# 26 leading Construction companies in Northern Ireland
Tamtam tracks 26 Construction companies headquartered in Northern Ireland. This list ranks all of them by number of employees on LinkedIn, led by GRAHAM Group, FP McCann Ltd and McLaughlin & Harvey Ltd. Their median headcount is 160. Half of them were founded in 1983 or later. The most common headquarters are Belfast (4).
The construction sector in Northern Ireland features a mix of established firms and more recent entrants. GRAHAM Group, founded in 1778, specializes in a wide range of construction and development projects across the UK and Ireland. McLaughlin & Harvey Ltd, established in 1853, also provides construction, civil engineering, and fit-out services. Newer companies like Alternative Heat Ltd, founded in 2003, focus on offsite fabrication for MEP solutions, while Kane Group, also from 2003, delivers building-service solutions. Omexom UK, founded in 1998, specializes in electricity infrastructure.
Many of these companies, such as FP McCann Ltd, the UK's largest precast concrete manufacturer, and McMullen Facades Limited, a specialist facade contractor, demonstrate a strong focus on specialized construction materials and components. A notable pattern is the concentration of headquarters in a few key locations, with Belfast, Magherafelt, and Banbridge each hosting multiple significant construction firms.
๐ฌ๐ง Northern Ireland ยท 26 companies ยท Updated Nov 12, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [GRAHAM Group](https://www.tamtam.ai/c/graham-group) (graham.co.uk)
Specializes in delivering construction and development projects across the UK and Ireland, encompassing building, civil engineering, interior fit out, facilities management, and investment projects. | Construction | ๐ฌ๐ง Hillsborough | 1,933 | 1778 |
| 2 | [FP McCann Ltd](https://www.tamtam.ai/c/fp-mccann-ltd) (fpmccann.co.uk)
UK's largest manufacturer of Precast Concrete Solutions also offers Quarrying, Ready Mix, and Construction services with award-winning projects in various sectors | Construction | ๐ฌ๐ง Magherafelt | 592 | |
| 3 | [McLaughlin & Harvey Ltd](https://www.tamtam.ai/c/mclaughlin-and-harvey-ltd) (mclh.co.uk)
Construction, civil engineering, and fit-out projects and facilities management services for public and private clients across diverse sectors throughout the UK and Ireland. | Construction | ๐ฌ๐ง Newtownabbey | 557 | 1853 |
| 4 | [Omexom UK](https://www.tamtam.ai/c/omexom-uk) (omexom.co.uk)
Specializing in electricity generation, transmission, distribution, and substation design and construction to support the energy transition for clients in the UK and Ireland | Construction | ๐ฌ๐ง Belfast | 394 | 1998 |
| 5 | [Alternative Heat Ltd](https://www.tamtam.ai/c/alternative-heat-ltd) (alternativeheat.co.uk)
A market leader in offsite fabrication for MEP solutions, offering high-quality products through experienced design engineers and skilled trades personnel | Construction | ๐ฌ๐ง Banbridge | 330 | 2003 |
| 6 | [MJM Marine](https://www.tamtam.ai/c/mjm-marine) (mjm-group.com)
A global marine outfitting company based in Northern Ireland, specializing in crafting high-spec, bespoke spaces for leading cruise liner brands worldwide | Construction | ๐ฌ๐ง Newry | 320 | 1983 |
| 7 | [Kane Group](https://www.tamtam.ai/c/kane-group) (kanegroup.co.uk)
Designing, developing, and delivering building-service solutions across the UK and Ireland with a focus on quality, health, and safety. | Construction | ๐ฌ๐ง Banbridge | 302 | 2003 |
| 8 | [H & J Martin Limited](https://www.tamtam.ai/c/h-and-j-martin-limited) (hjmartin.co.uk)
A construction company with over 175 years of experience, specializing in asset management, construction, and fit out services within Ireland | Construction | ๐ฌ๐ง Belfast | 183 | 1840 |
