International Journal of Architecture, Engineering and ConstructionVol 10, No 1, March 2021, 32021002, 1-10

Energy Savings by Improved Envelope Design: A CaseStudy of Office Buildings in Lucknow India

Farheen Bano∗ and Ritu Gulati

Faculty of Architecture, Dr. A. P. J. Abdul Kalam Technical University, Lucknow 226007, India

Abstract: This study aims to investigate the energy-saving potential of using energy conservation building codes (ECBC) fortwo commercial office buildings in Lucknow. DesignBuilder software was used to create calibrated simulation models of theselected buildings with existing specifications for estimating savings using ECBC recommended design strategies for buildingenvelope. A previous study examining six office buildings in Lucknow showed average energy consumption of almost 135 and316 kWh/m2/year in government and private office buildings. With the application of ECBC compliant envelope, energysaving was 13 and 58 kWh/m2/year, and percentage saving varied by 10% and 20% in these government and private officebuildings. Based on these assessments and patterns of energy utilization in commercial buildings, potential energy savings inLucknow for the next five years have been estimated to be 10,362 MWh/year, which is significant and structures a pertinentbase for this study.

Keywords: Energy conservation building codes, energy efficiency, building envelope, office buildings, Lucknow

DOI: http://dx.doi.org/10.7492/IJAEC.2021.007

∗Corresponding author. E-mail: bano.farheen@foaaktu.ac.in

1 INTRODUCTION

Energy is one of the basic requirements for economic de-velopment in almost all major sectors of the Indian econ-omy, including agriculture, industry, transport, commer-cial, and residential. In Uttar Pradesh, 46% of the totalenergy is used in buildings, 39% utilized by residential,and 7% by commercial sectors, as shown in Figure 1 (Ut-tar Pradesh Power Corporation Limited 2015). Lucknow,the capital of Uttar Pradesh and the center of the politi-cal seat, has numerous existing and upcoming private andgovernment high-rise office buildings. According to Saketet al. (2014), the increase in commercial buildings is 6%–8% annually. Studies have already established in variedcases that the energy consumption of a poorly designedmultistoried building is tremendously high. Lucknow iswitnessing rapid growth and thus has the opportunity ofconstructing buildings with energy savings. A sprawl-ing 100 acres (40 ha) IT city has been planned by thestate government at Chak Ganjaria farms, whereas Sul-tanpur road has already been deemed a special economiczone (TOI 2013).

Moreover, while the electric power generated in Luc-know is 1200 MVA, the peak load demand is 1500 MVA,and as per trends, the net power demand in 2023 would be2143 MVA, as presented in Figure 2 and Table 1 (Bhard-waj and Bansal 2011). The future trend of electricity pro-duction and demand in Bangladesh is similar (Chowdhury

Figure 1. Energy consumption in Uttar Pradesh (UttarPradesh Power Corporation Limited 2015)

et al. 2018). Hence, there is an urgent need to ensure en-ergy efficiency in buildings to manage electricity demandsin the future, especially in this region.

Building codes and standards help establish the min-imum criteria for various aspects of buildings, suchas structure, safety, and water requirements, followingwhich, a building becomes safe and habitable (Dhaka etal. 2014). Moreover, these regulations also facilitate themanagement of energy consumption in buildings. Accord-ingly, the Energy Conservation Building code (ECBC)

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Table 1. Total load and per capita demand for electric-ity in Lucknow (Bhardwaj and Bansal 2011)

Year Total load (MVA) Per capita demand (KVA)2001 524.7 23.12008 831.6 32.62023 2143 65.1

Figure 2. Lucknow electricity demand forecast for 2023(Bhardwaj and Bansal 2011)

was enacted by the Government of India on May 27,2007, for new commercial buildings because of their highpotential for energy efficiency and savings. The EnergyConservation Act (2001) empowers the Government ofIndia to prescribe ECBC in India. Whereas the Bureauof Energy Efficiency (BEE), an autonomous body underthe Ministry of Power, is responsible for implementingECBC in each state (Naidu and Ramesh 2015). Energyconsumption in commercial buildings, such as offices, ho-tels, hospitals, retail spaces, and shopping malls, can bemainly attributed to lights, office equipment, and heating,ventilation and air conditioning (HVAC) systems. Also,it varies with building type, activities, and climate ofthe location. Initially, ECBC set minimum performancestandards for commercial buildings with a connected loadof >500 kW or contract demand of >600 kVA, whereas,later, for expanding the scope of the measures, the ap-plicability of ECBC was modified to 100 kW connectedload and 120 kVA contract demand or greater (Singh etal. 2018). ECBC applies to five significant energy con-sumption areas in buildings, including building envelope,HVAC, service, water heating, lighting, electric power,and motors.

