Financial Feasibility of Opaque Envelopes in ECBC Complaint

Energy Efficient Indian Commercial Buildings: An Approach

for Maximising the Internal Rate of Return

Pranav Kishore

, Stuthi Shetty

, Bysani Sathwik

, Nandhini Selvam

, Vaibhav Jain

and Pradeep Kini

Centre of Sustainable Built Environment, Manipal School of Architecture and Planning,

Manipal Academy of Higher Education, Manipal, India

Manipal School of Architecture and Planning, Manipal Academy of Higher Education, Manipal, India

Keywords: Architecture Optimization, Internal Rate of Return, Energy Saving, Building Code, Energy Policy, Green

Building.

Abstract: Buildings are one of the major contributors to energy consumption and Green House Gas emissions. To

regulate harmful emissions the government is trying its best to overcome these problems by enforcing energy

conservation codes and rating systems for buildings in India. The developers and the investors of project are

more interested in the profit. The Internal Rate of Return of a project supports the selection of the project,

which is widely used worldwide. This study has been conducted to optimize the Internal Rate of Return (IRR)

to find out the best opaque wall section in the warm and humid climate of India with Energy Conservation

Building Code (ECBC) compliance, using wall thermal transmittance values as the constraints to control the

energy consumption within buildings. This will lead to the reduction electricity demand contributing towards

a mitigating the climate change and also to gain profit for the investors by annual energy savings from

sustainable commercial buildings. This study estimates an 18% to 40% IRR from the commercial building by

conforming with ECBC benchmarks.

1 INTRODUCTION

The world is undergoing a serious issue related to

climate change and buildings are one of the

contributors. The greenhouse gas emissions

especially, Carbon dioxide emissions have led to an

increase in the global surface temperature, which

results in an increase of the mean sea level due to the

melting of glaciers, thus harming the environment

that we live in. Global surface temperatures have

exceedingly increased over the last decade (2011-

2020) concerning 6500 years ago ranging from 0.2

to 1

C and now even further according to The

Intergovernmental Panel on Climate Change (IPCC)

report (IPCC). In the year 2015, the United Nations

adopted The 2030 Agenda for Sustainable

development which has a total of 17 goals called the

Sustainable Development Goals (SDGs), an urgent

call for action for all countries, which results in global

development while tackling climate change to

preserve the current environment (Nations, n.d.).

Among these 17 SDGs 4 of the goals (affordable and

clean energy, industry, innovation, and infrastructure,

sustainable cities and communities, responsible

consumption and production) are directly or

indirectly linked to the building sector. As

responsible architects, they must reduce the negative

impact on the climate and maximize the profit of

stakeholder or investor over the buildings for

whoever is requiring to help. On global level, the

building sector has become one of the major sources

of CO

emissions. Efforts are being made to develop

a more sustainable environment (Jiang, Liu,

Czarnecki, & Zhang, 2019). Everything started with

the United Nations Framework for Convention on

Climate Change (UNFCCC), introduced by United

Nations in 1992. The ultimate objective of UNFCCC

is to stabilize the greenhouse gases in the atmosphere

at a level which resulted in the formation of the

United States Green Building Council (USGBC) and

Leadership in Energy and Environmental Design

(LEED) – a Green building rating system.

Scientific literature shows that even if the most

aggressive mitigation measures are successful, we

130

Kishore, P., Shetty, S., Sathwik, B., Selvam, N., Jain, V. and Kini, P.

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for Maximising the Internal Rate of Return.

DOI: 10.5220/0011114300003206

In Proceedings of the 4th International Conference on Finance, Economics, Management and IT Business (FEMIB 2022), pages 130-139

ISBN: 978-989-758-567-8; ISSN: 2184-5891

can expect climate-related changes, such as

increasing temperatures over the next 30 years (Aijazi

& Brager, 2018). In the total GHG emissions 16% of

the emissions are due to embodied energy and the

remaining 86% is because of the operation of the

systems (Filippin, Larsen, & Ricard, 2018). So, it is

required to reflect on the operational energy

consumption, which leads to the price of the total

energy consumed. There is a spike of 29.2% increase

in the Energy Performance Index of the buildings i.e.

