Tim Lohmann, Director of Strategic Engineering at Keltbray, is an accomplished professional with over 35 years of experience in construction and engineering.

In this thought leadership article, Tim discusses the integration of circular economy practices into the industry; highlighting the transformation from standalone demolition to a holistic approach, advocating for the industry’s transition to re-use for reducing environmental impact, and offering foresight into the emergence of a more formalised and regulated circular economy landscape.


Could you provide some insight into your background and how you have found yourself to where you are now within Keltbray.

I have 35 years’ experience across the construction industry as a constructor and designer. I joined Keltbray in 2015 to support the growth of the Wentworth House engineering team. Since 2021 I have been the Director of Strategic Engineering for the Keltbray Group. I am passionate about the opportunities that our industry affords young people and how we support early careers. In the same way it is key that decisions that we make now take full recognition of the long-term importance of those decisions and that subsequent generations will rightly hold this generation accountable if we fail to consider the full implications of those decisions and act accordingly.


What developments have you been involved in your work that has incorporated circular economy practices?

I have seen a huge change in the scope of demolition from the complete demolition as a stand-alone activity to an integrated offering of demolition, removal for re-use and support of retained elements. These are often integrated into a wider delivery package which incorporates the recovered elements into the re-furbished structure. There are also schemes where the recovery of key elements for introduction into a circular economy flow is part of the scope. Some of the challenges about recovery is that the re-use marketplace is in its infancy and that the increased costs of the recovery are not reflected in the value of the recovered elements. We are innovating in this space with specialised tools and techniques.


Why do you think embracing circular economy practices is important within the construction and engineering sectors?

The carbon associated with converting raw materials into construction products is huge. Whilst there are challenges with re-use, these can be overcome with intelligent team behaviours. If we can increase the amount that we re-use relative to the amount of new, then the overall effect of our activities on the climate will reduce. We see that the energy content of recycled materials is much less than for raw materials (around 75% reduction for melt type materials)


How have you seen the circular economy evolve in your years in the industry.

There has always been a circular economy, but it is now becoming formalised rather than being embedded in demolition pricing. What we are seeing now is the proper assessment of what is within an existing asset and a plan for how this could be re-used in the scheme or recovered for broader re-use.  Hopefully we will see this develop into a register of all the components of that asset and a plan for how these can be re-used on a wider scale – ideally without decreasing the utility of them.


What challenges have you faced in implementing its practice/principles on projects?

Specifications take a long time to change and offering alternatives is hard as what complied previously may now be non-compliant. There is nervousness on the part of specifiers about material that may be old, distressed or non-compliant with current codes and this needs to be addressed with clear industry wide guidance on how we assess and use components in a circular economy.

The drivers of behaviour in any industry are key to implementing change. Procurement of demolition/refurbishment has historically been on a price driven basis, that clearly drives a culture of lowest price. If we want to change that behaviour then the procurement processes need to reflect the need to maximise re-use and minimise new material in the re-construction.


What do you think could be done to better facilitate the adoption of circular economy practices and embed them within projects going forward?

Regulatory – planning & taxation – regime that encourage proper circular principles and not window dressing. Ensure that the owner of the structure remains accountable for the re-use of all the recovered components – not just the shiny bits.

Standards for assessment of components and determination of cuts, we have four players – the original client and their design team, the contractor separating the components, the stockholder and the new client and their design team. The details and tolerances for cuts and separations, the acceptable sizes, how we deal with corners and the like should all be addressed by a standards team. Similarly, there should be standard methods of assessment of the components.

Support for hubs for circular logistics – collection, assessment, classification and cataloguing of what is available. Cash support for businesses in this space as the lag between recovering the material and being able to re-use it in a circular way has a high capital demand until the market is mature.


How do you see the circular economy space evolving in the near- and long-term future?

I expect that we will see the development several streams in the space:

  • Software based tools for the assessment of existing materials, operating a marketplace and tools for incorporating the old into the new
  • Specialist contractors making products from assets rather than waste
  • Specialist stockholders/aggregators who will enable the collection of a basket of products from the marketplace to assemble new assets
  • Audit / assurance bodies to ensure that the circular passports of material are appropriate – possible blockchain type approach