Castle

What Castle does

Castle (legally The Castle Building Services Organisation Ltd) is a privately held UK construction services firm headquartered in Hebburn, South Tyneside, founded in 2002 by Tony Lister and Allan Carr. The company operates four integrated service lines — Castle Design (architectural and design management), Castle Build (principal contracting), Castle MEP (mechanical, electrical, public health engineering), and Castle Green (renewable energy and sustainability) — delivering turnkey construction solutions across education, commercial, industrial, healthcare, leisure, retail, residential, and public-sector projects in the North East of England, Scotland, and Teesside. Its technical stack centres on in-house BIM expertise, 3D design analysis, Passivhaus-certified construction methodology, and a Net Zero Carbon by 2030 commitment, supported by ISO 9001, 14001, and 45001 certifications and Passivhaus Institute accreditation.

Castle makes money through project-based B2B contracts secured via competitive tendering and negotiation with tier-one main contractors (Morgan Sindall, Kier, Sir Robert McAlpine, Morrison Construction), property developers (UK Land Estates, Northumberland Estates), local authorities, and colleges. Revenue streams are diversified across MEP packages (typically £5M–£12M), full principal contractor mandates (up to £95M), and integrated design-and-build work, with multi-year contract durations. The company completed a £30M turnover in 2022/2023 and grew to £70M+ secured in 2024, against a £110M forward order book spanning 2024–2025, following a December 2023 management buyout that installed Tony Lister, Andrew Dawson, and Simon Groom as owners.

Following a 2021 strategic diversification from a pure-play MEP subcontractor into principal contracting, Castle now operates from offices in Hebburn, Edinburgh, Glasgow, and Teesside with a headcount of 200+ (up from 118 in August 2023). Its go-to-market relies on long-standing enterprise client relationships and repeat business, early stakeholder engagement, and a 'negotiate more than tender' approach. Underpinning differentiators include Passivhaus certification, BIM capability, a 95% apprentice-to-employee retention rate via partnerships with Gateshead College (PlanBEE) and Tyne Coast College, and a value proposition centred on integrated single-point-of-accountability delivery for education, space, advanced manufacturing, and public-sector clients.

Name

Castle

Legal name

Castle Building Services

Website

https://castlebs.co.uk

Company type

Private

Founded year

2002

Operating status

Operating

Headcount range

101–250 employees

Short description

Castle is a privately held UK integrated construction firm delivering design, principal contracting, MEP, and renewable energy services across the North East of England and Scotland, primarily serving education, public-sector, and industrial clients through tier-one main contractors. Founded 2002, headquartered in Hebburn, with 200+ staff.

Ownership category

akta.pro rank

Product category

Construction Services

NAICS

Nonresidential Building Construction (2362), Commercial and Institutional Building Construction (236220), New Multifamily Housing Construction (except For-Sale Builders) (236116), Architectural Services (54131)

SIC

General Bldg Contractors - Nonresidential Bldgs (1540), Operative Builders (1531), General Bldg Contractors - Residential Bldgs (1520)

akta.pro primary industry

Office & Corporate Building Construction (IMAFACAA)

akta.pro secondary industries

Multi-Family Residential Construction (Apartments, Condos, Townhomes) (IMAFABAB), System & Subsystem Commissioning (Mechanical/Electrical/I&C) (EUAEAJAB)

Keywords

• MEP engineering services
• Principal contracting
• Construction design build
• Renewable energy solutions
• Building services

Headquarters

HQ city

Hebburn

HQ country

United Kingdom

HQ region

Europe

Offices4 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. MEP Services (Mechanical, Electrical, Public Health): Full-service MEP provision including design, supply, installation, and commissioning of mechanical systems (drainage, domestic services, LTHW heating, underfloor heating, ventilation, HVAC, BMS, sprinklers, renewables) and electrical systems (LV installations, fire/intruder alarms, lighting, EV charging, data). This is the company's foundational and longest-established revenue stream.
2. Principal Contractor / Build Services: Full construction project delivery as principal contractor, covering design management, earthworks, groundworks, structural frame, building envelope, MEP, and external works including roads and car parks. This stream was developed through diversification in 2021 and is growing to match MEP turnover within 2-3 years.
3. Green / Sustainable Energy Services: Specialist sustainable services including EPC improvement, energy centres, photovoltaic installation, low-energy lighting, thermal comfort, and analysis/assessments. Delivered as part of MEP projects and as standalone consultancy.
4. Castle Design (Architectural Services): In-house architectural and design management services launched as a new division (Castle Design), providing turnkey design and build solutions. Revenue generated as part of integrated project delivery alongside MEP and Build divisions.