Based on the context mentioned above, this study as-pires to calculate the energy consumption of office build-ings in Lucknow and the potential of energy savings onapplying ECBC recommended design strategies for build-

ing envelope. The energy consumption of a building isexpressed as the energy performance index (EPI), whichis the ratio of the annual energy consumption (kWh) andthe total built-up area (m2) of the building. Further-more, the annual energy consumed in lighting, heating,and cooling is divided by the total built-up area of thebuilding to determine the lighting, heating, and coolingloads.

2 CLIMATE OF LUCKNOW: EXPECTEDPERFORMANCE OF THE BUILT FORM

This study was conducted in Lucknow city, the capital ofUttar Pradesh. It lies in a composite climate zone, as perECBC specifications, and is characterized by too highand low temperatures in summers and winters, respec-tively. In addition, in summers, direct solar radiationsare high while humidity is low and winds are strong andhot, whereas winters witness low temperature, high hu-midity, and cold winds. Besides, humidity is consistentlyvery high in monsoon (Figure 3).

Figure 3. Climate data of Lucknow (Bano and Kamal2016)

According to American Society of Heating, Refriger-ating and Air-Conditioning Engineers (ASHRAE 2016),heating degree days base 65◦F (HDD65) and Cooling de-gree days base 50◦F (CDD50) are calculated from read-ings of outside air temperature. HDD65 is the differencebetween the outside mean temperature of that day and65◦F, whereas when the mean temperature is more than50◦F; CDD50 is the difference between the outside meantemperature of that day and 50◦F. The annual HDD65and CDD50 for Lucknow are 375 and 9552, respectively

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(Fig. 4); this CDD50 is very high, and thus, energy re-quired for cooling is much more than the energy neededfor heating a building. Consequently, design strategiesthat reduce the cooling load would be more helpful thanthose that reduce the heating load.

3 ENERGY CONSUMPTION PATTERNIN OFFICE BUILDINGS

Bano and Sehgal (2020) derived the energy consump-tion pattern of office buildings at Lucknow from themean of surveyed data for six office buildings with energyuse indices >100 kWh/m2/year, having more than eightfloors and daytime working conditions. These six build-ings (three government and three private office build-ings) represent almost all upcoming office buildings in thecity. Their average, typical floor area is approximately1000 m2, average operational hours are 9 AM to 6 PMsix days a week throughout the year, and floor-to-floorheight is 3.6 m; the EPIs of government and private of-fice buildings are 136 and 217 kWh/m2/year, respectively(Bano and Sehgal 2020). The average working area perperson in these buildings is 10 m2, which is almost thesame as ASHRAE prescriptions, according to ASHRAE(2016) standard 90.1. One government and one private

office building, known as Shakti Bhawan and ShalimarTitanium (Figure 5), were selected for this study, theirspecifications nearing the average of examined ten officebuildings (Detailed specifications of these are given in Ta-ble 2).

4 SIMULATION MODELS

Verification of the energy savings using design strate-gies recommended by ECBC is imperative; we selectedDesign Builder software as the tool for simulation. Acalibrated simulation model was constructed and modi-fied as per ECBC compliant design strategies for build-ing envelope. These modifications included minimiza-tion of conduction and radiation losses from the walls,roofs, and windows. It is interesting to note that foroffice buildings, the EPI benchmark for a composite cli-mate is 86 kWh/m2/year for an air-conditioned space of<50% and 179 kWh/m2/year for an air-conditioned areaof >50% (ECBC 2017). In this study, the average EPIwas estimated to be approximately 200 kWh/m2/year forthe selected office buildings, giving an energy-saving po-tential range of 60%–10%.

