The experience we cannot afford to lose

Why retaining older workers, and passing on what they know, has become one of the most pressing questions in UK construction and infrastructure.

There is a quiet calculation taking place on sites and in offices across the country. It rarely makes the headlines, yet it will shape whether the next decade of building actually gets delivered. The people who hold the deepest understanding of how things get built are leaving. We are not replacing what walks out of the door with them.

This is not a soft, feel-good point about respecting our elders. It is a hard commercial problem. The knowledge held by experienced people is one of the few assets in this industry that cannot be bought in at short notice, cannot be poached from a competitor overnight, and cannot be trained into someone in a single year. When it goes, it tends to go for good. And right now it is going faster than we are building it back.

A workforce running down

The figures make the scale clear. Around a third of the UK construction workforce is now aged over fifty, while only about a fifth is under thirty. By 2036, more than 750,000 workers are expected to leave through retirement. Since 2019, over 320,000 skilled people have already exited the sector, many through early retirement or a move into other work. The total workforce averaged roughly 2.07 million in 2025, down on the previous year and well below the level of two decades ago.

Set against that decline, demand is rising. The Construction Industry Training Board estimates the sector needs in the region of 47,860 extra workers each year, close to 239,300 over five years, simply to keep pace. Looking further out, projections point to almost a million new recruits needed by 2032. Infrastructure work in particular is forecast to grow, with output expected to rise above three per cent in 2026 and a long-term public commitment of hundreds of billions of pounds to 2035. The work is coming. The question is who will deliver it.

The pipeline of new entrants is not keeping up. Fewer than half of construction apprentices complete their training, which leaves a thin annual yield of fully qualified people. Only around one in five firms employs an apprentice at all. So the gap cannot be closed by recruitment alone, and certainly not quickly. This is where the older end of the workforce stops being a demographic footnote and becomes central to the whole problem.

The Chartered Institute of Building warned some time ago that a great deal of knowledge and many vital skills were about to be lost, with too few people in line to replace either. Mark Farmer's well-known review of the industry put it more bluntly, describing a workforce time bomb and the prospect of a steep fall in available labour within a decade. Those warnings were not wrong. They were early.

What experience actually delivers

It is worth being precise about what we mean by experience, because the word is often used loosely. The value is not the passing of time. The value is what time produces in a capable person.

The first thing it produces is judgement. An experienced commercial lead can look at a programme and sense where the risk really sits, often before the data confirms it. An experienced project director knows which problems will resolve themselves and which will quietly sink the job if left alone. That instinct is pattern recognition, built from having seen the same situations play out many times in slightly different forms. You cannot download it. You cannot read it in a method statement.

The second thing is tacit knowledge, the kind that never makes it into a document. Experienced people are a living record of how the business and its clients actually work. They know which subcontractor delivers under pressure and which one talks a good game. They know how a particular client likes to be handled, what a difficult stakeholder really wants, and where the bodies are buried on a long-running framework. Research on older workers describes them, fairly, as the keepers of institutional knowledge that resists being written down. That description fits construction precisely.

The third thing is relationships. Major programmes are delivered through trust built over years. The phone call that unblocks a problem at half past seven in the evening happens because two people have a history. When an experienced figure leaves, that web of relationships frays, and the cost of rebuilding it is rarely accounted for.

There is a business case underneath all of this that is sometimes missed. Experienced workers tend to be steady. Studies of older employees consistently find higher retention, lower turnover, and strong performance in complex, judgement-based work. They are exactly the people you want around when a job is going wrong. The loss when they leave is therefore double. You lose the knowledge, and you lose the stability.

Why we let it slip away

If the value is so clear, why does the industry keep losing it? The honest answer is that we treat retirement as a cliff edge rather than a managed transition.

In too many firms, the relationship runs at full intensity right up to a leaving date, and then stops dead. There is no overlap, no handover worth the name, and no plan for the knowledge that has just walked out. The advice from those who study this is consistent and unglamorous. Do not wait until the week before the leaving party to think about it. By then it is already too late.

Age bias plays its part too. Surveys of older workers still find a large share reporting that they have seen or experienced discrimination at work. In a sector forever telling itself it has a shortage, quietly easing capable people towards the exit because of an assumption about age is close to self-harm. The assumption that an older worker is winding down, when many would happily keep contributing in a different shape, costs the industry skills it cannot spare.

