Why is construction chasing net zero while ignoring the carbon we are destroying?

The UK construction industry is under intense pressure to reduce carbon emissions. From embodied carbon calculations to material innovation and net zero targets, the focus is clear - build better, build cleaner and build more sustainably, but there is a glaring contradiction at the heart of this ambition. While we invest time, money and policy into reducing carbon, we continue to remove one of the most effective natural carbon stores we have – tens of thousands of trees and established hedgerows - often without properly measuring the impact, writes Aaron Morley at Ruskins, the tree and soil specialists.

According to the Woodland Trust, UK trees and woodlands store around 18 million tonnes of CO₂ every year. That is a significant contribution to national carbon reduction efforts, but when development takes place, particularly across housing and highways schemes, these assets are frequently removed as a matter of routine.

The carbon they store and their future capacity to absorb more, is effectively wiped out overnight. Crucially, this loss is rarely factored into project-level carbon reporting in any meaningful way.

One of the most uncomfortable truths is that we do not have a national figure for how many trees and hedgerows are lost each year due to construction and housebuilding. There is no centralised dataset. Losses are recorded locally, inconsistently and rarely brought together. At the same time, however, the industry is encouraged to report on tree planting and biodiversity net gain. This creates a distorted picture, because we only measure what we add and not what we remove.

Replacement is not equivalent

The standard response to tree removal is mitigation through planting, but the evidence suggests this approach is fundamentally flawed. Research highlighted by the University of Sheffield found that 39% of trees planted on new housing developments were dead or missing, while 48% of hedgerows expected to be delivered had not been installed. This is not a marginal issue. It is systemic.

Even where planting does succeed, a sapling cannot replace the environmental value of a large tree for decades. In carbon terms, the loss is immediate, while the benefit of replacement is delayed, often by a generation.

While trees receive attention, hedgerows are often overlooked, even though they are vital carbon stores and biodiversity corridors. According to the Tree Council, the UK has already lost around half of its hedgerows since World War II, with development playing a significant role.

Despite this, they are still routinely removed during construction, frequently without meaningful or successful replacement. This is a quiet, but significant environmental loss and one that is rarely discussed.

Nowhere is this contradiction more visible than in major infrastructure schemes. The A14 Cambridge to Huntingdon improvement saw the removal of over 500,000 trees, with reports suggesting that up to 90% of replacement planting failed to establish itself as reported by the Energy Management Summit in 2023.

This is not an isolated case. It reflects a wider pattern across construction where large-scale removal is followed by uncertain replacement outcomes – and here is the irony. At the same time, these projects are often presented as contributing to sustainability and economic growth.

There is another way and it already exists

If construction cannot plan works to retain large trees, there are alternatives that are available. The relocation of large trees and established hedgerows is not a new concept. It is an established and proven process used in both the UK and internationally.

With early planning and the right expertise, trees can be carefully lifted, moved and successfully re-established. This preserves their carbon value, maintains biodiversity and avoids the long-term environmental gap created by removal.

In many cases, it is entirely achievable. The issue is not whether it can be done. It is whether it is considered early enough in the design and planning process.

The current approach reflects a deeper issue within construction. Carbon reduction strategies tend to focus on materials, transport and energy use, all of which are important, but natural assets are often treated as secondary considerations.

Trees and hedgerows are seen as obstacles to be managed, rather than assets to be preserved. But from a carbon perspective, retaining a mature tree can deliver an immediate and measurable benefit, often far greater than marginal gains elsewhere in a project.

All this means that if the construction industry is serious about net zero, it needs to confront a simple, but uncomfortable question. Why are we working so hard to reduce carbon emissions, while simultaneously removing large volumes of stored carbon through the loss of large trees and hedgerows? And why are we not properly measuring it?

A call for change

This is not about stopping development. It is about delivering it differently.

It means:

• Measuring tree and hedgerow loss at a national level
• Accounting for carbon loss in project reporting
• Prioritising retention in design
• Considering relocation as a standard option, not an exception
• Ensuring that where planting does take place, it is supported by healthy soil and long-term management

These are practical steps. They are achievable and they align directly with the industry’s wider environmental commitments.

We are not short of ambition in construction. The drive towards net zero is real, but ambition without full accountability is not enough. Because until we recognise the true carbon cost of removing mature trees and hedgerows and act to reduce it, we will continue to undermine our own progress.

Because the most effective carbon saving on any project might not come from what we build. It might come from what we choose not to remove.