| 9 | [McMullen Facades Limited](https://www.tamtam.ai/c/mcmullen-facades-limited) (mcmullenfacades.com)
Leading specialist facade contractor, provides full design, fabrication, and installation of aluminium curtain wall and window systems for medium to large building projects. | Construction | ๐ฌ๐ง Moira | 178 | |
| 10 | [Dowds](https://www.tamtam.ai/c/dowds) (dowdsgroup.com)
A leading specialist contractor providing building services, construction, facilities management, and energy solutions in the UK & Ireland since 1978 | Construction | ๐ฌ๐ง Ballymena | 177 | 1978 |
| 11 | [Lagan Specialist Holdings](https://www.tamtam.ai/c/lagan-specialist-holdings) (laganscg.com)
Undertakes specialist contracting activities including Aviation & Infrastructure, Piling, Operations and Maintenance, Facilities Management, Fit Out, civil engineering, and building projects globally. | Construction | ๐ฌ๐ง Belfast | 175 | |
| 12 | [Heron Bros](https://www.tamtam.ai/c/heron-bros) (heronbros.com)
An award-winning construction and property development entity operating throughout the UK, Ireland, and Europe, focused on delivering excellence and sustainability | Construction | ๐ฌ๐ง Magherafelt | 163 | 1956 |
| 13 | [Irwin M&E](https://www.tamtam.ai/c/irwin-m-and-e) (irwinm-e.com)
Provides mechanical, electrical, energy, and renewables installation and maintenance services to clients in public and private sectors across the UK and Ireland. | Construction | ๐ฌ๐ง Portadown | 160 | |
| 14 | [Keystone Lintels](https://www.tamtam.ai/c/keystone-lintels) (keystonelintels.com)
The Keystone Group specializes in manufacturing steel lintels, roof windows, and masonry support systems, with a focus on innovative design and exceptional customer service | Construction | ๐ฌ๐ง Cookstown | 151 | 1989 |
| 15 | [Keylite Roof Windows](https://www.tamtam.ai/c/keylite-roof-windows) (keyliteroofwindows.com)
A leading supplier of roof windows, blinds, loft ladders, and accessories, committed to innovation, quality, and value for customers in Europe | Construction | ๐ฌ๐ง Cookstown | 112 | |
| 16 | [Copius Group](https://www.tamtam.ai/c/copius-group) (copiusgroup.com)
Provides comprehensive electrical, mechanical, and construction services for offshore and onshore projects, focusing on power, renewables, oil & gas, and critical infrastructure globally. | Construction | ๐ฌ๐ง Newtownabbey | 96 | 2008 |
| 17 | [Premier Electrics](https://www.tamtam.ai/c/premier-electrics) (premierelectrics.com)
Delivering comprehensive electrical services for prestigious clients in commercial, industrial, leisure, and retail sectors within Ireland, UK, and Europe since 1993 | Construction | ๐ฌ๐ง Magherafelt | 72 | 1993 |
| 18 | [Kilwaughter Minerals Ltd](https://www.tamtam.ai/c/kilwaughter-minerals-ltd) (k-rend.co.uk)
A family-owned company investing in people, offering secure employment, development opportunities, competitive benefits, and a range of career options in various fields | Construction | ๐ฌ๐ง Larne | 66 | 1939 |
| 19 | [Charles Brand Group Limited](https://www.tamtam.ai/c/charles-brand-group-limited) (charlesbrand.com)
The company offers customized Civil Engineering, Process, and M&E solutions to a range of public and private clients | Construction | ๐ฌ๐ง Belfast | 57 | |
| 20 | [SA3 POWER](https://www.tamtam.ai/c/sa3-power) (sa3power.com)
Provides specialized electrical services for data centers across Europe, including installations, fit-outs, lighting design, and inspection testing, adhering to high professional standards. | Construction | ๐ฌ๐ง Cookstown | 55 | 2017 |
| 21 | [Tinnelly Group](https://www.tamtam.ai/c/tinnelly-group) (tinnelly.com)