There is also a simple failure of imagination. We tend to think in binary terms. Someone is either a full-time employee or they are gone. The most useful arrangements sit in the space between those two states, and we are slow to design them.

How we keep the experience

Retention does not have to mean asking people to carry on exactly as before. The point is to keep the knowledge in the system, not to keep someone chained to a five-day week they no longer want.

Phased retirement is the most obvious lever and one of the most effective. Letting people scale back gradually, rather than exit all at once, keeps them engaged on terms that suit them and gives a clear window for handing on what they know. Organisations that have adopted this find it does two jobs at once. It retains the individual, and it creates the conditions for knowledge to move.

There are several practical shapes this can take, and the right one depends on the person and the role:

  • Consultancy and advisory arrangements, where an experienced figure steps back from day-to-day delivery but remains available for the difficult calls, the bid reviews, and the moments that need a steady hand.
  • Part-time and flexible roles, which allow someone to stay involved without the full weight of a programme, and which often suit people balancing work with other commitments.
  • Mentoring and knowledge-keeper roles, where the explicit job is to develop others rather than to carry the delivery load alone.
  • Boomerang and rehire pathways, which keep the door open to people who have left, so that a retirement is not automatically a permanent goodbye.

None of this is complicated. What it requires is a willingness to design roles around the contribution someone can still make, rather than forcing every relationship through the same full-time template. The firms that get this right end up with a pool of senior capability they can draw on flexibly, which is a real competitive advantage when programmes need experienced cover at short notice.

In the senior commercial and operational appointments I work on, this is becoming a live part of succession planning rather than an afterthought. Clients are starting to ask not only who replaces a departing director, but how the outgoing person's knowledge is captured and passed on before they go. That is the right question. It just needs asking earlier and more often.

How we make sure they share it with the young

Retaining experienced people only pays off fully if their knowledge actually transfers. Keeping someone on the books while their understanding stays locked in their own head is a half measure. The transfer has to be deliberate.

The most reliable method is structured pairing. Put an experienced person alongside someone earlier in their career, with knowledge transfer written into both their objectives, not left to chance. Mentoring, job shadowing, and job sharing all work, but they work best when they are planned and protected rather than squeezed in around the day job.

The crucial detail is what gets shared. It is not enough for the experienced person to explain what they do. They have to explain why. The why is where the judgement lives. Anyone can be shown the steps of a process. Understanding why those steps exist, what they are guarding against, and when to break them is the part that takes years to learn and minutes to lose. Good knowledge transfer keeps pressing on that question. Why did you make that call. What were you worried about. What would have happened if you had done it differently.

It is also a two-way street, and saying so openly makes the whole thing work better. The most successful arrangements are not a one-directional download from old to young. Experienced people pick up new methods, new technology, and fresh thinking from those they mentor. Younger colleagues are often far more comfortable with the digital tools now running modern programmes. Framing it as a genuine exchange, sometimes called reverse mentoring, removes the slight indignity that can come with being asked to hand over and step aside. People share more freely when they feel they are still learning too.

Beyond the personal relationship, knowledge needs somewhere to live. Communities of practice, where people working in similar roles across a business meet to compare notes, help spread know-how wider than a single pairing ever could. Capturing the thinking behind key decisions, even informally, builds a record that outlasts any one person. The aim is to move knowledge out of individual heads and into the shared memory of the organisation, so that a single retirement no longer threatens to take a whole capability with it.

Making it deliberate

The thread running through all of this is intent. The industry will not solve its experience problem by accident, and it will not solve it through recruitment alone, because the maths simply does not allow it. The young talent we need will take years to mature into the judgement we are losing now. The only way to bridge that gap is to hold on to the people who already have that judgement, for longer and in smarter shapes, and to make passing it on a real job rather than a hopeful assumption.

That means treating an approaching retirement as a planning event, not a diary entry. It means designing roles that let experienced people contribute without burning out. It means pairing them with the next generation on purpose, asking them to explain the why and not just the what, and being honest that the learning runs both ways. And it means dropping the lazy assumption that age is the same thing as winding down.

The experience leaving our sector took a working lifetime to build. We can let it walk out unremarked, and pay for it later in delayed programmes, repeated mistakes, and relationships that have to be rebuilt from scratch. Or we can decide it is worth keeping, and act while the people who hold it are still here to ask. The choice is in front of us now. It will not stay open for long.