Methodology and Quality Update

Latest Update on Methodology and Quality

23/07/2026

Statistical Presentation

Data description

The Construction Cost Index (CCI) presents data on the costs of construction inputs in the Kingdom of Saudi Arabia.

• Objectives:
  -    Measuring changes in the construction costs for Basic materials, labor, and the rental of machinery and equipment and Energy.
  -    Providing accurate data for economic analysis and decision-making.
• Choosing the base year:
  Choosing a reference year (base year) for calculating the index that reflects a stable state of the economy, which is 2023.
• Product classification:
  -    Classifying products into groups and categories based on their nature and use. 
  -     Adopting the National Classification of Economic Activities(ISIC Rev. 4), and the Central Product Classification (CPC).
• Calculating weights:
  Calculating the weights of activities and products based on their contribution to the domestic economy, using the results of the Structural Survey 2023 and the value-added results from the National Accounts 2023.
• Collecting prices:
  -    Collecting product prices periodically (monthly) to ensure the continuous update of the index by collecting data through field-based CAPI.
  -    Using the selling prices provided by contracting offices, engineering offices, and building materials retailers Wholesale.
• Calculating the index: 
  Applying the Laspeyres equation to calculate the index.
• Analyzing data:
  Analyzing the collected data to understand changes in prices, interpreting the results, and producing periodic reports.
• Publishing results:
  Publishing the index results regularly through reports and publications issued by the General Authority for Statistics (GASTAT).
• Providing data to economic analysts and decision-makers. 
  The index measures changes in the cost of a set of key components involved in the construction process, such as:
  -    Basic materials: Steel, cement, concrete, bricks, and others.
  -    Labor costs: Wages of workers and technicians.
  -    Equipment costs: Renting or operating heavy equipment.
  -    Related services: energy, and subcontracting works.

Classifications

The following classifications are applied in the Construction Cost Index.
National Classification of Economic Activities (SSIC Rev. 4):
It is a statistical classification based on the International Standard Industrial Classification of All Economic Activities (ISIC Rev. 4), used to describe the productive activities of an establishment.
Central Product Classification (CPC Ver. 2):
The CPC covers goods and services, and its purpose is to compile and organize all types of data that require product details.
Detailed data are collected through interviews to allow the production of outputs according to all relevant classifications.
Classifications are available on GASTAT's website: www.stats.gov.sa 

Statistical concepts and definitions

Key terms and concepts included in the Construction Cost Index are as follows:

• Construction Cost Index (CCI):
  A relative measure that measures changes in construction costs over two time periods for a basket of construction materials and construction services. It is an important index relied upon by planners and researchers in the fields of development and production in general.
• Monthly change rate: 
  It is an index that reflects the relative monthly changes in the prices of goods and services between the current month and the previous month.
• Annual change rate:
  It is an index that reflects the relative annual changes in the prices of goods and services between the target month and the corresponding month of the previous year.
• Goods:
  A set of products produced in the Kingdom of Saudi Arabia from consumer goods.
• Quantity:
  The output produced during the target month, measured using a specific unit of measurement (tons, kilograms, cubic meters, etc.).
• Price:
  It is the price of a good or service.

Data sources

The Construction Cost Index (CCI) data are based on two sources:
First source: Data for the Construction Cost Index (CCI) Survey are obtained from a field survey. 
Second source: Data from administrative records:

• Aramco.
• Saudi Energy (Saudi Electricity Company).
  Main variables published from the administrative data source are:
• Construction cost indices and change rates.
• Construction cost indices and change rates by sector.
• Construction cost indices and change rates by section.
• Construction cost indices series by sections and groups at the Kingdom level.

Designing the data collection tool

An electronic form (CAPI) was designed to ensure ease of use by field researchers. Data were collected using a questionnaire prepared and designed by specialists at GASTAT. During its design, international recommendations, standards, and definitions were taken into account, and it was also shared with relevant entities to gather their feedback and comments. The questions were formulated in a specific scientific manner to standardize the way questions are asked by field researchers.
Programming the questionnaire and developing the necessary tools for conducting Computer-Assisted Personal Interviews (CAPI).
Questionnaire sections:

• Geographical and economic activity data of the establishment.
• Availability of items.
• Goods and services items.
• Supporting attachments.

