Transcript
Page 1: An integrated cost-based approach for real estate appraisals

An integrated cost-based approach for real estate appraisals

Jingjuan Guo • Shoubo Xu • Zhuming Bi

Published online: 13 February 2013

� Springer Science+Business Media New York 2013

Abstract Real estate appraisal information systems have

been studied by many researchers in the past including

those systems that have integrated geographic information

systems, artificial neural networks, etc. This paper proposes

a new integrated approach for real estate appraisals which

can be used in real estate appraisal systems to improve

efficiency and accuracy. Motivated by the identified limi-

tations of existing cost approaches for real estate apprais-

als, we integrate some elements from sales comparison

approach and income approach into the cost approach to

improve the accuracy of the valuation of real estate

appropriately. As a result, the new integrated cost-based

approach is capable of taking all of the major factors into

accounts; these factors are closely related to the assets of

real estate in one way or another. In the implementation of

the new approach: (1) the concept of replacements cost is

revisited and expanded to consider dynamic, environ-

mental, and cultural factors in real estate appraisals; (2) the

conventional depreciation values and depreciation rates are

replaced by adjustment values and coefficients to include

both the positive and negative impact on the changes of

real estate value; (3) the theory of technology economics is

applied, six forces have been systematically analyzed to

determine replacement costs; and finally, (4) different

methods for value adjustments, including the algorithm

based on artificial neural network, have been utilized to

deal with the randomness and uncertainties of mass data for

the determination of adjustment values and coefficients.

Keywords Technological economics � Information

management for real estate appraisals � Financial

information systems � Financial information management

1 Introduction

Real estate appraisal is to estimate the value of real estate

based on the highest and best use of the property. Real estate

appraisals play significant roles to the health and soundness

of the world’s financial environment. Appraisals are essential

steps before properties can be transacted. Besides the trans-

actions, public interest in real estate markets and investments

trusts has also been grown rapidly [1]. Real estate appraisals

are extremely important to multiple participators: property

sellers and buyers have the great interests in estimating their

personal assets, municipalities and governments need to

determine the revenues which are largely depended on real

estate taxes, the financial institutions need to make their

banking policies and grant mortgage loans with the mini-

mized risks, and properties brokerages need to evaluate real

estate properties to help their clients make judicious deci-

sions [15]. Since the real estate is usually the significant

assets to most of people, undervalued or overvalued real

estates would cause an irreversible loss to owners or buyers.

Besides, since the purposes of appraisals are to estimate the

property’s equity, an over-valuation results in the under-

estimation of the default risk, which can be passed to buyers

or secondary mortgage providers.

It is critical to select an appropriate approach for real

estate appraisals. The statistics has shown that real estates

J. Guo (&) � S. Xu

School of Economics and Management, Beijing Jiaotong

University, Beijing 100044, China

e-mail: [email protected]

S. Xu

e-mail: [email protected]

Z. Bi

Department of Engineering, Indiana University Purdue

University Fort Wayne, Fort Wayne, IN 46805, USA

123

Inf Technol Manag (2014) 15:131–139

DOI 10.1007/s10799-012-0152-7

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can be easily undervalued or overvalued. For example,

Cannon and Cole [4] indicated that real estate appraisals

have been over 12 % lower or higher than the subsequent

sales prices; the conclusion was drawn based on the

National Council of Real Estate Investment Fiduciaries

(NCREIF) National Property Index in 1984–2010, which

consisted of two up and down market cycles. It had shown

that appraisals are differed from true values to real estate

significantly; in particular, an appraisal was too low when

the market was hot while too high when the market is cold.

Poor appraisals from inappropriate approaches or inexpe-

rienced appraisers would obviously delay or miss the

opportunities for sales and transactions. The appraisal

errors are actually systematic errors which can be remedied

by improving an appraisal approach and taking into all of

the major factors related to properties’ assets.

Three common types of real estate appraisals are cost

approach, sales comparison approach, and income capi-

talization approach [11]. Since the cost, sales, or incomes

related to the properties vary significantly from one place

to another and from time to time, at a specific location and

a specific time; an experienced appraiser should be able to

select the right appraisal approach for a specific property.

When the regional transactions are inactive or real estate

markets are immature, neither sales comparison approach

or income capitalization approach is applicable due to

the lack of historical transactions or income benchmarks.

In this situation, a cost approach is recognized as the most

appropriate approach for real estate appraisals. A cost

approach is established based on the fact that the value of a

property can be determined by summating the land value

and the depreciated value of further improvements made on

the property.

