Cast Stone - Smart Choice For Construction

Toby Marlow, Building & Construction Director from Haddonstone, outlines why cast stone is the smart choice for modern construction and historical renovation...

Natural stone, such as marble, slate and sandstone, has been a core construction material around the world for centuries; think the Taj Mahal, Palace of Westminster, the Palace of Versailles, and the Leaning Tower of Pisa, for example. Weather-resistance, beauty, durability, and low maintenance contribute to the appeal of natural stone yet today, natural stone’s drawbacks are apparent.

With sustainability at the heart of all modern building specifications and regulations, this material that requires time-consuming extraction methods, costly cutting and finishing processes, and where replenishment of stocks can be inefficient, is a great challenge.

Cast stone, first used to build a medieval fortification in Carcassone, France in 1138, is a versatile, cost-effective alternative which is also proven in some of the most iconic buildings of the world. It is a practical construction material which can be moulded into an array of intricate designs and, because each component, whether a coping, cornice or column, is created in moulds, it’s possible to create large quantities of each without compromising on quality and uniformity.

Cast stone, which can be reinforced with steel and cast with lifting sockets, boasts a consistency which is ideal for high-end developments where a cohesive, luxury aesthetic is demanded.

Key to the imaginative designer is the fact that the versatile stone can be produced in a number of coloured finishes meaning that replacing existing features when preserving or extending historic buildings is easily accommodated. The material is strong with a good freeze and thaw resistance compared to natural stone and, whether the restoration is structural or cosmetic, high specification cast stonework can help bring historical architecture back to life.

Turning to the environment and sustainability, using limestone aggregates from local quarries over heavy natural stone imported from more distant regions, lessens the environmental disruption and carbon footprint caused by the intense excavation and transportation of natural stone.  For further information, call 01604 770711 or visit  www.haddonstone.com

Beyond “Heritage Style”: Rethinking Rooflight Specification in Historic Buildings

By Paul Trace, Director, Stella Rooflight.......  

Over the past decade, the specification of rooflights in historic and sensitive buildings has evolved significantly. Advances in performance, detailing and thermal efficiency have  broadened what is possible, while planning authorities and conservation officers have  become increasingly familiar with rooflights as a legitimate way to introduce natural light  into traditionally challenging spaces. 

Alongside this progress, however, a subtle shift has taken place in how suitability is assessed.  Terms such as “heritage style” are now widely used to describe products intended for  conservation contexts, often implying that visual similarity alone is sufficient justification for  their use. While appearance is clearly important, this trend risks oversimplifying a far more  complex set of considerations rooted in material performance, longevity and long term stewardship.  Heritage is not a look to be applied. It is a responsibility, and one that extends well beyond the moment a project is signed off. 

Conservation as stewardship, not replication 

Historic buildings are not static artefacts. They are layered structures shaped by centuries of use, adaptation and repair. Every material introduced today becomes part of that ongoing story and, in time, part of the fabric future custodians must manage. True conservation has always been about stewardship rather than replication. It asks not only how an intervention appears at the point of installation, but how it will behave, age and endure over decades.

This distinction matters because many modern components are designed around relatively short replacement cycles, whereas historic buildings were never intended to be subject to frequent intervention. Roofscapes in particular demand careful consideration. They are among the most visually sensitive elements of historic buildings and are exposed to the harshest environmental conditions. Materials introduced here must do more than look appropriate on day one. They must withstand prolonged exposure, weather predictably and remain stable over the long term, often with limited opportunity for easy replacement. 

Day one acceptance versus long term impact 

Much of the discussion around rooflights understandably focuses on initial appearance. Sightlines, reflectivity, profile depth and proportion all play an important role in determining whether an intervention is visually acceptable. But conservation decisions rarely end at completion.

A more searching question is how a rooflight will perform and appear after twenty, thirty or fifty years in situ. Different materials age in very different ways. Some weather gradually and consistently, developing a surface character that feels increasingly at home within traditional roofscapes. Others rely on finishes or coatings that can degrade unevenly, leading to visual inconsistency or functional failure far sooner than expected. In modern buildings, replacement may be inconvenient. In historic buildings, it is often disruptive, costly and complex.

Access can be difficult, planning approvals may need to be revisited, and disturbance to historic fabric is rarely trivial. What initially appeared to be a modest intervention can quickly become disproportionate. From a conservation perspective, longevity is therefore not simply a performance metric. It is a measure of how respectfully a modern intervention allows a building to continue its life with minimal disruption. 

Reframing cost as risk in today’s financial reality 

Any discussion of specification must acknowledge the economic environment in which the construction industry currently operates. Across the UK, building projects are facing sustained cost pressures driven by labour shortages, wage increases, material price volatility and constrained margins. Recent forecasts suggest that building costs and tender prices are set to rise further over the coming years, reflecting structural pressures rather than short term fluctuation.

At the same time, recent budget decisions have increased employer costs, adding further strain to an industry already operating within tight financial parameters. In this context, it is entirely understandable that clients and project teams scrutinise upfront costs closely. Every specification decision is evaluated through the lens of immediate value for money. Products that appear cost effective at purchase price inevitably attract attention. However, in historic and listed buildings, this narrow focus can obscure the longer term risk profile of a decision.

A component that performs adequately in the short term but requires premature replacement can introduce significant future costs, not just financially, but in terms of programme disruption, planning complexity and impact on historic fabric. Seen this way, cost should be understood not only as an expense to be minimised, but as a proxy for long term risk. Materials and systems that prioritise durability and predictable ageing reduce the likelihood of repeat intervention at a time when budgets, resources and regulatory capacity are already under pressure. 