60 KWh/Sq.m per year to 78 KWh/Sq.m per year

(Gercek & Arsan, 2019).

India is responsible for 8% of the total GHG

emission (IPCC). The building sector in India is

accountable for 35% of the summed up energy

consumption and the energy use is increasing at the

rate of 8% (Khosla & Janda, 2019). To deal with

climate change, the Indian government introduced the

Energy Protection Act in 2001 which also oversees

the Bureau of Energy Efficiency (BEE) in its

framework. The BEE introduced the Energy

Conservation Building Code (ECBC) in the year

2007. Various Initiatives were taken by the

Government of India like National Building policies,

Smart city initiatives, building codes, and rating

systems to incorporate Energy Efficiency and to set

new benchmarks for building performance (Garg,

Kumar, Pipralia, & Garg, 2018).

A study conducted by Kishore N says that five

cities under all climate zones in India according to

National Building Code (NBC) were analyzed which

resulted in a temperature rise of 3.7-4.2 °C in the

future. The study propounds that there is a significant

overall increase in the energy load ranging from 18%

to 89% in 2020, 32% to 132% in 2050, and 85% to-

184% in 2080 if the residential buildings are operated

in the same manner. The use of passive strategies may

reduce the load by 50% to 60% in the future (Kishore,

2021).

Green building technology can be promoted by

strengthening the policy and incentive system.

Special training for employees, awareness towards

technological innovation, and an approach towards

integrated design application act as direct driving

forces towards Green Building Implementation

(Zhang, et al., 2019).

1.1 Technical Challenges

In the year 2002, India started the Green building

movement in India. In the following years, ECBC

was enforced which set benchmark constraints for the

building construction. The reference building model

developed by Bhatnagar Et al. performs better in the

Energy Performance Index than just the guidelines

from ECBC and ECBC+ in all the five climate zones

of India as per National Building Code (NBC), due to

the market transformation to LEDs. But, the envelope

in the reference buildings are inefficient due to the

higher cost of insulations (Bhatnagar, Mathur, & Garg,

2019). On the contrary, the study in this paper will help

to deal with the envelope. Many benchmarks and

standards have been defined for the Indian context but

the implementation needs reinforcement (Sharma,

2018). India has different climate zones and needs

different types of buildings, hence no single code

applies in the same manner to all these situations.

1.2 Financial Challenges

Higher occupancy generates higher demand for

electricity, causing a hike in energy loads leading to

energy poverty, especially in highly populated areas

in India. To tackle the energy poverty issue in India

the government has enforced policies such as the

Electricity Act of 2003, the National Electricity policy

of 2005, and so on with the agenda to expand electricity

supply, especially to rural areas which have resulted in

a considerable decline in energy poverty across the

country. Multi-dimensional energy poverty index and

district-level information are examined to estimate the

extent of energy poverty at a place (Sadath & Acharya,

2018). Also, for every building implementing

sustainability, the buyer has to pay a premium price

and the gap between the buyer's willingness to pay and

the cost of sustainable building imposes an economic

challenge, hence both these issues have to be

negotiated. Finally, the public views that the

construction industry and buyers are focused on short-

term benefits and not convincingly invested in the

concept of sustainability and hence withdraw their idea

of accepting change (Hoxha & Shala, 2019).

2 BACKGROUND STUDY

The reference building model of India states that the

cooling load of commercial buildings ranges from

16% to 28% based on the typology and occupational

hours of the building (Bhatnagar, Mathur, & Garg,

2019). The heat in the building can be cooled with

many strategies in which HVAC systems like VAV

and VRF systems are used which consume electricity.