Editing and validation rules:
Audit and control rules were incorporated into the questionnaire to ensure that the data collected is consistent, accurate, and logical. These rules were designed by establishing logical relationships between responses, questions, and various variables to assist the field researcher in directly detecting any errors during data entry.
To ensure the quality of the Construction Cost Index (CCI) data, four types of editing and validation rules were established, as follows:

• Automated control rules:
  These are rules established for the automatic aggregation of certain fields, or for the automatic validation of responses in specific fields that are consistent across certain forms, and there are five (5) such rules.
• Navigation rules between sections and fields:
  Special rules were programmed to regulate automatic navigation between sections and fields based on the respondent’s answers, totaling 3 rules.
• Error rules:
  These are rules that cannot be bypassed during the data entry process. The field researcher must correct the data by referring back to the respondent to verify its accuracy. The total number of these rules exceeds 2.
• Warning rules:
  These rules are designed to verify the validity of the data entered by the researcher. The field researcher may override them if the entered data are confirmed to be correct, with a total of 5 rules.
  Administrative data are collected based on standardized data request tables directed to data-owning entities to obtain periodic, harmonized, and documented data derived from administrative records related to the Construction Cost Index indicators, thereby ensuring improved data quality and integration across different data sources.

Questionnaire test (cognitive test)

The outputs of the previous cognitive testing were relied upon, and there was no need to repeat the test for this year. The interview sample consisted of a random sample of establishments. Cognitive testing was conducted on several questionnaire questions based on the cognitive testing pillars. Several observations were identified related to the following pillars: the overall concept of the question, clarity of question wording, clarity of the terms used in the question, and the appropriateness of the response options.

Statistical population

The statistical population of the Construction Cost Index (CCI) survey consists of all establishments engaged in the following economic activities:

• 4100: Construction of buildings.
• 4311: Demolition activities.
• 4321: Electrical installation.
• 4330: Building completion and finishing.
• 4390: Specialized construction activities.

In the Kingdom of Saudi Arabia, the survey covers the targeted economic sectors, specifically establishments classified by size (large, medium, and small) within the Business Frame, which serves as the list containing all units of the target population for this survey and other economic surveys conducted by GASTAT. The frame includes the classification of all establishments by economic activity at multiple levels, as well as establishment size, administrative regions, and other basic data used in designing various economic samples covered by the National Classification of Economic Activities (ISIC4). The sampling frame is a list of all establishments that meet the survey eligibility criteria as identified by the owning department.

Sample design

The sample was designed and selected using the cut-off sampling method, as the survey prioritizes focusing on establishments with the highest relative importance in terms of the volume of transactions related to construction cost prices in the Kingdom of Saudi Arabia. This was applied across the main survey target strata, namely economic activity at the fourth level of the National Classification of Economic Activities (ISIC4) for the specified activities (4100, 4311, 4321, 4330, and 4390), and the 13 administrative regions, while taking into account the number of items associated with each targeted survey activity:
Stratification:
To increase the efficiency of the sample and improve its representation of the target population, establishments in the sampling frame were classified into homogeneous strata to obtain more accurate results compared with a simple random sampling method of the same size. This also ensures a sufficient number of establishments and prices at publishable levels. Two levels of stratification were applied, as follows: 

• Stratification at the fourth-level classification of economic activity (ISIC4).
• Stratification at the level of administrative regions. 

Sample size:
The sample size was calculated for each stratum h within each study domain (economic activity at the fourth level of the International Standard Industrial Classification of All Economic Activities (ISIC4) and administrative region) based on achieving a specified number of price observations for each item. The calculation took into account the average number of items expected to be found at each outlet, as well as the anticipated non-response rate.
The sample was selected using the cut-off sampling method across all target strata. This method is based on ordering the sampling frame according to the relative importance of establishments, measured by the number of employees in each establishment. The above procedures resulted in a total sample size of 2,632 establishments.

Statistical unit

The statistical unit used in the Construction Cost Index (CCI) is the establishment.

Data collection

Survey data collection:
Construction Cost Index (CCI) data are collected through Computer-Assisted Personal Interviewing (CAPI).  
Data collection from administrative records:
Administrative data for the Construction Cost Index (CCI) are obtained from Aramco, covering gasoline and diesel prices, and from Saudi Energy, which provides electricity price data. 
The data is stored in GASTAT’s databases after undergoing auditing and review processes in accordance with established statistical methods and recognized quality standards. The data source can be referred to in case of any errors or observations regarding the data.

Data collection frequency 

Construction Cost Index (CCI) data are collected on a monthly basis.

Reference area

The Construction Cost Index (CCI) covers all 13 administrative regions in Saudi Arabia.

Reference period (time reference)

Construction Cost Index (CCI) data are referenced to the calendar month preceding the survey implementation period, during which the following activities are carried out: Collecting prices for construction cost items (goods and services) that reflect the price levels for that reference month.

Base period

The base year used for calculating the Construction Cost Index (CCI) is 2023.

Measurement unit

The results are calculated as percentages (%), representing the annual and monthly change rates in the general Construction Cost Index (CCI), as well as the annual and monthly change rates in the indices of the sub-economic activities (after calculating the economic activity indices).

Time coverage

Data are available from 2024 to 2026 on a monthly basis.

