Kaziwe Siame Kaulule is the managing director of Aggregate Industries’ Aggregates business. He is playing a key role in further enhancing the UK building materials major’s approach to circular construction, health and safety and producing a more skilled and engaged industry workforce for today and tomorrow. Guy Woodford reports
Kaziwe Siame Kaulule smiles broadly when talking about Ian White, known as ‘Speedy’, who left a lasting impression on him during an announced visit to one of Aggregate Industries’ quarries in the English Midlands. “I decided to show up at this site around 4 pm and found Speedy cleaning the workshop. I told him I found it very interesting that he was doing what he was doing when everyone else had clocked off. He then said something profound, ‘The job’s not done until all the day’s debris is swept from the floor’. That showed me the level of dedication he had to his work.”
Kaulule also met a logistics shovel driver at a company volunteering event. “Gary Howell had been driving a shovel for 20 years, and I asked him what else he might want to do. He said all he wanted to do was drive a shovel. He said it’s the most mentally stimulating job you can have. When driving, he said he was always thinking about whether there was someone around him to avoid when moving material and how he could work the most efficiently between different-sized material stockpiles. At the end of the workday, he asks himself, ‘What did I do today? What do I have to do tomorrow?’ Some studies show that shovel loaders thinking like this are 25% more productive than ones that don’t. In a wider context, this type of thinking and planning is what all great leaders need to be doing.
“I get more inspired by meeting people like Speedy and Gary than any PowerPoint presentation. The teams that work in a quarry and walk the workshop floor are salt-of-the-earth people. They will tell you straight what is going on. I visit a quarry at least once and often twice a month, and also like to be out visiting customers as much as possible.”
A Zambian national, Kaulule, known to colleagues and friends as ‘Kaz’, left his role as Lafarge South Africa CEO to join Aggregate Industries in November 2023, initially as group strategy and commercial growth director. He took up his current senior executive role at the nearly 4,000-employee company, the UK subsidiary of Switzerland-headquartered Holcim, formerly LafargeHolcim and the world’s biggest building materials producer, in August 2024.
With an impressive career spanning over 20 years, Kaz is a results-driven executive renowned for his inspirational leadership across diverse international landscapes, notably in Europe and Africa. His expertise encompasses operations, digital transformation, business development, mergers and acquisitions, and the achievement of commercial excellence.
As its CEO, Kaz led Lafarge South Africa to unprecedented success. Within 18 months, he doubled the enterprise value and achieved profitability, reversing a trajectory of over five years of losses.
Joining the global construction sector in 2004, Kaz has held pivotal roles in LafargeHolcim Group audit in France and various Group senior marketing, commercial, and strategy posts across various Southern African countries. He has also spearheaded digital ventures in the UK.
A holder of an MBA from the University of Oxford’s Saïd Business School, a Bachelor (Honours) of Commerce, and a Bachelor of Science from the University of Cape Town, Kaz brings academic rigour and practical experience to his work.
So, what have his priorities been in his first year as Aggregate Industries’ managing director of Aggregates?
“My Aggregates role is people-facing. Do we have the right people and the right level of engagement for the ambitions we are setting for ourselves? More fundamentally, are we operating safely, given our business?
“After that, it’s about the company being a UK leader in sustainability. Coming here from South Africa, I saw it as a big opportunity to drive forward circular construction at the scale that Aggregate Industries can offer. I would like us to have 20% of our products being made from recycled materials. We are currently around 7%.
“Another key focus is being a commercially focused organisation that is easy to do business with. We are revamping how we approach the market and our intensity within it. We are looking at which sections to focus on and what products the market needs. One of the things you find when you’ve been in a business for a long time is that you produce the same type of products. We now want to bring our customers on the circular construction journey. To do that means our commercial people need to have different conversations. In some areas, we have had to introduce different commercial people to have the impact we’re looking for.”
While Kaz admits that circular construction-linked products generally cost more than traditional ones, many customers are willing to pay a bit extra to gain added value in their business marketplace.
“When I first came to Aggregates Industries, and in my previous role, we were having conversations about recycling; some thought that recycled [building material] products should be cheaper, given they are recycled. That is not the case. You have to handle the used material and reprocess it carefully.
“It is about creating a value proposition. Part of that is not just that we recycle; our offer of external verification confirms what we are doing, and we have an ECOCycle brand that goes with that. The discussion with the customer has moved from one focused on price to one where the customer asks, ‘How can you make this a reality in my products?’ If you can make it a reality in their products, the customer reduces their carbon emissions, which can help them win contracts with municipalities.”
In recent years, Aggregate Industries has, says Kaz, been “walking the talk” regarding growing its circular construction business. “We have been market-leading when it comes to ambition. We have made significant acquisitions in this space. However, it’s not just about the acquisitions. We have been doing a lot internally on aggregate, asphalt and ready-mix [concrete], which has made a big difference given our scale. This means we can drive our ambitions downstream through the business. There is huge growth potential on that side. I would say that around 30%-35% of the materials we produce are used by our businesses in their work. What excites me even more is what we can do with our external customers around circular construction. We can change their business models.”
