Should I Use a Main Contractor or Manage the Trades Myself?

One of the most important decisions in a property development is how to organise the building work. Do we appoint one main contractor, manage individual trades, or combine the two?

I've seen the difference these choices can make to cost, programme and quality. The cheapest-looking option at the start isn't always the most profitable at the end. There isn't one answer for every development.

Option 1: Appointing a Main Contractor

A main contractor can coordinate the labour, subcontractors, materials, deliveries and construction programme under an agreed scope of work. That can be invaluable on complicated projects. The contractor needs to cover overheads, management and profit, and I have no objection to that. I simply want to understand what we're paying for. Appointing a builder doesn't remove our responsibility to monitor progress, variations, quality and the agreed specification.

Option 2: Managing the Trades Ourselves

We can appoint groundworkers, bricklayers, roofers, electricians, plumbers, joiners, plasterers and decorators directly, and purchase materials ourselves. That may save a contractor's margin, but somebody still has to coordinate the work. If the plumber isn't ready, the electrician may be delayed; an outstanding inspection or missing delivery can disrupt several trades. We need time, reliable people and a realistic programme.

Compare the Real Cost, Not Just the Quotations

Imagine a main contractor quoting £200,000 while individual trades appear to total £175,000. That £25,000 difference is not necessarily a saving. Have we included scaffolding, skips, temporary services, site facilities, plant, insurance, deliveries, waste removal and management? What happens if the project takes three months longer? We should compare the total cost of completion, including our time, finance and risk, using exactly the same scope.

Option 3: The Hybrid Approach — Something I've Used Successfully

I helped oversee a single new-build property for a friend using a hybrid arrangement. We appointed a main contractor to construct the building to an agreed watertight stage, including the superstructure, roof, windows and the relevant elements required to reach that point. After that, we coordinated the plumbers, electricians, joiners and other internal finishing trades ourselves. It gave us the benefit of experienced management of the main construction without automatically putting every finish through the main contract.

Drawing a Line in the Sand

We agreed the contractor's scope and handover point in advance. The agreed contract value was paid once the watertight building had been delivered and the necessary documentation provided to the new-build warranty provider and Building Control. This was essential: everyone needed to understand which work the contractor had undertaken and who would be responsible for the subsequent work. A handover does not erase liability for earlier defects, but a clear written scope, inspection records and documented handover help establish responsibility if something goes wrong.

Warranty, Building Control and Safety

A watertight-stage inspection does not itself guarantee the final new-build warranty certificate. Anyone planning a hybrid build should agree the arrangement with the warranty provider and Building Control in advance, including later inspections and completion requirements. Contractual defects liability, Building Control sign-off and warranty cover are different matters. We must also ensure the appropriate Construction (Design and Management) Regulations 2015 arrangements, including principal contractor and principal designer appointments where required, continue after handover.

Why Pay a Margin on a Kitchen We've Organised?

If I've chosen a kitchen supplier, negotiated the price, agreed the design, organised delivery and arranged installation, why should we automatically pay a main contractor a margin just because the kitchen passes through their contract? If the contractor genuinely procures, coordinates and takes responsibility for the installation, that has value. If we're doing those jobs ourselves, we should understand what additional service their margin buys. On our friend's project, taking direct control of the finishes saved a substantial amount of money.

Why One House Is Different from Ten

The economics of site management matter. For one new-build house, keeping a main contractor's site manager involved throughout the finishing stages can be disproportionately expensive. To be fair to the builder, a similar management team might oversee several houses on one site, spreading its cost across multiple units. Here we were fortunate: the owner was living on site and I was able to help coordinate the remaining work. We had regular supervision without the same contractor-provided overhead. Our time still had value, but the arrangement made commercial sense.

Quality and Control

The internal works were complicated, but they were largely about specification, sequencing and quality of finishes. We could take time choosing materials, discussing details and checking the work to achieve the standard we wanted. A good main contractor can also deliver excellent finishes, of course. The advantage here was direct control. Saving money is no achievement if the finished property loses value because the quality is compromised.

Which Approach Would I Choose?

It depends on the development. How complicated is the work? Are we building one house or twenty? Do we have reliable trades and enough time? Who will manage the programme, inspections and safety? What savings remain after all the extra costs? A main contractor may be right for one scheme, direct trade management for another, and a properly planned hybrid arrangement for a third.

Don't Forget — Developing Property Can Be Fun

We've talked about contracts, costs and risks, but developing property can be great fun. There's real satisfaction in making decisions, working with trades, solving problems and watching a building take shape. You can learn a hell of a lot very quickly. Some mistakes are part of learning; others can cost thousands of pounds. The important thing is recognising which decisions need more experience before we commit.

How I Can Help

My mentoring isn't about taking over your development. I want you to be involved, learn, ask questions and enjoy it. We can compare the construction options, examine quotations, identify missing items, discuss handovers and work out when specialist advice is needed. I've worked in property since the late 1980s, and I can help spot critical decisions before they turn into expensive mistakes. I want you to enjoy developing property and learn from the experience. My job is to help make sure the lessons don't come with an unnecessarily expensive price tag.