Prefabricated pipe racks, pump skids and electrical modules cut on-site labour by 30–50% and improve quality by moving welding, fitting and wiring into a controlled environment. In Nigeria, where site conditions can lose two days a week to weather, security, or logistics, moving as much work as possible into a covered facility is a strategic advantage, not a luxury.
The engineering case is now well established internationally. What has been missing here is the local supply base — and that is changing faster than most consultants realise.
What we prefabricate
Wet-riser assemblies, chiller pump skids, generator paralleling panels, and pre-populated cable-tray sections. Each arrives pressure-tested, meggered and ready to hoist. Typical modules are 3 to 8 metres long and sized to fit standard 40-foot flatbeds; anything larger becomes a lifting-and-access problem that erodes the saving.
For a recent Ikoyi tower we prefabricated the entire mechanical plant room as four pump skids and two chiller mounting frames. The plant room was operational three months earlier than the tender programme allowed, and site accidents in that package were zero across 42,000 person-hours.
Design for manufacture and assembly (DfMA)
Prefabrication only works when the design accommodates it. Modules need lifting points, splice locations, and site-adjustable connections. Detailers must think in shippable units, not floors.
We standardise on ANSI 150lb flanged interfaces at all module boundaries, grooved couplings inside modules for speed of assembly, and cable glands rated for the tropical service environment. Every module carries a factory acceptance test (FAT) certificate keyed to its serial number and drawing revision.
Logistics is half the battle
Lagos traffic is the enemy of just-in-time delivery. Our prefabrication logic pushes for a marshalling yard within 20 km of site, with three to five modules held in ready-to-hoist condition at any time. Hoisting slots are booked with the tower crane operator a week in advance and confirmed 24 hours before.
For sites where a marshalling yard is not possible, we sequence deliveries to arrive between 04:00 and 06:00, off-peak for both traffic and public safety. This is expensive in overtime and unavoidable.
Why the market hesitates
Local fabricators still need investment in QA and dimensional control. Crestmark works with a shortlist of vetted shops and inspects every batch before dispatch. Our QA regime includes weld radiography for pressure piping, dimensional survey against BIM coordinates to ±3 mm, and finish inspection under controlled lighting.
The other hesitation is commercial: quantity surveyors accustomed to unit-rate pricing struggle to price a modular package. We supply cost benchmarks — pump skid rates, panel rates, riser assembly rates — that translate module scope back into familiar QS categories, which usually settles the debate.
Where prefabrication doesn't pay
Small refurbishments, congested basements with existing services, and heritage buildings where every module has to be tailored. In those environments traditional in-situ execution is faster. The judgement call is programme-driven, not ideological.
BIM as the contractual language
Prefabrication without BIM is guesswork. Modules must be modelled to LOD 400, coordinated against structure, and clash-tested against every other trade before a single steel is cut. The BIM model is the contract; the drawings are extracts from it.
We enforce a weekly clash-detection cadence during the design-for-manufacture phase, with a target of zero unresolved hard clashes before shop drawings are released. Soft clashes (maintenance access, insulation envelope, valve handle swing) are triaged and either resolved or accepted with written justification. The register is shared with the client's design team weekly.
The model persists as the operational reference. Facilities teams inheriting a fully coordinated BIM model can plan replacements and interventions without opening walls to find out what is inside them. That single benefit repays the BIM investment within the first major maintenance cycle.
Skills and certification
The workforce for a prefabrication shop is different from a site workforce. Coded welders, panel builders certified to IEC 61439, and dimensional inspectors are the core roles. Nigeria has the raw talent; the shortage is in certified training pathways.
Crestmark sponsors two apprenticeships per year through partner shops, targeting 6G welding certification and IEC 61439 panel-build certification. This is a slow investment with a five-year horizon. It is also the only way the local market matures, and it is cheaper than importing labour when the pipeline of projects justifies it.
Commercial models that actually work
Traditional lump-sum tendering does not accommodate prefabrication cleanly because module scope crosses the traditional MEP/structural boundary. We favour a target-cost approach with a shared savings mechanism: the client and the contractor split any underrun against target 50/50, with a defined cap on contractor upside.
This aligns incentives around the actual driver of prefabrication economics — programme certainty — rather than trying to price uncertainty into a fixed rate. Every prefabrication project we have delivered on this basis has returned savings to the client. Every one we have delivered on traditional lump sum has broken even at best.