Bare Copper vs Insulated Copper Cable: Price Comparison & Complete Selection Guide
When specifying copper cable for an electrical installation, one of the first decisions is whether to use bare copper or insulated copper cable. On paper, bare copper costs 30–50% less per metre — but the total installed cost tells a different story once conduit, cleats, labour, and compliance requirements are factored in.
For electrical contractors and consultants working to BS 7671, the choice is rarely just about price. Insulated copper cable cost includes the safety and code compliance that bare copper alone cannot provide in most building applications. However, bare copper remains the correct — and more economical — choice for earthing conductors, bonding, and certain controlled environments.
This guide breaks down the real cost differences, the regulatory requirements under BS 7671, and a decision framework to help you specify the right type for every application — backed by Sorivo's 15+ years of cable manufacturing expertise across UK, European, and Middle Eastern projects.
Bare Copper vs Insulated Copper: What Makes the Price Difference?
The price gap between bare copper and insulated copper cable comes from three sources: material volume, manufacturing process, and insulation type.
Bare Copper Cable
Bare copper consists of solid or stranded copper conductors with no covering. It is produced in one manufacturing step — drawing and stranding — and sold by weight or by metre. Common forms include bare stranded earth conductors (to BS EN 60228 Class 2) and bare solid conductors for earthing and bonding.
Insulated Copper Cable
Insulated cables add one or more layers of polymeric material around the conductor. Each layer adds material cost and a manufacturing extrusion step. The insulation type dramatically affects both performance and price:
| Insulation Material | Relative Cost vs Bare Copper | Key Characteristics | Typical Life |
|---|---|---|---|
| PVC (Thermoplastic) | Base +30–50% (material only) | General-purpose, 70°C max, limited UV resistance | 15–25 years |
| XLPE (Cross-linked Polyethylene) | Base +50–70% | 90°C rated, higher ampacity, chemical resistance | 25–40 years |
| LSZH (Low Smoke Zero Halogen) | Base +60–90% | Fire-safe for public buildings, tunnels, data centres | 25–40 years |
| Rubber (EPR / HOFR) | Base +80–120% | Flexible, tough, for industrial portable equipment | 10–20 years |
The bare copper cable price per metre is essentially the copper commodity price plus a small stranding margin. An insulated cable of the same CSA must also recover the cost of the insulation compound and the additional extrusion and testing processes.
Bare Copper vs Insulated Copper: Side-by-Side Comparison
| Feature | Bare Copper | Standard Insulated (PVC) | Premium Insulated (XLPE/LSZH) |
|---|---|---|---|
| Upfront cost per metre | Lowest (benchmark) | +30–50% | +60–90% |
| Installed cost (incl. conduit/labour) | Higher — requires conduit, cleats, or enclosure | Lower — can be run directly on cable trays | Lower — same installation as standard insulated |
| Compliance (BS 7671) | Restricted — earthing/bonding only in most buildings | General wiring | General wiring + fire-safe zones |
| Mechanical protection | None — requires external conduit or armour | Built-in (insulation layer) | Built-in (insulation + optional sheath) |
| Scrap/recycling value | Highest (bare bright copper grade) | Medium (must strip insulation) | Medium (must strip insulation) |
| 25-year lifecycle cost | Moderate (no replacement, but higher install + maintenance) | Lowest (if replacement at year 18) | Lowest (no replacement within design life) |
| Current ampacity (same CSA) | Higher (no insulation derating) | Lower (insulation temp rating limits current) | Higher (XLPE rated 90°C vs PVC 70°C) |
| Typical applications | Earth electrodes, bonding, switchgear internals, lightning protection | Building wiring, general power, lighting | Industrial feeders, fire alarm, emergency systems |
BS 7671 Requirements: When Bare Copper Is Permitted vs Required
The IET Wiring Regulations (BS 7671:2018 +A2:2022) place specific restrictions on bare copper conductors. Understanding these is critical for both compliance and cost optimisation.
Separate Protective Conductors — Regulation 543.1.1
Where a protective conductor is not part of a cable assembly:
| Condition | Minimum CSA (Bare Copper) |
|---|---|
| With mechanical protection (e.g., in conduit) | 2.5 mm2 |
| Without mechanical protection | 4.0 mm2 |
| Buried — protected against corrosion AND mechanical damage | 2.5 mm2 |
| Buried — protected against corrosion but NOT mechanical damage | 16 mm2 |
| Buried — NOT protected against corrosion | 25 mm2 (copper only; aluminium not permitted) |
Earthing Conductor — Regulation 542.3.2 / Table 54.1
Bare copper is the standard choice for buried earthing conductors connecting the main earthing terminal (MET) to the earth electrode. For PME (TN-C-S) supplies, the minimum bonding conductor size is 10 mm2 copper.
