costs of fuelsup to point of introducing costs of fuels actual annual energy consumption is used to calculate the actual annual energy consumption is used to calculate the

annual carbon dioxide emissionannual carbon dioxide emission translated into a carbon indextranslated into a carbon index

Standard Assessment Procedure (2001)Standard Assessment Procedure (2001)

Calculate U-values Calculate U-values Check U-values are achievedCheck U-values are achieved Calculate Calculate

gross heat requirements (Heat Loss Rate)gross heat requirements (Heat Loss Rate) hot water requirementshot water requirements incidental & solar gainsincidental & solar gains effective gainseffective gains effective internal temperatureeffective internal temperature corrected degree-day parametercorrected degree-day parameter net space heating total energy requirementnet space heating total energy requirement

Select heating method (pumps, appliance efficiency)Select heating method (pumps, appliance efficiency) Calculate Total Energy RequirementCalculate Total Energy Requirement Estimate energy costs of total space heating, hot water & Estimate energy costs of total space heating, hot water &

pumpspumps Deflate energy by Energy Cost Factor – 0.96 1994, 1.05 2001Deflate energy by Energy Cost Factor – 0.96 1994, 1.05 2001

Carbon Index Calculations (2000 regulations)Carbon Index Calculations (2000 regulations)

Attempts to assess the true environmental performance of a Attempts to assess the true environmental performance of a buildingbuilding

Follow Standard Assessment Procedure to calculate Total Follow Standard Assessment Procedure to calculate Total Energy RequirementEnergy Requirement

Calculate CO2 emissions for buildingCalculate CO2 emissions for building Calculate Carbon Factor (CF)Calculate Carbon Factor (CF)

CF=CO2 (TFA+45) where TFA is total floor spaceCF=CO2 (TFA+45) where TFA is total floor space Carbon Index (CI) CI=17.7-9.0 log10(CF)Carbon Index (CI) CI=17.7-9.0 log10(CF) Complication of scale >10Complication of scale >10

Present regulations (2000) indicate that compliance is 11kg CO2 Present regulations (2000) indicate that compliance is 11kg CO2 per m2 – carbon index of 8 per m2 – carbon index of 8

If true scale was used Zicer & Elizabeth Fry would out perform If true scale was used Zicer & Elizabeth Fry would out perform the theoretical 10 out of 10 building.the theoretical 10 out of 10 building.

SAP

U-values

Total Energy Requirement

Energy costs

Energy Deflator

1-100

1-120 (SAP 2001)

CARBON Index

C02 emissions

Carbon Factor

>=8

Carbon emissions for same house designed to Carbon emissions for same house designed to different standardsdifferent standards

Variation of Carbon Emission and Carbon Index with Building Regulations

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6 7 8 9 10

Carbon Index

kg

CO

2/m

2 /yr

1976

19901985

2002

1994

Elizabeth FryZICER

Theorectical Perfection in 2002 Regulations

pre-war

1955

1965

Variation of Carbon Emission and Carbon Index problems with current Building Regulations

0

2

4

6

8

10

12

14

16

18

20

7 8 9 10

Carbon Index

kg C

O 2/m

2 /yr 2002

Elizabeth FryZICER

Theorectical Perfection in 2002 Regulations

Critique of the Standard Assessment Procedure (SAP) Critique of the Standard Assessment Procedure (SAP)

Energy efficiency index – but gives a rating that is monetary based Energy efficiency index – but gives a rating that is monetary based not energy basednot energy based

Assumes a general heating level in house – no variationAssumes a general heating level in house – no variation Hot water requirements based on floor area formula not occupancyHot water requirements based on floor area formula not occupancy Incidental gains based on floor area not occupancyIncidental gains based on floor area not occupancy

Standing charge ignored for electricity, included for gas. Oil doesn’t Standing charge ignored for electricity, included for gas. Oil doesn’t have a fixed charge (1994 & 2000)have a fixed charge (1994 & 2000)

Lower efficiency oil heating can give a higher SAP rating than more efficient Lower efficiency oil heating can give a higher SAP rating than more efficient gasgas

Energy Cost DeflatorEnergy Cost Deflator Unnecessary complication that allows for inflationUnnecessary complication that allows for inflation

1994 Regs – possible SAP rating of over 1101994 Regs – possible SAP rating of over 110 SAP of 100 achievableSAP of 100 achievable

2000 Regs – widen scale (over 120) to keep houses at similar value2000 Regs – widen scale (over 120) to keep houses at similar value Better to have max of 100 for zero energy houseBetter to have max of 100 for zero energy house

Effective changes in SAP rating with specific Effective changes in SAP rating with specific changes (1994 regulations)changes (1994 regulations)

SAP changes by:SAP changes by:

Change U-values by 10%Change U-values by 10% 2 – 32 – 3

Change window area by 10%Change window area by 10% 1 – 21 – 2

Change floor area by 10%Change floor area by 10% 4 – 54 – 5

Change heating from mains gas to Change heating from mains gas to LPG (little change in energy LPG (little change in energy consumption)consumption)

- 15- 15

Change heating from condensing Change heating from condensing gas to inferior oilgas to inferior oil

+5-10 !!!!!+5-10 !!!!!

