Quantity Surveyor

Onnec; Greater London; On-site; GBP 50,000 - 85,000; Full time

Job summary

ONNEC Group is hiring a Quantity Surveyor to support commercial success across hyperscale data centre projects. You will work with Project Managers, Commercial Managers and Operations to control costs, manage variations, and ensure contractual obligations are met.

The successful candidate will bring proven QS experience in construction, strong contract knowledge (JCT/NEC), and excellent negotiation and stakeholder skills, delivering high-quality outcomes within a fast-paced environment.

Qualifications

• Proven Quantity Surveying experience within a project delivery or construction environment.
• Strong commercial and contractual knowledge including experience with standard forms of contract (e.g., JCT, NEC).
• Excellent negotiation, communication, and stakeholder management skills.
• Commercially aware with the ability to identify risks and opportunities and provide practical solutions.
• Strong organisational skills with excellent attention to detail and ability to manage multiple priorities.
• Proficient in Microsoft Office, including Excel, Word, and PowerPoint.

Responsibilities

• Provide commercial support to project teams, ensuring projects remain compliant, commercially sound, and financially successful.
• Monitor project costs and performance against budget, identify risks and opportunities, and take action as needed.
• Manage variations and changes to scope, prepare and submit quotations, claims, and supporting documentation.
• Support monthly valuations, cost reporting, forecasting, and cost/value reconciliation activities.
• Administer contracts and subcontracts in line with contractual requirements and company procedures.
• Review and interpret contract terms, supporting management of claims and variations to protect margins.
• Build and maintain strong relationships with clients, subcontractors, consultants, and internal stakeholders.
• Collaborate across departments including Commercial, Finance, Legal, Design & Engineering, and Operations.
• Support development and consistent application of commercial processes and best practices.
• Assist with supplier negotiations and other commercial activities as required.
• Contribute to continuous improvement initiatives and special projects as needed.

Skills

Quantity Surveying

Commercial knowledge

Contractual knowledge

Negotiation

Stakeholder management

Organisational skills

Attention to detail

Multitasking

Team collaboration

Client relationships

Tools

Microsoft Office

Job description

ONNEC Group are a leading independent technology partner and global integrator, with over 30 years experience, and a 800+ team of global experts, specialising in providing end-to-end connectivity solutions that propel organisations everywhere.

From structured cabling to managed services, our end-to-end services give infrastructure that can be completely replied on. Design. Build. Deploy. Optimise. We offer a complete solution for business connectivity.

We are a rapidly growing organisation and finding and retaining the highest calibre of people is fundamental to us for the success of our business, we work hard to create a challenging, supportive and satisfying working environment for all our employees. ONNEC has successfully achieved the Investors in Diversity Foundational Award for our commitment to equality, diversity and inclusion in the workplace.

This is an opportunity to join a growing business delivering complex, high-profile projects within the data centre sector. Reporting to the Senior Commercial Manager, the Quantity Surveyor (QS) will play a key role in supporting the commercial success of projects, helping to manage costs, protect margins, and ensure contractual obligations are met.

Working closely with Project Managers, Commercial Managers and Operations teams, the QS will provide commercial support throughout the project lifecycle, from cost control and variation management to risk identification and contract administration.

The successful candidate will have experience working on Hyperscale Data Centre projects, a strong understanding of commercial and contractual processes, and the ability to build effective relationships across project teams. They will also help ensure that commercial procedures and best practices are consistently applied, supporting successful project delivery and strong commercial performance.

What you’ll be doing as our Quantity Survayor :

• Provide commercial support to project teams, helping to ensure projects remain compliant, commercially sound, and financially successful.
• Monitor project costs and performance against budget, identifying risks and opportunities and taking action where required.
• Manage variations and changes to scope, preparing and submitting associated quotations, claims, and supporting documentation.
• Support monthly valuations, cost reporting, forecasting, and cost/value reconciliation activities.
• Administer contracts and subcontracts in line with contractual requirements and company procedures.
• Review and interpret contract terms, supporting the management of claims and variations to protect and maximise project margins.
• Build and maintain strong working relationships with clients, subcontractors, consultants, and internal stakeholders.
• Work collaboratively across departments, including Commercial, Finance, Legal, Design & Engineering, and Operations.
• Support the development and consistent application of commercial processes and best practices.
• Assist with supplier negotiations and other commercial activities as required.
• Contribute to continuous improvement initiatives and support special projects when needed.

What we’re looking for in ourQuantity Survayor :

• Proven Quantity Surveying experience within a project delivery or construction environment, ideally with exposure to Hyperscale Data Centre projects.
• Strong commercial and contractual knowledge, including experience with JCT, NEC, and other standard forms of contract.
• Excellent negotiation, communication, and stakeholder management skills.
• Commercially aware with the ability to identify risks, opportunities, and practical solutions.
• Strong organisational skills with excellent attention to detail and the ability to manage multiple priorities.
• Proficient in Microsoft Office, including Excel, Word, and PowerPoint.
• Collaborative team player with a proactive, hands‑on approach and a commitment to delivering high‑quality outcomes.
• Ability to build and maintain strong relationships with clients, colleagues, suppliers, and subcontractors.
• Customer‑focused, adaptable, and able to perform effectively in a fast‑paced environment.
• Strong understanding of Structured Cabling and Hyperscale Data Centre technologies is desirable.