Our people

Alex Hole | Director

  • Alex brings over 20 years experience in design consulting in the built environment. A mechanical engineer by background Alex has played key roles in the design and delivery of multidisciplinary services engineering across multiple sectors including commercial, residential, healthcare, arts & culture and science & research buildings.

    Passionate about design and inspired by the magic that comes from the collaboration of teams, Alex brings a creative and inclusive mindset to consulting engineering.

Barry Martin | Director

  • Barry has an extensive background with the CSIRO as a Principal Research Scientist and brings to the team unique problem solving expertise.

    Over the years Barry has forged extensive experience in the area of public utilities, commercial buildings, government and health facilities. Barry is committed to finding effective solutions to complex problems.

Ben Cook | Director

  • Ben is a Chartered mechanical engineer with a wealth of experience in the design of mechanical building services systems with a key focus in healthcare projects.

    Ben’s extensive hands-on mechanical experience has provided him with a solid understanding of systems for across various building types.

Hadi Jalgha | Director

  • Hadi has over 20 years’ experience in the building engineering services field and HVAC services design. With a strong emphasis on project leadership, practical solutions and quality assurance, Hadi expertly leads the JHA mechanical team to ensure all core elements of a project are met, to the highest standards.

    Hadi's comprehensive project experience encompasses a wide range of sectors such as government, defence, health, education, residential and mixed-use, commercial, retail and transport sectors.

Jim Hatzimanolis | Director

  • Jim has over 30 years of relevant experience in the building industry, during which time he has occupied a range of roles, including Project Director for multidisciplinary projects and Lead Electrical Engineer for numerous complex facilities. Jim’s experience is capacious with a strong emphasis on health, education, residential/ mixed use, aged care and government commissions.

    Jim is the founder of JHA in 1995 and continues to be actively involved in the administration of the business, while being an active hands-on Director / Project Leader.

Marc Estimada | Director

  • Marc is a Director and Lead Building Services Engineer experienced in project design consultation, technical design and documentation for a diverse range of multidisciplinary projects. Marc has an acute sense of client requirements and sophisticated project management and delivery methodology.

    Marc's extensive experience includes university/tertiary education, early learning to secondary education, high-end/high-rise/boutique residential, commercial, government/high-security facilities and healthcare.

Nathaniel Siely | Director

  • Nathaniel is a Chartered electrical engineer who has been operating in the built environment sector for more than 15 years. Now based in our Brisbane office, Nathaniel brings a broad range of experience delivering projects within Australia and the UK.

    His primary project sector experience includes healthcare, education, defence, industrial, aviation and rail. Nathaniel relishes the challenge of working through difficult projects to deliver his clients their desired outcomes. He is a strong believer in clear, regular communication to keep expectations aligned and ensure everyone is moving in the same direction.

Tian Song | Director

  • Leading the JHA Queensland team from our Brisbane office, Tian is an accomplished Chartered mechanical engineer with RPEQ and NER endorsement. Tian has a broad range of experience within the building services industry, undertaking mechanical HVAC design and specializing in the management and delivery of multidisciplinary projects.

    Tian has a strong focus on client engagement and working collaboratively within project teams to develop robust and well thought out engineering solutions for projects. His project experiences include healthcare, education, defence, commercial, retail, auditing, residential, industrial, hospitality and sporting facilities amongst others.

Margaret Alousis | Senior Associate

  • Margaret is a Chartered Mechanical Engineer registered to practice in Victoria. Her career in the building services sector has spanned over 23 years and during that time, she has delivered an impressive portfolio of buildings around the world. What is consistent in Margaret’s approach is the use of rigorous design, meticulous attention to detail and the overarching principle of good communication.

    Based in our Melbourne office, Margaret specialises in health, education, premium residential, commercial office, community, sporting, and judicial facilities.

Brenton Burrows | Director

  • Brenton has over 20 years experience in the building industry, where he has applied vital design and practical skills through his time consulting and contracting.

    Brenton’s diverse abilities and innovation provide valuable insight at every level, while consistently delivering exceptional service with a client focus. His broad experience includes infrastructure, defence, health, public works, commercial and residential developments.

Darren Campbell | Technical Director

  • With eight years hands-on experience as a Licensed Plumber, four years as the Principal Hydraulic Officer at the Queensland Department of Public Works and twenty five years in the consulting field at Principal/Director level, Darren has a broad experience base in hydraulic engineering with application in design, documentation, specification and construction quality control for all project types.

    Darren's project experience is truly extensive and embraces every market sector for the full range of hydraulic services.

Diego Montelvere | Director

  • Diego has over 20 years of valuable experience in the hydraulic services industry. He has worked in the consultancy field for over 15 years, and prior to this, Diego worked as a plumbing sub-contractor for 6 years, giving him practical experience in the construction industry.

    Diego's wide range of expertise extends over sectors such as health, commercial, residential, hotels, retail, entertainment, education, public buildings and transport infrastructure.

Chris Hadjiyiannis | Director

  • Chris has a wealth of experience across wet and dry fire protection and mechanical services. A FPAA Fire Systems Design Accredited Practitioner, Chris has extensive experience in all areas of design, documentation, project management and commissioning for a wide range of projects including health, aged care, residential, hotels, commercial and government facilities.

