Construction Quality Control: Avoiding Costly Mistakes

By

Tom Proctor

Reviewed by 

Zoe Mullan

and Nicholas Dunbar

Last Updated Mar 2, 2026

By

Tom Proctor

Reviewed By

Zoe Mullan

and Nicholas Dunbar

Every construction project begins with a client's vision, which the design team translates into drawings and specifications. Contractors, subcontractors, and suppliers then provide the materials, equipment, and labour to bring that vision to life. With so many moving parts and stakeholders involved, ensuring the final result matches the design – and complies with regulatory requirements – presents a significant challenge.

Although excellence is the goal across the UK construction sector, rework and defect rates stay stubbornly high, hitting project profits, industry reputation, and the value clients receive for their budgets. Poor quality control also extends project programmes and keeps researchers and regulators busy trying to understand how to move the needle. To address this, firms must align strictly with the Building Safety Act 2022, UK Building Regulations, and standards such as ISO 9001.

What is Construction Quality Control?

Quality control (QC) in construction refers to the processes, procedures, and standards that ensure the final product meets design specifications, regulatory requirements, and client expectations. QC focuses on preventing and correcting deficiencies in materials and workmanship to deliver a safe and fit-for-purpose building. In essence, it answers the question: "Is the work done correctly?"

Why Construction Quality Control Matters

Quality control is essential in construction for several reasons:

• Regulatory Compliance & the Building Safety Act

  Strict adherence is non-negotiable. Under the Building Safety Act 2022, dutyholders must demonstrate that they are managing structural and fire safety risks, and replacing generic checks with rigorous evidence collection. The most stringent requirements apply to higher-risk buildings (HRBs).

• Cost Efficiency

  Rework, defects, and non-compliance can significantly inflate project costs.

• Reputation & Trust

  High-quality construction enhances a company's reputation and builds trust among clients and occupiers.

• Client Satisfaction

  Delivering a project that meets or exceeds expectations strengthens long-term relationships and supports business success.

Quality Control vs Quality Assurance

Although practitioners often use these terms interchangeably, QC and QA are distinct concepts. Quality Assurance (QA) focuses on the process – specifically prevention – and forms one component of a broader Quality Management System (QMS). ISO 9001 is the internationally recognised standard for QMS and encompasses not only QA, but also quality control, risk-based thinking, continuous improvement, and customer focus. 

Quality Control (QC) focuses on the product through inspection and testing to verify compliance with designs, project specifications, drawings, and the minimum standards set out in the Building Regulations and associated Approved Documents. Effective quality management requires both QA and QC working in tandem to achieve the best results.

The Four Types of Construction Quality Control

To ensure comprehensive coverage, practitioners typically categorise quality control methods into four types: 

1. Visual Inspections – Checking finishes, alignment, and cleanliness.
2. Destructive Testing – E.g., concrete cube crushing to verify strength.
3. Non-Destructive Testing – Ultrasonic or X-ray testing to inspect internal structures without causing damage.
4. Performance Testing – Pressure testing pipes or commissioning MEP systems.

Five Common Causes of Quality Issues

Despite industry advancements, quality control is a significant challenge. Several key factors contribute to poor outcomes:

1. Time Constraints & Rushed Construction

   Many projects operate under tight deadlines, which leads to rushed work, skipped steps, and overlooked details. Design-and-build contract models often result in works packages being tendered against preliminary designs, which increases the risk of poor buildability and quality struggles.

2. Prioritising Cost Over Quality

   A noticeable shift has taken place in construction practice, with affordability frequently taking precedence over longevity. Buildings constructed decades ago tend to exhibit superior durability compared to modern lightweight structures, which require precise detailing and high-quality workmanship to match older standards.

3. Material Substitutions & Product Quality

   Quality issues frequently stem from subcontractors substituting lower-cost materials to cut costs, imported materials lacking proper certification or testing, and poor documentation or unverified compliance certificates that compromise safety and durability.