The electricity demand is increasing every day. In

India, 56% of the electricity is generated by coal fired

power plants which release the highest amount of

emissions into the atmosphere when compared

to any other source (IEA, 2021). One of the

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for

Maximising the Internal Rate of Return

131

approaches to reduce energy consumption within the

building is to reduce heat transfer into the building.

Studying the building life cycle and certain market

participants, it is identified that “going green” can be

financially feasible and also profitable over the life

span of the building. But, certain factors delay the

decision-making of the developers and occupants in

choosing to "go green", especially in terms of

economic viability (Zhang, Wu, & Liu, 2017).

Scope: Literature over the past decade show

experiments and case studies conducted for the

financial returns in buildings due to the higher

investments in construction. However, this extra

investment should have brought higher rental because

of the characteristics of the green buildings. But the

situation is complex because the financial benefits of

green building have not been accounted for. As such a

study has not been conducted which can establish a

relation between the financial benefit and energy

efficiency of green building in a rapidly developing

economy like that of India. So this study uses the

reference building model of India for commercial

buildings as a base case to understand the same. RBM

(Reference Building Model) has been simulated

against the building energy codes of India to calculate

the Internal Rate of Return using the financial savings

from the energy efficiency of the building and also

bringing the extra cost associated with the construction

of green buildings to understand the design decisions

by various professionals of AEC(Architecture,

Engineering, and Construction) industry.

3 METHODOLOGY

3.1 Energy Simulation

3.1.1 Reference Building Model (RBM)

The reference building model of India for commercial

buildings has been considered for the study. In the

RBM, the buildings were divided into 2 types

Figure 1: High-rise building model Image by: (Bhatnagar,

Mathur, & Garg, 2019).

based on, no. of floors and types of functional hours

in each building, – Low-rise -8hr, Low-rise – 24hr,

high-rise – 8hr and high-rise – 24hr. A total of 230

commercial buildings have been analyzed for the

RBM study. Indian climate zones are divided into five

types according to NBC 2006, however development

of Indian RBM is only for four climate zones

excluding cold climate zone. The RBM analysis is

based on various inputs such as form, envelope, loads,

and systems, along with certain general categories

like location, ventilation requirements, etc. The study

is a four-step process: 1. Identification of building

typologies, 2. Building parameters identification, 3.

Sample size and data collection, 4. Determining

values of building parameters. (Bhatnagar, Mathur,

& Garg, 2019).

Figure 2: Low-rise building model Image by: (Bhatnagar,

Mathur, & Garg, 2019).

Figures 1 and 2 show the reference building models

for high-rise and low-rise building typology

respectively.

3.1.2 Energy Performance Calculator

For this study the RBM in the Warm and humid

climate is modeled in the Energy Performance

Calculator (EPC). EPC is an Excel-based tool that can

be used to calculate the energy performance of a

building. It is developed by IMAGINE lab at the

Georgia Institute of Technology. EPC uses energy

plus weather files, systems in building like Lighting

systems and HVAC systems, Building Integrated

Energy Generation System, zones and their

occupancy, and building envelope details to calculate

Energy Performance Index (EPI).

3.1.3 Thermal Transmittance

The heat from the exterior spaces transmits to the

spaces through a building envelope which has

conductivity in it known as thermal conductivity.

Thermal transmittance is a function of the thermal

conductivity and thickness of the envelope material.

FEMIB 2022 - 4th International Conference on Finance, Economics, Management and IT Business

132







(1)

  

  

  

3.2 Material Data

Opaque wall materials are combined to make

different sections, which causes a change in the

thermal transmittance of the combined wall section.

The different materials for the exterior finish, interior

finish, and block are taken as the variables for the

materials. These materials are taken from

optimization-based feasibility analysis for ECBC for

different opaque wall assemblies in India taken from

a study by Pranav Kishore et al (Kishore, Kini, & Raj,

2020) as shown in Table 1 and Table 2.