There would be differences in simulated and meteredenergy consumption values; the model’s calibrations were

Figure 4. HDD65 and CDD50 for each month of Lucknow

Figure 5. Office buildings: selected cases

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Table 2. Details of selected office buildings

Shakti Bhawan (Extension) Shalimar TitaniumYear of completion 1989 2002Open plan/cellular plan 60% cellular + 40% open plan 40% cellular + 60% open planBuilding footprint (m2) 1053 1891Total floor area (m2) 15718 22785No. of floors G+12 G+11Floor-to-floor height (m) 3.6 3.6Overall WWR 24 55Shading device 100 mm recessed window, no shading

deviceNo shading

Wall type 15 outer plaster 230 brick + 12 innerplaster

Stone + 230 brick + 12 inner plaster

Roof type 150 RCC + mud phuska + screed 150 mm RCC slab, screedGlass type Aluminum frame + 6 mm clear glass Aluminum frame + 6 mm reflected

glass structural glazingWorking hours 9 AM to 6 PM (6 days per week) 10 AM to 5 PM (6 days per week)

75% 7 days 25%Area per person (m2) 14.3 7.1HVAC system type Central AC system (VAV) Split/window AC/VRVEPI (energy performance index,kWh/m2/year)

135 316

Electricity consumption derived from electricity bill

Shakti Bhawan Shalimar Titanium

validated for these differences. Shakti Bhawan and Shali-mar Titanium office buildings were modeled using energysimulation software DesignBuilder V5.0. These modelswere calibrated with the help of monthly and annual elec-tricity bills obtained from their administrative offices. Tovalidate the simulation models, the widely accepted meanbias error (MBE) and coefficient of variance root meansquare error (CVRMSE) were calculated and found to be

within limits (Bano and Sehgal 2019). After a simulatedmodel of the selected cases was formulated with existingconditions, the building envelope components were modi-fied successively, namely walls, roof and glazing assemblymaterials, the addition of shading devices, transformingorientation, and window-to-wall ratio (Table 3), to meetECBC compliance. The energy savings by each compo-nent was calculated individually.

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Table 3. ECBC recommended parameters and simulation inputs of the two selected buildings (Bano and Kamal2016)

Elements ECBC recommendedvalues

Changes in building envelopeto meet ECBC compliance

Shakti Bhawan Shalimar TitaniumOrientation North-south North-south

Wallassembly U-value(W/m2·K◦)

0.440 15 mm outer plaster + 115brick wall + 50 mm EPSinsulation + 230 mm brickwall + 12 mm internal plaster(U-0.431)

15 mm outer plaster + 115brick wall + 50 mm EPSinsulation + 230 mm brickwall + 12 mm internal plaster(U-0.431)

Fenestration WWR 30–40% WWR = 20%, 30%, 40% WWR = 20%, 30%, 40%U-value(W/m2·K◦)

3.30 Double glazed low e glass(Pristine white planitherm),U-1.8

Double glazed low e glass(Pristine white planitherm)U-1.8

SHGC 0.25 (≤40% WWR)0.20 (40%< WWR ≤60%)

SHGC = 0.54 SHGC = 0.54

VLT 0.27 (WWR 20%)0.20 (WWR 40%)0.13 (WWR 80%)

VLT = 0.74 VLT = 0.74

Roofassembly U-value(W/m2·K◦)

0.409 RCC roof slab 150 mm +

PUF insulation 50 mm +

DPC + screed 40 mm +

internal plaster 6 mm(U-0.259)

RCC roof slab 150 mm +

PUF insulation 50 mm +

DPC + screed 40 mm+

internal plaster 6 mm(U-0.259)

Shading 600 mm deep overhang+ fins

Shading device – 600 mmdeep overhang + fins

Shading device – 600 mmdeep overhang + fins

5 SIMULATION RESULTS ANDDISCUSSION

Both selected cases were simulated with actual and mod-ified envelope parameters one at a time. Subsequentanalysis of results was conducted to reduce annual light-ing, heating, cooling, and total loads (EPI) for conclusiveinferences. The increase and decrease in consumptionswere compared among the different cases and the actualcase. The relative energy consumption (REC) methodwas used for comparing energy consumption in simulatedcases (McKeen and Fung 2014). REC for different sim-ulation cases was determined as the ratio of energy con-sumption after modification in the building envelope andenergy consumption of the building with the actual spec-ification Eq. (1). Previous studies had established thata positive REC indicates an increase in energy consump-tion, and a negative REC indicates a decrease in energyconsumption.