Pricing tiers

Go-to-market motion2 records

Distribution channels2 records

Marketing channels7 records

Core offering

Castle is a UK construction services company delivering integrated design, build, MEP (mechanical, electrical and public health) and renewable energy solutions across education, commercial, industrial, healthcare, leisure, residential, retail and public-sector projects. It operates as both a tier-one MEP subcontractor and a principal contractor, with contract values ranging from specialist MEP packages (~£5M) to full principal contractor mandates (up to £95M). Services span feasibility studies, cost planning, design management, construction delivery, commissioning and ongoing energy performance improvements including Passivhaus-certified and net-zero-ready buildings.

Product overview

Castle is a UK-based construction company offering integrated services through three main divisions: Castle Design (architectural and design management), Castle MEP (mechanical, electrical, public health engineering), and Castle Green (renewable energy and sustainability). The company also operates a Principal Contracting division that delivers full construction project delivery. These divisions work together to provide turnkey design and build solutions, with the ability to offer coordinated, fast and cost-effective project delivery. The company operates across sectors including education, commercial, healthcare, industrial, cleanroom, leisure, residential, retail, and custodial facilities.

Differentiator

Problem solved

Functional benefit

Products and services

• Castle MEP (Mechanical, Electrical and Public Health)

Named customers10 records

Segments7 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

14 partnerships are on record, tiered core and supporting.

• Morgan Sindall ConstructioncoreStrategic or Co-development PartnerCastle has a strong, ongoing relationship with Morgan Sindall Construction as MEP services subcontractor. Notable projects include Dumfries High School (£53M, full MEP services including HVAC, renewables, EV charging) and NESST at Northumbria University (£50M space skills centre). Morgan Sindall acts as main contractor on these education projects with Castle delivering specialist MEP packages.
• KiercoreStrategic or Co-development PartnerCastle has a longstanding relationship with Kier as MEP contractor on major projects including NETPark Phase Three in Sedgefield (11 industrial units, 30,000 sqm, 1.16MW PV system) and Culture House in Sunderland (6,691 sqm community/learning building). Both projects emphasise sustainability and carbon reduction.
• Sir Robert McAlpinecoreStrategic or Co-development PartnerCastle appointed by Sir Robert McAlpine to supply full MEP services for Northumbria University's North East Space Skills Technology Centre (NESST) — a £50M national space asset. This is a flagship project bringing together industry and academia for space research and technological development.
• Morrison ConstructioncoreStrategic or Co-development PartnerCastle has an established relationship with Morrison Construction as mechanical and electrical contractor for multiple Scottish school projects including East Calder Primary School (West Lothian, via hub South East) and Paisley Grammar School (Passivhaus-certified, first in the local authority). Morrison acts as main contractor with Castle delivering specialist MEP packages.
• UK Land EstatescoreStrategic or Co-development PartnerCastle has a long-standing, trusted relationship with UK Land Estates as principal contractor for multiple property development projects: St George's House refurbishment (Gateshead, Grade II-listed building), Maingate refurbishment (Team Valley), 50,000 sq ft industrial unit at Boldon Business Park, and the 43,000 sq ft Legrand advanced manufacturing facility at Cramlington. Castle has delivered multiple projects for this client over several years.
• Northumberland EstatescoreStrategic or Co-development PartnerCastle appointed as principal contractor by Northumberland Estates for Wynyard Retail and Trade Park — a major development in the Tees Valley including Sainsbury's superstore (48,000 sq ft), seven trade counter units, and Starbucks drive-thru. The project was delivered to BREEAM Very Good standard with significant renewable energy measures.
• Gateshead College (PlanBEE)supportingStrategic or Co-development PartnerCastle is a long-term supporter and sponsor of PlanBEE, a higher apprenticeship programme in the architecture, engineering, and construction sector. Castle provides work placements for PlanBEE apprentices (six 4-month placements over two years) and has hired PlanBEE graduates as full-time employees (including building services engineer Megan Groom who became a mentor). PlanBEE apprentices study at Gateshead College one day per week.
• South Tyneside College / Tyne Coast CollegecoreStrategic or Co-development PartnerCastle is principal contractor for the £95M relocation of South Tyneside College and South Shields Marine School from Westoe Village to South Shields town centre. This flagship project includes a new 15,000 sqm campus, listed building refurbishment, and 125-bed student accommodation. Castle has also provided work experience for T-Level students and apprenticeships through its supply chain. The college is part of Tyne Coast College group.
• South Tyneside CouncilcoreStrategic or Co-development PartnerCastle works in partnership with South Tyneside Council as delivery partner for the £95M college relocation — a cornerstone of the council's regeneration ambitions for South Shields town centre. The council provides strategic direction and funding coordination alongside the North East Combined Authority and Department for Education.
• North East Combined AuthoritysupportingStrategic or Co-development PartnerThe North East Combined Authority (led by Mayor Kim McGuinness) is a funding and strategic partner for the £95M South Tyneside College relocation project, contributing £18.2M as part of the drive to revitalise high streets across the region.
• Department for Education (DfE)supportingStrategic or Co-development PartnerThe Department for Education is a funding partner for the £95M South Tyneside College relocation project, contributing alongside the North East Combined Authority, Tyne Coast College, and UK Government. The college previously secured £22M from the DfE's FE Capital Transformation Fund.
• hub South West ScotlandsupportingStrategic or Co-development PartnerCastle works as MEP contractor on Dumfries High School, delivered by hub South West Scotland in partnership with Dumfries and Galloway Council, with funding from the Learning Estate Investment Programme. Castle has delivered multiple education projects through the hub model in Scotland.
• UK Space AgencysupportingStrategic or Co-development PartnerUK Space Agency is a funding and strategic partner for the NESST project (North East Space Skills Technology Centre) at Northumbria University, alongside Lockheed Martin UK Space. Castle is MEP contractor on this £50M national space asset being delivered by Sir Robert McAlpine.
• Lockheed Martin UK SpacesupportingStrategic or Co-development PartnerLockheed Martin UK Space is an industry partner for the NESST project at Northumbria University. Castle serves as MEP contractor on this space skills and technology centre being built by Sir Robert McAlpine.

