What is a subcontractor in construction?

With increasing regulations and compliance standards in the industry, such as CDM regulations, the Building Safety Act and the Procurement Act to name just a few, many main contractors and public sector buyers’ projects require more specialised skills and expertise than they have in their own teams to carry out various elements of their projects. It’s for this reason that main contractors find it makes business sense to bring in construction subcontractor experts for specific tasks for each of their projects rather than having to keep a full-time team with varied skills that might sit idle between projects. 

In this blog, we distinguish what a subcontractor is in the construction industry, along with examples, their typical roles and responsibilities and supporting solutions. 

What is a subcontractor?

Subcontractors can be either individuals or companies who are brought onto projects by main contractors or public sector buyers to provide their specialised expertise in order to carry out specific elements of a wider project. These skilled professionals or businesses handle specific tasks rather than dealing directly with the client, which is the main contractor’s responsibility.  

Examples of subcontractors in construction

Within the industry, subcontractors can be typically grouped into three overarching areas: 

1. Domestic Subcontractors

These are subcontractors who have been specifically selected and appointed by the main contractor.  

2. Nominated Subcontractors

This is when the client selects a subcontractor, negotiates the price and then instructs the main contractor to appoint the chosen supplier for the works.  

3. Named Subcontractors

A subcontractor is chosen from a list of pre-selected suppliers provided by the client. A work package is published by the main contractors and specified subcontractors are contacted and tenders are requested from these subcontractors. The successful subcontractors are then contracted to carry out the specific work. 

Construction sites and projects will need different specialist subcontractors at each stage of the project. At Constructionline, our platform connects the above subcontractors with main contractors looking for their services, depending on filter specified in their tenders.

Example Types of Subcontractors

 Here’s a look at some of the types of subcontractors you’ll find on many typical construction sites: 

• Site preparation contractors: These specialists get the construction site ready by handling excavation and earthwork.   
• Concrete contractors: They create foundations, footings, and other cement structures that give buildings their strength. 
• Framing contractors: These experts build the building’s skeleton and create structural components for walls and roofs.   
• Drywall contractors: Specialists who make interior walls and ceilings look professionally finished. 
• Roofing contractors: These experts shield buildings from weather by installing roofing systems and gutters. 
• Electrical contractors: You’ll find them on every construction site, installing wiring, panels, fixtures, and electrical systems.
• Plumbing contractors: They make sure water flows properly through buildings and install waste lines for safe sewage removal. 
• HVAC contractors: These specialists handle heating, ventilation, and air conditioning to keep building occupants comfortable. 
• Masonry contractors: They work their magic with bricks, stones, and concrete blocks for both structure and style. 
• Painting contractors: These professionals add the final touches inside and out, whilst also protecting surfaces. 
• Carpentry contractors: They focus on interior woodwork like doors, cabinets, and trim, unlike framing contractors who handle structural elements. 
• Landscaping contractors: These experts enrich outdoor spaces with plants, irrigation systems, and hardscaping.

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Roles and responsibilities of subcontractors in construction

Subcontractors share a core selection of common duties across their different trades. Their main job involves completing contracted work either personally or through their employees and suppliers. 

Subcontractors must also handle: 

		Technical expertise: Mechanical, electrical, and plumbing specialists need to provide detailed plans and shop drawings for their work.
		Installation and execution: They must properly install everything related to their trade, putting their expertise to use.
		Labour management: Each subcontractor manages their workforce to ensure the right people with the right skills show up at the right time.
		Collaboration: Success depends on working well with the main contractor and other trades to keep schedules on track.
		Safety enforcement: Safety comes first. Each team needs proper protective equipment and must follow strict safety protocols.
		Progress tracking: Accurate billing requires careful documentation of completed work and project milestones.
		Project closeout: The final steps include inspections, finishing installations, and providing documentation to the main contractor.

Construction Design and Management Regulations (CDM) require subcontractors to plan safe work practices and control risks, this safety responsibility is shared with the principal contractor. 

Subcontractors are the backbone of construction projects. They work independently under main contractors and bring specialised knowledge that helps projects move forward quickly.

