Top 10 Construction Companies in London

London’s construction sector is one of the most advanced and high-value industries in the UK, driving the city’s constant transformation. From major transport infrastructure and commercial landmarks to housing regeneration and sustainable developments, construction companies play a central role in shaping how London grows.

Behind these projects are firms with the expertise, engineering capability, and financial strength to deliver work worth millions and often billions of pounds. This guide highlights the top construction companies in London, showcasing the organisations leading innovation, scale, and reliability across the capital’s built environment.

1. Balfour Beatty

Balfour Beatty is one of the UK’s most influential infrastructure contractors, recognised for delivering some of the country’s most complex and high-value construction programmes. With over a century of engineering heritage, the company plays a critical role in shaping modern transport networks, energy infrastructure, and large-scale urban regeneration projects.

Its London portfolio reflects deep expertise in managing technically demanding builds where safety, coordination, and long-term resilience are essential. The firm integrates advanced digital construction tools to improve efficiency and sustainability. This combination of scale, innovation, and delivery capability makes Balfour Beatty a trusted partner on landmark infrastructure projects.

Notable Projects & Estimated Value

• Crossrail delivery packages — £500m–£1bn+ segments

• Battersea Power Station redevelopment — £9bn masterplan

Typical Project Scale

£100m – £1bn+

Strengths

Integrated infrastructure delivery, carbon reduction leadership, and high-risk project management expertise.

2. Morgan Sindall Group

 

Morgan Sindall is widely respected for its work in regeneration, public sector construction, and mixed-use development. The company has built a strong reputation for delivering projects that prioritise long-term community value alongside engineering excellence.

Its London work frequently focuses on education facilities, transport upgrades, and urban renewal initiatives. Morgan Sindall’s collaborative delivery model ensures efficient coordination between stakeholders and contractors. A strong sustainability focus reinforces its role in shaping future-ready infrastructure.

Notable Projects & Estimated Value

• Advanced university facilities — £50m–£150m

• Transport upgrade frameworks — £100m+ programmes

Typical Project Scale

£30m – £300m

Strengths

Urban regeneration expertise, stakeholder collaboration, and sustainable construction delivery.

3. Kier Group

Kier Group remains a major force in essential infrastructure construction across healthcare, justice, transport, and utilities. Its integrated service model allows projects to move seamlessly from design through long-term asset management.

In London, Kier contributes to modernising critical public infrastructure that supports economic growth. The company invests heavily in digital construction innovation and operational efficiency. This future-focused approach ensures high standards of quality and resilience.

Notable Projects & Estimated Value

• Rail upgrade schemes — £100m–£400m

• Government infrastructure builds — £50m–£250m

Typical Project Scale

£40m – £500m

Strengths

Lifecycle delivery capability, digital innovation, and infrastructure reliability.

4. Laing O’Rourke

 

Laing O’Rourke is recognised as a leader in engineering-driven construction and industrialised building methods. Its commitment to off-site manufacturing enables faster, safer, and more sustainable project execution. The company’s London portfolio includes complex infrastructure and structural engineering programmes requiring precision delivery.

By blending advanced fabrication techniques with project management expertise, Laing O’Rourke improves build quality and efficiency. This innovation-led approach sets it apart in high-value construction.

Notable Projects & Estimated Value

• Heathrow expansion involvement — £4bn+ programme

• Crossrail engineering packages — £300m–£1bn

Typical Project Scale

£100m – £2bn+

Strengths

Industrialised construction leadership, engineering innovation, and efficiency-driven delivery.

5. Mace Group

Mace is synonymous with delivering iconic London developments that reshape the skyline. The company operates across consultancy, development, and construction, giving it a comprehensive project lifecycle capability.

Its work often involves high-profile commercial, sporting, and regeneration schemes requiring complex coordination. Mace combines strategic planning with execution excellence to manage ambitious timelines and budgets. Sustainability and smart urban development remain central to its long-term vision.

Notable Projects & Estimated Value

• The Shard — ~£435m construction cost

• Tottenham Hotspur Stadium — ~£1bn development

Typical Project Scale

£80m – £1bn+

Strengths

Landmark project delivery, lifecycle management expertise, and urban regeneration leadership.

6. Sir Robert McAlpine

Sir Robert McAlpine is one of the UK’s most respected construction companies, known for delivering landmark commercial, infrastructure, and cultural developments. With a heritage dating back over 150 years, the company combines engineering expertise with modern construction innovation.