Real estate appraisals are challenging tasks that require

intensive efforts; the study in developing and enhancing

various appraisal approaches has been very active research

field. For examples, Gonzalez and Laureano-Ortiz [11]

argued that a real estate appraisal resembled to the psy-

chological process humans follow in utilizing their past

experiences to solve new problems; therefore, they pro-

posed to use case-based reasoning in valuating real estate.

Note that most popular methods are driven by sales market

data; in particular, for the automated software tools of

property appraisals. In applying these methods, it is com-

mon that comparable properties are similar to the subject

property; in this case, the value adjustments must be made

to deal with the differences. Narula et al. [20] modeled the

real estate appraisals as a multiple linear regression model

for optimization. It has been found difficult to define proper

predictor variables for real estate appraisals; and the ridge

regression technique has been improved by a combination

with genetic algorithm to estimate the values of real estate

appropriately. Ann et al. [1] suggested that cost is not

always the good source of adjustments. To address the

forecasting problems of real estate appraisals, artificial

intelligence and multiple linear regressions were applied to

valuate residential property. In comparing different

investment options in the real estate market; Seck [22]

discussed the substitutability of securitized real estate asset

and appraisal-based real estate assets. The empirical data

showed that the prices for the securitized assets, such as

real estate investment trusts or stock price index of home

building industry, could be changed randomly while the

prices of the appraisal-based assets can be more likely

predicted. Diaz and Hansz [7] proposed a taxonomic

approach to consider the impact of incentives and pressures

for real estate to provide favorable valuations. Lins et al.

[18] proposed a new approach called data envelopment

analysis to estimate the range of values for real estate.

It had shown some advantages in comparison with con-

ventional regression analysis methods which are commonly

used in real estate appraisals. Shiller and Weiss [23] pro-

posed a framework to compare various valuation systems

for real estate appraisals. Since the framework was devel-

oped for mortgage lenders, the best interest was confined to

the maximized benefits of mortgage lenders. Isakson [14]

developed a multiple regression analysis method to verify

the appraisal results of real estate; it was based on the

simplifications that the covariance between the adjusted

sale price of comparable properties and the characteristics

where adjustments are properly made is negligible for a

specific property. Traditional real estate appraisal approa-

ches have been found inefficient and not correct enough.

In financial information management systems, real

estate appraisal information systems have been studied by

many researchers in the past [6, 12, 21, 27, 38]. For

example, Liu et al. [19] developed an appraisal system

while the geographic information system was used as one

source of the real estate information, and artificial neural

network was applied to improve the reasoning process. The

system was implemented in the Matlab programming

environment and the result had shown the improved effi-

ciency and accuracy of system.

In this paper, the solution to the limitation of a cost

approach will be focused. In real estate appraisal, the cost

approach is suitable for the immature markets and the sit-

uations where sales comparison approach or income

approach are inapplicable due to the lack of transactions.

Besides, cost approach can also be expanded and applied in

the insurance valuations and damage claims. The underling

idea of a cost approach is to estimate the assets of real

estate by deducting the value loss from the replacement

cost. Obviously, conventional cost approaches do not take

into accounts of dynamic, cultural, or positive market-

demanding factors. These drawbacks affect the accuracies

of real estate appraisals. In most cases, the estimated values

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are much lower than the market values of real estate. The

recent progress on cost approaches have been limited to

perfect modeling processes and take advantages of modern

mathematic tools in real estate appraisals. For example, the

fuzz set theory is applied in selecting transaction cases and

determining adjustment factors; in addition, the multiple

regression method, Markov chain prediction, grey system

theory prediction model and artificial neural network are

also proposed for forecasting the changes of properties’

values [3, 9, 16, 17, 26, 39, 40]. However, the investiga-

tions on the root causes of appraisal discrepancies are

spare.

In applying a cost-based approach, we have observed

that no consideration of dynamic, environmental, and cul-

tural factors is the major cause to the inaccuracies of real

estate appraisal. Therefore, we propose to integrate some

major components from sale comparison approach and

income capitalization approach for the value adjustment of

appraisals. The main purpose is to apply our proposed

method to the development of a more effective real estate

appraisal information system. The rest of the paper is

organized as follow. In Sect. 2, the replacement costs are

revisited to take more significant factors into account; in

Sect. 3, the limitation of conventional cost approaches are

discussed; in Sect. 4, the new methodology has been pro-

posed to adjust the costs based on valuation adjustments

and valuation coefficients; in Sect. 5, the integration of cost

approach with the income capitalized and sales comparison

approach is introduced; in particular, back-propagation

(BP) artificial neural network (ANN) has been applied to

quantify the subjective data in real estate appraisals;

finally, the reported work and new contribution have been

summarized.