Sleeving Requirement — Regulation 543.2.7
Where a bare protective conductor is accessible — including the unsheathed CPC within twin and earth cable — it must be sleeved with green/yellow sleeving applied to within 12 mm of the termination.
Adiabatic Sizing Advantage
Bare copper conductors benefit from higher k-values under the adiabatic equation (Regulation 543.1.3):
| Condition | k-value (Bare Copper) | k-value (Insulated Copper) |
|---|---|---|
| Normal conditions | 159 (200°C final temp) | 115 (70°C PVC, 90°C XLPE) |
| Restricted areas (visible) | 228 (500°C final temp) | N/A |
A higher k-value means a smaller CSA may be sufficient for fault current protection — a potential cost saving when sizing bare earth conductors by calculation.
When to Choose Bare Copper vs Insulated Cable — Application Guide
Bare Copper — Recommended For:
- Earthing conductors — Buried connections from MET to earth electrodes (BS 7671 Table 54.1)
- Main protective bonding — Gas, water, and structural steel bonding (min 6 mm2, 10 mm2 for PME)
- Lightning protection — Down conductors and earth termination networks to BS EN 62305
- Switchgear and panel internals — Busbars, links, and internal earthing within LV switchboards (IEC 61439-1)
- Railway earth mats — Bare copper stranded conductors buried in track ballast for traction return and equipotential bonding
- Greenfield earth grids — Substation earthing grids where bare copper is directly buried
Insulated Cable — Recommended For:
- General building wiring — Power, lighting, and socket circuits to BS 7671
- External lighting and supplies — SWA armoured (BS 5467) or LSZH armoured (BS 6724) where the cable enters public areas
- Industrial feeders — XLPE insulated, SWA or AWA armoured for high current capacity (BS 5467)
- Fire alarm and emergency systems — LSZH (BS 7629-1, BS 6724) for circuit integrity in fire conditions
- Data centres and public buildings — LSZH mandatory under BS 7671 for escape routes and ventilated spaces
- Flexible connections — Rubber HOFR or PVC/PVC flexible cords for portable equipment and machinery
Selection Decision Matrix
| Installation Condition | Recommended Cable Type | Rationale |
|---|---|---|
| Buried earth electrode connection | Bare copper (16 mm2 min, protected) | Direct contact with soil required; BS 7671 Table 54.1 |
| Protective conductor in conduit | Bare copper (2.5 mm2 min) or insulated | Both acceptable; bare is cheaper, insulated avoids sleeving requirement |
| Building general power circuit | Insulated cable (PVC or XLPE) | Bare not permitted for general wiring; BS 7671 requires insulation for live parts |
| High-temperature environment (>70°C) | XLPE insulated | PVC degrades above 70°C; XLPE rated 90°C continuous, 250°C short circuit |
| Public area / escape route | LSZH insulated (BS 6724) | Low smoke and zero halogen mandatory for safety in fire |
| Outdoor exposed / direct sunlight | Insulated, UV-stabilised (XLPE or special PVC) | Bare copper oxidises; standard PVC degrades under UV without carbon black |
| Switchgear panel internal earth bar | Bare copper | Lower cost, easier inspection, higher k-value for fault sizing |
| Substation earth grid | Bare copper (stranded, 50–120 mm2) | Corrosion-resistant direct burial; EN 50522 earthing design |
Total Cost of Ownership: Bare Copper vs Insulated Cable Over 25 Years
The real cost difference is not the per-metre price but the total installed cost over the system life. Below is a 25-year TCO comparison for a typical 50-metre run of 16 mm2 copper conductor in three configurations.
| Cost Component | Bare Copper (+ conduit) | PVC Insulated (PVC/PVC) | XLPE/LSZH (BS 6724) |
|---|---|---|---|
| Cable material cost (50 m) | £45 | £68 | £85 |
| Conduit / cable tray | £35 | £0 (tray only, £12) | £0 (tray only, £12) |
| Cleats / fixings / glands | £20 | £10 | £12 |
| Material subtotal | £100 | £90 | £109 |
| Installation labour (estimated) | £120 (2-person, conduit bending + pulling) | £80 (1-person, tray laying) | £85 (1-person, tray laying) |
| Total installed cost | £220 | £170 | £194 |
| Expected replacement at year | Not replaced (metal only) | Year 18 (PVC embrittlement) | Not needed (25-year design life) |
| Replacement cost | £0 | £140 (50% of original, labour only if conduit reused) | £0 |
| 25-year total cost | £220 | £310 | £194 |
| Annualised cost | £8.80/yr | £12.40/yr | £7.76/yr |
The TCO comparison reveals a counter-intuitive finding: XLPE/LSZH insulated cable can have a lower 25-year cost than bare copper with conduit, because it eliminates the replacement cycle and reduces installation labour. Bare copper remains competitive only where conduit is already required for other circuits, or where the copper is used exposed (e.g., within switchgear panels).
