What Is a Bunded Oil Tank? A Complete UK Guide for Homeowners & Businesses

If you rely on heating oil for your home or business, choosing the right storage solution is essential. Bunded oil tanks are widely regarded as the safest and most compliant option for oil storage in the UK, offering superior protection against leaks, spills, and environmental damage.

In this guide, we explain what a bunded oil tank is, how it works, and why it is often recommended over single-skin oil tanks. We’ll also cover UK oil tank regulations, common installation locations, and how bunded tanks help you stay compliant while protecting your property and the environment.

What Is a Bunded Oil Tank?

A bunded oil tank is a double-skinned oil storage tank designed to provide an extra layer of protection against oil leaks. It consists of:

  • An inner tank that stores the heating oil
  • An outer tank (bund) that acts as secondary containment

If the inner tank fails or leaks, the outer bund captures the oil before it can escape into the surrounding ground or drainage systems. This significantly reduces the risk of pollution and costly clean-ups.

Bunded tanks are increasingly considered best practice for domestic, commercial, and agricultural oil storage. For a detailed overview of how oil storage tanks are constructed and classified, this guide offers additional background: https://www.jdpipes.co.uk/knowledge/storage-tanks/basic-guide-to-oil-storage-tanks.html

Key Features of Bunded Oil Tanks

Bunded oil tanks are engineered to meet modern safety, environmental, and regulatory standards. Their design makes them a long-term, low-risk solution for storing heating oil across residential, commercial, and agricultural settings.

Main Features

  • Double-wall construction: The inner tank stores the oil, while the outer bund provides secondary containment, capturing up to 110% of the tank’s capacity in the event of a leak.
  • Built-in spill containment: Any leaks, drips, or overflows are safely contained, preventing oil from reaching soil, drains, or watercourses.
  • Weather-resistant materials: Typically manufactured from high-grade polyethylene or steel, bunded tanks are UV-stabilised and designed to withstand harsh UK weather conditions.
  • Overfill prevention systems: Many modern bunded tanks include alarms or valves that reduce the risk of spills during oil deliveries.
  • Longer service life: Thanks to the additional protective layer, bunded tanks often last longer than single-skin alternatives when properly maintained.

These features make bunded oil tanks the preferred choice for homeowners, insurers, and regulatory bodies alike.

How Do Bunded Oil Tanks Work?

The operation of a bunded oil tank is simple but highly effective. Heating oil is stored in the inner tank and monitored via a gauge. If the inner tank develops a fault, oil is safely contained within the outer bund rather than leaking into the environment.

Core Components

  • Inner tank: Holds the heating oil
  • Outer bund: Captures leaks or overflows
  • Oil level gauge: Allows easy monitoring
  • Overfill prevention valve: Helps prevent spills during deliveries

This dual-layer design is the key reason bunded oil tanks are considered the safest option for oil storage.

Benefits of Bunded Oil Tanks Over Single-Skin Tanks

When comparing oil storage options, bunded oil tanks offer clear advantages over traditional single-skin tanks, which rely on just one layer of protection.

Why Choose a Bunded Tank?

  • Enhanced environmental protection: The outer bund acts as a fail-safe, preventing oil pollution that could damage soil, wildlife, and nearby water sources.
  • Reduced financial risk: Oil spills can result in costly clean-up operations and potential fines. Bunded tanks significantly lower this risk.
  • Improved regulatory compliance: In many UK situations, bunded tanks are either required or strongly recommended, helping future-proof your installation.
  • Insurance-friendly: Many insurance providers favour bunded tanks and may refuse cover for older or non-compliant single-skin tanks.
  • Peace of mind: Knowing your oil storage system includes secondary containment provides reassurance, particularly for properties in sensitive locations.

For these reasons, bunded oil tanks are now widely considered the gold standard for heating oil storage.

UK Regulations for Bunded Oil Tanks

Oil storage in the UK is governed by strict environmental and safety regulations. In many situations, bunded oil tanks are compulsory, particularly when tanks are located near watercourses, drains, or environmentally sensitive areas.

This article explains when bunded oil tanks are legally required and why they are strongly recommended for domestic properties: https://certasenergy.co.uk/news/certas-energy-news/what-is-a-bunded-oil-tank-is-it-compulsory-for-your-home/

Compliance Checklist

  • Tank must be installed by a qualified professional
  • Regular inspections should be carried out
  • The bund must be kept clear of debris and liquids
  • Any signs of damage or leaks should be addressed immediately

Staying compliant helps avoid fines, environmental damage, and invalidated insurance policies.

Typical Installations for Bunded Oil Tanks

Thanks to their robust design and regulatory approval, bunded oil tanks are suitable for a wide range of installation environments.

Common Installation Areas

  • Residential properties: Often installed in gardens, alongside driveways, or on purpose-built tank bases. Bunded tanks are particularly recommended for homes near drains or boundaries.
  • Commercial premises: Offices, warehouses, and industrial sites frequently use bunded tanks to meet health, safety, and environmental requirements.
  • Farms and rural properties: Essential for agricultural operations and off-grid homes where reliable access to heating oil is critical.
  • Environmentally sensitive locations: Areas near rivers, streams, boreholes, or conservation zones where additional spill protection is required.

Correct siting and professional installation are key to ensuring long-term safety and compliance.

Choosing the Right Bunded Oil Tank

Selecting the correct bunded oil tank depends on several factors, including available space, oil usage, and local regulations.

What to Consider

  • Tank capacity: Choose a size that matches your consumption without overfilling or frequent deliveries.
  • Material: Plastic bunded tanks are lightweight and corrosion-resistant, while steel tanks may be preferred for certain commercial applications.
  • Location: Space restrictions, access for deliveries, and separation distances all play a role.
  • Future compliance: Installing a bunded tank now can help avoid costly upgrades later if regulations tighten.

At Oil Tanks Plus, we provide expert advice to ensure you select a tank that meets both your practical needs and legal obligations.

Explore our full range of bunded oil tanks here: https://www.oiltanksplus.co.uk/oil-tank-range/bunded-oil-tanks/

Conclusion

Bunded oil tanks are a smart investment for anyone storing heating oil in the UK. Their double-skinned design provides superior protection, helps meet regulatory requirements, and reduces the risk of environmental damage and costly repairs.

If you’re unsure which oil tank is right for your property or need expert advice on installation and compliance, our team is here to help.

Get in touch with Oil Tanks Plus today to discuss your requirements or request a quote.