2 Replacement cost: revisit and analysis

Replacement cost in a cost approach refers to a summation

of all of the necessary costs, payable taxes and anticipated

profit to acquire or rebuild the new real estate project

equivalent to the subject property. A replacement cost

represents a typical cost of a specific real estate, which can

be valued as the amount of cost to construct this property

under a given market environment; therefore, it is also

called fair cost [31, 37]. Based on the principle of substi-

tution, the value of an existing property can be measured

by the cost of constructing a substitution with the same

utilities within the property [5]. From this point of view, a

replacement cost also reflects the cost of an equivalent

property with the same utilities of the subject property. The

replacement cost can be different from the value of the

same property based on the highest and best use. In other

words, real property with the same replacement cost can be

of different use. It is unnecessary to correlate replacement

cost to functions, utilities and the ways to make profits.

Traditionally, the replacement cost in a cost approach

focuses on the long-term cost with a hidden assumption of

an equilibrium of market in a long period of time. The

replacement cost under this assumption represents the

construction cost at the specified market environment when

the appraisal is conducted; however, it does not take into

consideration of other important factors such as those

caused by the relations between supplies and demands.

Based on the aforementioned discussion, it is our

observation that traditional replacement cost in a cost

approach has a narrow meaning which covers only the part

of the market price of the real estate. To enhance real estate

appraisals, we propose to integrate some major components

from sales comparison approach and income capitalization

approach in assessing the replacement cost. The replace-

ment cost will be revised to include (1) the cost with the

best functions and utilities, (2) some invisible costs which

cannot be represented by the price under the highest and

best use, and (3) the adjustment cost reflecting the influ-

ences of the relations of supplies and demands when the

appraisal is performed. As a result, the revised replacement

cost will be an average market price of the subject property

with the given functions and utilities in a market at long-

term equilibrium.

3 Limitations of traditional cost approaches

In this section, the discussion is focused on the limitations

of traditional cost approaches in dealing with the adjust-

ment of price factors.

3.1 Influence of price factors

The market value of a real estate property can be deter-

mined based on the principle of substitutions; the major

factors under consideration include the market environment

and its fluctuation, the relations of supplies and demands,

surrounding economic atmosphere, and income capitali-

zation. Most of the researchers have emphasized on the

influence of external factors on the value of real estate, and

the significant external factors are material, economic,

social and governmental factors. Based on the theory of

technology economics, the evaluation criteria of technol-

ogy proposals are eight elements, i.e., politics, defense,

society, culture, technology, economy, environment and

natural resources [2]. In applying the theory of technology

economics for real estate appraisals, the influence of poli-

tics and defense can be integrated as the government factor,

and the influence of technology, environment, and natural

resource can be integrated as the material factor [24, 25,

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30]. However, the culture factor has to be taken into con-

sideration individually. In modern society, culture and

civilization has been treated as a comprehensive indicator

of the cohesion and creativity for a nation to compete with

others and gain its strength over time. Therefore, the

evaluation of the cultural factor should be distinguished

from those of other factors. In real estate appraisals, it

becomes necessary to consider the cultural factor as an

independent adjustment factor. As a result, the price

adjustment of real estate should be determined by material,

economic, social, governmental, and cultural factors.

3.2 Important cost factors yet considered

In a cost approach, the replacement cost is mainly land cost

and construction cost, and the other costs are considered by

applying the value depreciation, which is called as loss or

devaluation alternatively.

Depreciation can be only applied to the situation where

the factors bring an adverse effect on the value of real

estate. As a consequence, traditional cost approaches are

not able to take into account of the positive influence on

real estate asset from various factors. More specifically, (1)

invisible capitals relevant to nonmonetary factors cannot be

directly included in replacement cost. It brings the diffi-

culties in reflecting historical and cultural assets of ancient

buildings, cultural and tourism value of real estate prop-

erty, and the value of the brand property in the replacement

cost. (2) The favorable assets brought by better functional

designs of the subject property cannot be easily considered;

since existing cost approaches focus on the adjustment of

depreciation corresponding to the adverse factors; while

a property with better functions and utilities cannot be

adjusted as functional increments. (3) The change of the

environment has either positive or negative impact on

the real estate assets. Again, existing approaches ignore the

real estate appreciation led by the improvement in envi-

ronmental conditions. Note that the adverse impact on the

surrounding environment can be treated as a devaluation

factor related to a functional loss, while the increased

utilities and investment benefits from the improvement of

environment have to be taken into consideration separately.

