About Us
A collaborative of professionals.
We are a group of exceptional project managers with credentials and experience in architecture, facilities management, capital needs assessments, Passive House, sustainability, and other specialties. While only one of us might be assigned to a project, our clients benefit from our group’s shared knowledge and expertise.
Principals
Leadership
Founders who set the tone for the firm — combining decades of construction, design, and development experience.
Douglas Tierney
Principal
Douglas Tierney has been helping property owners across the United States achieve their project goals for over 20 years. After graduating from Colgate University, Doug worked in construction contract administration for Mostue & Associates Architects (now Davis Square Architects). In 2008 he moved into direct owner representation when he joined The Community Builders, a national developer of affordable housing. As their Director of Construction for the New England Region, he managed a variety of complex developments over a 6-year period. He has since gone on to serve as Director of Construction for Cambridge Housing Partners, a Denver-based housing developer, and Broder Management, a Massachusetts-based developer of luxury housing and hotels. As a Certified Passive House Builder (CPHB), Doug has a passion for great exterior envelope details, energy efficiency, historic renovations, teamwork, and clear expectations for all team members. He currently lives in Natick, MA with his wife, two children, and dog.
Brooks Mostue, AIA
Principal
Brooks Mostue has over 45 years of experience as a registered architect, contractor, real estate broker, and developer in Massachusetts and abroad. He is a founding principal of Mostue & Associates Architects, Inc., and its successor Davis Square Architects, Inc.; The Casali Group, Inc. construction project managers; Pentimenti LLC and Gibson & Quincy, LLC real estate developers; and The China Vision Project. Brooks’ work spans a broad range of academic, corporate, and residential projects, many of which involve historic and architecturally significant buildings. He is enthusiastic about affordable housing, energy efficiency, and environmental protection. A graduate of Harvard College and the Harvard Graduate School of Design, Brooks has taught and participated in design studios at Harvard, and other schools in Boston and Rhode Island. He has volunteered on building committees for the Town of Lincoln, MA, and is the past president of the Board of Trustees for Farrington Memorial. Brooks has restored four of his own homes of historic significance and is currently renovating a house with one of his three daughters. Brooks and his wife Patty reside in Lincoln, MA.
THE COLLABORATIVE
Our Team
Architects, project managers, and construction professionals — each bringing distinct expertise to every engagement.
Amy Bloom, RA, LEED
Owner’s Project Manager
Amy Bloom is a Registered Architect and LEED Accredited Professional with 20 years of experience in design and construction management. She graduated from the Rhode Island School of Design school of Architecture in 2003. Amy worked for Lieb Architects, Architects and Associate Designers, and Davis Square Architects prior to developing her own Woman-Owned (WBE) firm, Amy Bloom Architecture, based out of Andover, in 2013. Amy has successfully completed over 90 projects in and around the Merrimack Valley focusing largely upon historic renovations, accessibility upgrades, affordable housing, single and multifamily housing, and light commercial tenant fit-outs. She has been an active member of the Andover Historic Preservation Commission since 2021 and joined Tierney as a Project Manager in 2023. Amy enjoys candlepin bowling and is the top female bowler in her league.
John Cavacas, CDT, FMA
Owner’s Project Manager
John Cavacas is a seasoned manager with over 30 years of experience in Owner’s representation. In addition to construction project management, John’s expertise extends to estimating, scheduling, constructability analysis, contract documents (CDT), facilities management (FMA), and real estate sales (license #0761231). Prior to joining Tierney, John was the Construction Representative for Colliers International for the new Cape Cod Technical High School. He is a proud graduate of Southeastern Massachusetts University’s (UMASS Dartmouth) Construction Management program. John lives in Centerville with his wife Marcie.
Melanie Coo, RA
Owner’s Project Manager
Melanie Coo, RA, has been a licensed Architect for over 20 years, with extensive work in affordable and multifamily housing. A graduate of Wellesley College, and with a Master of Architecture from MIT, Melanie’s career includes large multi-unit new construction and rehabilitation projects, as well as small custom retail and residential projects. With Next Phase Studios, she was an associate with the team building the Genzyme Center — among the first LEED Platinum certifications in the country for a large commercial building. During several years with Mostue & Associates (now Davis Square Architects), Melanie was promoted to Senior Associate, managing teams on many affordable housing projects. Her several awards include a Boston Society of Architects’ Design Award, an Energy Star award, and a 2009 National Housing & Rehabilitation Association “Timmy” award for best historic rehabilitation. Most recently she has been overseeing construction as an Owner’s project manager for Acorn Holdings. Melanie has renovated 3 of her own homes, including an appearance on HGTV. Melanie lives in Concord, MA with her husband, 2 teen sons, and many pets.
Nathan Dalke, LEED
Owner’s Project Manager
Nathan Dalke joined Tierney in 2021 after 12 years with the Design and Construction Department of The Community Builders. At TCB, he acted as full-time Clerk of the Works on site for several large rehabilitation projects before being promoted to Construction Manager, and later Senior Construction Manager, for both new construction and occupied rehab projects in the greater Boston area. During his time with TCB, Nathan worked on several company-wide initiatives, including their Climate Taskforce focused on identifying and implementing Sustainability and Resiliency programs within specific projects. He also piloted an Enhanced Capital Needs Assessment process to ensure proper Sustainability and Resiliency goals and initiatives were being identified and addressed during early Project Scoping. Nathan is a LEED Accredited Professional and holds a Bachelor’s Degree in Architecture from the University of Arkansas’ Fay Jones School of Architecture. Nathan is an aspiring carpenter, outdoorsman, gardener, and avid cyclist. He lives in Hyde Park, MA with his wife and two children.