The rise of “heritage style” products 

At the same time, the marketplace has seen a noticeable increase in products described as “heritage style”. In many cases, this reflects manufacturers seeking to expand their portfolios into what is perceived as a resilient or specialist sector, often driven by price sensitivity and volume.

There is nothing inherently wrong with broader market participation. The challenge arises when heritage suitability is defined primarily by visual cues, without sufficient consideration of material longevity, ageing behaviour or long term compatibility with historic structures. Surface similarity can be persuasive in planning submissions, particularly where time pressures limit deeper interrogation.

Yet heritage performance cannot be assessed on appearance alone. A product may satisfy an aesthetic requirement today while creating avoidable challenges decades later. This trend highlights the importance of informed specification. It is not about restricting choice, but about ensuring that decisions are grounded in a clear understanding of long term consequences, rather than short term visual reassurance. 

Thinking in decades, not product cycles 

Conservation is, by its nature, an intergenerational discipline. Decisions made today will be inherited by future owners, architects and conservation officers, who will judge them not by intention, but by outcome. The most successful interventions are often those that attract the least attention over time.

They age quietly, perform reliably and do not demand repeated intervention. They become part of the building’s fabric rather than a recurring problem to be managed. As discussions around rooflights in historic buildings continue to evolve, there is an opportunity to move beyond the language of “heritage style” and towards a more meaningful consideration of heritage impact. Longevity, material integrity and long term performance should sit at the centre of that conversation.

By thinking in decades rather than product cycles, and by reframing cost in terms of risk and legacy, we can make specification decisions that genuinely respect the buildings entrusted to us. In doing so, we protect not only individual projects, but the integrity of our built heritage for generations to come. To find out more about genuine conservation rooflights for your project contact the Stella Rooflight team on 01794 745445 or email info@stellarooflight.co.uk  

www.stellarooflight.co.uk

Timber Treading Lightly On The Landscape - The Future For Carbon Negative Building Materials

It was back in 2012 in its Living Planet Report when the World Wildlife Fund asserted that, if the Western developed nations continued with their pattern of consumption, we would need three planet’s worth of resources by 2050. During the years since then, consumerism and population have expanded across regions like Africa and parts of Asia, with supposedly sustainable activities such as sourcing the minerals required for electrical vehicles steadily scarring once pristine landscapes.

Meanwhile, the extra 1.1 billion people added to the population over that time not only have to be fed but also accommodated which means the need to access sufficient environmentally-friendly, and ideally carbon negative, building materials has become just as important a goal as maximising the cultivation of drought resistant plants. Undoubtedly, the UK is by no means the only country where housebuilding is failing to keep up with the crisis in demand.  

MMC solutions require material advancements

The past quarter century has seen significant increases in the use of Offsite technology or Modern Methods of Construction (MMC), with engineered timber being the most popular primary material across the sector in most of Europe; with producers of competing materials also embracing sustainability goals. 

Carbon negative materials are defined as those which sequester more carbon than they emit during their life cycle with other examples including hempcrete and recycled steel, aluminium or concrete.  All of them, though particularly the trio of metals, constitute a precarious balance involving embodied energy, the depletion of natural resources and the time required for their replacement.  Significantly, however, the formation of ores and other mineral deposits are defined by geological epochs rather decades. 

As an increasingly important and costly factor, the amount of energy which goes into producing common building materials is well understood, with recycled steel requiring 74% less energy for its manufacture than the virgin product, a figure which rises to 95% for recycled aluminium which is popular for secondary structural elements like curtain walling.

Recycled steel is also now being utilised for a minor proportion of the rebar required to take the tensile forces within reinforced concrete, while recycled aggregates and waste products, like pulverised fuel ash and ground granulated blast furnace slag, are routinely specified to offset the use of energy intense cement. Ironically though, the supply of PFA and GGBS is rapidly reducing as coal-fired power plants and steel foundries are razed to the ground in the fight to counter Climate Change, making the construction industry’s quest for “ConcreteZero” ever more difficult. 

The harsh reality, then, is that the heavyside construction methodologies which shaped so much of the infrastructure which surrounds us is desperately scrabbling to reach the level of sustainability which for timber can quite literally come naturally.  This fact does not, of course, mean that timber-based building systems are automatically virtuous, and due diligence has to be employed to ensure that their specification will be good for the planet.  

As the recent COP 30 in Brazil reminded us, forests are the lungs of the Earth, a resource we squander at our peril which is why chain of custody and whole life strategies for the use of wood are crucial. Indeed, the need for constant vigilance was highlighted last year by the organisation Earthsight when it produced the video entitled “Blood stained Birch” which exposed how since the start of the war in Ukraine, more than €1 billion of Russian plywood has been wrongly given FSC- accreditation by China and sold into Europe. 

Once fully implemented, the European Union’s Deforestation Regulation (EUDR) will offer a substantial bulwark against illegal and unsustainable cropping of timber, but responsible manufacturers have already made significant strides to ensure their own operations are as well managed and transparent as possible.

With a high proportion of the company’s supplies of raw materials coming from properly-managed forests within the British Isles, and huge investment having been made in areas like production, transport and cutting waste, coupled with the use of biomass for the drying processes and a policy of only buying power from guaranteed renewable sources, the entire product range of West Fraser in the UK has now achieved Carbon Negative status.

This ensures its own customer network can be assured that the panel products they are using to produce structural insulated panels (SIPs) and other offsite systems like floor cassettes, as well as for sheathing, decking and other applications, all fully meet the spirit as well as the regulations which will expand the use of carbon negative building materials.

https://uk.westfraser.com