Among Aggregate Industries’ acquisitions linked to circular construction has been the Q4 2024 acquisition of Land Recovery, a leading supplier of primary and recycled construction materials.
Land Recovery was founded in 1982 by the Beecroft family and has grown continually to become a leading supplier of construction and demolition materials. This includes supplying primary rail ballast, handling and treating spent ballast, and recycling a proportion of it into new products for the rail network or bringing it back into the value chain to create products such as ready-mix, precast concrete, and asphalt.
The company employs 85 people plus 18 contractors and has four sites. Its main UK operations base is Stoke-on-Trent, where it conducts most of its business. It also has a rail yard site in Dewsbury, West Yorkshire, and quayside sites at Lowestoft, East Anglia, and Ellesmere Port, Cheshire.
Another key circular-construction-linked acquisition was the Q3 2023 purchase of OCL Regeneration, a leading provider of highway waste recycling solutions. The integration of the Kent-headquartered business has further strengthened Aggregate Industries’ asphalt and surfacing operations, where it is a key player on National Highways and local authority contracts.
In Q4 2022, Aggregate Industries launched Your Carbon Report, the UK building materials industry’s first fully customisable carbon reporting tool offering customers accurate carbon data by product or project. The tool produces a report using data from across Aggregate Industries’ business areas to provide a comprehensive cradle-to-site assessment. The tool looks at the whole manufacturing process, from raw material extraction to transportation, to provide a full and accurate carbon assessment of the products.
The report can be generated quickly, from request to supply, and allows customers the flexibility to interrogate the data to identify where future carbon savings can be made. To assure customers that the solution includes all necessary material flows and is in line with industry best practices, all data in the carbon reporting tool is independently audited by Circular Ecology.
Aggregate Industries can produce up to 35 million tonnes of building materials annually. While unwilling to disclose exact current production numbers for commercial reasons, Kaz offers his perspective on the present health of UK building materials demand.
“Everyone knows that the 2024 market has been challenging following another decline in demand in 2023. However, Aggregate Industries’ results have remained resilient. Part of that is by stressing that we are growing our business in a declining market through acquisitions, new recycled products and new brands. We have seen a lot more interest in our sustainable products like ECOCycle, and it’s the same when you go downstream with ECOPact for our ready-mix business and other brands for other business areas.
“We have seen the housing market decline substantially, so all the conversation needs to be around how to adjust UK planning regulations to get more houses built and built more quickly and address the reported labour shortage. We and the rest of the British building materials industry have the capacity to supply the materials required to meet the new Government’s target of building 300,000 new homes a year for the next five years. What’s great is that we can now build sustainable housing. If 20% of your aggregates are recycled, those houses are more sustainable. It’s the same as going down the value chain, having more ready-mixed concrete produced with recycled aggregates, and then you also have reduced cement content, further lowering emissions.”
Kaz says everyone in the UK construction and building materials industry knows that changing planning laws to encourage more housebuilding “needs to be happening.” He fully supports the industry championing on this issue carried out by entities such as the Mineral Products Association (MPA), the London-based trade association for the aggregates, asphalt, cement, concrete, dimension stone, lime, mortar, and industrial sand industries.
Kaz says that Aggregate Industries’ trading resilience has also been helped by falling interest rates and its ongoing supply of building products to major UK infrastructure works, including HS2 [high-speed rail network] and coastal renewable energy and protection projects. Building materials for HS2 have mainly come from Aggregate Industries’ English Midlands sites. Building materials for the coastal projects have come from Aggregate Industries’ Glensanda ‘super quarry’, Europe’s largest granite quarry, situated on a remote peninsula north of Oban and uniquely accessible only by sea.
Kaz also reports a growth in commercial activity in southwest and southeast England, the latter largely linked to the Port of Tilbury on the River Thames at Tilbury in Essex. At what is London’s principal port, Aggregate Industries is building a state-of-the-art grinding station and storage facility. This represents a significant investment to support the ambitious growth plans for the company’s cement business.
The Tilbury facility, due to be completed on-site and fully operational in 2026, will allow the firm to supply customers 24 hours a day with conventional, low-carbon, and circular cementitious materials from five loading heads.
The primary objective of this strategic investment is to meet the increasing demand for sustainable building materials in an evolving market.
The development investment includes new plant equipment for manufacturing blended cements and lower-carbon cement components, including GGBS and alternative raw materials from construction demolition materials, as well as providing a major import hub.
In line with the company’s sustainability strategy, the project demonstrates Aggregate Industries’ ongoing commitment to lower-carbon construction. In particular, the project boasts a significant commitment to circularity principles, ensuring that wherever possible, all potential construction demolition materials are re-used or recycled.
