Cable Labelling Lessons from Parliament's £40 Billion Restoration

In February 2026, the Restoration and Renewal (R&R) Client Board presented MPs and peers with two options for restoring the Palace of Westminster. A full decant, where both Houses vacate the building, would cost up to £15.6 billion and take 19 to 24 years. A phased approach, with Parliament remaining on site during works, could take up to 61 years and cost £39.2 billion (Restoration and Renewal Client Board, 2026).

These numbers are staggering, but the underlying cause is straightforward: decades of deferred maintenance. The R&R Client Board's report stated that continuing the current approach is "unsustainable" and will lead to "expensive managed decline" with "increasing safety and operational risks." At present, £1.5 million is spent every week simply keeping the building functional.

Map of the Parliamentary Estate and surrounding area. The Palace of Westminster covers 34 acres, with 1,100 rooms across 65 different floor levels. Image: Joint Committee on the Palace of Westminster (2016).

Among the most pressing concerns are the building's mechanical and electrical (M&E) services. Heating, water, sewage, and electrical systems are outdated, with steam pipes running alongside power cables throughout the structure. In the month the report was drafted alone, problems included a heating failure in the House of Lords, sewage system issues, and multiple toilets out of action.

It is worth acknowledging the remarkable work of the contractors and in-house maintenance teams who keep Parliament operational day after day. They manage a building whose services are well past their expected lifespan, navigating asbestos-affected areas, congested risers, and undocumented infrastructure, all while ensuring that the business of government continues uninterrupted. The fact that the Palace still functions at all is a testament to their skill, resourcefulness, and dedication. The challenges they face are not of their making: they are the inherited consequence of decades of deferred investment in a building that has never been closed long enough for a proper overhaul.

The Palace of Westminster's basement has been described as a "cathedral of horror" because of the tangled mass of pipes, cables, and wiring buried behind layers of newer installations (Joint Committee on the Palace of Westminster, 2016). The problem is rooted in how cable labelling and cable marking were handled, or rather, not handled, over many decades.

Because Parliament has never been fully closed for renovation, electricians have historically only had time to install new cables without removing old ones. The result is an estimated 250 miles of cabling that needs to be stripped out and replaced. In one room alone, there are reportedly over 3,500 cables, many of which cannot be removed because nobody can identify what they do.

Overlapping cables in Plant Room B beneath the Palace of Westminster. Following rationalisation of the 3,500 cables running through this space, some 800 cables proved impossible to remove, in some cases because they could not be identified. Image: Joint Committee on the Palace of Westminster (2016).

A working telephony system inside the Palace of Westminster. There are approximately 20 of these banks around the Palace, with over 1,400 individual terminal points spread across them. Without consistent labelling, tracing and maintaining these connections becomes extraordinarily difficult. Image: Joint Committee on the Palace of Westminster (2016).

The specialist teams currently surveying and cataloguing Parliament's infrastructure deserve particular credit. Over recent recesses, more than 50 engineers, architectural surveyors, acoustics specialists, and ecologists have spent thousands of hours investigating the building, examining over 2,300 rooms and spaces to build the most detailed record of the Palace ever created (Restoration and Renewal Delivery Authority, 2024). This painstaking work, carried out in confined and often hazardous conditions, is precisely what allows the restoration to move forward. The problems they are documenting are the result of historical constraints, not current shortcomings.

This is what happens when cable labels are absent, when wire labels deteriorate and are never replaced, and when cable identification is treated as optional rather than essential. Without proper labels for cables, every maintenance task becomes an investigation. Every repair risks disturbing unknown circuits. Every upgrade requires extensive surveying before a single wire can be touched.

The Palace of Westminster may be an extreme case, but the underlying issues are common across older buildings, from Victorian-era hospitals to listed commercial properties, churches, and public infrastructure. According to the Building Conservation Directory, a surprisingly large number of buildings across the UK still retain wiring installed in the mid-19th century, presenting fire risks that often go unrecognised until a major renovation begins.

Proper cable labelling serves several critical functions in any building, whether it is 10 years old or 150.

The Wiring Regulations exist precisely to prevent situations like Parliament's cable chaos. Section 514 of BS 7671 sets out requirements for identification and notices, including labelling of distribution boards, circuit breakers, and cable schematics. Following these standards from day one is the most cost-effective way to protect any building's electrical infrastructure.

Restoration projects present unique cable labelling challenges. Access is often restricted, environments may contain asbestos or other hazards, and the sheer volume of undocumented cabling can be overwhelming. Here is a practical approach to cable labelling in these settings.