Scale indicators14 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• McLaren Construction Group: Privately held UK construction group delivering commercial, residential, education, and industrial projects with integrated design and build services. Comparable to Castle in private ownership, integrated delivery model, and education/commercial mix.
• Wates Group: Privately held UK construction services group offering design, build, fit-out, and MEP services across commercial, education, and public sectors. Closely comparable to Castle in scope (integrated services, regional delivery, education/public sector focus) though materially larger in scale.
• Bowmer + Kirkland: UK-headquartered privately held construction and property services group delivering design & build, fit-out, and MEP across commercial, education, and industrial sectors. Comparable to Castle in integrated delivery model and education sector presence, with similar mid-tier scale.
• Willmott Dixon: UK construction services company with strong education, public sector, and residential focus. Directly comparable to Castle's education sector emphasis, design & build approach, and commitment to local social value / apprenticeship programmes; larger in scale.
• ISG: UK-based construction services firm specialising in fit-out, construction, and engineering services across commercial, education, and public sectors. Comparable integrated offering to Castle, with broader geographic reach and similar mid-market positioning.
• TClarke: UK mechanical and electrical building services contractor with growing sustainability and renewables offering. Direct competitor in Castle's core MEP space, with a similar emphasis on education, commercial, and public sector projects.
• NG Bailey: UK's largest independent MEP and building services contractor, delivering mechanical, electrical, and sustainability services across commercial, education, and infrastructure. Direct competitor to Castle's MEP division and a potential barrier to scale-up of Castle's MEP business nationally.
• SES Engineering Services: UK MEP contractor (part of the Atalian group) delivering mechanical, electrical, and renewable services across construction sectors. Closely comparable to Castle's MEP division in scope, customer mix (main contractors, developers, public sector), and project scale.

Broad incumbents

• Balfour Beatty: Major UK-listed infrastructure and construction group with broad capabilities in buildings, civils, and MEP. Overlaps with Castle on education, commercial, and public sector building work, but at materially larger scale and with significantly different risk profile and geographic reach.
• Mace Group: Global construction and consultancy group with strong UK presence in construction management, fit-out, and MEP delivery. Competes with Castle on commercial and education schemes at a larger scale, with deeper resources and international reach.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/the-castle-building-services-organisation-ltd

Revenue estimate

Valuation estimate

Number of profiles

Profiles17 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Castle