The 4 different types of wall finish typologies (F1

= both side finish, F2 = both exposed, F3 = finished

inside and exposed outside and F4 = exposed inside

and finished inside) have been considered for the

study. The number of layers of finishes has been

restricted to three layers as per practical application.

The materials used in the study are accepted and used

in the compilation of materials used in the industry

which complies with ECBC 2017 and is tested by

CARBSE, CEPT Ahmedabad, and verified by CSBE,

MAHE, Manipal.

3.3 Energy Conservation Building

Code

Buildings consume a significant proportion of energy

resources, so the Bureau of Energy Efficiency (BEE

– India) has launched Energy Conservation Building

Code (ECBC) in the year 2007 to establish minimum

building performance standards for the commercial

buildings of India, which is a regulatory tool to limit

the energy footprint of the commercial buildings.

Section 4 in ECBC explains the building envelope.

The building envelope is considered as skin of

building, which consists of walls, openings, and roof.

These components play a crucial role in the heat

transfer into the building. It is required to maintain the

thermal comfort of the occupants in a building as it

affects the functionality of the occupants. If the heat

transfer is very high then the temperature in the space

increases and HVAC systems are used to achieve

thermal comfort. As the HVAC systems consume

more amount of energy, which leads to more

expenditure on the systems. So ECBC 2017 provides

us the different benchmarks for the envelope based on

climate zone, type of building and different levels of

Table 1: Block materials and exterior finish materials for wall (Shetty, Kishore, Kini, Acharya, & Raj, 2020).

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for

Maximising the Internal Rate of Return

133

Table 2: interior finish materials for wall (Shetty, Kishore, Kini, Acharya, & Raj, 2020).

efficiency like ECBC, ECBC+, and super ECBC. In

this study, only warm and humid climate was

considered, so the benchmarks used for the wall of

different levels of ECBC in warm and humid climate

for commercial buildings are as per Table 3.

Table 3: maximum u-factor values.

ECBC ECBC+ ECBCSuper

Maximum thermal

transmittance for the opaque

external walls in W/sqmK

0.40 0.34 0.22

3.4 Internal Rate of Return

IRR is an evaluation method that measures the

financial gains of an investment. The rate (R) at

which NPV is zero is the IRR.

  

∑

















= 0 (2)

Where, NPV = net present value

R= discount rate

t= time of the cash flow

= net cash flow at time t

= total initial investment cost

3.5 Regression for Electricity Price

The study makes use of linear regression for

calculations. All the electricity prices from 2011 to

2019 have been collected and a simple curve is

plotted with the available data points and the equation

of the curve is used for the prediction of the price of

electricity per unit in the future as in Graph 1. In the

past prices did not change much, due to communist

government in the state and also due to COVID crisis.

This graph infers the rise in electricity price per unit

over the building life span along with the rise in trend

of price related to the internal rate of return across the

expected life-span of the building (Ramesh, Prakash,

& Shukla, 2010).

Graph 1: Regression line showing electricity prices over the

year.

y = 0,0193x

- 116,92x

+ 235539x - 2E+08

R² = 0,9157

2011 2013 2015 2017 2019

Price of electricity per unit

(KWh)

Year

FEMIB 2022 - 4th International Conference on Finance, Economics, Management and IT Business

134

Figure 3: Optimization process flowchart.

3.6 Optimization

The process of obtaining the best solution from a set

of solutions that support the objective is termed

optimization. Optimization starts with selecting an

objective function and determine dependent and

independent variables to make a complete domain of

results and the final solution is obtained from the

domain which gives the best solution to the objective

function satisfying all constraints (Fogel, 1994).

The MS Excel evolutionary solver has been used

for optimization. The objective function is given in

terms of f(x

, x

, … x

), where ‘x’ can be the point

of minima or maxima of the function. The objective

function is taken as maximizing the IRR, variables are

block material for wall, exterior wall finish material,

interior wall finish material, and their respective

number of layers along with constraints as their

respective thicknesses which can range from 6 inches

to 12 inches. The maximum thermal transmittance of

the opaque wall section will be determined by the

selected level of ECBC from ECBC 2017 handbook.

