Main contractor or manage the trades yourself? How a build is run in Ireland

What a main contractor takes on

You sign one contract, for one price basis, with one programme. The main contractor prices the whole job from your drawings and specification, appoints and pays the subcontractors (groundworks, blocklayers, roofers, electricians, plumbers, plasterers), buys or coordinates the materials, sets up the site, and carries the insurances that a working site needs: public liability, employer's liability and contractors all-risks cover on the works themselves.

They also usually take two statutory roles. Under the construction safety regulations they are normally appointed as Project Supervisor for the Construction Stage (PSCS), the person responsible for coordinating safety on site. Under the Building Control (Amendment) Regulations they are the assigned builder: the party that signs the Certificate of Compliance (Undertaking by Builder) at the start and, with the assigned certifier, the Certificate of Compliance on Completion at the end, without which a new house cannot lawfully be occupied.

What you are paying for, beyond the trades' own prices, is that coordination and that liability: the preliminaries (site set-up, scaffold, welfare, supervision, insurance) and the contractor's overhead and profit on the whole job. Whether that is worth it depends on how much of it you could do yourself, and how much risk you can afford to hold.

The alternative: direct labour

Direct labour means you are the contractor. You engage each trade separately, sequence them, buy the materials, and hold the site together between them. Done well, on a straightforward extension with a good local network, it can cut the cost noticeably: there is no margin on the subcontracted work and no preliminaries beyond what you actually need.

Everything the main contractor carried now sits with you. A delay in one trade is your problem to re-sequence. A defect between two trades (the plumber's pipe through the plasterer's wall) has no single party responsible for it. Your home insurance almost certainly excludes works in progress, so you need a self-build or contract-works policy and you need each trade's own public liability cover to be real and current. And the statutory roles do not disappear: someone must be PSCS if the trigger applies, and on a project that needs the full building-control certificates, someone must be the assigned builder. On a self-build that someone is you.

VAT works against direct labour in one specific way. A builder's service is charged at the reduced 13.5% rate and, within Revenue's two-thirds rule, the materials they supply as part of that service ride at the same rate. Materials you buy yourself at the merchant carry the standard 23%. On a materials-heavy job that gap eats into the margin you saved.

Side by side

The honest comparison is not price alone. It is who holds each risk.

The building-control side, whichever you choose

Work that needs a commencement notice needs it either way. The notice is lodged on the Building Control Management System not more than 28 days and not less than 14 days before work starts, and it names the builder. For a new dwelling, an extension over 40 m², or any works needing a fire safety certificate, the notice is accompanied by the design certificates and the assigned certifier's and builder's undertakings.

Since 2015 the owner of a single dwelling or a domestic extension can opt out of that statutory certification by lodging a declaration with the notice. Opting out removes the certificates; it does not remove the duty to comply with the building regulations, and it leaves you without the completion certificate that a buyer's solicitor will one day ask for. Many self-builders opt out and engage an architect or engineer to inspect anyway. It is a decision to make with advice, not by default.

Safety duties you keep as the client

The construction safety regulations apply to homeowners as clients. If the project involves more than one contractor, is likely to last more than 30 working days or 500 person-days, or involves particular risks (working at height, excavation, demolition), you must appoint a Project Supervisor for the Design Process and a Project Supervisor for the Construction Stage, in writing, and notify the Health and Safety Authority where the duration trigger applies. With a main contractor the PSCS appointment is usually them and the PSDP is usually your designer. With direct labour, you make both appointments yourself, and you can only appoint someone competent to do it.

Checking a contractor before you sign

Get three prices on the same drawings and the same specification, and compare the exclusions before the totals: a low price that excludes the groundworks, the kitchen fit and the connection fees is not low. Ask for the insurance certificates and read the dates and the limits. Ask for a tax clearance certificate. Ask for two finished jobs you can see and one you can phone.

Then look at the record. Every commencement notice is public, and a contractor who has been building steadily leaves a trail of them. PlanningLeads shows the commencement notices behind every planning application on the site, and where the statutory register names a company as the builder we show it, at organisation level only. A builder who claims fifteen extensions last year should have fifteen notices somewhere.

The Regulation of Providers of Building Works Act 2022 puts the Construction Industry Register Ireland (CIRI) on a statutory footing, with the Construction Industry Federation appointed as registrar. At the time of writing the register's own site says it is still being established, so treat CIRI membership as a useful signal, not a substitute for the checks above.

Whichever route you take, get it in writing: the price basis (fixed, or measured against a schedule), the programme, the stage payments, a retention held until the snag list is closed, and who is the assigned builder and the PSCS. A written contract is not a sign of distrust. It is the document both of you will reach for when something goes wrong.

On a bigger scheme: who you actually contract with

On an apartment scheme or a commercial build the question is not whether there is a main contractor but who it is, because the main contractor is the party that buys every trade and supply package. The developer named on the planning file signs nothing with a roofer. For trades and suppliers this is the useful direction to read the record in: the commencement notice, not the planning grant, is the moment the buyer appears. That is why PlanningLeads flags sites breaking ground and, where the register names one, the appointed main contractor.