Source: Monahan, J (2002) MSc Dissertation UEA; Source: Monahan, J (2002) MSc Dissertation UEA;

Turner, C. (2003) BSc Dissertation UEATurner, C. (2003) BSc Dissertation UEA

2006!!!2006!!!

Draft 2005 Building RegulationsDraft 2005 Building Regulations

Comes into force 6Comes into force 6thth April 2006 April 2006 Will use SAP 2005Will use SAP 2005 Technical changesTechnical changes

Changes in how U values are calculatedChanges in how U values are calculated Thermal bridging – weighted average to be considered, not Thermal bridging – weighted average to be considered, not

just designjust design Pressure testing of buildings for developments over a Pressure testing of buildings for developments over a

specific sizespecific size U-values windows – include framesU-values windows – include frames Information on lighting use Information on lighting use Estimates of overheating in summer includedEstimates of overheating in summer included Shading issues relating to solar gain must be addressedShading issues relating to solar gain must be addressed

Draft 2005 Building Regulations: ComplianceDraft 2005 Building Regulations: Compliance

Greatest change is how compliance is achieved - five Greatest change is how compliance is achieved - five criteriacriteria::

Dwelling Emission Rate (DER)Dwelling Emission Rate (DER) Gives considerable latitude in designGives considerable latitude in design

Limits on design flexibility Limits on design flexibility limits trade-offslimits trade-offs

Limit effects of solar overheatingLimit effects of solar overheating South facing windows, ventilationSouth facing windows, ventilation

Quality of construction – evidence of actual performanceQuality of construction – evidence of actual performance Quality of workmanshipQuality of workmanship Pressure testing of large buildings & developmentsPressure testing of large buildings & developments

Providing informationProviding information Maintenance and operation of the buildingMaintenance and operation of the building (Home Information Pack)(Home Information Pack)

Dwelling Emission Rate (DER)Dwelling Emission Rate (DER)

Is equal to CO2 emissions per unit floor area Is equal to CO2 emissions per unit floor area for space and water heating and lighting less for space and water heating and lighting less emissions saved by energy generationemissions saved by energy generation

New dwellings & extensionsNew dwellings & extensions

Non Dwellings & large dwellings >450mNon Dwellings & large dwellings >450m22

Building Emission RateBuilding Emission Rate

SAP

U-values

Total Energy Requirement

Energy costs

Energy Deflator

1-100

1-120 (SAP 2001)

CARBON Index

C02 emissions

Carbon Factor

>=8

Target Emission

Rate

C02/m2

Dwelling Emission Rate

DER<TER

UK National Calculation Methodology (NCM) for UK National Calculation Methodology (NCM) for energy performance of buildingsenergy performance of buildings

Compliance with the 2006 amendments to Part L of the Building Compliance with the 2006 amendments to Part L of the Building Regulations in England and Wales (similar for Scotland and N. Regulations in England and Wales (similar for Scotland and N. Ireland)Ireland)

Dwellings: NCM new version of the existing Standard Dwellings: NCM new version of the existing Standard Assessment Procedure (SAP)Assessment Procedure (SAP)

Non domestic buildings: Non domestic buildings: Simplified Building Energy Model Simplified Building Energy Model (SBEM) (SBEM)

prototype www.ncm.bre.co.ukprototype www.ncm.bre.co.uk user interface called iSBEM.user interface called iSBEM. Purpose: Purpose: to produce consistent and reliable evaluations of energy to produce consistent and reliable evaluations of energy

use in non-domestic buildings (and some domestic buildings) use in non-domestic buildings (and some domestic buildings) for building performance certification purposes (eventually)for building performance certification purposes (eventually)

(Home information packs - 1 June 2007)(Home information packs - 1 June 2007)

SAP 2005 RegulationsSAP 2005 Regulations Basic methods similar to previous regulationsBasic methods similar to previous regulations Calculations more complicatedCalculations more complicated Takes into considerationTakes into consideration

window frameswindow frames solar gainsolar gain energy for lightingenergy for lighting effect of thermal bridgeseffect of thermal bridges energy generated by micro CHP, photovoltaics, etc energy generated by micro CHP, photovoltaics, etc

Problems with monetary values remainProblems with monetary values remain

Recalibration of scale Recalibration of scale A house with a previous SAP rating will be reduced A house with a previous SAP rating will be reduced

SAP 2005 rating is related to the energy cost factor (ECF) by:SAP 2005 rating is related to the energy cost factor (ECF) by: If ECF>=3.5, SAP 2005 = 111-110*log10(ECF)(1)If ECF>=3.5, SAP 2005 = 111-110*log10(ECF)(1) If ECF<3.5, SAP 2005 = 110-13.96*ECF (2)If ECF<3.5, SAP 2005 = 110-13.96*ECF (2)

