The construction industry is one of the largest markets in the global economy, playing a vital role in creating essential environments for people’s lives. According to the Global Construction 2030 – CIOB Executive Summary*1,the global construction market is projected to grow by $8 trillion, an 85% increase from 2015, reaching a total scale of $17.5 trillion by 2030, accounting for 14.7% of global GDP.  However, a staggering estimate reveals that additional costs caused by design errors in the construction market amount to $85 billion annually, highlighting a significant challenge for the industry as a whole.
This article delves into the overview of additional costs stemming from design errors, explores the causes and impacts of these errors, and provides insights based on various research findings.

Overview of Additional Costs Due to Design Errors

In the construction industry, various issues often arise during the progress of projects, resulting in significant additional costs for their resolution. According to research by Ingvaldsen(1994, 2001)*2 , approximately 40% of problems occurring in the construction industry may be attributed to errors in the design process. Furthermore, a study by Lopez & Love (2012)*3 on additional costs caused by design errors in construction projects found that, on average, direct costs accounted for 6.85% and indirect costs for 7.36% of the contract amount. The research also indicated that additional costs due to design errors do not vary significantly based on procurement methods or project types.

It is important to note that Ingvaldsen’s research primarily focuses on the Norwegian construction industry. However, the potential impact of 40% of additional costs being attributed to design errors is significant for the industry. Assuming that 90% of the construction market is cost-based, the additional costs caused by design errors could amount to as much as $865 billion annually. The calculation is as follows:

・$17.5 trillion*90％*Additional Cost Approx.14％（6.85%+7.36%)*40%＝Approx. $865 billion

The Current Situation of Additional Costs in the Construction Market

Additional costs refer to expenses incurred in construction projects to address deviations from the original plan or to resolve arising issues. The primary types of additional costs include the following:

1. Correction Costs（Redesign and Repair Expenses）
Expenses incurred for redesigning or additional construction work to rectify design errors.

2. Costs Due to Construction Delays
Additional expenses for labor, equipment, and management resulting from extended project timelines.

3. Safety Risk Management Costs
Expenses for redesign, safety measures, and accident prevention to comply with safety standards.

4. Quality Control and Inspection Costs
Additional expenses for inspections, testing, and adjustments to address and rectify design errors.

5. Project Reassessment and Design Modification Costs
Expenses incurred for reviewing and readjusting the overall project or related projects.

6. Operational and Maintenance Costs
Higher maintenance and management expenses for facilities or buildings resulting from design errors.

7. Legal and Contractual Costs
Legal expenses such as litigation fees, settlement payments, compensation, and attorney fees.

These costs can escalate significantly the later design errors are discovered. Moreover, beyond the additional expenses incurred within the project, it is not difficult to imagine that such issues can indirectly lead to a decline in corporate value. This may manifest as a loss of future project opportunities due to diminished trust in the company, or even a drop in stock prices.

Causes and Impacts of Design Errors

auses of design errors? Based on the studies by Musa(2016)*4  and Mahamid（2021）*5 , the primary causes of design errors are summarized as follows:

1.Time Constraints
Time constraints during the design phase are a major factor contributing to design errors. When designs must be completed within a limited timeframe, thorough verification and reviews may be overlooked, allowing mistakes to go unnoticed. Additionally, rushing to meet tight schedules can compromise the quality of the design.

2.Insufficient Funding
A lack of adequate funding for construction projects, such as insufficient budget allocation for thorough investigations needed to produce high-quality design documents, can be a contributing factor to design errors.

3. Lack of Communication
A significant factor contributing to design errors is the “lack of communication” among project stakeholders. When the intentions of designers, contractors, and clients are not effectively conveyed, the design may fail to reflect the intended requirements accurately.

4.Frequent Change Orders
Frequent changes to construction requirements are another major factor leading to design errors. In large-scale projects, designs may need to adapt to evolving circumstances. When these changes are not accurately reflected in the design or adequately communicated among stakeholders, issues can arise.
Especially in long-term, large-scale projects, the multitude of change orders over time increases the likelihood of errors.