The income will be determined from the savings of

EPI by changing the building envelope which leads to

the parameters which affecting the objective i.e. roof,

wall, and fenestrations. After choosing a wall, the

thermal transmittance of the wall changes due to the

materials present in it. Table 4 summarizes the

categories considered within the study to optimize the

data in terms of IRR.

Table 4: Input, objective function, variables, and

constraints.

Input ECBC Compliance

Type of building

Functional hours

Type of finish

Objective

function

Maximizing the IRR

Variables Interior finish Number of layers

Block

material

Number of layers

Exterior

finish

Number of layers

Constraints

thermal transmittance of wall

<=0.40 - ECBC

thermal transmittance of wall

<=0.34 - ECBC+

thermal transmittance of wall

<=0.22- ECBC Super

6 inches < Thickness of wall < 12

inches

The optimization starts with the change of the values

in the variable which is the opaque wall material and

then checks for the optimality which is maximum

IRR and then the solver is run until the iterations are

repeating the same solution and then converged. The

detailed flow of result identification is depicted in

Figure 3.

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for

Maximising the Internal Rate of Return

135

4 RESULTS AND DISCUSSION

From graph 2 of the results of the evolutionary

optimization of IRR for Low-rise 8hr functional

building, we can say that ECBC and ECBC+ have

shown similar results for all kinds of wall finish

typology. The IRR in both the compliances ranges

from 23% to 33% for finish type F1 and F2. The years

from which the IRR change becomes very minimal

range from 24

year to 14

year for finish type 1 and

finish type 4 respectively. The achieved thermal

transmittance (u-value) for the highest IRR i.e. 33%

is 0.33 W/Sq.mK. The selected block material for

wall is ECBC rated foam concrete of dimensions

24in x 8in x4in, the exterior finish for all the cases is

Mangalore roof tile (terracotta tile) and interior finish

of ECBC rated hardboard of thickness 6 mm in all the

types of ECBC and types of finishes. All the finishes

are of one layer only to achieve the maximum IRR.

The growth of IRR for every case is increasing for

certain years and the change is becoming negligible

after some years. There is no optimum solution for

ECBC super low-rise 8hr because of the thickness

constraint, which gives the minimum thickness as 6

inches and maximum of 12 inches of thickness for

attaining a thermal transmittance (u-value) value of

0.22 W/Sq.mK. The solution for ECBCSuper can be

achieved only by adding insulation to the wall or by

increasing the thickness of the block material.

Graph 2: Low-rise 8hr building.

From graph 3 of the results of the evolutionary

optimization of IRR for Low-rise 24hr functional

building, the IRR in both the compliances ranges

from 22% to 31% for finish type F1 and F2. The years

from which the IRR change becomes very minimal

range from 22

year to 45

year for finish type 4 and

finish type 2 in ECBC and ECBC+ respectively, and

finish type 1 in ECBC.

The achieved thermal transmittance (u-value) for

the highest IRR i.e 31% is 0.33 W/Sq.mK. The

selected block material for wall is ECBC rated foam

concrete of Size- 24in x 8in x4in for results of all

finishes in ECBC and finish type F1 but for the finish

Graph 3: Low-rise 24hr building.

type 2, finish type 3, and finish type 4 the optimum

material for maximizing the IRR is ECBC rated foam

concrete of Size- 24in x 8in x4in of 2 layers, the

exterior finish for all the cases is Mangalore roof tile

(terracotta tiles) and ECBC rated hardboard of

thickness 6 mm in all the types of ECBC and types of

finishes. All the finishes are of one layer only to

achieve the maximum IRR. There is no optimum

solution for ECBCSuper for low rise-24hr building

because of the thickness constraint which gives the

minimum as 6 inches and maximum of 12 inches for

attaining a thermal transmittance (u-value) value of

0.22 w/Sq.mK. The solution for ECBC can be

achieved only by adding insulation to the wall or by

increasing the thickness of the block material.