Eli Herman, CEM, LEED, CPHB
Owner’s Project Manager
Eli Herman has 20 years of experience in the construction industry, ranging from carpentry and cabinetmaking to extensive work in sustainability and energy efficiency to managing large scale new-construction and renovation projects. After earning his MDS in Sustainable Design from the Boston Architectural College, Eli went on to earn his CEM, LEED AP-Homes, and PHIUS Certified Builder accreditations. He has a passion for high-performance buildings and a focus on helping owners and developers get the best bang for the buck through whole systems design. He has fully renovated three of his own homes in addition to thousands of units of housing. He enjoys gardening, disc golf, and outdoor adventuring. He lives in North Reading with his wife, daughter, puppy, cat, and two rats.
Pam Maryanski
Operations/ Assistant Project Manager
Pam Maryanski joined Tierney in 2023 and serves a dual role as both their Operations Manager and an Assistant Project Manager. A graduate of Smith College and former classroom teacher, she brings keen organization, communication, and relationship-building skills to her work. Her interests in architecture, affordable housing, and project management led her to this role. She is currently pursuing further professional development in the fields of construction and business. Pam is driven by a desire to increase equity in access to housing in Massachusetts and is grateful for the lovely home she and her daughter share in Medford.
Peter Rex, CPHB
Owner’s Project Manager/ Clerk of the Works
Peter Rex came to Tierney after attending Colgate University. At Colgate, Peter earned a Bachelor of Arts degree in Environmental Geography. He has had internship experience with Davis Square Architects and the Planning Department for the Town of Andover, MA. Peter has participated in research studies which explore regional transit-oriented development and evaluate municipal vulnerability to natural hazards. He has also completed graduate coursework through UMass Boston’s Center for Rebuilding Sustainable Communities after Disasters. A Certified Passive House Builder (CPHB), Peter brings a passion for energy efficiency and combatting climate change through green building. He currently lives in Cambridge, MA.
Katelyn Rivera
Assistant Project Manager
Katelyn Rivera serves as an Assistant Project Manager at Tierney Development Services. She supports project coordination across a range of residential and affordable housing projects, assisting with documentation, scheduling, communication, and overall project organization. She is a graduate of Boston College, where she developed a strong interest in sustainability, housing equity, and the built environment. Her work at Tierney reflects a growing focus on affordable housing, residential retrofits, and climate-conscious construction practices. She brings a thoughtful, detail-oriented approach to her role and is committed to continued professional development within the construction and project management fields. Katelyn lives in Lynn, MA with her two cats.
Steve Rubino
Owner’s Project Manager
Steve Rubino joined Tierney in 2026 with 17 years of experience in construction and real estate development. A graduate of Roger Williams University’s Construction Management program, Steve spent 12 years with Turner Construction in roles ranging from Field Superintendent to Project Engineer, working on healthcare, education, lab/office, and condominium projects throughout Boston and Cambridge. He then spent five years with Samuels & Associates, managing design and construction initiatives across a diverse portfolio of commercial and mixed-use developments. His primary focus there was the Landmark Center Phase III redevelopment, a $900 million lab/office high-rise with 550,000 square feet of Class A office space. Steve holds a MA Construction Supervisor License and a certificate in Real Estate Finance from Boston University. He lives in Pembroke, MA with his wife and twin daughters.
Andrew Sansom, LEED
Owner’s Project Manager
Andrew Sansom is a Registered Architect, LEED Accredited Professional (AP), and Certified Passive House Builder (CPHB). He has spent more than twenty years in the commercial real estate services sector advising clients on their real estate and occupancy planning. Before Andrew came to Tierney, he led design and construction for all commercial tenant space in a new 1 million sf LEED Platinum Certified office tower in downtown Boston. His career has focused on representing both owners and occupiers of commercial, industrial, and multifamily residential real estate. Andrew is driven by a desire to help clients achieve their goals for making their buildings more sustainable and lessening their impact on the environment. He is particularly interested in the intersection of sustainability and equity in addressing the New England region’s housing crisis. Andrew lives and works in Winchester with his wife and two children, and when not on site or advising clients, he enjoys flying airplanes as a private pilot, traveling, hiking, and fly fishing.
Halle A. Thomas, AIA
Owner’s Project Manager
Halle Thomas, AIA, earned her Master of Architecture from the University of Michigan’s Taubman College of Architecture and Urban Planning and her Bachelor’s degree in Environmental Design in Architecture from the University of Colorado Boulder. She is a Registered Architect with more than a decade of experience leading complex mixed-use development projects from early planning and entitlements through construction and completion. Prior to joining Tierney in 2025 as an Owner’s Project Manager, Halle spent 13 years with Millennium Partners, where she managed large-scale urban developments in Boston. Her expertise includes owner’s representation, consultant coordination, budgeting, scheduling, and construction oversight. She is involved with the Urban Land Institute and professional architecture organizations, where she focuses on advancing housing attainability and thoughtful, community-centered development.
Cody Wero
Owner’s Project Manager
Cody Wero joined Tierney in 2025, with 15 years of experience in the affordable housing sector. His previous work at New Ecology, Inc. included acting as a rater/verifier for several sustainable construction programs including Energy Star, LEED, and Passive House (PHIUS). Cody has extensive experience in performance testing of building envelope and mechanical systems. His background ranges from gut rehab projects of historic mill buildings to high-performance new construction projects with ambitious sustainability goals. Cody brings a passion for raising industry standards and making sustainable construction practices a norm. He lives in Providence, RI with his wife, children, dog, and cat.