One of Mr. Mantone’s most valuable assets is his experience and knowledge of a multitude of construction types including industrial facilities, schools, offices, supermarkets and retail buildings, surgical, healthcare, data facilities and large scale solar. Being involved in a diverse group of construction environments gives him the strong engineering base and ability to apply this knowledge to various design scenarios and operating a business involved in these environments.

Prior to forming DJM, David worked for three reputable engineering firms as a Project Manager, Team Leader, Client Manager and Principal. Through 20+ years of experience in managing many different types of construction projects, David has a great deal of overall knowledge in building design and the ability to manage and design challenging projects.


Mr. Smith is one of the Principal’s at DJM and during a career spanning over 27 years, he has designed a broad range of building infrastructures involving chilled and hot water systems, variable air volume systems, rooftop units, unit ventilators, laboratory fume hood systems, restaurant kitchen exhaust systems, electrostatic precipitators, hydraulic power systems, pump stations, low and high pressure steam systems, utility infrastructure, compressed air systems, medical gas systems, dust collection systems, plumbing, and fire protection systems. These systems were utilized in building types that included schools, laboratories, office buildings, hospitals, cultural centers, houses of worship, military buildings, restaurants, retail stores, single- and multi-family housing, and industrial settings.

Lance has managed projects from conception through construction, performing client owner contact, lease negotiations, consultant coordination, construction document preparation, specifications, shop drawing review, and construction inspection.  Mr. Smith is LEED® certified by the U.S. Green Building Council.


For over two decades, Mr. Widdis has been involved in the planning, design, management and construction phases within the architectural and engineering industry. He has performed duties of Senior Project Manager, Electrical Team Leader and MEP Team Leader. Chad brings a diverse background of project history in various sectors, along with proven electrical design expertise associated with office buildings, supermarkets, retail, cold storage and restaurant applications.

While well versed in new construction, Chad is especially strong when dealing with the increasingly large number of major renovations to existing structures. From tackling the challenging design aspects head on - to working closely with the construction team to ensure the client is getting the best solution – Chad has proven himself to be an invaluable asset to the industry and a trusted resource for both end users and contractors alike.


Mr. Ventura is a highly experienced project manager and electrical engineer with over 35 years of experience in various types of commercial projects, tenant fit-outs, corporate office interiors, building infrastructure, and mission critical systems. He is respected for his pro-active planning, technical expertise and excellent communication skills. He works diligently with a broad range of clients to understand their needs and help them reach their goals. He collaborates with team members to focus on reaching cost-effective solutions within schedule constraints.


Ms. Wade has been a senior mechanical designer, specializing in plumbing systems for over 30 years. She has designed plumbing systems including sanitary waste and vent, grease waste, storm drainage, water distribution and gas piping. Laurie brings a diverse background of project history in various sectors, including banks, zoos, office buildings, churches, public schools, vocational schools and colleges.


Mr. Higgins has 6+ years of experience in DC and AC systems for large scale solar installations including rooftops, ground mounts, and carports in numerous states. He is well versed in National Electrical Code and the governing interconnection requirements of multiple states and for various types of installation. Along with Solar design, Kevin has experience in the Mechanical, Electrical, and Plumbing designs of various construction types including multi-dwelling residence, supermarkets, Schools, and Retail buildings.


Mr. Vergara has notable experience in the design of mechanical systems for a variety of applications including schools, commercial office buildings, healthcare facilities, pharmaceutical manufacturing facilities, retail stores, restaurants, supermarkets, military buildings, residential, mixed-use and hospitality buildings. He has designed a wide range of mechanical systems including unitary rooftop systems, variable air volume systems, energy recovery units, variable refrigerant flow multi-split systems, water source heat pumps, central plant hot water boiler and chilled water systems, computer room cooling systems, and surgical room laminar flow with HEPA filtration air handling systems. In addition, he has extensive experience with the use of Revit Building Information Modeling software for the design of MEP systems while part of multi-discipline, collaborative design teams.

In addition, Arjay Vergara is LEED® certified by the U.S. Green Building Council.


Mr. Doyle is responsible for the design of plumbing systems including sanitary waste and vent, grease waste, domestic water piping, natural gas piping and storm drainage systems. His project design experience includes various commercial building types such as supermarkets, restaurants, retail buildings, medical facilities and office buildings