Publication frequency

Construction Cost Index (CCI) results are published on a monthly basis in accordance with the approved statistical plan.

Statistical processing

Error detection

Thorough procedures are implemented to detect errors in the field data, while supporting methods are applied to measure quality indicators, in accordance with methodological procedures that ensure the accuracy and consistency of the data. These procedures include the following:

• Identifying illogical or out-of-range values. 
• Classifying the data and verifying its accuracy, with reference to the primary data source whenever any errors or data quality issues are identified.
• Reviewing the internal consistency between variables to verify the logical coherence of the values and indicators.
• Comparing the current data with previous data to ensure the integrity of the time series before processing the data and producing the final results.
• Reviewing data published by other official sources as supporting data for comparison and verification of the accuracy of the values and statistical trends.

Data integration and matching from multiple sources 

The Construction Cost Index (CCI) relies on comparing data received from multiple sources when reviewing certain of its indicators to achieve data integration and enhance the accuracy and comprehensiveness of the data. This is achieved by utilizing data from other programs within the department, as well as statistical data published by GASTAT.

Imputation and calibration

First: In case of missing data from points of sale:

• Verification of point of sale status:
  -    Verifying whether the outlet is temporarily or permanently closed.
  -    Verifying the existence of refusal to cooperate or a temporary field obstacle.
• Revisiting the outlet:
  -    In cases of temporary unavailability, the point of sale is revisited at a later time within the same survey cycle.
• Replacement of the outlet:
  -    If the outlet is permanently closed or has ceased operations, a similar alternative point of sale is selected from the same category and geographical location.
• Documentation of the case:
  -    Recording the observation in the system and specifying the reason for the absence and the action taken (refusal, closure, relocation, etc.).
  Second: In case of missing data from items (goods or services):
•  Identifying the type of disappearance:
  -    Is the item temporarily unavailable or permanently discontinued?
• Treatment of temporarily missing items:
  -    Calculating the average price based on similar items or from other points of sale within the same city.
  -    Automatically resuming pricing once the item reappears in the market.
• Treatment of permanently discontinued items:
  -    Verifying the item’s discontinuation across more than one point of sale and over more than one survey cycle.
  -    Removing the item from the sample and replacing it with an alternative item that has the same consumption characteristics.
  Applied statistical estimation:
  GASTAT adopted the internationally recognized formulas for calculating the main index indicators. 

Seasonal adjustments

Not applicable, as the final results for each year are published based on data from official sources.

Adjustment of preliminary results 

Not applicable, only final results will be published.

Resources used

Quality dimensions

Suitability

A criterion that indicates the extent to which the product meets users' needs.

User needs 

Internal users in the GASTAT for the Construction Cost Index data:

• National accounts.
  Several external users and beneficiaries greatly benefit from the Construction Cost Index (CCI) data, including:
• Government entities.
• Regional and international organizations.
• Research institutions.
• Media.
• Individuals.

Key variables that external users benefit from:
 

Completeness 

The Construction Cost Index (CCI) data are based on the (field) survey conducted monthly by GASTAT. The survey falls under the classification of (Economic Statistics) and is conducted on a sample of contracting offices, engineering offices, and building materials retailers operating in the targeted economic activities. It should be noted that the data are complete.

Accuracy and reliability 

A criterion that indicates the extent to which calculations or estimates are close to the accurate or true values that reflect reality.

Overall accuracy 

• Data quality is enhanced through the selection of researchers based on a set of practical and objective criteria related to the nature of the work, as well as their qualification and training.
• Alert, prevention, and correction rules are applied during the data collection process through the electronic questionnaire of the Construction Cost Index (CCI) to improve data quality.
• The data is examined against previous years to identify any significant changes.
• The internal consistency of the data is checked before it is finalized.
• The links between variables are checked and coherence between different data series is confirmed.

Timeliness and punctuality 

Timeliness: A standard that indicates the length of time between the availability of information and the occurrence of the event.
Punctuality: It reflects the time lag between the data publication date and the target date when publication actually occurs.

Timeliness 

GASTAT applies the Special Data Dissemination Standard (SDDS) issued by the International Monetary Fund (IMF). According to this standard, all statistical agencies are required to publish data on a monthly basis, with a time lag not exceeding 6 weeks (42 days) after the end of the reference period. If the data are from different sources, they may be published at a different frequency.

Punctuality 

Publication takes place in accordance with published release dates for 
the Construction Cost Index (CCI) on GASTAT’s webpage.
The data are available at the expected time, as scheduled in the statistical release calendar. If the publication is delayed, reasons shall be provided.

Coherence and comparability

A standard that refers to the necessity of internal and temporal consistency of statistics, their logical coherence, and their comparability and integration across different regions and sources.