As a summary, only the devaluations are considered in

existing cost approaches, some positive impacts, such as

the situation when the market demands exceed supplies,

should also be considered in real estate appraisals to reflect

the value fluctuations due to non-equilibrium markets.

4 Proposed improvement of cost approach

In calculating the replacement cost in dynamic and turbu-

lent environment; it becomes necessary to take into account

both of positive and negative factors. Both sides of factors

are reflected in the revised replacement cost of real estate.

In existing cost approaches, there are three adjustment

factors in determining the replacement cost: materials,

functions and economical depreciation. Based on the dis-

cussion in Sect. 3.2, the culture factor has the contribution

to real estate asset since it becomes more and more

important to our society. Therefore, the culture factor is

considered as the fourth adjustment factor. Since the values

of the construction and the land are assessed separately, it

is necessary to categorize material, functional, economical

and cultural factors under the catalogues of the construc-

tion value and the land value. At the end, the value

adjustment factors of real estate should be illustrated in

Fig. 1. Correspondingly, the value of the subject property

is estimated by Eqs. (1) and (2). Note that individual

adjustment value or adjustment coefficient in Eqs. (1) or

(2) can be positive or negative.

V ¼ Vl þ Vb þ Vm þ Vf þ Ve þ Vc ð1Þ

After the classifying the adjustments of values into the

types of land value and construction value, respectively,

V ¼ Vlð1þ Rml þ Rfl þ Rel þ RclÞ þ Vbð1þ Rmb þ Rfb

þ Reb þ RcbÞð2Þ

where V the appraisal value of real estate, Vl the replacement

cost of land, Vb the replacement cost of construction, Vm, Rml,

Rmb material value adjustment, physical value adjustment

coefficient of land and construction, Vf, Rfl, Rfb functional

value adjustment, functional value adjustment coefficient of

land and construction, Ve, Rel, Reb economic value adjustment,

economic value adjustment coefficient of land and construc-

tion, and Vc, Rcl, Rcb Cultural value adjustment, cultural value

adjustment coefficient of land and construction.

4.1 Calculation of replacement cost

Based on the theory of technology economics, six basic

forces are used as evaluation criteria to assess technology

proposal [33–36]. To refine the replacement cost, the

resources for labor and production have been decomposed

into six types: labor, capital, material, resources, transit and

time. To construct a real estate, the labor cost is the sum-

mation of the manpower consumption of designers, con-

structors and managers during the real estate project, which

can be represented by wages. The capital cost relates to the

occupation of facilities and constructions, which can be

described by the deprecation expense and overhaul spends.

The material cost includes the use of the raw materials,

components and parts, which takes into account of the cost

of all material consumptions. The transit cost occurs during

the service of the human flow, the material flow and

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information flow, which represents the cost in logistics.

The nature resource cost mainly refers to the land occu-

pation, which is equivalent to the monetary compensation

of the land expropriation, demolition, land transferring fees

and expenditure on environmental impact. The time-related

cost is the time taken during the real-estate development,

which is valued in terms of capital cost [28, 29].

Due to the variety and abundance of the resources

involved in the development of real estate, the costs on six

forces are further decomposed into land-related costs and

construction-related costs. The land-related costs are

calculated based on the level of compensation for land

expropriation and demolition at the time of appraisal; while

the labor, capital, material and transit resources costs of the

constructions are divided into direct costs and indirect

expenses. The direct costs can be determined by taking the

references of similar real estate projects. The indirect

expenses are primarily management fees and sales

expenses. Indirect expenses can be reasonably estimated

based on the direct costs with the adjustment of cost

coefficients. The capital cost is calculated over the entire

construction period as the total investment the project

needs. The development taxes are straightforward and can

be estimated by following the related regulations of

country and area. Besides, the income capitalization can be

estimated by the industry average profit margin. At the end,

the replacement cost can be calculated by

V ¼ ðCh þ Ca þ Cm þ Cn þ Ctr þ CtÞ þ P

¼ ðCl þ Ccl þ PlÞþ ½ðCh þ Ca þ Cm þ CtrÞð1þ roÞ þ Ccb þ Pb�

ð3Þ

where Cl land acquiring and developing cost, Ccl capital

cost of land developing, Pl land developing profits,

Ch human resource consumption, Ca capital resource con-

sumption, Cm material resource consumption, Cn nature

PhysicalValue

AdjustmentFactors

FunctionalValue

AdjustmentFactors

EconomicValue

AdjustmentFactors

Design Life Span

Construction Quality

Maintenance Conditions

Function Layout

Building Equipment

Decoration and Fitment

Historial Value

Brand and Art Value

Laws and Regulations

Interest Rate

Price Level

Market Supply and Demand

culturalValue

AdjustmentFactors

Land

Building

Land

Building

Land

Building

Land

Building

Land Development Status

Safety of Structure

Land Natural Conditions

Nature of Use

Population and SocialDevelopment

Fashion and Preferences

Economic GeographicalCondition

City and CommunityEnvironment

Culture Value

ValueAdjustmentFactors forReal EstateAppraisal

Fig. 1 Adjustment factors in

real estate appraisals

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resource consumption, Ctr transit resource consumption, Ct

