Mark Gillies, director of technical solutions at Burdens, looks at the key role that geosynthetic materials can play in new housing developments, in particular how they can underpin cost-saving strategies. 

For many housebuilders and developers, groundworks remain one of the most unpredictable – and expensive – elements of a project. Challenging ground conditions and rising material costs, paired with the increasing pressure to deliver sustainable projects, are forcing the industry to rethink traditional construction methods. This is where geosynthetics are becoming increasingly important.

How developers can use geosynthetic materials

Geosynthetics are polymer materials which are designed to improve ground performance. Typically supplied in sheet or grid form, geosynthetics can be used in a wide range of applications, such as working platforms, drainage systems, access roads and ground stabilisation. Having been widely adopted in major infrastructure projects for decades, they can often be underused in housing development projects.

One of the most significant benefits geosynthetics offer is the ability to reduce, or even eliminate, the need for imported stone. Traditionally, when building on weak or variable ground, developers rely on thick layers of aggregate to create stable working platforms or access routes. In some cases, this can mean hundreds or even thousands of tonnes of stone being brought onto site.

By acting as a separation and stabilisation layer, geotextiles prevent aggregate from being lost into soft ground, while geogrids interlock with the stone to distribute loads more effectively, resulting in a far more efficient use of materials. In practical terms, this can reduce the thickness of stone required by 30-50% – depending on ground conditions – delivering immediate cost savings.

For housebuilders, the financial implications are considerable. Less stone means fewer deliveries, reduced haulage costs and lower fuel usage. It also means less excavation, as thinner construction layers require less digging and disposal of spoil. When multiplied across an entire housing development, particularly on sites with poor ground conditions, these savings can quickly run into hundreds of thousands of pounds.

Improving efficiency onsite

Beyond direct cost savings, there are also programme benefits. Importing large volumes of stone takes time and creates logistical challenges, particularly on constrained or urban sites. By reducing the number of vehicle movements, geosynthetics can help accelerate construction programmes and minimise disruption to surrounding communities.

They also play a critical role in enabling development on more challenging land. As the availability of straightforward brownfield and greenfield sites declines, developers are increasingly looking at marginal land – areas with weaker ground that would traditionally require extensive ground improvement. Geosynthetics provide a cost-effective way to make these sites viable without resorting to excessive usage of materials on developments.

Despite these advantages, geosynthetics are not always specified at the outset of a project. In many cases, they are introduced later as a value engineering exercise, once costs begin to escalate. However, the greatest benefits are realised when they are considered early in the design process. Early engagement allows engineers and contractors to optimise the design, rather than simply substituting materials at a later stage.

Another key consideration is specification. Not all geosynthetics perform the same function, and selecting the wrong product can lead to underperformance or unnecessary cost. This is where technical expertise becomes critical – understanding ground conditions, load requirements and application specifics ensures the right solution is used from the start.

Ultimately, geosynthetics are not just a substitute for traditional materials; they are a smarter way of building. For housebuilders and developers looking to control costs, improve efficiency and unlock more challenging sites, a better understanding of these materials could offer a significant competitive advantage.

Mark Gillies is director of technical solutions at Burdens