Sustainable Construction · June 2026
Construction and demolition waste makes up around 60% of everything England throws away. Some of it ends up in landfill. Some of it ends up back in the ground as recycled aggregate — doing the same job, at lower cost, with a fraction of the carbon. This is what Suffolk contractors and developers need to know.
Most construction specifications in the UK still default to primary aggregate. Virgin quarried stone, extracted, processed, and trucked to site — because that is what the spec sheet has always said and nobody has pushed back. It is not the cheapest option anymore. It is often not the most compliant option anymore. And for a growing number of Suffolk projects, it is not the most sensible option anymore either.
Recycled aggregates have been available at commercial scale for years. They carry CE marking. They meet British and European standards. They are produced locally. The supply chain exists. The barrier, for the most part, is familiarity — or rather the absence of it among the people writing the specs and the people approving the procurement.
This guide is a practical reference for contractors, developers, civil engineers, and project managers working in Suffolk and the wider East Anglian region. What recycled aggregates are. What they are certified to do. Where they work well, where they are sometimes misunderstood, and what the numbers look like when you compare them honestly against the alternative.
What Recycled Aggregates Actually Are
Recycled aggregates are produced by crushing and processing construction and demolition (C&D) waste — predominantly concrete, brick, hardcore, and reclaimed asphalt pavement. The raw material goes through primary and secondary crushing, screening, and quality control to produce graded fractions that are consistent enough to specify and reliable enough to use.
The main product types you will encounter in Suffolk: Recycled Concrete Aggregate (RCA) comes from processing crushed concrete and is one of the most widely available grades. Mixed Recycled Aggregate (MRA) is produced from blended C&D waste and is typically used in unbound applications such as sub-base and fill. Recycled Asphalt Planings (RAP) are used in road construction and surfacing where the bituminous content is an advantage. Crushed brick can be used for drainage and fill where particle size requirements allow.
The standards that govern their use are not new. BS EN 12620 covers aggregates for concrete. BS EN 13242 covers aggregates for unbound and hydraulically bound materials in road construction and civil engineering. CE marking under these standards confirms the product has been tested against declared performance characteristics. A supplier delivering certified recycled aggregate is not asking you to take a risk — they are delivering a product with a documented performance record.
"The question is not whether recycled aggregate is an approved material. It is whether the person writing the spec knows that it is."
Certified producers such as Holcim UK are processing up to 98% of demolition material back into usable product. That is not a niche recovery rate. That is industrial scale reclamation of what would otherwise be landfill or low-value fill.
The Numbers You Should Know
Let's make this concrete. The environmental case for recycled aggregates is strong, but the commercial case is what moves procurement decisions. Both deserve honest attention.
C&D Waste and Carbon Context
Industry data from McCarthy Waste, Holcim UK, and Earthline Ltd
The commercial picture is context-dependent but directionally clear. Recycled aggregate is typically priced below equivalent primary material. The differential varies by grade, volume, and distance from supply, but for common applications like Type 1 sub-base or crushed concrete fill, the cost advantage is consistent and meaningful. On larger civil projects — road construction, ground improvement, car park sub-base — that differential adds up fast.
There is also a procurement angle that some developers are beginning to pay attention to. Planning conditions and environmental impact assessments increasingly reference waste hierarchy compliance. A specification that defaults to primary aggregate without considering the recycled alternative may face scrutiny. That is not imminent regulatory pressure for every Suffolk project — but it is a direction of travel worth getting ahead of.
Where They Work — and Where People Wrongly Think They Don't
The most common reason recycled aggregates are excluded from specifications is not technical — it is assumed. Someone on the project assumes that recycled means lower quality, or that the engineer will not approve it, or that the client will not accept it. In most cases none of those assumptions hold up. The table below sets out the realistic picture by application.
| Application | Recycled Aggregate — Realistic Position | Common (Often Unfounded) Objection |
|---|---|---|
| Road sub-base (Type 1) | Widely used, certified to BS EN 13242. Standard specification on many highway and civil projects. | "It won't compact properly." It does — when correctly graded and moisture-conditioned. |
| Trench backfill | Suitable for most utility trench backfill applications. Cost-effective at volume. | "The utility company won't allow it." Most now have specific guidance approving certified recycled material. |
| Car park construction | Recycled sub-base is the standard approach on many commercial car park projects. Proven performance record. | "The client's engineer will reject it." Rarely happens when the material is properly certified and the case is presented clearly. |
| Drainage layers | Single-size recycled concrete aggregate works well in drainage blanket and filter layer applications. | "The permeability won't be consistent." Quality-controlled RCA performs comparably to primary drainage stone. |
| Structural concrete | Possible at certain replacement ratios under BS EN 12620. Requires close engineering oversight. | This objection is more valid — full replacement in structural concrete is not routine and requires careful design. |
The honest answer is that recycled aggregate can replace up to 100% of primary aggregate in some applications and zero in others. The sensible approach is not blanket adoption or blanket exclusion — it is application-by-application assessment using the technical guidance that already exists.