REC% =

Energy Consumption afterModification in Envelope

Energy Consumptionwith Actual Envelope

− 1 (1)

5.1 Government Office Building – ShaktiBhawan

WWR recommended by Mahoney’s Table for Lucknowis 15–25% (Bano and Tahseen 2017). Thus, the energy-saving potential of Shakti Bhawan is less because of itsWWR = 24%. Also, it has maximum windows in thenorth and south directions, which are considered suitableorientations. The building’s metered and simulated EPIswith original conditions were 135 and 129 kWh/m2/year,respectively. First, simulations were performed to deter-mine the optimum WWR range of 20–60% (recommendedby ECBC). Second, simulations were performed to estab-lish energy savings achieved by changing building enve-lope components as per ECBC recommendations, initiallyone by one, and finally, all in a combination. These mod-ifications were made as per Table 3, which depicts theECBC recommendations for building envelope and spec-ifications of the improved building envelope (as per men-tioned recommendations) for both Shakti Bhawan andShalimar Titanium.

The simulation results showed that maximum energysaving was achieved for WWR = 20% (refer to Table 4and Figure 6). In contrast, lighting and heating loadswere reduced remarkably for WWR = 30%, with a si-

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multaneous increase in EPI of only 2%. Combined withshading devices and glazing type, WWR of 30% resultedin maximum energy savings, and it was further tested insimulation cases. Furthermore, when WWR was mod-ified from 40% to 60%, the energy required for coolingincreased tremendously, because of which, the EPI of thebuilding also escalated considerably, irrespective of thedecrease in the heating and lighting loads.

Subsequently, the influence of each envelope parame-ter and their combined effects on the reduction of an-nual loads were calculated and analyzed (Table 5 and

Figure 6. Simulation results for WWR of ShaktiBhawan

Figure 7):(1) Modification of orientation to N-S direction did not

result in remarkable energy savings, probably due toits H-shape. In contrast, the EPI has reduced by 1%,possibly because of the more extended facade beingoriented N-S.

(2) Modification of WWR from 24% to 30% resultedin increased EPI, although the energy consumed inlighting and heating was reduced. However, it maybe possible that by modifying the glazing type andadding shading devices on windows, the cooling loadreduced, resulting in EPI reduction.

(3) The building’s heating and cooling loads decreasedconsiderably by decreasing the U-value of walls androofs, which resulted in the reduction of EPI by 2%for each case.

(4) On altering glazing type in fenestration from clearto double glazed low e glass, lighting loads increasedwhile heating and cooling loads decreased. Conse-quently, EPI decreased, which shows the influence ofcooling load on EPI.

(5) Despite the increase in lighting and heating loads,on the addition of horizontal and vertical shadingdevices on windows, EPI decreased by 3%, resultingin a decrease in the cooling load, probably due tolesser radiation entering the building.

(6) On applying low e double glass in fenestrations andadding shading devices on fenestrations, annual en-ergy saving was highest (up to 3%).

Table 4. Energy consumption pattern in Shakti Bhawan while varying WWR from 20% to 60%

WWR% Lighting REC% Heating REC% Cooling REC% EPI REC%20 18.61 1% 0.21 3% 78.51 −4% 126.95 −2%

24 (actual) 18.35 0% 0.20 0% 81.36 0% 129.32 0%30 17.48 −5% 0.19 −6% 85.40 5% 132.00 2%40 17.07 −7% 0.18 −12% 91.54 13% 137.41 6%50 16.42 −11% 0.17 −14% 100.10 23% 144.60 12%60 16.15 −12% 0.17 −15% 112.16 38% 155.42 20%

Figure 7. Simulation results after incorporating ECBC recommended design strategies for Shakti Bhawan

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Table 5. Simulation results after incorporating the ECBC recommended design strategies

ECBC Recommended designstrategies

Lighting REC% Heating REC% Cooling REC% EPI REC%

Actual envelope conditions 18.35 0% 0.20 0% 81.36 0% 129.32 0%N-S orientation 17.57 −4% 0.20 0% 80.95 −1% 128.17 −1%WWR = 30% 17.48 −5% 0.18 −10% 84.90 4% 132.00 2%Wall assembly 18.35 0% 0.12 −40% 79.43 −2% 127.07 −2%Roof assembly 18.35 0% 0.01 −97% 78.79 −3% 126.60 −2%Glazing 19.87 8% 0.16 −20% 75.87 −7% 125.36 −3%Shading device (0.6 moverhang)

18.70 2% 0.23 15% 77.89 −4% 126.29 −2%

Shading device (0.6 moverhang and fins)