time resource consumption, ro overhead rate, Ccb capital

cost of house-building, and Pb profit of house-building.

4.2 Value adjustments and adjustment coefficients

To calculate value adjustments and adjustment coefficients,

the multi-level comprehensive evaluation method in the

theory of technological economics is applied [29].

First, real estate adjustment factors in Fig. 1 are evaluated.

Each factor has been decomposed layer by layer until the

details are sufficient to qualify the corresponding cost. As a

result, the comprehensive evaluation has been divided into

three levels [13]: the first level is for the comprehensive

adjustment coefficients of land or construction, the second

one is for the comprehensive adjustment coefficients which

include material, function, economics and culture, and the

lowest level includes the specific indicators which have some

impacts on the values of land and construction.

Weights are assigned for each factor to aggregate all of the

costs involved in the hierarchical structure. Firstly, begin-

ning with the lowest level, according to the characteristics of

each factor, use a scoring method or indexing method to

define a quantified value to take into account the contribution

of this factor to a higher level of a comprehensive factor.

Secondly, in determining the weights of cost factors, the

relative importance between two factors is specified by the

experts, and the judgment matrices could be constructed

through comparing about their relative importance. Thirdly,

the value adjustment coefficients at the middle level are

calculated with the least square method with the multipli-

cation of the satisfaction coefficients and the importance

coefficients. Following the similar steps from the bottom to

top levels, the values for land and construction can be cal-

culated from the comprehensive adjustment coefficients.

There is no doubt that the implementation of above method

relies on available knowledge, experience and the under-

standing of the real estate appraisers. For example, the scores

are determined by the subjective judgments and ratings from

the valuators. Due to the uncertainties how the factors can

affect the value of the real estate, a systematic method is

helpful to reflect the degree of influence on these cost factors

quantifiably. Therefore, some widely used approaches, such

as the back propagation (BP) artificial neural network (ANN)

model, the income capitalization approach, sales comparison

approach, have be integrated into our cost approach to deal

with the uncertainties and dynamics.

4.2.1 ANN-based income capitalization approach

For a real estate yielding an income, its cost factors will

be eventually reflected by the sale (vacancy) rate and/or

its rental price; therefore, the impact of each cost factor

can be measured by the corresponding change of the

vacancy rate, rental price, and the operating cost to sus-

tain the impact. Do and Grudnitski [8] proposed to use an

ANN method for real estate appraisals, it has been widely

used for the classification, clustering, and forecasting. By

applying an ANN-based method, the impacts of the cost

factors on the new income of the real estate are predicted

by using massive historical data of the property or other

similar properties. In the process of evaluating, firstly,

four major cost factors are normalized based on the

accumulated data from the past, i.e., the statistics

approach is used on the data of similar projects and expert

knowledge to convert data into quantified numbers

between [0, 1]. The standard feature factors are then set to

the qualitative factors. The available data of cost factors

and the standard feature factors are compared to trans-

form qualitative factors into the relative value between [0,

1] based on the degree of similarity. In applying BP

neural network, the values of cost factors are set as the

inputs, and the annual income is set as only output. The

information included in data samples can be automati-

cally retrieved by the network and stored as network

weights. Through self-adaption and self-organization, the

neural network is capable of memorizing, recalling, and

imagining the information from the data samples about

the cost factors [10].

In applying the BP-ANN, the eigenvalue of the real

estate is input, and the annual income is predicted.

Meanwhile, the predicted annual income is compared

with the average annual earning, and the difference is the

capitalized income to measure the adjustment value. This

method can be used to estimate the value change caused

by multiple factors or a single factor. For the value

change caused by multiple factors, the comprehensive

adjustment value could be gained by capitalizing the

difference between the predicted annual income and that

of an alternative real estate. For the value change aroused

from a single factor, the value adjustment can be capi-

talization of the discrepancy of the annual income caused

by unique material, functional, economic or cultural

factor. Value change can be calculated in Eqs. (4) and (5),

respectively. When the value adjustments Da, Db, Dc,

Dd are positive, the corresponding cost factors influences

the real estate values positively; otherwise, the influence

will be the depreciation.

