Resin Bound vs Tarmac: Drainage Compliance for UK Driveways

When planning a new driveway for your UK home, choosing between resin bound surfacing and traditional tarmac involves more than just aesthetics and cost. With increasingly stringent drainage regulations and the growing emphasis on Sustainable Drainage Systems (SuDS), understanding how each material performs in terms of water management has become crucial for homeowners across Britain. This comprehensive guide explores the drainage compliance requirements for both resin driveways and tarmac installations, helping you make an informed decision that meets both your practical needs and regulatory obligations.

Understanding UK Drainage Regulations for Driveways

Since October 2008, planning permission has been required for driveways over 5 square metres that use impermeable materials and don’t provide adequate drainage or runoff to permeable areas. This legislation, introduced across England and Wales, aims to reduce surface water flooding and protect our urban drainage systems from overwhelming rainfall events.

The regulations distinguish between two types of surfaces:

• Permeable surfaces: Allow water to soak through into the ground beneath
• Impermeable surfaces: Prevent water infiltration, causing runoff into drains or surrounding areas

In Scotland, similar regulations apply through the Flood Risk Management Act 2009, whilst Northern Ireland follows comparable guidelines under their planning policies. Local authorities from Birmingham to Brighton have become increasingly vigilant about enforcing these rules, with potential fines for non-compliance ranging from £1,000 to £5,000.

Resin Bound Driveways: The SuDS-Compliant Solution

Resin bound surfacing has emerged as the gold standard for SuDS-compliant driveways across the UK. This innovative material combines natural aggregates with UV-stable resin to create a smooth, attractive surface that’s inherently porous.

How Resin Bound Achieves Permeability

The structure of resin bound surfacing creates tiny voids between the aggregate particles, allowing water to drain through at rates typically exceeding 850mm per hour—far surpassing the heaviest UK rainfall events. This permeability is achieved through:

• Open matrix structure allowing water infiltration
• Typical thickness of 15-20mm providing adequate drainage capacity
• Compatible sub-base materials that maintain permeability throughout the system

Professional installers in areas like Manchester and Leeds, where heavy rainfall is common, report that properly installed resin bound driveways can manage even the most intense downpours without surface water accumulation.

Planning Permission Advantages

Because resin bound surfaces are classified as permeable, they typically don’t require planning permission regardless of size. This can save homeowners £206 (the standard householder planning application fee in England) and avoid the 8-week waiting period for approval. However, it’s essential that the entire system, including the sub-base, maintains permeability to qualify for this exemption.

Tarmac Driveways: Traditional but Challenging

Traditional tarmac remains popular across Britain due to its durability and relatively lower initial cost—typically £50-£80 per square metre compared to £60-£100 for resin bound. However, standard tarmac is completely impermeable, creating significant challenges for drainage compliance.

Making Tarmac Compliant

To avoid planning permission requirements, tarmac driveways must incorporate additional drainage measures:

• Drainage channels: ACO drains or similar systems directing water to soakaways (£30-£50 per linear metre)
• Permeable borders: Gravel or planted areas alongside the driveway for water runoff
• Gradient design: Sloping the surface towards permeable areas rather than the highway
• Soakaways: Underground drainage systems (£500-£1,500 depending on size)

These additional requirements can add 20-30% to the overall project cost, potentially negating tarmac’s price advantage over resin bound solutions.

Comparative Drainage Performance

When evaluating drainage capabilities, the differences between resin bound and tarmac are substantial:

Water Management Capacity

Resin Bound:

• Infiltration rate: 850-1,000mm per hour
• No surface water pooling
• Reduces burden on municipal drainage systems
• Helps recharge groundwater naturally

Tarmac:

• Zero natural infiltration
• 100% runoff requiring management
• Prone to pudding without proper gradients
• Increases pressure on storm drains

Long-term Performance

In regions like the Lake District or Welsh valleys, where annual rainfall exceeds 2,000mm, resin bound driveways maintain their drainage performance for 15-20 years with minimal maintenance. Tarmac drainage systems, however, require regular cleaning of channels and gullies to prevent blockages—an annual cost of approximately £100-£200 for professional maintenance.

Cost Implications of Drainage Compliance

Understanding the true cost of achieving drainage compliance is crucial for budgeting your driveway project:

Resin Bound Investment

• Base installation: £60-£100 per m²
• No additional drainage infrastructure needed
• No planning permission fees
• Lower long-term maintenance costs
• Typical 40m² driveway: £2,400-£4,000 complete

Tarmac with Drainage

• Base installation: £50-£80 per m²
• Drainage channels: £500-£1,000
• Soakaway system: £500-£1,500
• Potential planning fees: £206
• Annual maintenance: £100-£200
• Typical 40m² driveway: £3,500-£5,000 including drainage

Whilst tarmac appears cheaper initially, the additional drainage requirements often make the total investment comparable to or exceeding resin bound options.

Regional Considerations Across the UK

Different regions of the UK face varying challenges regarding drainage compliance:

High Rainfall Areas

In Scotland’s west coast, Cumbria, and Wales, where annual rainfall can exceed 3,000mm, resin bound surfaces offer significant advantages. Local authorities in cities like Glasgow and Cardiff actively promote SuDS-compliant surfacing through their planning guidance.

Urban Heat Islands

London, Birmingham, and Manchester experience urban heat island effects, where impermeable surfaces contribute to higher temperatures. Permeable resin bound driveways help mitigate this by allowing evaporative cooling, whilst also reducing flood risk in these densely populated areas.

Clay Soil Regions

Areas with heavy clay soils, such as parts of Essex, Hertfordshire, and the Midlands, present unique challenges. Here, even permeable surfaces may require additional sub-base preparation to ensure adequate drainage. Professional contractors typically recommend a deeper sub-base (300-400mm) in these locations, adding approximately £15-£20 per m² to project costs.

Environmental Benefits and Future Regulations

The environmental advantages of permeable surfacing extend beyond mere compliance:

• Flood prevention: Reduces surface water runoff by up to 100%
• Water quality: Natural filtration removes pollutants before groundwater recharge
• Biodiversity: Maintains soil moisture for surrounding vegetation
• Carbon footprint: Resin bound typically uses recycled aggregates

The Environment Agency predicts stricter regulations by 2025, potentially requiring all new driveways to meet enhanced SuDS standards. Properties with resin bound driveways will already comply, whilst tarmac installations may require expensive retrofitting.

Making the Right Choice for Your Property

When deciding between resin bound and tarmac for your driveway, consider these factors:

Immediate Priorities

• Budget constraints vs long-term value
• Aesthetic preferences and kerb appeal
• Time constraints (planning permission can delay projects by 8-12 weeks)
• Local flooding history and drainage capacity

Future Considerations

• Potential property value increase (SuDS-compliant driveways add approximately 2-3% to property value)
• Maintenance commitments and costs
• Environmental responsibility and sustainability goals
• Adaptability to climate change and extreme weather events

Conclusion

Whilst both resin bound and tarmac driveways can be made compliant with UK drainage regulations, resin bound surfacing offers a significantly more straightforward path to compliance. Its inherent permeability eliminates the need for complex drainage systems, planning permission applications, and ongoing maintenance of drainage infrastructure. Although the initial investment may be marginally higher than basic tarmac, the long-term benefits—including reduced maintenance, environmental advantages, and future-proof compliance—make resin bound driveways an increasingly popular choice for environmentally conscious UK homeowners. As drainage regulations continue to tighten and climate change brings more extreme weather events, investing in a truly permeable driveway solution represents both practical wisdom and environmental stewardship.