4. Lack of Attention to Detail

   Quality issues also arise from improper waterproofing and fire system installations, poorly sealed buildings that lead to insulation and weatherproofing inefficiencies, and inconsistent quality in finishes and carpentry.

5. Snagging & Defect Management

   Snagging is the process of identifying minor defects before Practical Completion. An efficient snag list ensures contractors rectify issues before handover. However, poorly executed sealing, inadequate finishing, and undetected defects may not qualify for warranty claims yet significantly affect the building's usability and occupant satisfaction.

Everything's being engineered with cost in mind rather than with longevity. Short-term cost savings are prioritised over the long-term durability and quality of buildings. If you go back to...the forties, fifties and sixties, brick houses were like bunkers...they're still standing today… But the rate at which newer properties that are being built are effectively becoming defective, or… wearing out, is much faster than it used to be.

Tom Proctor

Solutions Engineer, Enterprise

Procore

A Six-Step QC Workflow

Implementing a structured workflow ensures consistency across projects: 

1. Plan – Define standards using Inspection and Test Plans (ITPs).
2. Execute – Ensure skilled workmanship throughout the build.
3. Inspect – Carry out routine site checks.
4. Test – Verify materials such as steel and concrete against specifications.
5. Correct – Vectify any snags immediately upon detection.
6. Verify – Complete the formal sign-off required for Practical Completion.

The Cost of Quality

Viewing quality control as an unnecessary expense is a common misconception. Understanding the Cost of Quality (COQ) instead enables firms to make more informed decisions.

Upfront preventative costs include:

• Additional inspections and quality checks
• Enhanced procurement and material vetting
• More time allocated to design coordination and planning

Failure costs – the consequences of poor quality – include:

• Expensive rework and project delays
• Higher warranty and defect rectification costs
• Increased legal and reputational risks

Industry data suggests rework alone can account for between 2% and 20% of project budgets, meaning that prioritising quality control from the outset can significantly reduce these hidden costs.

Building a Culture of Quality

Achieving better quality in construction requires an industry-wide cultural shift. Just as safety has become a shared responsibility across all stakeholders, quality must be embedded as a collective priority. Clients and designers should ensure buildability and durability are factored into designs; main contractors must emphasise stringent quality checks and skilled workmanship; and suppliers and subcontractors should commit to using compliant, high-quality materials.

Inspection & Test Plans (ITPs)

The Inspection and Test Plan (ITP) is the central document controlling quality on UK sites. It details precisely what to check and incorporates Hold Points, where work pauses for inspection, and Witness Points, where inspection is optional but notified.

Digital Quality Control & the "Golden Thread"

Moving from paper-based systems to digital platforms creates a Golden Thread of information – a digital audit trail, now a mandatory legal requirement under the Building Safety Act 2022 for all HRBs. By integrating quality control into every phase of construction, from design through to post-occupancy, the industry can deliver safer, more durable, and higher-value buildings for the future.

Quality control in construction is the foundation for long-term success. It is simply about ensuring excellence, reducing costly rework, and strengthening industry reputation. By investing in robust QC processes, the construction sector can build better structures and a much stronger foundation for the future.

Written by

Tom Proctor

Solutions Engineer, Enterprise | Procore

14 articles

Before joining the world of technology, Tom worked as a Contract Administrator. This hands-on experience gives him a unique perspective that he leverages in his current role at Procore, where he has been for the past two years. Tom is passionate about helping construction businesses understand best practices around project management solutions and the many benefits they can provide.

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Reviewed by

Zoe Mullan

27 articles

Zoe Mullan is an experienced content writer and editor with a background in marketing and communications in the e-learning sector. Zoe holds an MA in English Literature and History from the University of Glasgow and a PGDip in Journalism from the University of Strathclyde and lives in Northern Ireland.

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Nicholas Dunbar

Content Manager | Procore

65 articles

Nick Dunbar oversees the creation and management of UK and Ireland educational content at Procore. Previously, he worked as a sustainability writer at the Building Research Establishment and served as a sustainability consultant within the built environment sector. Nick holds degrees in industrial sustainability and environmental sciences and lives in Camden, London.

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