Vt ¼ 1� xð ÞXn1

t¼1

Dat

ð1þ iÞtþXn2

t¼1

Dbt

ð1þ iÞtþXn3

t¼1

Dct

ð1þ iÞtþXn4

t¼1

Ddt

ð1þ iÞt

!

ð4Þ

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Rt ¼ð1� xÞ

V0

Xn1

t¼1

Dat

ð1þ iÞtþXn2

t¼1

Dbt

ð1þ iÞtþXn3

t¼1

Dct

ð1þ iÞtþXn4

t¼1

Ddt

ð1þ iÞt

!

ð5Þ

where VT, RT comprehensive adjustment value and coeffi-

cient, n1, n2, n3, n4 income period influenced by material,

functional, economic and cultural factors, Da, Db, Dc,

Dd the discrepancy of annual incomes between the subject

property and other properties caused by material, func-

tional, economic and cultural factors, i capitalization rate,

and x income tax rate.

An income capitalization approach can also be used to

calculate the value adjustments of construction when the

cost factors have an impact on the income in the period of

construction. Eqs. (6) and (7) are used for the calculation.

When material, functional, economic and cultural factors

lead to the increase of surplus service life, at, bt, ct, dt are

positive; otherwise, these variables are negative when the

factors lead to decrease.

Vt ¼ 1� xð ÞXDn1

t¼1

at

ð1þ iÞtþXDn2

t¼1

bt

ð1þ iÞtþXDn3

t¼1

ct

ð1þ iÞtþXDn4

t¼1

dt

ð1þ iÞt

!

ð6Þ

or

Rt ¼ð1� xÞ

V0

XDn1

t¼1

at

ð1þ iÞtþXDn2

t¼1

bt

ð1þ iÞtþXDn3

t¼1

ct

ð1þ iÞtþXDn4

t¼1

dt

ð1þ iÞt

!

ð7Þ

where at, bt, ct, dt average market income determined by

material, functional, economic and cultural factors in future

t year, and Dn1, Dn2, Dn3, Dn4 increased or decreased of

remaining useful life of the property affected by material,

functional, economic and cultural factors.

4.2.2 ANN-based sales comparison approach

As shown in Fig. 1, although the land cost is the main

component value of the real estate, the other factors,

especially the material, functional, and cultural factors

have their impacts on real estate majorly through con-

struction. In a cost-based approach, the land cost can be

estimated from the land market information. Therefore, the

challenge of the evaluation lies in the value adjustment of

construction. However, the value adjustment of construc-

tion can be extracted by using the sales comparison

approach. Since the value loss is determined by the sellers

and the buyers in the market, the common cost that the

constructions have in their sales prices are analyzed in

massive information sales data, and then this common cost

is compared with that of the subject property, the differ-

ence is the value adjustment of construction. This approach

is suitable for the real estate appraisal when the comparable

transactions are similar to the construction. However, the

land conditions are quite different, or the sale cases and

the estimated properties are not in the same region. One

has to follow the procedure as below to determine value

adjustment,

1. Estimate the replacement cost for each comparable

transaction;

2. If possible, use the market sales data of the virgin

space as an estimation of the land value of each

comparable transaction;

3. Deduct the land value from a selling price to retrieve

the construction cost of each comparable transaction.

4. The discrepancy between the replacement cost and the

value of the real estate will be the adjustment value.

By comparing the adjustment value with the corre-

sponding replacement cost, the value adjustment

coefficient can be obtained. The resulted calculation

equations are shown in Eqs. (8) and (9). When

P \ (Vb ? Pl), the factor will produce the positive

influence to the building; otherwise, the influence will

be embodied as loss.

VT ¼ Vb � Pb; Pb ¼ P� Pl;

and

VT ¼ Vb � ðP� PlÞ ¼ ðVb þ PlÞ � P ð8Þ

or

RT ¼ðVb þ PlÞ � P

Vb

ð9Þ

where P sale price of the real estate, Pb the construction

unit value, and Pl the land unit value.

Note that the similar constructions are not necessary

having the same value adjustment. For the generalization,

one can still use the ANN-based approach to predict the

effect of construction’s value adjustment caused from dif-

ferent factors. The value influences of material, functional,

economic and cultural factors do not need to be distin-

guished. Therefore, one can choose main factors influenc-

ing the construction cost as the inputs. The value

adjustment of construction (Vb ? Pl - P) of the actual

sold transaction will be the only output. Reasonable sim-

ulation results can be obtained by training the test data.