A mid-sized commercial development in Ipswich requires 2,500 tonnes of Type 1 sub-base for car park and access road construction. Primary limestone aggregate is specified as standard. A switch to certified recycled Type 1 sub-base from a Suffolk supplier cuts material cost, eliminates long-haul haulage from a distant quarry, contributes to the project's waste hierarchy compliance documentation, and avoids approximately 2,250 tonnes of CO₂ equivalent. The engineer reviews and approves. The project completes on time. Nothing significant changes except the line in the spec and the cost on the bill of quantities.
The Specification Question
Getting recycled aggregate into a project starts at specification stage, not procurement. By the time you are ordering materials the question is already settled — and if nobody asked it during design, the answer will default to primary aggregate by inertia.
What to look for when reviewing a supplier's credentials: CE marking under the relevant harmonised standard (BS EN 13242 for unbound aggregate, BS EN 12620 for concrete aggregate) is the baseline requirement. This confirms the product has been assessed against declared performance characteristics and that the declaration of performance is in place. Beyond that, WRAP Quality Protocol certification indicates the material has been recovered and processed in accordance with the Environment Agency's framework for recycled aggregate — which matters for regulatory compliance and client assurance.
The Highways England Specification for Highway Works (SHW) and its successor documents now accommodate recycled aggregate in multiple applications, including Clause 803 (Type 1 granular sub-base). Local authority highway engineers in Suffolk are familiar with certified recycled aggregate. The conversation has moved on from whether to use it to which grade and which supplier.
Suffolk's Supply Picture
One of the persistent myths about recycled aggregate is that it has to come from somewhere far away, or that the local supply is thin and unreliable. That is not the case in Suffolk. The region has active suppliers producing and distributing recycled aggregate products across the county and into the wider East Anglian market.
Earthline Ltd, based in Suffolk, supplies recycled aggregates locally including Type 1 recycled sub-base, recycled concrete aggregate (RCA), crushed concrete, and mixed recycled aggregate. Their product range covers the most common civil engineering applications — road sub-base, drainage layers, hardcore fill, car parks, and trench backfill — which means the materials needed for the majority of construction projects in the county are available without long supply chains.
Local supply has two advantages that are easy to overlook. First, shorter haulage distances reduce the transport carbon component of the material's footprint — which is already substantially lower than primary aggregate, but locally sourced product reduces it further. Second, supply chain resilience. Importing aggregate from a distant quarry introduces lead time and logistics risk. A local recycled aggregate supplier with active stockpiles can respond more quickly to changes in project schedule or volume requirement.
National suppliers including Holcim UK also operate within the region, providing certified recycled aggregate products with the documentation and quality systems that larger projects and frameworks require. The point is that Suffolk contractors and developers are not operating in a thin market — the supply base exists, the certification is in place, and the products are ready to specify.
"The supply chain for recycled aggregate in Suffolk is not a future aspiration. It is operational now. The gap is in specifications, not supply."
Where We Sit In All Of This
SOOM works with construction businesses, developers, and civil contractors — primarily in the franchising and operations space, but with a clear view into how organisations make procurement and project decisions. We are not aggregate suppliers and we are not specifying engineers. We are not in the business of telling you which product to buy.
What we do see, repeatedly, is the gap between what is available and what organisations actually specify. Sustainable materials are available at competitive prices, from local suppliers, to certified standards. The reason they are underused is not technical or commercial — it is informational. People do not specify what they do not know about, and habits formed in procurement tend to persist long after the circumstances that created them have changed.
Same applies to operational efficiency. Same applies to technology adoption. Same applies to aggregate specification. The organisations that close the gap between what is possible and what they are actually doing tend to do it because someone decided to ask the question rather than accept the default.
If you are a Suffolk contractor, developer, or civil engineering practice and this is the first time you have looked seriously at recycled aggregate specification, the practical next step is straightforward: speak to a local certified supplier, get the product data sheets, and put the question to your next project engineer. The answer will probably surprise you.
The question worth asking your next contractor or procurement lead: when did we last review whether our standard aggregate specification is still the right one?