5. Lack of Technical Knowledge or Misunderstanding
Design errors can also occur when designers lack proficiency in the latest technologies or software, are unaware of updates to design standards or regulations, or misinterpret them. Additionally, materials or construction techniques used in past projects may no longer be available or permissible due to legal restrictions, potentially leading to errors. When new materials or construction techniques are introduced, if designers do not fully understand their technical properties, incorrect designs may result.

6. Simple Errors Due to Carelessness
When designers are overwhelmed with multiple tasks and high workloads, simple human errors can occur. These include calculation mistakes, inaccuracies in data entry, incorrect annotations on design drawings due to carelessness or insufficient verification, and overlooked checks. Sometimes, such errors might even stem from simple misunderstandings. These mistakes can occur regardless of the designer’s intentions or level of expertise.

Particularly, “time constraints” and “insufficient funding” could be considered fundamental causes that lead to other factors. For instance, the need to meet tight deadlines may result in insufficient time for proper communication or thorough investigations, forcing the design process to be completed prematurely. Similarly, a lack of funding often prevents adequate verification and detailed analysis during the design phase, frequently leading to significant problems later in the project.

Details of Design Errors

Design errors can appear in various forms. Looking at past cases, the following are typical examples of design errors:

1. Drawing Errors
These include mistakes in architectural, structural, or mechanical drawings. Common errors involve incorrect dimensions, inappropriate material details, and omissions in instructions. According to  the survery by Ministry of Land, Infrastructure, Transport and Tourism (MLIT)*6 , drawing errors were the most frequently reported type of design mistake. In Dosumu(2018)*7  study, architectural and structural drawings were highlighted as particularly prone to errors. Key issues identified included incorrect dimensions in architectural drawings, errors in structural design calculations, inaccuracies or insufficient details in specifications, and omissions of critical details.

2. Errors in Setting Site Conditions (such as ground and wind environment)
Particularly in structurally complex projects such as high-rise buildings or large-scale mixed-use facilities, mistakes in setting structural conditions can lead to critical issues. These errors may result in insufficient building strength or safety concerns, ultimately requiring significant revisions and corrections.

3. Error in material selection
When the materials selected by the designer are not suitable for the actual construction environment or do not meet the standards, it may result in the need to replace the materials or carry out renovation work after construction.

Such design errors, if discovered in the later stages of an ongoing project, require time and cost for correction, which can ultimately lead to significant additional expenses that greatly exceed the overall project budget.

Conclusion

In the future, reducing additional costs caused by design errors in the construction industry will require improving accuracy in the early stages of design and preventing mistakes from occurring in the first place. Preventing design errors can ultimately lead to greater efficiency across the construction market, enhancing productivity and contributing to sustainable growth.

At Tektome, we are developing an AI-driven architectural design platform using generative AI to address this challenge in the construction industry. In the upcoming articles, we will discuss the challenges related to design errors as perceived by Tektome and our strategies for resolving them.

 

 

  1. Global Construction Perspectives and Oxford Economics(2015),Global Construction 2030
  2. Ingvaldsen Thorbjørn(1994) Byggskadeomfanget i Norge. Utbedringskostnader i norsk bygge-/eiendomsbransje – og erfaringer fra andre land
  3. Robert Lopez&Peter E. D. Love(2012),Design Error Costs in Construction Projects
  4. Shamsudeen Musa(2016),EFFECTS OF DESIGN ERRORS ON CONSTRUCTION PROJECTS
  5. Ibrahim Mahamid(2021),Effects of Design Quality on Delay in Residential Construction Projects
  6. MLIT(2015), Ensuring the Quality of Design Deliverables
  7. Oluwaseun S Dosumu(2018), An assessment of the causes, cost effects and solutions to design-errorinduced variations on selected building projects in Nigeria