SAP rating scale (1-100) - SAP100 is achieved at zero ECFSAP rating scale (1-100) - SAP100 is achieved at zero ECF Can be >100 if house is net exporter of energyCan be >100 if house is net exporter of energy

Summary Table of U-values for different Summary Table of U-values for different Building RegulationsBuilding Regulations

1976 1985 1990 1994 2000 2005 U – Values W m-2 oC-1

SAP < 60

SAP > 60

External Wall 1.0 0.6 0.45 0.45 0.35 0.45 0.35 Roof 0.6 0.35 0.25 0.2 0.16 0.25 0.16 Floor 1.0 0.6 0.45 0.35 0.25 0.45 0.25 Windows not

specified not

specified not

specified 3.0 2.0* 3.3 2.0

Windows as % of external walls

equivalent to 17%

12 -

Windows as % of total floor areas

- - 15 22.5 25 22.5 25%

English housing tenure by SAP rating, 2001English housing tenure by SAP rating, 2001ODPM (2003)ODPM (2003)

Effects of Building Regulations Part LEffects of Building Regulations Part L

2002, 2005 & 2008 amendments should 2002, 2005 & 2008 amendments should increase efficiency of new build and increase efficiency of new build and extensions by 25%extensions by 25%

……but will it?but will it?

What are the barriers to using building What are the barriers to using building regulations to reduce energy use and regulations to reduce energy use and

carbon emissionscarbon emissions

??

UK residential sector accounts for 30% total UK residential sector accounts for 30% total UK energy demandUK energy demand

1990 – 20031990 – 2003 Total UK energy demand increased 7.3%Total UK energy demand increased 7.3% Residential energy increased 17.5%Residential energy increased 17.5%

Since 1970Since 1970 Energy use per household changed littleEnergy use per household changed little Overall energy use for residential sector increased Overall energy use for residential sector increased

by 32% by 32% At household levelAt household level

Reduction in heat loss – energy savingReduction in heat loss – energy saving Increases in energy demand – lights & appliancesIncreases in energy demand – lights & appliances

Population & householdsPopulation & households

UK populationUK population current aprox 60 millioncurrent aprox 60 million 2050 62.5 – 72 million2050 62.5 – 72 million

Age structureAge structure 2003 – 76.2 men, 80.6 women2003 – 76.2 men, 80.6 women 2031 – 81.0 men, 84.9 women2031 – 81.0 men, 84.9 women Total population over 65Total population over 65

• 2002 10.9 m, 2031 12.7 m, 2060s 17 m2002 10.9 m, 2031 12.7 m, 2060s 17 m

Household sizeHousehold size 1961 3.01; 2004 2.33 1961 3.01; 2004 2.33 One person households: 1971 18%, 2002 29%One person households: 1971 18%, 2002 29%

Effects of household size on energy useEffects of household size on energy useFawcett et al (2000)Fawcett et al (2000)

Construction & demolitionConstruction & demolition

Building regulations are for Building regulations are for new houses & extensionsnew houses & extensions

In UK very low levels of In UK very low levels of construction & demolitionconstruction & demolition

2002/3 167,000 housing starts2002/3 167,000 housing starts 1996 – 2004 nearly 160,000 1996 – 2004 nearly 160,000

dwellings demolished – dwellings demolished – 20,000/year20,000/year

If we continued at this rate the If we continued at this rate the average house will last 1000 average house will last 1000 years!years!

Future of household energy Future of household energy supply lies in the hands of:supply lies in the hands of:

Central governmentCentral government 400 local authorities 400 local authorities 25 million households25 million households Appliance and fuel supply industriesAppliance and fuel supply industries Construction building servicesConstruction building services

FragmentedFragmented Multiple suppliers of specialist productsMultiple suppliers of specialist products Huge number of sub contractorsHuge number of sub contractors Costs saved by:Costs saved by:

• reducing capital costs reducing capital costs • standard componentsstandard components• standard practicesstandard practices

Whole life costs/life-cycle costsWhole life costs/life-cycle costs

typical costs for owning a building are in the ratio of :typical costs for owning a building are in the ratio of : 1 for construction costs 1 for construction costs 5 for maintenance costs 5 for maintenance costs 200 for building operating costs 200 for building operating costs

Source: Royal Academy of EngineeringRoyal Academy of Engineering

Life cycle cost (LCC)Life cycle cost (LCC)

LCC = Capital CostLCC = Capital Cost+ Present worth of Maintenance and Energy Cost  + Present worth of Maintenance and Energy Cost  - Present worth of Salvage value- Present worth of Salvage value

Capital costCapital cost initial capital expense for equipmentinitial capital expense for equipment the system design, engineering, and installation. the system design, engineering, and installation.

Maintenance: operation and maintenance costs/year Maintenance: operation and maintenance costs/year Energy cost: yearly fuel cost. Energy cost: yearly fuel cost. Salvage value: net value in the final yearSalvage value: net value in the final year

http://wcm.nu/LCC/lcc_calculation.htmlhttp://wcm.nu/LCC/lcc_calculation.html

Thank youThank you