Its London portfolio includes complex urban builds that demand precision planning and technical excellence. The firm is recognised for managing high-profile projects where quality, sustainability, and stakeholder coordination are critical. This blend of heritage craftsmanship and forward-thinking delivery makes Sir Robert McAlpine a trusted partner on major developments.

Notable Projects & Estimated Value

• Bloomberg European Headquarters — ~£1bn development

• Battersea Power Station phases — £100m+ packages

Typical Project Scale

£50m – £1bn+

Strengths

Complex urban construction expertise, heritage project delivery, and sustainability-led engineering solutions.

7. Tarmac Trading Ltd

Tarmac is a cornerstone supplier in the UK construction ecosystem, providing materials that support major infrastructure and urban developments. Its products underpin highways, commercial builds, and public works across London.

With a strong emphasis on low-carbon innovation, Tarmac is advancing sustainable material solutions. The company’s operational scale ensures reliability across complex supply chains. Its role is essential to the physical foundation of modern construction.

Notable Projects & Estimated Value

• Wembley Stadium materials — £700m development

• Structural supply contracts — £50m–£200m

Typical Contract Scale

£5m – £150m

Strengths

Sustainable materials innovation, supply reliability, and infrastructure resilience.

8. Amey PLC

Amey focuses on infrastructure support and asset lifecycle management, ensuring essential public systems operate efficiently. Its London involvement spans transport upgrades, environmental infrastructure, and long-term maintenance frameworks.

The company leverages smart monitoring technologies to optimise asset performance. Amey’s holistic delivery model supports sustainability and operational longevity. This positions it as a critical partner in infrastructure stewardship.

Notable Projects & Estimated Value

• Thames Tideway Tunnel — £4.5bn programme involvement

• Airport upgrades — £50m–£200m

Typical Programme Scale

£25m – £500m

Strengths

Lifecycle infrastructure management, smart asset monitoring, and sustainability-driven delivery.

9. Wates Group

Wates combines heritage craftsmanship with forward-looking sustainability goals. The company prioritises regeneration projects that deliver social and economic value to communities. Its London work includes housing development, public facilities, and major refurbishments. Wates integrates environmental responsibility into every stage of construction. A strong culture of safety and ethics reinforces its reputation for dependable delivery.

Notable Projects & Estimated Value

• Station redevelopments — £100m–£600m

• Housing programmes — £30m–£250m

Typical Project Scale

£20m – £500m

Strengths

Community-focused development, sustainability leadership, and high-quality delivery standards.

10. Keller Group

Keller is a global specialist in geotechnical engineering, providing foundation solutions for technically complex urban construction. Its London projects enable safe building in challenging ground conditions.

The company’s expertise supports tunnelling, piling, and structural stability in high-risk environments. Continuous innovation allows Keller to minimise environmental impact while improving performance. Its engineering precision is essential to large-scale infrastructure success.

Notable Projects & Estimated Value

• Underground expansion support — £100m+ packages

• Crossrail ground engineering — £200m+

Typical Project Scale

£5m – £300m

Strengths

Advanced foundation engineering, risk mitigation expertise, and precision delivery.

 

Conclusion

London’s construction industry continues to drive the city’s growth, combining engineering expertise, innovation, and sustainability to deliver projects at every scale. The companies highlighted here represent the leaders shaping London’s infrastructure, skyline, and communities. As demand for smarter, greener development rises, these firms remain central to building a resilient and future-ready capital.

FAQs About Construction Companies in London

What makes a construction company top-tier in London?

Experience, project scale capability, safety standards, and sustainable delivery define leading contractors.

Do these companies handle billion-pound projects?

Yes, many regularly deliver infrastructure and commercial projects worth hundreds of millions to billions.

Are these firms involved in sustainable construction?

Most prioritise low-carbon materials, energy efficiency, and environmentally responsible building practices.

Do they work only in London?

No, while active in London, these companies operate across the UK and internationally.

Can these contractors handle complex urban projects?

Yes, they specialise in technically demanding builds in dense city environments.

Do they offer full project lifecycle services?

Many provide integrated services from design and construction through maintenance and asset management.

Are these companies suitable for commercial developments?

Yes, they frequently deliver offices, mixed-use developments, and large commercial facilities.

Do they work with public sector infrastructure?

Several are major partners on rail, transport, healthcare, and government construction projects.

How important is sustainability in modern construction?

It’s critical sustainability now drives planning, materials selection, and project delivery standards.

Why are large construction firms preferred for major projects?

Their scale, expertise, and risk management ensure reliable delivery of high-value developments.