Label as you survey

Before any cable is moved or replaced, it should be identified and labelled. Using a portable cable label printer such as the Fox-in-a-Box® thermal printer allows engineers to print durable cable labels on site, as each cable is traced and identified. This approach turns the survey process into a labelling process, so no cable goes back into a riser or trunking run without proper identification.

Choose LSZH labels for enclosed spaces

Heritage buildings typically have enclosed voids, basement risers, and ventilation shafts where smoke and toxic gas from a fire could spread rapidly. Low Smoke Zero Halogen (LSZH) cable labels are designed to produce minimal smoke and no halogen gases if exposed to fire, making them the appropriate choice for these environments. Fox-Flo® tie-on cable labels are manufactured from LSZH material and carry London Underground approval, making them suitable for the most demanding enclosed environments.

Use durable label materials

Restoration projects are intended to last decades. Cable labels must match that lifespan. Thermal transfer printed labels, as produced by the Fox-in-a-Box® system, use resin ribbons that create permanent, smudge-proof text resistant to chemicals, moisture, and abrasion. For cables that need wrap-around identification, Prolab® High Performance Tape provides a self-laminating wrap-around label with a clear protective tail that shields the printed area from environmental damage.

Standardise your labelling scheme

One of the lessons from Parliament is the danger of inconsistency. When multiple teams label cables over decades without a common standard, the result is confusion. Using label design software such as Labacus Innovator® ensures that every label follows the same format, font, and data structure. Cable schedules can be imported directly from spreadsheets, eliminating transcription errors and ensuring consistency across large projects.

Fire is generally regarded as the greatest single threat to heritage buildings. The Palace of Westminster caught fire 40 times between 2008 and 2012, and the 2019 Notre-Dame fire in Paris served as a stark reminder of how quickly a heritage building can be devastated. Lord Hain described Parliament's fire risk as having "a Notre Dame inferno incubating in the palace."

In this context, every component in the building matters, including cable labels. Standard PVC labels can produce dense, toxic smoke and release halogen gases when burned. In the confined spaces typical of heritage buildings, such as the basement risers and ventilation shafts found throughout the Palace of Westminster, these gases can be lethal and corrosive to equipment and building fabric.

LSZH (Low Smoke Zero Halogen) labels address this risk directly. They are engineered to produce minimal smoke and zero halogen gases in a fire, helping to maintain visibility for evacuation and reducing toxic exposure. For any project involving enclosed spaces in heritage or public buildings, LSZH cable labels should be specified as standard.

BS 6701:A1 2017, adopted as a supplement to the BS 7671 18th Edition, also strengthened requirements for cable performance in fire conditions. While this primarily concerns the cables themselves, specifying LSZH cable labels alongside LSZH cables ensures a consistent fire safety approach throughout the installation.

How do you label cables in a heritage building?

The approach is similar to any building, but with additional considerations. Use LSZH label materials for enclosed spaces, choose a portable label printer for on-site printing during surveys, and ensure labels are durable enough to last the building's expected maintenance cycle. Tie-on cable labels are often preferable in heritage settings because they do not leave adhesive residue on historic fabric.

What are LSZH cable labels?

LSZH stands for Low Smoke Zero Halogen. These cable labels are manufactured from materials that produce minimal smoke and no halogen gases when exposed to fire. They are required or recommended in enclosed public spaces, underground environments, rail, marine, and heritage buildings where smoke and toxic gas spread could endanger occupants.

Does BS 7671 require cable labelling?

Yes. Section 514 of BS 7671:2018+A3:2024 (the 18th Edition of the IET Wiring Regulations) sets out requirements for identification and notices on electrical installations. This includes labelling of distribution boards, circuit identification, and safety notices. The standard applies to both new installations and significant alterations to existing ones.

How can I label cables that are already installed?

Tie-on cable labels and wrap-around cable labels are both suitable for retrofitting onto existing cables without disconnection. Tie-on labels such as Fox-Flo® attach using cable ties and can be fitted at any accessible point along the cable. Wrap-around labels such as Prolab® High Performance Tape wrap around the cable sheath with a self-laminating clear tail that protects the printed text.

What information should be on a cable label?

At a minimum: cable reference or circuit number, origin (from), destination (to), and cable type or size. For heritage and restoration projects, consider adding the installation or survey date and the responsible contractor's reference. Using standardised software to generate labels from cable schedules ensures all required fields are populated consistently.