A family-owned group specializing in recycling metals, removing asbestos, and handling demolition projects with over 60 years of experience | Construction | ๐ฌ๐ง Newry | 35 | 1959 |
| 22 | [CP Hire Ltd](https://www.tamtam.ai/c/cp-hire-ltd) (cphire.com)
A construction equipment rental company with 10 depots, providing top-notch customer service and support throughout the UK for 45 years | Construction | ๐ฌ๐ง Coleraine | 25 | 1971 |
| 23 | [National Building Services](https://www.tamtam.ai/c/national-building-services) (nbsni.co.uk)
This company offers Facilities Management services across multiple locations, allowing clients to focus on core business while outsourcing support services | Construction | ๐ฌ๐ง Newry | 25 | 2008 |
| 24 | [Sustainable Homes By Bayview](https://www.tamtam.ai/c/sustainable-homes-by-bayview) (bayviewcontracts.com)
Leading provider of whole house energy solutions, specializing in central heating, renewable energy, home insulation, and building maintenance with extensive experience in energy efficiency projects | Construction | ๐ฌ๐ง Newry | 20 | 2001 |
| 25 | [Premix Concrete](https://www.tamtam.ai/c/premix-concrete) (creaghconcrete.com)
Leading producer of innovative concrete products since 1976, serving diverse markets with high-quality solutions for construction projects | Construction | ๐ฌ๐ง Antrim | 12 | |
| 26 | [O'Hanlon Electrical Ltd](https://www.tamtam.ai/c/o-hanlon-electrical-ltd) (oelni.com)
An experienced electrical contractor offering a wide range of services for public, commercial, industrial, and private sectors in the UK and Ireland | Construction | ๐ฌ๐ง Dungannon | 9 | 1976 |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 12, 2026.
## More company lists in Northern Ireland
- [The largest companies in Northern Ireland](https://www.tamtam.ai/l/largest-companies-northern-ireland) (354)
- [Multinational companies in Northern Ireland](https://www.tamtam.ai/l/multinational-companies-northern-ireland) (84)
- [Manufacturers in Northern Ireland](https://www.tamtam.ai/l/manufacturers-northern-ireland) (48)
- [Retail chains in Northern Ireland](https://www.tamtam.ai/l/retail-chains-northern-ireland) (40)
- [Software Development companies in Northern Ireland](https://www.tamtam.ai/l/software-development-companies-northern-ireland) (30)
- [Companies with in-house R&D in Northern Ireland](https://www.tamtam.ai/l/r-and-d-companies-northern-ireland) (28)
- [Retail companies in Northern Ireland](https://www.tamtam.ai/l/retail-companies-northern-ireland) (27)
- [Family-owned companies in Northern Ireland](https://www.tamtam.ai/l/family-owned-companies-northern-ireland) (27)
- [Financial services firms in Northern Ireland](https://www.tamtam.ai/l/financial-services-firms-northern-ireland) (26)
- [Food and Beverage Manufacturing companies in Northern Ireland](https://www.tamtam.ai/l/food-and-beverage-manufacturing-companies-northern-ireland) (25)
## The same list elsewhere in United Kingdom
- [Construction companies in the United Kingdom](https://www.tamtam.ai/l/construction-companies-united-kingdom) (797)
- [Construction companies in England](https://www.tamtam.ai/l/construction-companies-england) (667)
- [Construction companies in Scotland](https://www.tamtam.ai/l/construction-companies-scotland) (51)
- [Construction companies in London](https://www.tamtam.ai/l/construction-companies-london) (125)
## The same list elsewhere
- [Construction companies in the world](https://www.tamtam.ai/l/construction-companies-in-the-world) (10,143)
- [Construction companies in Europe](https://www.tamtam.ai/l/construction-companies-in-europe) (4,272)
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Source: https://www.tamtam.ai/l/construction-companies-northern-ireland