No single contractor could master all these technical skills alone. The partnership between main contractors and subcontractors means each part of the project gets expert attention: and it’s this teamwork which means construction work meets meet both technical standards and quality expectations. 

Read more about CDM Regulations →

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Advantages of using subcontractors in construction

Subcontractors bring valuable expertise to construction projects of all sizes. The construction industry has embraced subcontracting as a standard practice over the last few years. Choosing subcontractors instead of main contractors, or public sector buyers having to handle everything in-house, creates strategic benefits beyond just convenience:

1. Access to specialised expertise

Subcontractors bring specialised knowledge that main contractors don’t usually have in-house. Construction projects need various skills – from electrical work to plumbing and roofing. Specialists who focus on specific trades build deep expertise that general construction contractors can’t match. 

2. Cost efficiency and financial flexibility

By relying on specialist subcontractors, main contractors can keep their core teams lean, reducing overhead during slower periods. Subcontractors also offer fixed-price quotes, making it easier to predict project costs. 

3. Equipment and resource optimisation

Specialised construction tasks need expensive equipment that main contractors can’t practically buy and maintain. Subcontractors, however, will use their specialist equipment regularly across many jobs for different contractors. This creates an efficient system where specialised tools get full use across the industry instead of sitting idle with individual companies. 

4. Enhanced scheduling flexibility

Construction project deadlines and timelines are often disrupted by weather, material delays, and unexpected challenges. Subcontractors help mitigate these issues by quickly adjusting their timelines and mobilising as needed.

Main contractors can coordinate multiple subcontractors simultaneously to accelerate progress or manage setbacks more effectively. This flexibility allows project teams to scale up or down quickly, as subcontractors can deploy skilled crews faster than main contractors could recruit and train new staff—resulting in more agile and responsive project management. 

5. Construction risk management and liability distribution

Subcontractors help distribute construction risk across multiple parties, rather than placing it solely on the main contractor. Each subcontractor assumes responsibility for their own scope of work, including any defects that may arise. Subcontractors with robust internal processes and structures ensure that risk is allocated to those most capable of managing it.  

Additionally, licensed subcontractors typically carry their own insurance, further limiting the main contractor’s exposure to potential claims. 

6. Geographic flexibility

Running projects in multiple regions creates big challenges for construction companies so utilising local construction subcontractors solve this problem. They will know suppliers, and area-specific requirements and it’s this more localised expertise helps navigate permits and work with local authorities. 

7. Innovation and quality improvements

Specialist subcontractors often bring innovative solutions to construction projects, staying at the forefront of advancements in their fields. They introduce main contractors to cutting-edge methods, materials, and technologies that can elevate project outcomes.  

Regular collaboration with these experts exposes main contractors to the latest industry practices across a range of specialties. In a competitive market, this drive for innovation is further fuelled by the need for specialists to continually improve and differentiate their services.

8. Simplified management and administrative efficiency

Managing specialised work through subcontractors can simplify project administration. Instead of directly supervising a wide range of specialised workers, main contractors manage fewer, more focused subcontractor relationships. This streamlined structure reduces administrative burden and paperwork.  

Subcontractors take responsibility for overseeing their own teams, allowing main contractors to concentrate on overall coordination and quality assurance—resulting in a more efficient project delivery process. 

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How subcontractors are hired in construction

Pre-Qualification Questionnaires (PQQs)

Pre-qualification questionnaires (PQQs) are very helpful for main contractors and other contracting authorities to help sort and screen large numbers of potential subcontractors for their projects. In recent years, PQQs have been standardised across the construction industry; comprised with a set of questions designed to evaluate and align subcontractors’ compliance levels and practices to the objectives and goals of the wider construction project. 

For example, main contractors use PQQs to check if subcontractors meet regulations such as the Common Assessment Standard, Building Safety Act, SSIP and so on before then inviting them to tender on the project using tools such as Tender Management. 

The Pre-Qualification Questionnaire (PQQ) process helps identify a shortlist of subcontractors capable of handling specific aspects of a project. This structured approach ensures that only suitably qualified companies progress to the detailed tender stage, saving time and resources for all parties. 