    An expert communicator and multidisciplinary project team leader, Chris leads the JHA fire services team.

Jeffrey Ng | Director

  • Jeffrey has over a decade of extensive experience in the building services industry and is actively involved in the HVAC & ESD sectors. He has worked in various sectors including healthcare, large scale mixed used developments, NABERS & Green Star rated commercial buildings and institutional buildings.

    With notable professional accreditations such as CBD, NABERS and Green Star, Jeffrey’s experience across both ESD and HVAC design provides him an in-depth understanding of the practicalities of design and cost of construction to meet the demand of the evolving “green” building market.

Kosma Tzannes | Director

  • With over 15 years of consulting experience in the electrical building services and electrical infrastructure industry, Kosma’s experience ranges across a diverse array of projects including L3 ASP substation design, overhead and underground high and low voltage design, authority asset relocation (electrical & telecommunication), subdivision master planning, street lighting, as well as complete electrical and telecommunication building services design works.

    Kosma leads the JHA High Voltage/ Level 3 ASP infrastructure team with vast practical experience and knowledge across Ausgrid, Endeavour Energy, Essential Energy, main telecommunication providers, and infrastructure authorities.

Joanna Pan | Specialist Lighting Group Manager

  • Jo brings a unique approach to the creative lighting team, attributable to her background in interior architecture. Her extensive training within spatial design has proved to be a valuable asset, with her ability to comprehend and visualise illumination clearly in 3D spaces and apply such techniques into lighting design.

    Jo continues to push the boundaries of light and darkness in her design, providing striking lighting installations for our clients. Jo’s experience in the building services industry is extensive, with hands-on involvement in entertainment, hospitality, high-end residential, heritage and commercial fit-out sectors.

Tommy Sailing | ICT Group Manager

  • Tommy is a highly experienced engineer specialising in next-generation communications, integrated smart buildings technologies and electronic security.

    Adopting a ‘whole building services’ approach to ICT services design, Tommy ensures that projects are provided with a bespoke, practical and integrated solution. Tommy is skilled in assisting our clients understand new possibilities, getting the most out of their investment in ICT, and ensuring that their technological objectives are exceeded.

Alex Frew | Audio Visual Technology Group Manager

  • Alex has more than 20 years’ experience in the audio visual technology industry from stage production and crewing through to installation and design. This practical experience is further supported by a Masters of Architectural Science (Audio and Acoustics).

    Alex has a passion for technology systems which are designed to improve and simplify the people’s lives.

    Focused on the user experience, Alex looks to provide solutions which are fit for each customer’s need and purpose.

George Petropoulos | Vertical Transport Group Manager

  • George has over 27 years’ in-depth vertical transportation knowledge, based on his extensive experience in working with industry leading VT companies such as Kone, Otis, and Liftronic.

    George has a wide range of experience on projects within various building sectors such as health, residential, retail, commercial, industrial, transport, government and public domain.

    Complimentary skill sets in building design through Traffic Analysis, System Interfacing & Integration and design aesthetic for new buildings and modernisation solutions for existing buildings. Management capability of service and maintenance for existing building Vertical Transport Capital Equipment.

Jorge Reverter | Acoustic Group Manager

  • Jorge brings over 20 years of comprehensive experience in the acoustic consultancy field in Australia and Spain.

    His experience includes a broad spectrum of acoustics projects covering: transport infrastructures, land planning, room acoustics, building acoustics, noise and vibration control for building services, environmental noise control and assessments, programming and computer modelling.

Lawrence Yu | ESD Group Manager

  • With over 19 years in ESD consulting, Lawrence is a seasoned professional specializing in providing bespoke sustainability solutions for the built environment. Lawrence combines deep expertise in ESD regulations and uses cutting-edge benchmarking tools like Green Star, NABERS, NatHERS, and WUFI to design buildings that optimize energy usage, reduce carbon emissions, and enhance the overall comfort and wellbeing of building occupants.

    From hotels and aquatic centres to commercial and residential developments, Lawrence has a proven track record of delivering exceptional results across diverse sectors. Having served on the BASIX Thermal Comfort Protocol Working Group, the GBCA Academy Advisory Group, and the ABSA Technical Advisory Committee, Lawrence is committed to staying at the forefront of his profession and driving progress in the ESD industry.

Matthew Beament | Civil Group Manager

  • Matthew is a Chartered civil engineer with over 15 years' experience specialising in stormwater design from conceptualisation, delivery documentation, to site inspections and sign-off of works.

    Specialising in high-end residential developments, Matthew's experience also covers notable commercial, public domain and education developments.

John Holdich | Senior Associate

  • John is a Chartered Building Services Engineer, Chartered Project Manager and a WELL Accredited Professional.

    Specialising in hydraulic and mechanical services design, sustainability design and asset management, John has valuable extensive experience delivering landmark projects in Australia, the Middle East and the United Kingdom. He has particular expertise in the correctional, transport and industrial market sectors to compliment our Melbourne office.