Eric Hammarberg

Associate Principal

a man standing in front of a buildingEric Hammarberg has been surrounded by construction his entire life, the third generation of a family of building contractors. He has cultivated a technical expertise in craftsmanship and construction, sharing with his team an array of projects. He has worked many aspects of construction, including masonry and carpentry, and found success in historic preservation as a primary form of sustainable building.

Eric’s experience spans from design and project manager for many historic restoration and preservation projects including the New York Public Library’s plaster ceiling restoration, St. Patrick’s Cathedral, the Chrysler Building, the Metropolitan Museum of Art and stabilization at Lefferts Historic House. He has extensive experience conducting condition surveys, preservation methodologies, façade evaluations and restorations, project programming, specification research and writing, and reviewing accessibility, environmental and landmark rules compliance.

His expertise in preservation includes investigation, protection of historic structures adjacent to new construction, repair and restoration of historic stone and brick masonry, repairs of historic plaster and tall urban structures as well as repairs to terra cotta and various roofing materials. Prior to joining Henson Architecture as Associate Principal, Eric spent the last seven years as Associate Principal for WJE Engineers & Architects. Eric brings his vast knowledge of historic restoration across New York City Landmarks, structural and exterior envelope design and investigative expertise to the firm.

The Association For Preservation Technology Northeast Chapter (APTNE)

Founding Board Member

Maplewood Historic Preservation Commission

Class A Member
2004 – Present

International Concrete Repair Institute (ICRI) and Technical Committee 410 Masonry Terra Cotta Guidelines



Lucy G. Moses Preservation Award

Winner for the Restoration of the Hispanic Society of America Museum and Library

a stack of different colored blocks on top of each other

North American Copper in Architecture Awards

Copper award for Restoration of the Hispanic Society of America Museum and Library



Lucy G. Moses Preservation Award

Winner for plaster ceiling restoration of the Stephen A. Schwarzman Building, New York Public Library


Lucy G. Moses Preservation Award

Winner for Restoration of Gottesman Hall


Spring 2023


GRFC as an Alternative Replacement Material for Terra Cotta

New York, New York

Fall 2017

AIA New York

Stewardship of Decorated Ceilings in Great Public Spaces

with Kim Lovejoy and Sarah Kloze
New York, New York

Fall 2016

APT International

Fibrous Plaster: Specifying Reinforcement Systems for a Robust 19th-c. Technology

with Kim Lovejoy
New York, New York


NYTimes and WNYC Morning Edition

Interviewed for the work at the New York Public Library Rose Reading Room and Bill Blass Lending Room Ceiling Restoration

Fall 2001, Spring 2019

Historic Districts Council

Emergency Shoring & Stabilization of Historic Structures

The Shore Thing: A Practical Seminar on Shoring Methods and Case Studies for Historic Buildings

Spring 2010

The History Channel

Modern Marvels

Chrome televised broadcast

Spring 2009

International Conference on Protection of Historical Constructions (PROHITECH)

Protection of Historic Urban Structures During Adjacent Construction

Spring 2009

Lorman Education Services Seminar

Teamwork, Tools, Testing and Intuition: The Architect’s and Engineer’s Investigation and Repair Decision Making Process

Spring 2009

12th Annual International Preservation Trades Workshop

Historic Preservation: Easements, Tax Incentives and Litigation

Spring 2009

ICRI Connecticut Chapter

A Place for the Trades

Spring 2008

Lorman Education Services Seminar

Proper Assessment and Planning for Structural Renovations of Existing Buildings and Structures

Spring 2007

General Society of Mechanics and Tradesmen

Restoring 2 Skyscrapers, Empire State/Chrysler Building


Structural Engineers Association of New York

Practical Solutions to Building Envelope Problems – Local Law 11/98

Presented at Buildings NY Conference in 2004 and NeoCon Trade Fair in 1999


American Society of Civil Engineer’s Forensic Engineering Symposium, with the Structural Engineering Institute Structures Congress

A Case Study of Early Steel Curtain Wall: The Chrysler Building, New York, New York

Presented at the Stainless Building Seminar in 2005 and 20th Century Exterior Architectural Metals Conference in 2003

Spring 2003

ProCon AIA

Historic Roofing, Beyond the Basics

Fall 2002

The History Channel

Modern Marvels – The Chrysler Building

first broadcast October 2002

Fall 2001

Association of Preservation Technology Annual Conference

Observations of Historic Structure’s Performance at the World Trade Center

Also given at RESTORE New York in 2002 and 2003


The Greater New York Construction User Council

Local Law 11: A/E Process

2001 & 2000

University of Hartford Construction Institute

Roofing Systems: A Survey of the Basics and Some Special Cases


MIT’s Technology and Conservation Conference

Windows in Commercial Buildings/Skyscrapers: Case Histories on the Empire State and Chrysler Buildings


Skyscraper Museum

Exterior Restoration of the Chrysler Building: Fast-Tracking a Landmark



Seventh Congress on Forensic Engineering, American Society of Civil Engineers

Benefits of Helical Bar Reinforcing in Preserving Historic Masonry Facades

Jared M. Shoemaker



Protection of Historic Urban Structures During Adjacent Construction

Keith Kesner and Derek Trelstad


Fourth Forensic Engineering Congress, American Society of Civil Engineers

90 Feet – The Difference an Avenue Makes: Protection of Existing Historic Structures During Adjacent Construction

Keith Kesner and Derek Trelstad



The Chrysler Building, A Case Study of Early Steel Curtain Wall