Castle Square’s design, development, and construction team has substantial expertise in the energy efficiency and affordable housing arena.


Castle Square Tenants Organization, Inc.

Castle Square Tenants Organization, Inc. (CSTO) is a non-profit 501(C)3 organization founded in 1987 with the goal of preserving affordable housing in the Castle Square community.  CSTO’s mission is preserving Castle Square Apartments as affordable housing for low-and-moderate income residents into perpetuity and providing comprehensive community and social supports for residents and the surrounding community.



WinnCompanies is one of the largest affordable housing developers and property managers in the United States, with a strong interest in developing and operating properties as efficiently as possible.   Winn has one of the largest portfolios of solar photovoltaics on affordable housing in the country and has made substantial energy efficiency improvements to its existing housing portfolio.   It currently has a number of historic mill conversions under development, one of which will be LEED Platinum, demonstrating how to successfully integrate energy efficiency and historic preservation goals.


Building Science Corporation

Building Science Corporation specializes in building technology consulting.   Building Science is internationally recognized for expertise in moisture dynamics, indoor air quality, and forensic (building failure) investigations. It is also on the leading edge of the design of sustainable communities and buildings. Building Science believes in promoting energy efficiency and environmental responsibility within the constraints of marketable and affordable building technology.  Building Science Corporation is a technical provider for U.S. Department of Energy’s Building America program.


Elton + Hampton Architects

Elton + Hampton Architects is a full service architectural and planning firm dedicated to serving those who live and work in Massachusetts’ urban areas.  Our award-winning designs focus on rebuilding and stabilizing blighted neighborhoods, in serving disadvantaged, disabled, and elderly populations, and in creating Innovative, sustainable, community architecture that complements the past and endures for the future.


Petersen Engineering, Inc.

Petersen Engineering, Inc. – Established in 1992, Petersen Engineering has provided design services for energy efficiency commercial and residential applications.  As a mechanical engineering consulting firm, Petersen Engineering, specializes in mechanical systems, energy efficiency, integrated design, sustainable and green design.


Pinck & Co. Inc.

Pinck & Co. Inc. provides owner representation for non-profits and institutional owners undertaking design and construction projects.  They have extensive expertise in green affordable housing.  At Castle Square they are acting as the owner’s representative for CSTO and construction project manager for the CSTO/Winn partnership, including tracking LEED and workforce reporting requirements.

Biome Studio

Biome Studio coordinates teams of designers and developers to achieve deep energy and water savings that go far beyond standard green building goals.   Biome Studio’s mission is to lead the path toward zero energy buildings and neighborhoods.  Its portfolio includes very practical energy efficiency and renewable energy projects on large multifamily affordable housing to bold, cutting edge projects such as deep energy retrofits and interactive, sculptural, and installation scale artwork.  Biome Studio facilitated the financing and design for the Deep Energy Retrofit portion of the Castle Square renovation and developed


Rees-Larkin Development

Rees-Larkin Development is a real estate development firm specializing in the development of quality affordable and mixed-income housing in New England communities.  The mission of the firm is to create thoughtful, sustainable, and financially-viable communities that are, in themselves, assets to the larger community.

Klein Hornig LLP

Klein Hornig LLP was founded in 2002 with a mission of providing uncompromising service and legal expertise to the affordable housing and community development industry. With offices in Boston and Washington, DC, the firm represents nonprofit and for-profit developers, public agencies, tenants’ associations, lenders, syndicators and others in structuring, managing and closing all types of multilayered affordable housing and community development transactions,  including  projects utilizing Low Income Housing Tax Credits, public housing/mixed-finance, Section 202, tax-exempt bonds and New Markets Tax Credits.

VIVA Consulting

VIVA Consulting is a firm with deep expertise in all aspects of the community development industry.   VIVA works with public, private and nonprofit community development firms across the country to develop affordable housing and commercial projects, to craft strategic or business plans, to study industry trends and best practices, and to improve property and asset management operations.

CWC Builders, Inc.

CWC Builders, Inc., founded in 1946, has built and renovated residential and commercial properties throughout New England valued at close to one billion dollars. We have established an outstanding reputation of applying a progressive approach to the business of building, while we remain faithful to a tradition of completing jobs on time, within budget and to unparalleled standard of craftsmanship.

Backus Associates

Backus Associates specializes in nonprofit resident associations with owner representation on refinancing and renovation, asset management, leadership development, community visioning, and social and educational program development. Deborah Backus has over twenty years of experience working in the Boston region to develop viable communities.