Graph 4: high-rise 8hr building.

From graph 4 of the results of the evolutionary

optimization of IRR for High-rise 8hr functional

buildings, we can say that ECBC and ECBC+ have

shown similar results for all kinds of finishes in high-

rise 8hr functional buildings. The IRR in both the

compliances ranges from 28% to 40% for finish type

F1 and F2. The years from which the IRR change

becomes very minimal range from 17

year to 25

year for finish type 4 in ECBC and ECBC+

respectively, and finish type 3 in ECBC. The

achieved thermal transmittance (u-value) for the

highest IRR i.e. 40% is 0.33 W/Sq.mK. The selected

block material is ECBC rated foam concrete of Size-

24in x 8in x4in for finish type 1, finish type 2 in

FEMIB 2022 - 4th International Conference on Finance, Economics, Management and IT Business

136

ECBC, and finish type 1 in ECBC+ but the optimum

material for maximizing the IRR is ECBC rated foam

concrete of Size- 24in x 8in x4in of 2 layers in finish

type 3 and finish type 4 in ECBC and finish type 2,

finish type 3 and finish type 4, the exterior finish for

all the cases is Mangalore roof tile (terracotta tiles)

and ECBC rated hardboard of thickness 6 mm in all

the types of ECBC and types of wall finishes. All the

finishes are of one layer only to achieve the maximum

IRR. There is no optimum solution for ECBCSuper

for high rise-8hr buildings because of the thickness

constraint which gives the minimum as 6 inches and

maximum of 12 inches for attaining a thermal

transmittance (u-value) value of 0.22 w/Sq.mK. The

solution for ECBC can be achieved only by adding

insulation to the wall or by increasing the thickness of

the block material.

Graph 5: high-rise 24hr building.

From graph 5 of the results of the evolutionary

optimization of IRR for high rise-24hr functional

building, the IRR in both the compliances ranges

from 28% to 40% for finish type F1 in ECBC and F2

in ECBC+. The years from which the IRR change

becomes very minimal range from 17

year to 38

year for finish type 4 in ECBC+ and finish type 1 in

ECBC. The achieved thermal transmittance (u-value)

for the highest IRR i.e. 40% is 0.33 W/Sq.mK. The

selected block material for the wall is ECBC rated

foam concrete of Size- 24in x 8in x4in in results of all

finishes in ECBC and finish type 3 and finish type 4

in ECBC and all the finishes of ECBC+, the optimum

material for maximizing the IRR is ECBC rated foam

concrete of Size- 24in x 8in x4in of 2 layers, the

exterior finish for all the cases is Mangalore roof tile

(terracotta tiles) and ECBC rated hardboard of

thickness 6 mm in all the types of ECBC and types of

finishes. All the finishes are of one layer only to

achieve the maximum IRR. There is no optimum

solution for ECBC super for high rise-24hr building

because of the thickness constraint which gives the

minimum as 6 inches and maximum of 12 inches for

attaining a thermal transmittance (u-value) value of

0.22 w/Sq.mK. The solution for ECBC can be

achieved only by adding insulation to the wall or by

increasing the thickness of the block material.

Graph 6 is an IRR over a total of 100 years of the

building. It explains how it changes over a period of

time. At the beginning of the time, the IRR is in

negative values as there is only expenditure on the

walls and no income from it and the savings from the

energy-saving starts from the first year and it goes on

as the maintenance for the walls are considered as

Graph 6: Change of IRR over time.

