It sounds too good to be true: a way for contractors to cut landscaping costs without drifting from design intent, compromising on aesthetics, or reducing performance.

At Marshalls Landscaping, we are proving this can be done, time after time. In fact, it is one of the unique ways we add value through Marshalls Design & Engineering (MaDE). This dedicated team of specialists helps reduce project risk while enhancing buildability and still ensuring long-term performance. And when it comes to paving, there is another hidden benefit that contractors also love. 

An easy target

Through no fault of its own, landscaping is often subject to bigger budget pressures than almost any other element of a construction project. This is because landscaping is typically the final stage, when contingency funds have already been used and cost overrun is a genuine risk. If a project has incurred higher than expected costs during earlier phases, it is only natural for a contractor to try and claw that back from the landscaping.

The easy target here is to switch out the specified surface paving for a lower aesthetic quality product. However, this usually means drifting away from design intent, which negatively impacts the overall look and feel of a public space. Instead, what if you could take cost out of the invisible elements, so that the design doesn’t change above ground? This is where the unique expertise of MaDE comes into play.

Applied engineering expertise

MaDE provides expert support to align three key project elements: design intent, technical performance and delivery certainty. As part of MaDE, our pavement engineering team has built up decades of experience and specialist knowledge in this area. We regularly apply this knowledge to take cost, carbon, time or all three out of projects for hard landscaping contractors.

By analysing the complete context of a project, we help contractors make fully informed decisions on specification. This can include when to go with bound or unbound paving, by considering KPIs like load tolerances and maintenance costs over the service life.

Unbound might come with lower material and construction costs but have higher maintenance costs. Bound might deliver lower maintenance costs but is a false economy if other contractors are going to need regular access to services and utilities underneath it. Even when a rigid structure is required, we can typically still identify efficiencies.

Our engineers understand how every layer of the substrate performs, both individually and in combination. Our accurate calculations can reduce construction depth, delivering savings on materials, time on site and muck-away costs – or even help you switch from a bound to unbound paving design. At the same time, we ensure that the pavement remains engineered to withstand site-specific traffic requirements.

By taking a holistic approach, MaDE can make evidence-based recommendations for materials, accounting for attributes including performance, cost and carbon.

Avoid overengineering

Part of the issue is that pavement specifications are often overengineered, and there are two main reasons for this.

The first is that, while the British Standard offers excellent guidance, like all standards it is reliant on empirical and historical evidence. It can’t offer site-specific analysis and is naturally conservative. An obvious example is load tolerances for traffic, which are measured per million standard axles (MSA). If a pavement only needs to accommodate 0.7 MSA – about 20 HGVs per week - this is not specified in BS 7533, meaning you can end up with an overengineered system.

Applying pavement engineering to right size the system for the correct MSA can take out significant cost.

The other challenge is that local authorities and highways authorities tend to err on the side of caution. In particular, highways prefer very robust systems with low maintenance costs. By interrogating the spec, we can better understand what is genuinely required from pavement performance. For example, does the pavement really need HGV load-bearing tolerances, if the only vehicles that will operate in that area are maintenance type 3.5t LCVs?

Significant savings

The surface slab or block is typically the easiest target for cost cutting. It is an obvious line on the spreadsheet and replacing it with a cheaper alternative could reduce costs per square metre by a few pounds.

However, the 80/20 rule applies here. The surface on average is about 20 percent of the system cost. Why focus on trying to take cost out here – at the risk to design intent – when you could take more cost out of the 80 percent that is below ground?

Reducing the substrate depth, along with recommending alternative material choices, can deliver significant savings – and sometimes shifting from bound to unbound paving is also possible. Most of the savings are achieved through lower material costs, but that also translates into less time on site. Fundamentally, applying our engineering expertise during the design phase results in a lot less digging and much faster installation.

For example, by demonstrating a project in Port Talbot could switch from bound to unbound paving, combined with making changes to the sub-base, we were able to shave £500,000 off their landscaping costs. 
Similarly, paving an HGV depot in Bedford achieved £125,000 in construction savings and a 50% reduction in programme. And a town centre paving project delivered £120,000 in construction savings and a 33% reduction in programme.

At a time when input and labour costs are rising, this can make a big difference to margins – and there is another area where it can have a huge impact.

The hidden benefit

Tier one contractors are leading on construction’s drive to Net Zero, setting ambitious sustainability targets.

By significantly reducing the substrate depth and recommending alternative material choices without compromising on compliance or performance, Marshalls Landscaping can help contractors achieve serious, quantifiable savings on embedded carbon emissions.

Working with FM Conway on a footway for Westminster Council, we were able to deliver a 46% carbon saving per square metre of materials used in the footway construction by reducing paving depth, foundation build up and material specification. We also saved an estimated 4kg per sqm by reducing paving unit depth from 63mm to 50mm units.

This is not a one-off: the HGV depot job achieved a 52% cut in carbon emissions, while the town centre delivered a 33% reduction. 

Early access

Whenever Marshalls Landscaping is asked to quote for supply of pavement, we analyse the specification to see if we can help the contractor make savings. In over 90% of cases, we can deliver a tangible benefit.

However, you don’t have to wait until that stage to get us involved. All parties are welcome to consult the pavement engineering team much earlier in the project. In this way we can help provide project confidence in every phase from design to delivery.

Civil engineers are experts, not specialists – but we are both. Our pavement engineering team can provide that missing layer of specialist knowledge to help you take out cost without compromising on aesthetics, compliance, or performance – and deliver a reduction in carbon at the same time.

Find out more

Marshalls Landscaping has decades of experience across complex public realm and commercial projects, delivering some iconic UK landscapes.

Through this, we have developed a deep understanding of surfaces, substrate and the engineering expertise that sits behind them.

This unique combination of UK manufacturing expertise with in-house design and engineering expertise can add genuine value to your landscaping project.

Written By

Mark King
Mark King

Mark has been a valued part of the Marshalls team since 2015, and currently heads up the pavement engineering team. Within this role, Mark has supported some of the company’s largest-scale projects, including the Birmingham Midlands Metro Alliance and the redevelopment of York central.

Read Mark's full profile.