Aggregates Business reported in December 2024 that a key milestone had been reached in the project with the inflation of a groundbreaking dome silo that sits within the new multi-million-pound cement import, manufacturing and distribution facility.
The 45m tall, 32m diameter dome is designed to store up to 30,000 tonnes of cement to support local demand for building materials. These materials will be used across numerous construction projects in the region. Once operational in 2026, this facility will allow Aggregate Industries to serve its customers 24/7 with conventional, low-carbon, and circular cementitious materials from five loading heads.
During construction, over 25,000 tonnes of concrete from the existing site have already been recycled and reused, and over 10,000 tonnes of recycled asphalt planings have been incorporated into new asphalt products. Aggregate Industries also incorporates lower-carbon materials throughout every construction aspect, including using the firm’s ECOPact readymix.
Local stakeholders and businesses are already seeing potential economic benefits, as the project is expected to stimulate demand for trade and materials in the region. More than 100 jobs are expected to be created during the scheme’s construction phase, with a further 30 full-time permanent positions generated once the site is operational.
Commenting on a key focus for 2025 for the 1,300-employee-strong Aggregates side of Aggregate Industries’ business, Kaz says: “Given our emphasis on sustainability and circular construction, there is a lot of innovation and new ideas we need to bring to the table. We need an engaged workforce whose working environment allows them to create good ideas.
“We also want to push up internally the use of sustainable products. There will be a big step-change in 2025, as we aim to produce three million tonnes of sustainable products for our internal and external works, up from two million tonnes in 2024. We also want to further integrate the recycled building materials businesses we’ve acquired. Through the Land Recovery acquisition, we will be the first UK building materials business to certify the use of blended ballast, comprising 50% virgin ballast and 50% reprocessed. I want Aggregate Industries to be the UK’s most sustainable and profitable business. We’re on the right track to achieve that in 2025.”
Will Aggregate Industries look to make further acquisitions, including circular construction-linked acquisitions, in 2025? “We’re always looking at good opportunities where there is complementarity. The circular construction element of any potential deal is important. We are not done on the acquisitions front. We want to grow internally and with M&A [mergers and acquisitions]. Our acquisitions in recent years have brought an entrepreneurial spirit to Aggregate Industries, which is great. From our side, we bring them a bigger playing field and the right level of [regulatory] compliance and rigour through our brands.”
Is there a danger that a very high percentage of recycled aggregate or ready-mix concrete and cement in construction works can negatively impact final-build quality? “The quality of the recycled building material is based on the quality of the raw building material you are reprocessing,” says Kaz. “We have examples from countries such as Switzerland where construction projects use 60% recycled materials. It’s phenomenal, and legislation in that country allows for this. From a Holcim Group perspective, we were involved in an affordable housing project in France, and everything on the site used recycled materials, from aggregates to cement. It shows it can be done. By the end of 2025, you will see our recycled product brands very clearly in the marketplace.”
Kaz emphasises how Aggregate Industries is keen to increase its embrace of digitaliisation and AI (artificial intelligence)-inclusive technology. “I was once the general manager for a digital business in the UK. We were building a digital solution called Lead Retail, which enabled users to order [clothes and other high street items] on their mobile phones. Holcim has adopted it, and it’s how most of our customers interact with us. We are in the process of rolling out several digital tools that are customer-facing and that make it easier for people to do business with us. One of the digital tools is called Rocks, and another is Click It. Rocks helps with internal logistics; Click It allows customers to place orders.
“We are using AI to improve [employee] on-site behavioural safety. When some of our loader drivers are loading and unloading materials, they wear goggles that track what is happening with their eyes. It records what is catching their attention, and you can analyse hot spot incidents and predict where safety issues must be addressed. We also want to do more with AI technology around predictive fleet maintenance. AI has not replaced anybody. Even with ChatGPT, its biggest benefit is helping you become a better version of yourself!”
Kaz is based in Holcim’s central London office, around an hour’s commute from St Albans, a small city in Hertfordshire, just over 20 miles north of London, where he lives with his wife and three children.
“What I take from my working life in countries like South Africa and Zimbabwe is that industries can change rapidly due to political events or market shifts. It teaches you to be agile and adaptable in your business approach. It’s a strength I can lead on given the UK building materials industry is changing in its more focused approach to sustainability.”
How does Kaz describe his leadership style? “High [employee] empowerment but also high accountability for the results. I like to see a high support-high challenge environment in my teams. The biggest thing in any company is its people. I’m passionate about having the right people to deliver the best results. I like challenging the status quo and asking why we do this or that. I want to know how I can make the biggest positive impact on the business area I’m working in.”
Kaz is also keen to develop Aggregate Industries’ young apprenticeship talent and identify future leaders who can drive the business forward.
“Our apprenticeship programme is crucial. The economic cycle does not come into play; it is a non-negotiable investment. I started as an intern in this business at Lafarge Zambia in 2004. The only reason I am where I am today is because I was allowed to grow. I strongly believe in investing in young talent, not because it’s a cliché, but because it works.”