What Is A Subcontractor In Construction? Role, Responsibilities and Benefits

Updated July 2025

The construction industry thrives on collaboration. From towering commercial builds to intricate renovations, no single company can do it all. That’s where subcontracting comes in — an essential part of how modern construction projects are delivered on time, on budget and to a high standard.

But what does subcontracting actually involve? How does it work in practice? And why is it such a critical part of the supply chain?

In this guide, we break down the role of subcontractors in construction, explore different types of subcontracts and explain why subcontracting is such a valuable strategy for both main contractors and specialist trades. Whether you’re new to the industry or looking to expand your subcontracting business, read on to better understand this vital construction model.

What Is A Subcontractor?

A subcontractor is a skilled individual or company hired by a main contractor to perform specific tasks on a construction project. Subcontractors are not directly contracted by the client but work under the direction of the main contractor. They bring specialised expertise such as electrical, plumbing, HVAC, or structural steel installation.

Related Reading: What Is A Contractor?

What Is Subcontracting In Construction?

Subcontracting is the process where a main contractor outsources specific parts of a project to external specialists known as subcontractors. These specialists complete well-defined tasks, such as electrical wiring, HVAC installation, or masonry, that require expertise beyond the scope of the main contractor’s in-house team.

Subcontracting allows construction projects to:

• Be completed faster through simultaneous workstreams
• Meet compliance and safety standards with expert oversight
• Reduce costs by avoiding permanent hires or new training
• Scale operations without expanding internal resources

Whether you’re building a commercial skyscraper or renovating a housing development, subcontracting plays a critical role in delivering projects on time and within budget.

Related Reading: How To Become A Contractor (In UK Construction)

Contractor Vs Subcontractor: What’s The Difference?

Understanding the difference between a contractor and a subcontractor is key to navigating any construction project:

Contractor	Subcontractor
Hired directly by the client	Hired by the main contractor
Manages the entire construction project	Handles specific tasks within the project
Responsible for compliance and delivery	Delivers their scope under main contractor supervision
Oversees multiple trades and teams	Often a specialist in one trade

In essence, the main contractor oversees the entire project and ensures it meets the client’s expectations. The subcontractor, on the other hand, focuses on completing their specific assignment to professional standards, often bringing niche knowledge or tools to the project.

Related Reading: What Is Contractor Management? A Guide

What Does A Subcontractor Do In Construction?

Subcontractors take on highly defined parts of a construction project. Depending on their trade, a subcontractor may be responsible for:

• Installing electrical or plumbing systems
• Pouring concrete or laying bricks
• Fitting windows, doors and insulation
• Carrying out roofing or flooring work
• Providing specialist design-and-build services (e.g., HVAC or fire safety)

Subcontractors typically manage their own teams, tools, materials and scheduling — all under the scope and supervision of the main contractor. They are expected to deliver high-quality work on time, following the project’s specifications and being compliant with health and safety regulations.

Related Reading: A Guide To Health And Safety Procedures For Contractors

Related Reading: How To Manage Contractors’ Health And Safety On A Construction Site.

5 Reasons Why Subcontracting Is Essential In Construction

Subcontracting plays a pivotal role in delivering construction projects that are safe, timely, and cost-effective. Whether on a residential build or a large-scale infrastructure project, subcontractors provide the hands-on expertise and flexibility that main contractors often can’t maintain in-house.

Here are the top reasons why subcontracting is so widely used in the construction industry:

1. Access to Specialised Skills

Construction projects involve a wide range of tasks — from electrical work and plumbing to steelwork, carpentry and environmental engineering. It’s nearly impossible for a single contractor to have all these capabilities internally. Subcontractors fill these gaps by offering deep, trade-specific expertise that improves both quality and safety outcomes.

2. Scalability and Capacity

Subcontracting allows construction companies to scale operations quickly without hiring full-time staff. When demand increases — such as during large infrastructure builds or peak construction seasons — subcontractors can be brought in to expand workforce capacity. This ensures that projects don’t stall due to labour shortages.

3. Faster Project Delivery

Using multiple subcontractors enables different phases of a construction project to run concurrently. For example, while one team installs the framework, another can handle plumbing, and a third can complete interior fit-outs. This simultaneous workflow model saves time and accelerates delivery without compromising on quality.

4. Cost Efficiency

Hiring full-time specialists and investing in new equipment can be expensive. Subcontractors often already have the tools, training and certifications required for their niche tasks. By engaging construction subcontractors on a project basis, main contractors can reduce overheads, optimise budget spending and avoid long-term commitments.

5. Project Flexibility

Every construction project is different, and the ability to adapt quickly is critical. Subcontracting provides a flexible workforce that can be tailored to each project’s unique needs — whether sourcing a niche trade for a heritage renovation or ramping up manpower for a fast-track commercial development.

Related Reading: How Do Contractors Get Clients? Guide To Getting More Work

Common Types Of Subcontracts In Construction Projects

When it comes to subcontracting in construction, there isn’t a one-size-fits-all contract. The type of subcontract agreement chosen depends on factors like project scope, risk tolerance and how predictable the work is.

Here’s a breakdown of the most commonly used construction subcontract types — each offering a different balance of flexibility, cost control and accountability.

Subcontract Type	Description	Best For
Lump Sum (Fixed Price)	A set price is agreed upon for the entire scope of work. The subcontractor bears most of the risk for cost overruns or delays.	Predictable tasks with clear deliverables and timelines.
Cost Plus	The subcontractor is reimbursed for actual costs (materials, labour, equipment) plus a pre-agreed fee or markup.	Complex or evolving projects where the scope may shift.
Time and Materials (T&M)	Payment is based on the time spent and materials used, often with agreed hourly rates. The final cost may vary depending on the workload.	Projects with undefined or flexible scopes.
Unit Price	Payment is based on measurable units of work (e.g. per square metre, per installation).	Work that can be easily measured in quantities.
Design and Build	The subcontractor handles both the design and execution of a task. This integrated model improves efficiency and accountability.	Tasks where seamless design-to-delivery is beneficial.

How To Choose The Right Subcontract Type

Choosing the appropriate subcontract type in construction comes down to risk sharing and project predictability. Fixed-price contracts offer budget control but less flexibility, while cost-plus or T&M agreements are ideal when the final scope isn’t fully defined.

Whether you’re a main contractor looking to allocate work or a specialist looking to win jobs, understanding these subcontract types is critical for clear expectations, reduced disputes and successful project outcomes.

Become A Trusted Subcontractor Through Veriforce CHAS Certification

Subcontracting plays a vital role in the construction industry by connecting skilled professionals with the specific demands of each project. Whether you’re a tradesperson, specialist business, or service provider, working as a subcontractor allows you to contribute your expertise to larger construction projects — all while maintaining flexibility and control over your workload.

If you’re looking to grow your subcontracting opportunities, getting certified is a smart next step. Veriforce CHAS is one of the UK’s leading providers of supply chain risk management and compliance services, connecting over 2,500+ clients with qualified, safe, and compliant contractors.

• Demonstrate your commitment to safety, compliance and quality
• Get noticed by top-tier construction clients across the UK
• Win more work and grow your subcontracting business.

Join Veriforce CHAS today and put your business at the forefront of the construction supply chain.