Doug Waitt
Founder (Big Kahuna)

After 36 years as DDMi’s fearless leader, Doug retired as of 12/31/2024. Non-business emails may be sent to him at [email protected]

Kitty Waitt
Bookkeeper 1988 – 2024

Kitty is passing on the torch and is joining Doug in retirement in early 2025.

Andrew W. Arsenault, P.E., LEED AP
Co-Owner, President, Engineer of Record

[email protected]
207-337-2473

Andy Arsenault is a licensed Professional Engineer in the states of NH, ME, MA, VT, RI, CT, NY, NJ & CO. He brought a diverse background to DDMI in June 2013 having worked for large and small engineering firms, mechanical contractors and HVAC equipment manufacturers’ rep firms. Andy is a proud UNH graduate with bachelor’s and master’s degrees in Mechanical Engineering. He lives in Rye, NH with his wife Judy, a couple of dogs and occasional visits from their combined five grown children and three grandchildren.

Rick Gagnon
Co-Owner, Plumbing Project Manager

[email protected]
603-668-5027

Manchester was Rick’s family’s home base when his father was deployed during 20-years of service with the Army. Rick graduated from West High School in 1977 and from N.H. Vocational Technical College with an Associates in Applied Science in Drafting Technology in 1979.

Graduating from the Tech on a Thursday, he started the following Monday at Concept Mechanicals, drafting plumbing, HVAC, and fire protection. As he gained experience, he eventually assumed responsibility for the plumbing design, drafting and estimating. Rick was part of the interview team tasked with hiring an HVAC draftsperson. With an urgent need to hire someone, the consensus was that “the next person through the door gets the job” . . . low and behold, in walked Doug for an interview! That was the start of a friendship and long working relationship.

In 1982, Concept Mechanicals consolidated with their parent company, Seppala & Aho Construction Co., Inc. When S&A closed in 1991, Rick’s responsibilities included Plumbing Department Manager, as well as plumbing design, drafting and estimating.

Rick met his wife, Julie, on a blind date in January 1983 and they married in May 1984. After a short temp position turned into a full-time job for Julie at S&A in 1984, they have continued to work together ever since, through the S&A years right into their home-based business.

Rick worked with Doug and James on side jobs starting in 1984, while still working at S&A (ink on mylar pin-bar overlay system, until James taught Rick & Julie the AutoCad basics). After a short stint with Palmer & Sicard in the Fall of 1991, Doug convinced Rick that he could keep him busy full time and Rick and Julie have been pushing out DDMI projects ever since, doing plumbing design/drafting and HVAC drafting in the early years, and eventually dedicating their time to the plumbing side of projects.

Rick and Julie love it when a plan comes together but very much enjoy their time away from the office doing all kinds of outdoor activities and spending time with family.

David Magnuson
Co-Owner, HVAC Project Manager

[email protected]
603-463-1086

Dave has over thirty years of experience in the HVAC industry, beginning in the field as a duct fabricator and installer.  He gained experience in the field with later roles included project manager and estimator. In 1999 he transitioned from HVAC field work to a fulltime drafting and design.   2008 marked the beginning of his work with Design Day Mechanicals, Inc, and in 2015 he became a co-owner.

Dave’s hobbies and interests include gardening, music, electronics design, gem mining, lapidary work and general tinkering.

Monique Magnuson
Co-Owner, HVAC Project Manager, Treasurer, Bookkeeper

Email for HVAC projects: [email protected]
Email for Bookkeeping: [email protected]
603-463-1086

Prior to joining the DDMi team in 2010, Monique explored many different professions to decide what she wanted to be when she grew up. She has worked as a pharmacy technician, a life skills facilitator for adults with acquired brain injuries, an executive assistant, a customer service supervisor, a realtor, an upholsterer and more.  The common theme through all her exploration in professions has been a desire to grow and learn new skills

Upon joining DDMi, Monique spent the first several years devoting her time to LEED energy modeling.  In 2015 she became a Co-Owner and transitioned from LEED modeling to drafting and designing HVAC, where she continues to learn and grow. Monique continues with DDMi as an HVAC Project Manager but in January of 2025 also has taken on the position of DDMi Bookkeeper.

Hobbies and interests include sewing, gardening, knitting/crochet, music, reading and, most importantly, finding a way to have a good laugh at least once a day.

Simone Flynn, P.E.
Co-Owner, Vice President, Senior Project Manager

[email protected]
603-913-4470

Simone graduated from Rensselaer Polytechnic Institute in 2014 with a Bachelor’s degree in Mechanical Engineering. Upon graduating, she worked as a mechanical designer for 3 years at another HVAC design firm before deciding to take a break from the 9-5 grind and try out real estate. After two successful and educational years in the real estate industry, and some self-discovery, Simone realized her passion for engineering and jumped back in by joining the team at DDMI. In 2022 she obtained her Professional Engineering License. Her hobbies include camping, pickleball, pottery, and making apple cider and maple syrup on her homestead in Durham, NH where she lives with her husband Shaun and two young daughters!

Iris Waitt
Co-Owner, Project Manager

[email protected]
603-801-2221

Iris spent her entire childhood growing up just below the original Design Day corporate headquarters, but it wasn’t until October 2015 that she joined the company herself. In fact, she spent most of her younger life puzzled as to why her dad and uncle were so magnetically drawn to look up at the ductwork spiderwebs in the ceilings whenever they went out for a family dinner. Satisfied to let the mystery lie, she received a bachelor’s degree in psychology from Boston University in 2013 and began life after college working as a case manager in the substance abuse treatment field.