How to Specify Quality Copper Cable — Practical Checklist
Whether you choose bare or insulated copper, verifying quality at the point of specification prevents costly failures. Use this checklist when evaluating suppliers:
- Conductor material verification — Confirm oxygen-free or high-conductivity copper (minimum 99.9% Cu). Insist on a mill test certificate to BS EN 1976 or BS EN 13601.
- CSA tolerance — Check that the cross-sectional area meets the declared value within ±1% for Class 2 stranded (BS EN 60228). Undersized copper can cause overheating at rated current.
- Strand count and lay length — Class 2 stranded conductors must have the correct number of strands for the CSA. For example, 16 mm2 Class 2 requires 7 strands; a lower strand count may indicate a non-compliant product.
- Insulation thickness — For insulated cables, verify wall thickness to the relevant standard (BS 6004 for PVC, BS 5467 for XLPE/PVC, BS 6724 for XLPE/LSZH). A micrometer check on a sample end is quick and effective.
- Smoothness and concentricity — The insulation should be concentric around the conductor. Eccentric insulation leads to weak points and premature failure.
- Batch traceability — A reputable supplier provides metre-marked cable with batch numbers. This enables traceability back to the raw material certificate — essential for warranty claims and quality audits. Sorivo supplies every cable reel with full batch traceability and a mill test certificate on request.
- Oxidation inspection (bare copper) — Bare copper should arrive with minimal oxidation. Heavy black or green discolouration indicates poor storage or long shelf time.
Conclusion: How to Choose Between Bare Copper and Insulated Cable
The choice between bare copper and insulated copper cable depends on three factors: application (is bare copper permitted?), total installed cost (including labour, conduit, and lifecycle), and environment (indoor/outdoor, temperature, fire risk).
Choose bare copper when: the conductor is used for earthing, bonding, or internal switchgear connections; it is mechanically protected (conduit or enclosure); and the higher k-value can reduce required CSA through adiabatic calculation.
Choose insulated cable when: the conductor carries live current in a building circuit; the environment requires fire-safe materials (LSZH); or the total installed cost of bare copper + conduit exceeds the cost of insulated cable.
For most commercial and industrial building installations, XLPE/LSZH insulated cable offers the best 25-year value — even though its upfront insulated copper cable cost is higher than bare copper alone.
Need Help Specifying the Right Cable?
Our technical team at Sorivo can review your project requirements and recommend the optimal conductor type — bare or insulated — with full documentation including mill test certificates, BS 7671 compliance statements, and batch traceability.
Request a free technical specification review — email sale@sorivocable.com or call +86 19282905529 (24/7 support) with your project voltage, distance, and installation conditions.
Frequently Asked Questions
Is bare copper cable cheaper than insulated copper cable?
Yes, bare copper costs 30–50% less per metre than the equivalent insulated cable. However, when you factor in conduit, cleats, and additional labour for installing bare copper, the total installed cost of bare copper can equal or exceed insulated cable — especially for longer runs. Our TCO analysis shows XLPE/LSZH insulated cable can have a lower 25-year cost than bare copper in conduit.
What size bare copper earth conductor do I need for a TN-C-S supply?
For a PME (TN-C-S) earthing system, BS 7671 requires the main protective bonding conductor to be at least 10 mm2 copper. The earthing conductor (MET to earth electrode) must comply with Table 54.1 — minimum 16 mm2 if protected against mechanical damage, or 25 mm2 if not protected.
Can I use bare copper for general building wiring?
No. BS 7671 requires that live conductors in building wiring be insulated. Bare copper is only permitted for protective conductors (earth and bonding) and within switchgear enclosures. For general power and lighting circuits, use PVC (BS 6004), XLPE (BS 5467), or LSZH (BS 6724) insulated cables.
Does bare copper have higher ampacity than insulated copper?
Bare copper in free air has a higher continuous current rating than insulated cable of the same CSA, because there is no insulation to limit operating temperature. However, this advantage is only usable in controlled environments. In practice, bare copper’s ampacity is limited by the ambient conditions and the need to avoid contact with adjacent conductors or building materials.
What is the scrap value difference between bare and insulated copper cable?
Bare copper wire falls into the “dry bright wire” scrap grade — the highest value classification, currently around £7,900/tonne (Q2 2026 UK). Insulated copper cable scrap is graded lower because the insulation must be stripped or processed, currently around £2,800/tonne. The difference reflects both the insulation weight and the processing cost to recover the copper.
What is the difference between bare copper and tinned copper?
Tinned copper is coated with a thin layer of tin to prevent oxidation and improve solderability. It costs approximately 10–15% more than bare copper. Tinned copper is preferred in marine environments, high-humidity installations, and photovoltaic applications where corrosion resistance is critical. For a detailed comparison, see our guide on bare vs tinned copper cable.