About us

Personalised Service
Founded in 1989, PSA are Building Services Engineers specialising in mechanical and electrical design, project management, energy conservation, surveys, Clerk of Works, compliance and more—all in-house.
We prioritise personalised service with active senior management involvement and enhanced site inspection during construction.
With memberships in professional bodies like CIBSE, BSRIA, IET, Low Carbon Energy Assessors (LCEA), CHAS, Constructionline, North West Consortium of NHS Trusts, we bring advanced expertise to every project.
Our commitment to sustainability is integral to our design approach, ensuring both environmental and economic considerations are seamlessly integrated into our work.
Our Values
The values that fuelled our inception – integrity, teamwork, client-centricity, innovation, and a commitment to education – continue to be the driving force behind the culture at PSA.
We invite you to join us on this journey, where expertise meets ethics, and success is measured not only in technical achievements, but in the lasting relationships we build with our clients and the positive impact we make on the built environment community.


Our sustainability commitment
At PSA, sustainability isn’t just a buzzword—it’s the cornerstone of our approach to building services and renewable energy solutions. We’re dedicated to creating a greener, more resilient future for generations to come.
- Client Empowerment: We guide our clients towards the most environmentally responsible energy solutions, ensuring a sustainable future without compromising on performance or cost-effectiveness.
- Leading by Example: We’re committed to continuously reducing our own carbon footprint, setting the standard for our industry and inspiring the next generation of environmental stewards.
- Sustainable Partnerships: We carefully select and recommend products and services that align with our environmental values, fostering a network of sustainability-focused collaborations.
Our Actionable Pledges:
- Annual Accountability: We
produce a yearly sustainability report, transparently measuring and
outlining steps to reduce our carbon footprint across our offices and
transport fleet. - Continuous Innovation: We
invest in our team’s expertise through dedicated Continuous Professional
Development hours, ensuring our engineers stay at the forefront of
sustainable technologies and practices. - Client Education: We commit to
sharing our knowledge, helping our clients understand the long-term
benefits of sustainable choices in clear, accessible language.
By choosing PSA, you’re not just selecting a service provider—you’re partnering with a team that’s passionate about building a sustainable future, one project at a time.
Our History
Founded in 1989 by Stephen Pettit and his wife Barbara, née Singleton. Stephen, like many of our clients, once experienced the frustration of unethical consultancies solely focused on profits.
Dissatisfied with the industry status quo, Stephen and Barbara envisioned a consultancy that would redefine the narrative – one driven by integrity, teamwork, and a commitment to creating a happy workplace.
Fuelled by the desire to deliver more than a basic service, Stephen left his engineering role at the NHS and started on a path to build a consultancy that places the client’s experience at the forefront.
They began their journey renting a basement office from Sir George and Milena Grenfell Baines, where Sir George would often challenge Stephen on how we would service his unconventional competition entries.
After a short time they decided to extend the garage at home which became their new office home, but it wasn’t long before it was time to expand after taking on two engineers.
The core values of PSA are rooted in the belief that a project’s success extends beyond technical expertise. It’s about fostering a culture of collaboration, trust, and genuine care for what the client is looking to achieve.
