About Us

Portsmouth, New Hampshire

JSN was established in 1987 to provide engineering and design services to the construction industry throughout New England. Currently operating with a staff of ten to twelve, JSN completes hundreds of projects each year. We have over 500 clients including architects and designers, contractors, owners, developers, and municipalities. We are a hardworking and creative firm that places our client’s needs first.

Jeffrey S. Nawrocki

P.E. – CEO

Jeff graduated from the University of NH in 1982 with a B.S. in Civil Engineering and has been practicing engineering since. After working in the precast industry for five years designing and constructing bridges, parking garages, and buildings, Jeff started the company in 1987 to develop a diversified engineering practice. Jeff is licensed in NH, MA, ME, NJ, VT

Sarah E. Desiderio

P.E. – President

Sarah graduated from the University of New Hampshire in 2000 with a B.S. in Civil Engineering. While working full time, Sarah obtained a M.S. in Engineering, Structural degree from the University of Massachusetts Lowell in 2004. Sarah earned her professional license in October 2006. Sarah was with JSN from 2004-2015 and returned in April 2018. Sarah is licensed in NH, MA, ME, NY, CT, RI.

Matthew J. Allen

P.E. – President

Matt graduated from the University of New Hampshire in 1993 with a B.S. in Civil Engineering. Matt joined JSN in June of 1995. Matt earned his professional license in April 2000. Matt is licensed in NH and MA.

Roger V. Brown

LEED AP– Project Designer

Roger has been Project Designer with JSN since 1990.

Chuck Tinkham

P.E. - Senior Structural Engineer
Chuck earned his professional license in April of 2012 and joined JSN in May of 2012.

Charlie Bardwell

E.I.T. Structural Engineer
Charlie joined the team at JSN in February 2018.

Alden Blais

E.I.T. Project Engineer
Alden joined the team at JSN in June 2021.

Isabella A. Avila

E.I. Project Engineer
Isabella joined the team at JSN in August 2021.

Nick A. Yenchek

E.I.T. Project Engineer
Nick joined the team at JSN in July 2023

Lisa A. Rohr

Office Manager / Accounting / Insurance
Lisa joined the team at JSN in January 2004

Mary Hansen

Bookkeeper
Mary has been with JSN since 1993