When the test data is with a satisfactory accuracy, it can be

used in the valuation to acquire the adjustment value Vt0.

Inf Technol Manag (2014) 15:131–139 137

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Because the sold transactions were collected from dif-

ferent marketing transaction conditions, and took place in

different times, it’s necessary to further adjust Vt0 as:

Vt ¼ V 0t � f1 � f2 ¼ V 0t �100

sd

� piv

pifð10Þ

where f1 the adjustment coefficient of transaction condi-

tion, f2 the adjustment coefficient of transaction time, sd the

scoring of the comparable sold case, piv the price index of

the appraisal time, and pif the price index of the compa-

rable sold case.

5 Summary and future work

Traditional cost approaches estimate the replacement cost

of real estate mainly based on the costs on land and con-

struction with an assumption of the long-term stable mar-

ket; the definition of the replacement cost is narrow and the

calculation overlooks the dynamic, environmental and

cultural factors which cause the discrepancy between the

appraisal and the true market value of real estate. In this

paper, both of positive and negative factors related to the

value adjustments are considered, in particular, special

attentions have been paid on no-monetary or invisible

factors such as environmental and cultural factors and the

relations of supplies and demands. The new cost-based

approach has been proposed. The value depreciation and

depreciation rate have been substituted by the value

adjustments and adjustment coefficients. This is a break-

through to advance the theory of cost approach.

In implementing the proposed cost-based approach, it

has been integrated seamlessly with income capitalization

approach and sales comparison approach: income capital-

ization approach is utilized to determine the land related

value adjustments and sale comparison approach is utilized

to determine the construction related value adjustments.

Artificial neural networks are used in both cases to deal

with dynamics, uncertainties, as well as the subjective

knowledge from experts. Major cost factors have been

divided into material, functional, economic and cultural

factors; these factors are further assessed under the cata-

logues of land value and construction value, respectively.

The replacement cost has been evaluated by qualifying the

contributions from six basic forces of a technology pro-

posal under the theory of technology economics. The new

method has theoretically supported the innovative idea on

improving the appraisal accuracy with the consideration of

dynamic, environmental, cultural factors. Besides, it has

firstly integrated sales comparison and income capitaliza-

tion approaches in the cost-based approach. Since ANN-

based methods have been inventively applied to determine

the adjustment coefficients and values, the implementation

of new cost approach requires high-performance computers

to deal with massive market data, which may increase

complexity of the evaluating process. Therefore, our future

research effort in this field will be focused on (1) the

exploration and refinement of cost factors in detail levels to

further increase the accuracy of estimated value of real

estate; (2) the adaption of parallel computing to improve

the efficiency for the determination of the adjustment

coefficients and values; and (3) the development of a

commercial software for real estate appraisals [3],

Acknowledgments This project was partially supported by the

NSFC (National Natural Science Foundation of China) Grant

71132008 and the Changjiang Scholar Program of the Ministry of

Education of China.

References

1. Ann J, Byun H, Oh K, Kim T (2012) Using ridge regression with

genetic algorithm to enhance real estate appraisal forecasting.

Expert Syst Appl 39:8369–8379

2. Betts R, Ely Silas (2000) Basic real estate appraisal, 5th edn,

South-Western

3. Bi X, Su W, Wang L (2012) An analysis on the macroscopic

growth process and stage of information systems development in

Chinese enterprises. Inf Technol Manage 13(4):273–280

4. Cannon S, Cole R (2011) How accurate are commercial real

estate appraisals: evidence from 25 years of NCREIF sales data.

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1824807

5. Cao J (1997) Theory and method on modern real estate valuation,

Publishing House of Zhongshan University, Guangzhou, ISBN:

306012797 and 9787306012791

6. Chen X, Fang Y (2012) Enterprise systems in financial sector—

an application in precious metal trading forecasting. Enterp Inf

Syst. doi:10.1080/17517575.2012.698022

7. Diaz J, Hansz J (2010) A taxonomic field investigation into

induced bias in residential real estate appraisals. Int J Strateg Prop

Manage 14(1):3–17

8. Do A, Grudnitski G (1992) A neural network approach to resi-

dential property appraisal. Real Estate Apprais 58(3):38–45

9. Duan L, Xu L (2012) Business intelligence for enterprise sys-

tems: a survey. IEEE Trans Industr Inf 8(3):679–687

10. Gao Z, Li Z (2008) System engineering. Northwestern Poly-

technic University Press, Xian

11. Gonzalez A, Laureano-Ortiz R (1992) A case-based reasoning

approach to real estate property appraisal. Expert Syst Appl 4(2):

