Timber Extensions Breathe New Life Into Aging Concrete Buildings

Retrofitting concrete structures with sustainable timber can reduce embodied carbon and create healthier, more inviting spaces.

Apr. 2, 2026 at 7:27am

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Concrete buildings across cities are in need of major renovations or face demolition, but experts say adding timber extensions can provide a more sustainable solution. By retaining existing concrete structures and adding lightweight, low-carbon timber, buildings can significantly reduce their carbon footprint while also creating warmer, more biophilic indoor environments. Timber extensions can be built offsite to minimize disruption, and are gaining traction as a practical way to modernize aging concrete buildings.

Why it matters

As cities grapple with the environmental impact of the construction industry, retrofitting existing concrete buildings with timber extensions offers a promising path forward. This approach aligns with sustainability targets to reduce embodied carbon, while also enhancing occupant health and wellbeing through the use of natural materials.

The details

Timber Development UK's sustainability director Charlie Law explains that by keeping the existing concrete structure and adding a timber extension, either upwards or outwards, the building's carbon footprint per square meter is much lower than demolishing and rebuilding. Timber is a low-carbon material that is also lightweight, cost-effective, and flexible to use. Timber extensions can also be built offsite to minimize disruption. Architect Richard Meacham adds that timber brings a sense of warmth and connection to nature, which is valuable as companies try to lure workers back to the office. One example is Google's New York office, which incorporates salvaged wood, and its California Crossman offices, which feature indoor timber canopies.

  • In the coming years, hundreds of concrete buildings across cities will require major renovations or face demolition.

The players

Charlie Law

Sustainability director at Timber Development UK.

Richard Meacham

Architect and design integration director at DIRTT.

Fred Schwass

Chief development officer at General Projects, a developer that retrofitted a former Woolworths headquarters in London with a timber extension.

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What they’re saying

“By keeping an existing concrete building in place, but increasing its useable floor area by the addition of a timber extension, either upwards or outwards, we are avoiding the waste of embodied carbon emission of demolishing the existing building and having to build new.”

— Charlie Law, Sustainability director, Timber Development UK

“Everybody loves wood, and it's a material we just naturally connect with. It's also just inherently a sustainable choice, because wood sequesters carbon, and one of the best things you can do is use it in its natural state.”

— Richard Meacham, Architect and design integration director, DIRTT

“I think the norm going forward will be more and more hybrid buildings, where you have cross-laminated timber slabs with steel frames.”

— Fred Schwass, Chief development officer, General Projects

What’s next

As cities and developers continue to explore sustainable renovation solutions, the use of timber extensions on aging concrete buildings is expected to gain further traction, particularly in Europe where this approach is already gaining ground.

The takeaway

Retrofitting concrete buildings with timber extensions offers a promising path to reduce embodied carbon, enhance occupant health and wellbeing, and breathe new life into aging urban infrastructure without the need for demolition.