19.32 5% 0.25 25% 76.77 −6% 124.82 −3%

All building envelopeparameters (WWR = 30)

18.68 2% 0.08 −60% 68.16 −16% 116.31 −10%

All building envelopeparameters (WWR = 20)

27.40 49% 0.01 −95% 68.30 −16% 125.16 −3%

Table 6. Energy consumption in Shalimar Titanium with varying WWR from 20% to 60%

WWR% Lighting REC% Heating REC% Cooling REC% EPI REC%20 21.54 37.27% 1.70 18.53% 202.71 −14.10% 279.96 −5.57%30 17.95 14.38% 1.61 12.27% 207.71 −11.98% 281.28 −5.13%40 16.26 3.66% 1.51 5.91% 214.78 −8.99% 286.55 −3.35%50 15.71 0.10% 1.44 0.41% 222.05 −5.91% 293.19 −1.11%

55 (actual) 15.69 0.00% 1.43 0.00% 236 0.00% 296.48 0.00%60 15.64 −0.35% 1.37 −4.16% 229.32 −2.83% 300.32 1.30%

(7) Lastly, after modifying all the building envelope pa-rameters according to ECBC, the annual saving inelectricity was 3% when WWR = 20%, and 10%when WWR = 30%. As a result, WWR = 30% isrecommended for maximum energy saving for Luc-know’s composite climate.

5.2 Private Office Building – Shalimar Tita-nium

The WWR of Shalimar Titanium is 55%, which is muchmore than that recommended by Mahoney’s Table forthe composite climate of Lucknow, increasing its energy-saving potential; however, it is jeopardized by its E-Worientation, which increases potential heat gained by thebuilding. The metered and simulated EPIs of ShalimarTitanium is 316 and 297 kWh/m2/year. Simulation out-puts on changing WWR from 20% to 60% showed maxi-mum energy saving when WWR was 20%; the differencesin savings in WWRs of 20% and 30% were not signifi-cant (0.44%). Moreover, heating and cooling loads arevery high when WWR = 20%, suggesting that when cou-pled with other passive features, as ascertained in ShaktiBhawan’s case, WWR = 30% could be the optimum value(Table 6 and Figure 8).

Simulation results (refer to Table 7 and Figure 8) wereanalyzed after modifying features of the building envelope

Figure 8. Simulation results for WWR of Shalimar Ti-tanium

of Shalimar Titanium one at a time and then in combina-tion (as per Table 3). Observations from the simulationsare as below:(1) Heating and cooling loads decreased on changing the

building’s orientation from E-W to N-S, most likelydue to the reduction of heat gain in summers andincrease of heat gain in winters, respectively, afterwhich, EPI also decreased by 2%.

(2) On account of high WWR, the wall area is less in the

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Table 7. Simulation results after incorporating the ECBC recommended design strategies in Shalimar Titanium

ECBC recommended designstrategies

Lighting REC% Heating REC% Cooling REC% EPI REC%

Actual envelope conditions 15.69 0.0% 1.43 0% 236 0.0% 296.48 0.0%N-S orientation 15.69 0.0% 1.17 −18% 231 −2.1% 291.49 −1.7%Wall assembly 15.69 0.0% 1.24 −13% 235.35 −0.3% 295.63 −0.3%Glazing 16.25 3.6% 1.21 −15% 219.69 −6.9% 280.51 −5.4%Roof assembly 15.69 0.0% 0.89 −38% 231.13 −2.1% 292.02 −1.5%WWR = 30% 17.95 14.4% 1.61 12% 207.73 −12.0% 281.28 −5.1%Shading device (0.6 mOverhang)

16.87 7.5% 1.73 21% 220.73 −6.5% 281.7 −5.0%

Shading device (0.6 moverhang and fins)

16.04 2.2% 1.82 27% 214.33 −9.2% 274.56 −7.4%

All building envelopeparameters WWR = 30%

19.13 21.9% 0.6 −58% 176.16 −25.4% 238.26 −19.6%

All building envelopeparameters WWR = 20%

28.28 80.2% 0.55 −62% 175.43 −25.7% 246.63 −16.8%

Shalimar Titanium, and therefore, a decrease in EPIon modification of wall assembly is not significant.Moreover, on altering fenestration glazing from singlepane reflected glass to double pane low e glass, theenergy saving is 5.4% because of decreased coolingand heating loads.