229–246

12. Guo J, Gong Z (2011) Measuring virtual wealth in virtual worlds.

Inf Technol Manage 12(2):121–135

13. Huang S (2006) The research of historical buildings evaluation

index system. Ph.D. Thesis, Tongji University

14. Isakson H (1998) The review of real estate appraisals using

multiple regression analysis. J Real Estate Res 15(1/2):177–190

15. Kettani O, Oral M, Siskos Y (1998) A multiple criteria analysis

model for real estate evaluation. J Global Optim 12(2):197–214

16. Li L (2011) Introduction: advances in e-business engineering. Inf

Technol Manage 12(2):49–50

17. Lin Y, Duan X, Zhao C, Xu L (2012) Systems science method-

ological approaches. CRC Press, Boca Raton, FL

18. Lins M et al (2005) Real estate appraisals: a double perspective

data environment analysis approach. Ann Oper Res 138(1):79–96

138 Inf Technol Manag (2014) 15:131–139

123

Page 9: An integrated cost-based approach for real estate appraisals

19. Liu X, Deng Z, Wang T (2011) Real estate appraisal system

based on GIS and BP neural network. Trans Nonferrous Met Soc

China 21:s626–s630

20. Narula S, Wellington J, Lewis S (2012) Valuating residential real

estate using parametric programming. Eur J Oper Res 217(1):

120–128

21. Qian Y, Jin B, Fang W (2011) Heuristic algorithms for effective

borker deployment. Inf Technol Manage 12(2):55–66

22. Seck D (1996) The substitutability of real estate assets. Real

Estate Econ 24(1):75–95

23. Shiller R, Weiss A (1999) Evaluating real estate valuation sys-

tems. J Real Estate Financ Econ 18(2):147–161

24. Song B, Xu S (2009) The theory of material flow substance. Syst

Res Behav Sci 26(2):251–258

25. Tian Y, Xu S, Wang L, Chaudhry P (2009) On relationships

between material flow and economic development in an eco-

nomic–material flow system. Syst Res Behav Sci 26(2):259–267

26. Wang P, Xu L, Zhou S, Fan Z, Li Y, Feng S (2010) Novel

Bayesian learning method for information aggregation in modular

neural networks. Expert Syst Appl 37(2):1071–1074

27. Xia Y, Su W, Lau R, Liu Y (2011) Discovering latent commercial

networks from online financial news articles. Enterp Inf Syst. doi:

10.1080/17517575.2011.621093

28. Xiong Y, Guo J, Zhou F, Xu S (2007) Theory of construction

project optimization resources scheme. J Beijing Jiaotong Univ

(Soc Sci Ed) 6(2):18–22

29. Xiong Y (2006) Theory and methodology of construction project

resource allocation optimization. Ph.D. Thesis, Beijing Jiaotong

University

30. Xu L, Swanson G, Samuelson K (2009) Systems science and

enterprise integration, technological economics and the theory of

material flow. Syst Res Behav Sci 26(2):123–127

31. Xu S (1988) The theory of technological economics. Jiangsu

People’s Publishing House, Nanjing. ISBN 7-214-204-300

32. Xu S (2006) Theory of six forces on factors of production.

J Beijing Jiaotong Univ 5(3):15–20

33. Xu S (2009) Theory of six forces of essential factors of pro-

duction. Syst Res Behav Sci 26(2):211–218

34. Xu S (2009) Doubling guarantees quadrupling—theory and

practice. Syst Res Behav Sci 26(2):225–234

35. Xu S (2009) A theoretical study on commodity material flow.

Syst Res Behav Sci 26(2):235–249

36. Xu S (2011) Study on comprehensive appraisement theory of tech-

nology program. J Beijing Jiaotong Univ (Soc Sci Ed) 10(1):36–39

37. Xu S (2012) Technological economics, Economic Science Press,

Beijing, ISBN:978-7-5141-0908-5

38. Xu S, Xu L, Basl J (2012) Introduction: advances in e-business

engineering. Inf Technol Manage 13(4):201–204

39. Zeng L, Li L, Duan L (2012) Business intelligence in enterprise

computing environment. Inf Technol Manage 13(4):297–310

40. Zhou S, Xu L (2001) A new type of recurrent fuzzy neural network for

modeling dynamic systems. Knowl Based Syst 14(5–6):243–251

Inf Technol Manag (2014) 15:131–139 139

123


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