Cardiff is running its largest programme of city-centre construction in a generation, and a significant share of it sits in places that cannot be sealed off. Tram track through a working public square. Platform works inside an operating railway station. A 16,500-seat arena rising next to a leisure complex that stays open through the build. Perimeter fencing solves most site crime. These sites don’t have a proper perimeter, which changes what protection has to look like.
What is actually being built
Three programmes are running at once. Cardiff Crossrail phase 1a, a £100m tram-train link from Cardiff Central to Cardiff Bay via Callaghan Square, moved into enabling works in June 2026 with Graham as principal contractor and completion targeted for summer 2028. The scheme includes new tram platforms at Cardiff Central, an extra platform at Cardiff Bay, and a twin-track route cutting through Callaghan Square.
The New Cardiff Bay Arena broke ground in September 2025. Robertson Group is the main contractor on the £300m, 16,500-capacity venue at Atlantic Wharf, with opening projected for 2028, and the arena forms phase one of a wider 30-acre regeneration delivering over 155,000 square metres of mixed-use development around it.
Cardiff Central station redevelopment and the Callaghan Square regeneration sit alongside both. Add the Euro 2028 deadline hanging over Principality Stadium, and the city has a fixed date that nobody wants to miss, which is the kind of pressure that pushes the programme ahead of everything else, including site protection.
The perimeter problem on linear works
Tram works do not have a compound in any meaningful sense. They have a corridor, and that corridor moves. Callaghan Square is staying open to traffic through the first phase with lane reductions rather than closures, so the working area sits inside a live highway with pedestrians and cyclists routed around it daily.
Heras panels on a linear job get relocated constantly. Every relocation creates a gap somebody has to notice. On a site running utility diversions beneath a carriageway, the exposed plant is often a cable drum or an excavator parked in a lane rather than kit locked inside a yard. Copper cabling for electrification is the obvious target. It strips fast, it sells anonymously, and a single overnight loss on a diversion can hold a whole phase.
Cameras struggle here for a structural reason rather than a technical one. A camera tower covers a fixed field. A site that shifts 30 metres a week outgrows its own coverage, and the survey rarely gets redone until after something goes missing.
Working next to venues that never close
Atlantic Wharf builds around an operating Red Dragon Centre, the Wales Millennium Centre and the wider Cardiff Bay leisure footfall. Cardiff Central handles passengers throughout the platform works. On a Principality Stadium event day, a crowd of over 70,000 moves through the same streets the plant is parked on.
That mix pushes the job away from perimeter defence and toward access control and public interface. Officers spend more time verifying deliveries, turning back members of the public who have wandered through a gap, and managing the interface between site traffic and pedestrian flow than they do watching a fence line. Contractors comparing construction security Cardiff quotes should ask directly how a provider staffs a perimeter that changes weekly, because a price built on a static gate assumption will not survive contact with the programme.
Event days need planning in as their own category. A site adjacent to a stadium egress route on an international weekend is a different risk profile from the same site on a Tuesday, and the officers covering it need briefing rather than just rostering.
Trespass carries more weight than theft here.
Plant theft still costs UK construction over £800 million a year, with more than 11,000 plant and equipment thefts reported annually and an average loss around £45,000 per incident. Recovery rates sit below 25%. Those figures hold in Cardiff as anywhere.
Urban sites carry a second exposure that greenfield sites mostly do not. People climb scaffolding for a view. Rough sleepers use partially enclosed structures. Groups treat a half-built plot as a shortcut between the Bay and the city centre after closing time. Each of those is a health and safety liability for the principal contractor, not a theft loss covered by insurance, and it’s why night cover on an urban plot earns its cost even in a quarter where nothing gets stolen.
South Wales Police attend when called. Attendance time on a Saturday at 2 am in a city with a busy night-time economy is not a number any contractor should build a programme around.
What layered cover looks like on an urban plot
The measures that hold up on constrained sites are the unglamorous ones:
- Control every access point through a single manned gate with a delivery schedule the officer actually holds.
- Re-survey camera coverage each time the working area moves, rather than at mobilisation only.
- Immobilise plant left in the public realm overnight, including battery removal and cab locking.
- Store cable drums and small plant in reinforced containers instead of open compounds.
- Log patrols, access and incidents in a form an insurer will accept without argument.
Joining the NCATT alert network costs nothing and gives sight of what is happening on neighbouring sites, which matters in a city where several major schemes are running within a mile of each other.
Questions worth asking before you appoint
Ask who is physically on site rather than whose name is on the contract, since subcontracted cover is common and licence checks slip when a shift gets filled at short notice. Ask for SIA licence numbers and verify them yourself against the SIA register. Ask what happens on a no-show at 10 pm on a Sunday.
Nationwide operators such as Alpha Security Services run SIA-licensed officers across England, Scotland and Wales, which matters on a scheme where cover has to scale between phases rather than sit flat for two years. Any provider that hesitates on licence verification has answered a different question than the one you asked, and that answer is worth having early.