Learn more about PQQ Procurement processes →

Compliance Standards for subcontractors

Over recent years, in order to be successful in a bid for a construction project, it’s become increasingly important for subcontractors to be able to demonstrate compliance with a range of legal, safety, and operational standards. These requirements have become more robust in response to evolving regulations focusing on building safety legislation such as the Building Safety Act, and reflect the industry’s growing focus on construction risk management, sustainability, and accountability.

To ensure subcontractors can deliver safe, high-quality work, PQQ frameworks such as the Common Assessment Standard (CAS) and SSIP (for health and safety) standardise how contracting authorities assess the suitability of subcontractors for their project. These frameworks streamline construction procurement processes while raising the bar across several key areas: 

• Safety and Competence: Subcontractors must provide evidence of strong health and safety systems. Certifications through SSIP (Safety Schemes in Procurement) is often required to verify this, alongside compliance with CDM 2015 regulations. This includes providing risk assessments, method statements, and ensuring staff hold certifications. 

• Insurance and Legal Protection: Main contractors will also expect subcontractors to carry appropriate insurance, such as public liability, employers’ liability, and where applicable, professional indemnity. These safeguards protect all parties from legal and financial risk, especially on public sector projects. 

• Operational and Environmental Standards: Quality assurance is essential. Many buyers look for recognised certifications like ISO 9001 to confirm robust management processes. Increasingly, ISO 14001 is also expected, reflecting the sector’s push for sustainability and environmental accountability. 

• Financial Health: Subcontractors must demonstrate financial stability—often through audited accounts, credit checks, or verified references—to ensure they can withstand project demands and timelines to minimise construction risk for main contractors and buyers. 

• Regulatory Readiness: Legislation, including the Building Safety Act and Procurement Act, demands traceability and clear accountability from subcontractors, particularly for higher-risk works. Subcontractors must now show how they manage compliance documentation and maintain a ‘golden thread’ of safety information throughout a project’s lifecycle. 

Subcontractors  Discover how you can demonstrate your compliance to major construction companies with a Constructionline membership in order to win more work and minimise duplication.  Sign up for a Constructionline membership today

Main contractors & public sector buyers  Explore how our construction supply chain management solutions can make finding, selecting and inviting subcontractors to tender can strengthen your supply chain and improve your construction project delivery.  Book a demo today

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Construction software for subcontractors

Modern construction software plays a vital role for subcontractors who want to boost operations and secure more projects. These tools help specialty trades tackle their unique challenges in documentation, project management, and business growth and ultimately win more work. 

Demonstrating compliance

The Building Safety Act marks one of the biggest shifts in UK building regulation since 1984. Construction software for subcontractors helps handle these complex requirements by creating a central hub for compliance documentation.

Constructionline and similar platforms give subcontractors the ability to:

• Show they meet Building Safety Act standards through updated assessment profiles
• Display their expertise for regular construction and high-risk building projects
• Get social value credentials verified quickly

Construction software solutions also help subcontractors to reduce administration costs and time leaving more time to focus on finding more work opportunities.

Learn more about how Constructionline’s software for subcontractors helps you demonstrate your compliance →

Finding projects from main contractors and public sector buyers 

Finding the right projects remains a challenge for subcontractors. Digital platforms now combine construction opportunities from various sources to address this need. 

Constructionline’s Marketplace connects contractors together with over 500,000+ project construction leads. It provides you with the ability to find new construction leads and view Market Intelligence data all in one place. Subcontractors save time by avoiding searches across multiple websites.

These platforms come with: 

1. Smart search tools using keywords, location filters, and publish dates 
2. Alert systems that notify subcontractors about relevant new projects 
3. Early access to pre-tender stage projects 

Submitting tenders to work on construction projects

Submitting tenders for construction projects can be a complex and time-consuming process for subcontractors. Utilising advanced tender management software, such as Tender Management, can significantly streamline this process. Subcontractors can receive and respond to tender enquiries quickly and efficiently, straight from their inbox.

We sent out 15,000+ ITTs from our platform!

By utilising construction software for subcontractors, they can enhance their efficiency, ensure stronger compliance, and improve their chances of securing projects in today’s digital construction environment.

Find out more about Tender Management →