-90

-70

-50

-30

-10

0 20406080100

INTERNAL RATE OF RETURN (IRR)

YEAR

lowrise 8 hr F1 lowrise 8 hr F2 lowrise 8 hr F3

lowrise 8 hr F4 lowrise 24 hr F1 lowrise 24 hr F2

lowrise 24 hr F3 lowrise 24 hr F4 highrise 8 hr F1

highrise 8 hr F2 highrise 8 hr F3 highrise 8 hr F4

highrise 24 hr F1 highrise 24 hr F2 highrise 24 hr F3

highrise 24 hr F4

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for

Maximising the Internal Rate of Return

137

negligible. In the initial approximate time duration of

20 years the IRR is increasing in a haste and does not

increase rapidly after the 20 years. The change in IRR

over the time duration is almost constant (as the

change is very minimal). Similarly, it is repeated for

every building and every finish but the year over

which it becomes almost the same with the next year,

changes in every case.

A study conducted by Sau Wai Lee for the

economic evaluation of roof thermal insulation in the

equatorial climate of Malaysia says that the IRR

ranges from 6.33% to 15.83% based on the material

that is used as the insulation for the roof. By

increasing the performance of the building using the

correct composition of the roof, they were able to

achieve the IRR (Lee, Lim, Chan, & Von, 2017).

5 CONCLUSION

This study shows that converting a conventional

building to an energy-efficient building even with

optimization of one component of the building

envelope yield a lot of savings. The savings are

considered as the income with the cost of the wall as

the expenditure and the IRR is calculated. The results

explain that the best block material is foam concrete

with the required thickness and the exterior finish is

Mangalore tiles (terracotta tiles) and the interior

finish is hardboard, which gives us a range of 18% to

40% IRR which is very high. Figure 4 shows the

sections of the optimum exterior wall composition.

Figure 4: Cross-section image of a wall section using the

most recurring material selection after optimization.

Anyhow there was no feasible solution that could

satisfy the constraints of ECBCSuper because an

increase in thickness of the wall will reduce the

thermal transmittance (u-value) but for the thermal

transmittance (u-value) constraint of the ECBCSuper

was 0.22 W/Sq.mK which cannot be attained with the

given constraint of thickness i.e. it lies between 6

inches and 12 inches. For ECBCSuper the solution

can be obtained by adding insulation to the interior

finish so adds high resistance to heat in the walls.

Fund disclaimer: The author(s) received no

financial support for the research, authorship,

and/or publication of this article.

REFERENCES

Aijazi, A., & Brager, G. S. (2018). Understanding Climate

change impacts on building energy use. ASHRAE

Journal, 60(10).

Bhatnagar, M., Mathur, J., & Garg, V. (2019).

Development of reference building models for India.

Journal of building engineering, Elsevier, Journal of

building engineering 21 (2019) 267-277;

https://doi.org/10.1016/j.jobe.2018.10.027.

Filippin, C., Larsen, S. F., & Ricard, F. (2018).

Improvement of energy performance metrics for the

retrofit of the built environment. Adaptation to climate

change and mitigation of energy poverty. Energy and

Buildings, Elsevier, Volume 165, 15 April 2018, Pages

399-415; https://doi.org/10.1016/j.enbuild.2017.12.050.

Garg, N., Kumar, A., Pipralia, S., & Garg, P. (2018).

Initiatives to achieve energy efficiency for residential

buildings in India: A review. Indoor and built

environment, Sage journals, https://doi.org/10.11

77%2F1420326X18797381.

Gercek, M., & Arsan, Z. D. (2019). Energy and

environmental performance based decision support

process for early design stages of residential buildings

under climate change. Sustainable cities and societies,

Volume 48, July 2019, 101580; https://doi.org/10.1016/

j.scs.2019.101580.

Hoxha, V., & Shala, F. (2019). The benefits and challenges

of sustainable buildings in Prishtina, Kosovo.

Facilities, Facilities, Vol. 37 No. 13/14, pp. 1118-1152.

https://doi.org/10.1108/F-08-2018-0097.

IEA, I. E. (2021). India Energy Outlook 2021. World

Energy Outlook Special Report.

