Why Most Climate Impact in Construction Is Locked in Before the First Brick Is Laid

Every building that goes up tomorrow was designed yesterday — and most of its climate impact was already decided then.

That’s not rhetoric. It’s how the construction system works.

The built environment is one of the largest sources of global emissions, not only because of how buildings are used, but because of how they are designed, specified, and constructed. By the time construction begins, the most consequential decisions have already been made.

Buildings are emissions systems, not just structures

A building is more than a physical object. It’s a long-term emissions system.

Early design decisions determine:

• which materials are used

• how much energy the building will demand

• how adaptable it will be over time

• whether it can be reused, retrofitted, or dismantled

Once these choices are locked in, changing them later becomes expensive, inefficient, or impossible. Retrofitting can reduce operational emissions, but it rarely undoes the impact embedded in materials and construction.

Why design decisions outweigh later fixes

Much of the public focus on “greener buildings” sits at the end of the process — insulation upgrades, efficient boilers, solar panels. These matter, but they operate within constraints already set.

The size of the building, its structural system, the materials specified, and whether an existing structure was reused or replaced all shape emissions over decades. These are design-stage decisions, not post-completion adjustments.

In other words, many of the most important climate outcomes are decided before a single brick is laid.

The hidden weight of materials

Concrete, steel, glass, and aluminium underpin modern construction — and they come with heavy carbon costs.

A significant share of a building’s total emissions can be traced back to material extraction, manufacturing, and transport. This “embodied carbon” is spent upfront. Once it’s embedded in a structure, no amount of operational efficiency later can remove it.

That’s why material choice at the design stage carries such outsized influence over long-term impact.

Growth makes early decisions even more critical

A large proportion of the buildings that will exist in coming decades haven’t been built yet. That makes today’s design choices unusually powerful.

When development happens at scale, small assumptions — about materials, layout, lifespan, or reuse — are multiplied across cities and generations. This is why the construction sector is so central to climate outcomes, and why change is slow once projects move beyond the drawing board.

A real-world shift in approach

Some developments are beginning to treat design as a climate lever rather than a technical formality.

Choosing structural timber over traditional steel and concrete, for example, doesn’t just reduce emissions marginally. It fundamentally alters the emissions profile of a building over its entire life. These decisions don’t rely on future behaviour or perfect operation — they change the system itself.

Why this keeps happening

Three structural forces explain why early design decisions continue to dominate climate outcomes:

1. Upfront cost biasProcurement systems often prioritise lowest initial cost, even when lifetime impacts are higher.

2. Misaligned incentivesDesigners, contractors, operators, and occupants are often responsible for different stages, weakening accountability for long-term outcomes.

3. Regulatory focus on operation, not originBuilding standards tend to concentrate on energy use after completion, leaving embodied emissions largely unaddressed.

None of this requires bad intentions. It’s the predictable result of how the system is organised.

A better question for business leaders

Instead of asking:

How do we make this building more efficient once it’s built?

A more useful question is:

What decisions are we making now that will shape its impact for the next 30 to 50 years?

That reframing moves climate responsibility upstream — where the real leverage sits.

Why this matters to Stories of Business

Stories of Business exists to examine how ordinary business decisions shape long-term outcomes.

Construction is a clear example of this dynamic at scale. Climate impact here isn’t driven by slogans or individual behaviour. It’s driven by design briefs, procurement rules, material choices, and incentive structures — decisions that rarely make headlines, but define the world we live in.

That’s the lens we return to, again and again:business as a system, decisions as drivers, and consequences that last far longer than the moment they’re made.