(3) The heating load is reduced significantly (38%) onthe addition of insulation in roof assembly, proba-bly due to a remarkable reduction in U-value thatrestricts heat losses from the roof. As a result, EPIis also reduced.

(4) On the modification of WWR from 55% to 30%,lighting and heating loads increased; however, cool-ing loads decreased by 12%, possibly due to reducedheat gain from windows. Consequently, an annualenergy saving of 5.1% was achieved in this case.

(5) After adding horizontal and vertical shading deviceson windows, EPI decreased by 7.4% because of re-duced direct solar radiations entering the buildingthrough the high percentage of glazed area in Shali-mar Titanium.

(6) Applying ECBC recommendations on building enve-lope, the annual energy saving was 17% in WWRs of20% and 30%. Therefore, to achieve optimum energysavings combined with other passive techniques re-quired for the composite climate of Lucknow, WWRshould be 30%.

5.3 Comparison of Two Office Buildings:Shakti Bhawan and Shalimar Titanium

A comparison of Shakti Bhawan and Shalimar Titaniumoffice concerning their metered and simulated annual en-ergy consumptions and annual energy savings is shownin Table 8. Compared with Shalimar Titanium, ShaktiBhawan has less potential for energy saving because of

its already optimum WWR coupled with recessed win-dows providing shading. Its H-shape plan facilitates thebuilding’s self-shading, and mud-phuska roofing restrictsheat gains and losses from the roof. Contrarily, WWR =

55% in Shalimar Titanium, with no shading devices andno roof and wall insulation. Heating and cooling loadsof the building were considerably increased in all scenar-ios, possibly due to a significant amount of heat gain insummers and loss in winters (Figure 9). Total saving af-ter incorporating ECBC recommended building envelopeis 10% in Shakti Bhawan and double in Shalimar Tita-nium, 20% (Figure 9).

6 CONCLUSION

As stated in section 2, due to the high value of CDD50,the energy required for cooling a building in Lucknowwould be much higher than the energy required for heat-ing. Moreover, it is evident from the simulation resultsthat passive features, such as WWR, glazing type, andshading device, reduce the energy required for cooling,affecting EPI. The analysis concluded that N-S orienta-tion is the optimum direction for energy efficiency whencooling loads are considered. Furthermore, wall and roofinsulation also significantly affect the cooling and heat-ing loads of the building. Also, the optimum WWR for acomposite climate was derived, that is, 30%.

This study authenticated tremendous potential for en-suring energy saving by implementing ECBC guidelinesin Lucknow’s fast-growing city. Thus, there is an ur-gent need to implement ECBC guidelines on numerousoffice buildings in the city, especially in the upcomingones, because incorporating ECBC design strategies atthe planning stage would be more economical than ap-plying it on older buildings. Further, the energy usagepotential of private office buildings (with WWR in the

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Table 8. Comparison of simulation results for Shakti Bhawan and Shalimar Titanium

Selected buildings Shakti Bhawan (2 PM 12 thMarch)

Shalimar Titanium (2 PMMarch 12)

Metered energy consumption

135 kWh/m2/year 316 kWh/m2/year

Simulated energy consumption (realconditions) 129.32 kWh/m2/year 296.48 kWh/m2/year

Simulated energy consumption afterapplying ECBC recommendedbuilding envelope (orientation + wall+ roof + WWR + glazing + shading)

116.31 kWh/m2/year 238.26 kWh/m2/year

Energy saving in ecbc recommendedbuilding envelope (kWh/m2/year) 13.01 kWh/m2/year 58.22 kWh/m2/year

Energy saving in ecbc recommendedbuilding envelope (%) 10% 20%

Figure 9. Comparison of energy savings in Shakti Bhawan and Shalimar Titanium on the application of ECBCrecommended design strategies for building envelope

range 40%–80%) is more than that of government of-fices. The average EPI is estimated to be approximately200 kWh/m2/year. Furthermore, on changing buildingenvelope parameters as per ECBC guidelines, energy sav-

ings in a government and private office were 10% and 20%,respectively. On following all ECBC recommendations,energy savings could increase up to 40% or more. Usingthese estimates and the trends of increase in commercial

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buildings (being is 6%–8% annually), the potential of en-ergy savings in the city of Lucknow has been predictedto be 10,362 MWh/year in the next five years, validatingthe use of ECBC compliant strategies for the same.

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