However, the genetic allure of the diffusers and mitered elbows above couldn’t be resisted forever, and she has now been working for Design Day for most of her adult life. When not in front of a computer or poking through a crawl space looking for as-built treasure, Iris enjoys traveling, hiking with friends, baking bread and putzing around her house.

Mark R. Renaud
Sr. Plumbing Designer

[email protected]
603-234-8292

Mark joined the DDMI team full time in January 2016 after working (38) years in mechanical contracting his duties included estimating, project management and plumbing design. He holds master plumbing and gas fitter licenses in the state of New Hampshire and is a graduate of Manchester Community College with a (2) year degree in plumbing and HVAC design. He enjoys mountain biking, snow shoeing and other outdoor activities. He lives in Goffstown, NH with his wife Nicki and loves spending time with his stepchildren Alyssa and Garret and grandchildren Michael, Penny, Zoey and Axel.

Tyler Wilson, E.I.T.
Engineer-in-Training, HVAC Designer

[email protected]
603-521-2604

Tyler Wilson joined the DDMI team in June 2019 and is an Engineer-in-Training (EIT) in the state of NH. Tyler grew up with his parents and two brothers in Derry, NH, and currently lives in Milton, NH. He graduated from Worcester Polytechnic Institute with a bachelor’s degree in Mechanical Engineering and is currently working towards his master’s degree also in Mechanical Engineering at WPI. While at WPI, Tyler wrestled for four years, and played on the club rugby and golf teams. Now that his full-time college career is over, he enjoys exercising, playing guitar and piano, and spending time with friends and family.

Travis B. Somero, P.E.
Senior Designer

[email protected]
603-533-0318

Travis Somero is an Engineer in Training in the state of NH. He is an alumnus of Southern New Hampshire University, where he received a bachelor’s in mechanical engineering in 2018. Before coming on board Design Day Mechanicals, Travis worked in the construction field when not in college. Travis Somero currently resides in New Ipswich, NH where he is close to his family and friends.

Shaun Flynn
Designer

[email protected]
301-787-5598

After graduating from Rensselaer Polytechnic Institute in 2014 with a BS in Mechanical Engineering, Shaun moved to NH and went to work at a local manufacturing company. Over the years, Shaun worked his way up in the Aerospace industry, became proficient in CNC programming, and worked as a project manager for SpaceX and Blue Origin production.

After an epiphany in the woods, Shaun decided to join his wife, Simone, in the HVAC industry so that they could raise their family together at home. Since then, Shaun has been growing as an HVAC and Plumbing designer and a father of two girls. In his spare time, Shaun practices Brazilian Jiu Jitsu, works as a Maine and NH Guide, and runs outdoor education programs.

Mathilde Krebs
Senior Project Manager

[email protected]
207-475-2451

Mathilde joined the DDMI team in February 2020 after working for a consulting engineering firm in Portland ME, a manufacturer in France, and exploring New Zealand and Canada. Born and raised in France, her master’s in general engineering from Icam (Nantes, France) taught her she knows not much about a lot of things and decided to pursue a double master’s with the Polytechnique School of Engineering in Montreal (Canada) but this time specializing in mechanical engineering for the built environment. Part nerdy energy modeler/computational fluid dynamics analyst/mechanical engineer, part down to earth wood worker, part crazy motorcycle rider, she enjoys vacuuming the daily Bernese mountain dog load of shedded hair when (and only) in need of mental rest. Mathilde lives in South Berwick with her husband Mark and their two dogs River and Kit, at the confluence of the Salmon Falls and the Great Works rivers where they enjoy watching the bald eagles and tidal ebb and flow.

Matt Morrissey
HVAC & Plumbing Project Manager

[email protected]
978-278-5121

Matt is one of two HVAC & Plumbing Designers who joined DDMI on January 1, 2021 as part of collaboration between DDMI and Building Facilities Engineering Company (BFEC). BFEC was a consulting engineering firm that operated out of Beverly, MA under the ownership and management of Mr. Joel Gordon, P.E.

Matt grew up in Lynn, MA and attended LVTI High School where he majored in drafting and design. In January of his senior year, Matt joined BFEC and began working directly under Joel part-time as part of a co-op program, later transitioning to full-time upon graduation in 2001. Over the following years he attended classes at NSCC and would eventually complete the Engineering Science (AS) degree program.

Matt currently lives in Peabody, MA with his wife Maria and their two children.

Herman Pardon
HVAC Designer

[email protected]
646-346-9428

Herman joined the Design Day Mechanicals team in August 2024. He is a Mechanical Engineer, certified Passive House Designer, and honorably discharged veteran. In 1995 he joined the Army after high school where he learned about HVAC. After leaving the Army, he got a degree in Graphic design which provided him with an 18-year career as a Product Designer. After the arrival of his son, he decided that engineering was his true calling and went back to school. In 2018, he obtained a bachelor’s degree in mechanical engineering from The City College of New York. In 2020, Herman completed Passive House certification and found that there is a need for more mechanical engineers who understand HVAC systems for Passive House buildings. This is how he returned to HVAC and absolutely loves it. Herman lives in Wappingers Falls, NY with his wife, son, and 2 dogs. He is a woodworker and an athlete.