Site Supervisor (Mechanical)

Harmony is on a mission to be the best life safety partner to work with and for. Rated an ‘Outstanding Employer’ by Best Companies in 2025, we are only getting bigger and stronger — and we’re looking for A-players to help us get there.
We are one of the UK’s fastest-growing life safety contractors, delivering passive fire protection, building fabric, height safety and fire door services across residential, social housing, commercial and public sector buildings nationwide. We are growing rapidly across all divisions as demand for compliant, high-quality fire safety services continues to accelerate.

We are now looking for a Height Safety Supervisor to lead our height safety field teams, taking ownership of the quality, safety and delivery of planned and reactive height safety works across our client portfolio. You will be responsible for the day-to-day leadership of a team of Height Safety Engineers in the field — overseeing the planning and execution of inspections, installations and reactive works, and ensuring all activity is completed safely, compliantly and to the standard our clients expect.

You will act as the key point of escalation for your team on site, providing technical guidance, conducting quality checks and making sure method statements and risk assessments are followed correctly on every job. Working closely with the service admin and scheduling teams, you will help coordinate workloads, support the booking of remedial works and contribute to quoting and asset register updates where required. You will also play an active role in the development of your engineers, supporting their training and progression within the business. This is a field-based role requiring regular travel to client sites.

Quality and Compliance Management — ensure all mechanical works, including sprinkler installations, dry and wet risers, smoke ventilation and associated mechanical systems, are completed to Harmony, BS9251, BS9990, BS EN 12845 and industry standards. Carry out timely checking of works on site and ensure accurate data input and record keeping throughout.

Site Management — oversee site set-up and sign-off, stock management, delivery of prelims, pre-condition surveys and post-inspections to allow for final sign-off by the Project Manager. Identify and flag variation opportunities to the Project Manager immediately.

People Management — resolve day-to-day issues, boost team morale, manage conflict and identify resource requirements. Maximise the productivity and utilisation of colleagues and subcontractors on site.

Quality Control — ensure all mechanical works are certifiable and compliant, delivered to both client and Harmony expectations. Carry out regular spot checks, record findings accurately and ensure all certification, pressure test and commissioning documentation is completed correctly at each stage.

Client Management — attend pre-start meetings and ensure the site is always tidy and representative of Harmony’s brand. Carry out onsite resident liaison where required and communicate works clearly to those affected.

Communication — provide regular progress updates to the Project Manager and weekly reports to the client. Attend calls as needed and agree reporting frequency with the Project Manager.

Health and Safety — implement Harmony’s H&S policy across all sites. Induct new trades, ensure completion of all relevant H&S paperwork, deliver regular toolbox talks and maintain a safe working environment through ongoing training and auditing.

An A-player mindset — high standards, extreme ownership and the drive to do things properly, the first time.

Proven experience in a mechanical supervisory or senior trades role within fire safety, sprinklers or a closely related discipline.

Hands-on experience with sprinkler systems, dry and wet risers or smoke ventilation, including testing, commissioning and certification to relevant British Standards (BS9251, BS9990, BS EN 12845).

Experience running projects to time and on budget across multiple sites.

Comfortable working flexibly across the South of England, with a willingness to travel as required.

Strong understanding of relevant mechanical regulations and compliance requirements.

A strong problem solver who sees things through to completion.

Ability to build and maintain good working relationships with clients, subcontractors and colleagues.

Proactive, confident, tenacious and resilient.

An ambassador for Harmony’s values and behaviours on every site.

This is a chance to run live sites for one of the UK’s fastest-growing fire safety specialists — the kind of work where you can see what you’ve delivered at the end of every week and know it makes residents safer. At Harmony, we ask a lot — and we give a lot back. The hours are real, the standards are high and the work is demanding, but for those who show up, deliver and go the extra mile, the rewards follow. A-players here enjoy a competitive salary, a Personal Development Plan with ongoing training and coaching, unlimited holiday, a bonus scheme paying up to 50% of annual salary, enhanced maternity and paternity, lunch, snacks and refreshments on us every day at the office (fresh fruit and Takeaway Fridays included), a team social budget, cycle to work, an auto-enrolment pension, two major company events a year and our Reward and Recognition scheme — including European mini-breaks for those who go above and beyond. It is a collaborative, high-energy environment focused on doing things the right way — technically, practically and safely — and none of it is a perk for showing up; it’s what we share with the people pulling the business forward.
Harmony is an equal opportunity employer. We consider all applicants for employment regardless of age, disability, sexual orientation, gender identity, family or parental status, race, colour, nationality, ethnic or national origin, religion or belief. We want everyone who works with us to feel valued and to make a difference.