Why waiting is the most expensive thing in construction

Every construction project has obvious costs. Steel, concrete, timber, labour, plant, fuel and materials all appear neatly within budgets, cost plans and valuations. They are measured, monitored and scrutinised from tender through to completion, but one of the largest costs on almost every project rarely appears as a line item – and that’s the time lost through waiting, writes John Ridgeway.

We are talking here about waiting for drawings, waiting for approvals, waiting for planning conditions to be discharged, waiting for procurement decisions and waiting for information. Add on waiting for materials, waiting for clients to make up their minds and waiting for one trade to finish before another can begin – and you get the picture.

According to McKinsey, stagnant productivity means construction becomes between 1% and 3% more expensive every year above inflation, while research by FMI and Autodesk found project managers spend almost half of their working time collecting and managing information, rather than delivering projects. Together, the figures reveal an uncomfortable truth. Construction's biggest hidden cost is often not the work itself, but the time spent waiting for information, approvals and decisions

We can see therefore, that construction spends an extraordinary amount of time waiting and the irony is that this hidden cost often exceeds the value of many of the physical materials being installed. The industry has become exceptionally good at measuring what it buys, but it is far less effective at measuring the cost of standing still.

Time Is Construction's Most Valuable Resource

Unlike materials, time cannot be recovered. A delayed delivery can eventually arrive. An additional contractor can sometimes be appointed. More money can occasionally solve a problem. Lost time, however, is permanent.

Every day a project remains idle continues to generate overheads. Site management remains in place. Welfare facilities continue to operate. Temporary works stay installed. Plant sits on hire. Security remains necessary. Financing costs continue to accrue. Supply chain programmes begin to slip and what initially appears to be a relatively small delay can quietly develop into a significant financial problem.

Research by McKinsey has consistently highlighted that poor productivity remains one of construction's biggest challenges, with delayed decisions, inefficient claims management and fragmented project delivery all contributing to unnecessary time loss across projects. McKinsey also notes that construction productivity has remained largely stagnant across many developed economies for decades despite advances in technology.

Waiting Multiplies

One of the unique characteristics of construction is that very few activities happen in isolation. Every task depends upon another. The groundworker, for example, waits for the drainage design. The concrete contractor waits for reinforcement. The steelwork contractor waits for fabrication drawings. The façade contractor waits for structural completion. The fit-out contractor waits for the building to become watertight. Facilities management waits for commissioning.

It is easy to see how one delayed decision can affect dozens of organisations. Unlike manufacturing, where production lines can often be rebalanced, construction projects operate as interconnected sequences. When one activity stops, the effects ripple through the programme. This is why seemingly minor delays can become disproportionately expensive. It is not the original delay that causes the greatest damage, but the chain reaction that follows.

Decision-Making Is Often the Biggest Bottleneck

Interestingly, many delays are not caused by engineering problems. They are caused by decisions that simply take too long.

Design approvals remain outstanding. Specifications continue to evolve. Value engineering exercises reopen completed discussions. Client changes arrive after procurement has begun. Planning conditions take longer than expected to discharge.

Every delayed decision creates uncertainty and uncertainty is expensive. Research published in the journal Sustainability identified delayed client decision-making, incomplete information, poor coordination and communication as major contributors to construction project delays. The researchers concluded that improving decision-making processes could significantly reduce conflicts, claims and programme overruns.

The irony is that nobody deliberately delays a project. Most delays occur because every individual decision appears relatively small, but collectively, they become enormous.

Procurement Has Become a Waiting Game

The global supply chain disruptions experienced over recent years exposed another hidden cost - procurement.

Projects that once relied upon predictable lead times suddenly found themselves waiting months for electrical equipment, structural steel, façade systems and mechanical plant.

Many contractors responded by ordering earlier. Others redesigned schemes around material availability rather than technical preference. However, while supply chains have improved, procurement uncertainty remains a significant commercial risk.

Early procurement has increasingly become as important as design itself because a drawing has little value if the product cannot arrive when it is needed.

The Hidden Cost Nobody Calculates

Perhaps the biggest issue is that waiting rarely appears in traditional cost reporting. A delayed approval might extend a programme by two weeks. On paper, the approval itself costs nothing. In reality it may generate additional preliminaries, extended supervision, revised subcontractor programmes, plant standing time, increased financing costs and additional inflation exposure.