IPCC, T. I. (n.d.). Global Warming of 1.5 degrees Celcius.

The Intergovernmental Panel on Climate Change.

Jiang, A., Liu, X., Czarnecki, E., & Zhang, C. (2019).

Hourly weather data projection due to climate change

for impact assessment on building and infrastructure.

Sustainable cities and society, Elsevier, Volume 50,

October 2019, 101688; https://doi.org/10.1016/

j.scs.2019.101688.

Khosla, R., & Janda, K. B. (2019). India’s building stock:

towards energy and climate change solutions. Building

research and information, Taylor and Francis, Volume

47, 2019; https://doi.org/10.1080/09613218.2019.15

22482.

Kishore, N. (2021). Impact of climate change on future

bioclimatic potential and residential building thermal

and energy performance in India. Indoor and built

environment, Sage journals, https://doi.org/10.1177

%2F1420326X21993919.

FEMIB 2022 - 4th International Conference on Finance, Economics, Management and IT Business

138

Kishore, P., Kini, P., & Raj, A. (2020). Optimization-based

feasibility analysis for Energy conservation building

code compliance of opaque wall assemblies in different

climatic zones of India. Procedia Manufacturing,

Elsevier, Volume 44(2020), pages 221-228.

Nations, U. (n.d.). Department of Economic and social

affairs, Sustainable Development. Retrieved from

United Nations: https://sdgs.un.org/goals

Sadath, A., & Acharya, R. H. (2018). Energy Poverty and

Economic Development: Household-level Evidence

from India. Energy and Buildings, Elsevier,183:785-

791; http://dx.doi.org/10.1016/j.enbuild.2018.11.047.

Sharma, M. (2018). Development of a ‘Green building

sustainability model’ for Green buildings in India.

Journal of cleaner production, Elsevier, Volume 190,

20 July 2018, Pages 538-551; https://doi.org/10.1016/

j.jclepro.2018.04.154.

Shetty, S., Kishore, P., Kini, P., Acharya, R. R., & Raj, A.

(2020). Energy Conservation Building Code (ECBC)

based optimum wall composition with respect to

thermal transmittance and thickness for different

commercial pockets of Tier-1 city in temperate climatic

zone of India. Procedia Manufacturing, Elsevier,

Volume 44, 2020, Pages 229-236; https://doi.org/10.10

16/j.promfg.2020.02.226.

Zhang, L., Wu, J., & Liu, H. (2017). Turning green into

gold: A review on the economics of green buildings.

Journal of cleaner productions, doi: 10.1016/j.jcle

pro.2017.11.188.

Zhang, Y., Wang , H., Gao, W., Wang, F., Zhou, N.,

Kammen, D. M., & Ying, X. (2019). A Survey of the

Status and Challenges of Green Building Development

in Various Countries. Sustainability, MDPI,

Sustainability 2019, 11(19), 5385; https://doi.org/10.3

390/su11195385.

Ramesh, T., Prakash, R., & Shukla, K. K. (2010). Life cycle

energy analysis of buildings: An overview. Energy and

Buildings; Elsevier, Energy and Buildings 42 (2010)

1592–1600; doi:10.1016/j.enbuild.2010.05.007.

Lee, S. W., Lim, C. H., Chan, S. A., & Von, K. L. (2017).

Techno-economic evaluation of roof thermal insulation

for a hypermarket in equatorial climate: Malaysia.

Sustainable cities and society, Volume 35, November

2017, Pages 209-223; https://doi.org/10.1016/

j.scs.2017.08.011.

Fogel, D. B. (1994). An Introduction to Simulated

Evolutionary Optimization. IEEE Transactions on

Neural Networks,, Vol. 5, No. 1, January 1994.

Financial Feasibility of Opaque Envelopes in ECBC Complaint Energy Efﬁcient Indian Commercial Buildings: An Approach for

Maximising the Internal Rate of Return

139