Comparability - geographical

Statistical data related to the Construction Cost Index (CCI) are fully comparable geographically within Saudi Arabia, as well as at the regional and international levels.

Comparability - over time 

The survey started in 2024 as a monthly survey. Below are the main changes that have occurred to the survey: 

• Annual comparison, by comparing the target month with the corresponding month of the previous year.
• Monthly comparison, by comparing the target month with the previous month.

Coherence- cross domain

The data are consistent, as their coherence is verified against all other statistics containing similar indicators. These procedures contribute to ensuring integration and coherence among statistics, enhancing data reliability and the quality of the analyses based on them, and ensuring that the results are free from any unjustified inconsistencies.

Coherence- annual and sub-annual statistics 

Not applicable, as the Construction Cost Index (CCI) is published on a monthly basis, and there are no annual publications.

Coherence- national accounts 

The Construction Cost Index (CCI) is consistent with the foundations upon which the Gross Domestic Product (GDP) and national accounts data are based.

Coherence- internal 

The Construction Cost Index (CCI) estimates for the reference period have full internal coherence, as they are all based on the same corpus of microdata, and they are calculated using the same estimation methods.

Accessibility and clarity

Users’ accessibility of data and the extent to which accurate or aggregate data are available. It also refers to the availability of the Methodology and Quality Report.

News

The announcements for each publication are available on the statistical calendar as mentioned in 10.1. The news can be viewed on GASTAT’s website at the link: 
News

Publications

GASTAT issues publications and reports on the Construction Cost Index on a regular basis within a pre-prepared dissemination plan and are published on GASTAT’s website. GASTAT is keen to disseminate its results in a manner that serves all types of users, including publications in various formats that contain dissemination tables, charts of data and indicators, the Methodology and Quality Report, and the questionnaires used, in both Arabic and English.
The results of the Construction Cost Index (CCI) are available at:
Construction Cost Index

Online database

Not available.

Microdata accessibility

Not available.

References and standards

Construction Cost Index (CCI) standards:
GASTAT carries out all its statistical activities in accordance with a unified methodology that is consistent with the nature of each statistical product. In doing so, it relies on the Statistical Business Process Manual, which is aligned with the procedures adopted by international organizations in coordination with the relevant entities.

• For more details, you can refer to the attachment.
  Generic Statistical Business Process Model(GSBPM)
• International Recommendations for Energy Statistics (IRES):
  Concepts, definitions, issues, and classifications aligned with the international recommendations for energy statistics adopted by the United Nations Statistics Division.
  International Recommendations for Energy Statistics (IRES) 

Quality assurance

GASTAT is committed to the following principles: Impartiality; user-oriented statistical products; quality of processes and outputs; effectiveness of statistical processes; and minimizing respondent burden. 
Data are validated through quality procedures and controls implemented at various stages of the statistical process, including data entry, data collection, and other final controls.

Quality assessment

GASTAT carries out all statistical activities in accordance with the National Model (Generic Statistical Business Process Model (GSBPM)). During the comprehensive evaluation phase, which is the final phase of the GSBPM, information collected throughout each phase or sub-process is used to prepare an evaluation report summarizing all quality-related challenges associated with each statistical process. This report serves as an input for improvement and development actions.

Confidentiality

Confidentiality - policy

According to Royal Decree No. 23 dated 07/12/1379, data must always be kept confidential and must be used by GASTAT for statistical purposes only.
Therefore, the data is protected in the data servers of GASTAT.

Data processing confidentiality

Data from the SMEs survey are presented in the right tables in order to summarize, understand, as well as extract their results. Moreover, to compare them with other data, and to obtain statistical significance about the selected study population. However, referring to such data indicated in tables is much easier than going back to check the original questionnaire that may include some data like names and addresses of individuals, and names of data providers, which violates the data confidentiality of statistical data.
“Anonymity of data” is one of the most important procedures. To keep data confidential, GASTAT removed information on individual persons, households, or business entities in such a way that the respondent cannot be identified either directly, such as by name, address, contact number, identity number, etc., or indirectly by combining different, especially rare, characteristics of respondents, such as age, occupation, education, etc.

Dissemination policy

Statistical calendar

The Construction Cost Index (CCI) has been included in the Statistical Calendar. 
Statistical Calendar

User accessibility

One of GASTAT’s objectives is to better meet its clients' needs; therefore, it provides them with the results of the Construction Cost Index (CCI) Publication as soon as they are released.
GASTAT also receives clients' questions and inquiries regarding the publication and its results through various communication channels, such as:

• GASTAT’s official website: www.stats.gov.sa
• GASTAT's official email address:  info@stats.gov.sa
• Official visits to GASTAT’s official head office in Riyadh or one of its branches in Saudi Arabia.
• Official letters.
• Unified number: (199009).