By the time these indirect costs have accumulated, the original delay has become remarkably expensive. The financial impact was never the approval itself. It was everything that waited because of it.

Better Information Means Faster Decisions

However, there could be a real solution. Digital technology is often presented as the answer to construction productivity. Artificial intelligence, Building Information Modelling (BIM), digital twins and cloud collaboration platforms undoubtedly improve information flow, but their greatest value may be much simpler than many people realise. They reduce waiting.

When the latest drawings are immediately available, decisions happen faster. When site progress is visible in real time, problems are identified earlier. When project teams share reliable information, fewer assumptions are made and fewer activities need to stop while clarification is sought.

According to research undertaken by FMI and Autodesk, poor-quality project data contributes directly to poor decision-making, while engineers and project managers spend a significant proportion of their working time simply collecting and searching for information instead of making progress.

So, can construction eliminate waiting? Probably not. Construction will always involve approvals, inspections, procurement, planning conditions and coordination between multiple organisations, so some waiting is unavoidable.

Unnecessary waiting, however, is different. Projects with early contractor involvement, collaborative procurement, clearer governance, delegated decision-making and better digital information often experience fewer interruptions because decisions happen before they become programme-critical.

The objective therefore, should not be to remove every delay. It should be to remove every avoidable one.

The Real Cost of Standing Still

Construction has traditionally focused on reducing the cost of materials, improving labour productivity and finding more efficient ways to build. Perhaps the next major productivity breakthrough lies somewhere else. Perhaps it lies in understanding the true cost of waiting.

Because every hour spent waiting is an hour when people, equipment and expertise are generating no value. Concrete can always be poured tomorrow. Steel can always be erected next week. Materials can always be reordered, but the time spent waiting for all of those things is gone forever.

So, perhaps the most expensive material on any construction project isn't concrete, steel or timber at all. It's time.

Frequently Asked Questions

1. What are the biggest causes of delays on construction projects?

Construction delays are commonly caused by late design information, planning approvals, procurement issues, labour shortages, material availability, adverse weather, client changes and poor communication between project teams.

2. How do project delays increase construction costs?

Delays increase costs by extending site overheads, plant hire, labour, supervision, financing costs and subcontractor programmes. Even relatively small delays can have significant financial consequences across an entire project.

3. Why is time considered one of the most valuable resources in construction?

Unlike materials or equipment, lost time cannot be recovered. Every day a project is delayed adds costs through extended site operations, reduced productivity and disruption to the overall construction programme.

4. What is the hidden cost of waiting in construction?

Waiting creates indirect costs that are often overlooked, including idle labour, plant standing time, delayed subcontractors, extended preliminaries, financing charges and lost productivity throughout the supply chain.

5. How does poor decision-making affect construction projects?

Delayed decisions can disrupt procurement, postpone site activities, extend programmes and create uncertainty across multiple trades. Fast, informed decision-making is essential for maintaining project momentum.

6. Why is procurement so important to project delivery?

Effective procurement ensures materials, equipment and specialist products arrive when needed. Long lead times, supply chain disruption and late ordering can significantly delay construction programmes and increase costs.

7. How can digital technology reduce construction delays?

Digital tools such as Building Information Modelling (BIM), cloud collaboration platforms, project management software and digital document control improve communication, accelerate decision-making and reduce information-related delays.

8. What is early contractor involvement (ECI)?

Early Contractor Involvement (ECI) brings contractors into the design process before construction begins. This improves buildability, identifies risks earlier, supports better procurement planning and helps reduce programme delays.

9. Why do construction delays affect multiple trades?

Construction projects are highly sequential. When one activity is delayed, many subsequent trades cannot begin their work, creating a domino effect that impacts the overall programme and project costs.

10. How can construction projects improve productivity?

Improving productivity involves better planning, clearer communication, earlier decision-making, efficient procurement, digital collaboration, realistic programming and reducing unnecessary waiting throughout the project lifecycle.

11. What are project preliminaries in construction?

Preliminaries are the indirect costs of running a construction site, including site management, welfare facilities, temporary works, security, insurance, plant and administration. Delays often increase these costs significantly.

12. Why is reducing waiting time important in modern construction?

Reducing unnecessary waiting improves productivity, shortens construction programmes, lowers project costs, increases profitability and enables clients to occupy buildings sooner while making better use of labour, materials and equipment.