BOSTON, MASSACHUSETTS
JULY 29, 2025
2
THE CHRISTIAN SCIENCE PLAZA RESTORATION & REPAIR
THE MOTHER CHURCH EXTERIOR PRESERVATION & RESTORATION 3
THE MOTHER CHURCH INTERIOR PRESERVATION & RESTORATION
APPENDIX
APPENDIX OF SUPPORTING MATERIALS WITH ARCADIS WITH SGH WITH FINEGOLD ALEXANDER
Highlights: The Arcadis design team set out to restore, repair and improve upon the 14-acre Christian Science Plaza, Boston’s largest publicly accessible private open space to make it more welcoming to the community and visitors in all four seasons, both day and night. Designed in 1968 by I.M. Pei & Partners’ Araldo Cossutta and Sasaki Associates’ Stu Dawson, the Plaza is a national icon and a designated Boston Landmark. This project was the Plaza’s first comprehensive restoration in 45 years.
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Client/Owner
The First Church of Christ, Scientist
Owner’s Project Manager Redgate
Prime Consultant/Landscape Architect Arcadis
Construction Management Consigli Construction Inc.
Waterproofing & Structural Engineer Simpson, Gumpertz & Heger (SGH)
Civil Engineer & Green Infrastructure Nitsch Engineering
Garage Structural Engineer LeMessurier Consultants
Water Feature Design DEW Inc.
MEP Engineer Jaros Baum & Bolles
Lighting Design
Signage & Wayfinding
Irrigation
LAM Partners
Roll Barresi & Associates Inc (RBA)
Irrigation Consulting, Inc.
Arborist Bartlett Tree Experts
Materials Conservator Preservation Technologies Associates, Inc.
Geotechnical Expertise GEI Consultants, Inc.
Snowmelt HVAC Engineer Engineered Systems, Inc.
Cost Estimator AM Fogarty & Associates, Inc.
Finished Professional Photography Chuck Choi Architectural Photography
Highlights: Simpson Gumpertz & Heger (SGH) lead the exterior restoration that addressed chronic leaks that damaged both the facade, structure, and the interior. The comprehensive repairs included masonry restoration, flashing installation, roof replacement, and restoration of the terra cotta features including the two semi-domes and the cupola.
The semi-domes were originally built over a Guastavino shell, which was to be preserved in the repairs. SGH wanted to incorporate durable waterproofing and so developed an innovative terra cotta rainscreen assembly hung from tensioned stainless-steel cables that do not penetrate the new flat-seam copper roof below and incorporates modern enclosure detailing while using a tried-andtrue roofing system to retain the appearance of the semi-domes and preserve the Guastavino structure.
Highlights: 180 ft above grade, the terra cotta cupola that tops the central dome is an iconic feature of the church extension. The cupola was suffering from cracking and spalling due to water infiltration and corrosion of the embedded steel frame and anchors. Given access and constructability challenges, SGH worked with TFCCS to evaluate multiple repair options and materials, eventually choosing to replace in-kind. To lessen field conditions, SGH worked with contractors to create a virtual mockup of the entire cupola that resulted in a seamless construction and limited scaffolding and access costs.
Highlights: The churches are built on thousands of wood piles. Due to lower ground water levels, the tops of multiple piles have deteriorated, resulting in differential settlement. The most dramatic settlement occurred at the TMCO tower, which was rotating out of plane. To lessen further deterioration, SGH developed a monitoring program and ground water recharge system. At the tower, SGH designed a new support structure, including micro-piles, to support and realign the tower, giving care not to damage the interior finishes or stain glass windows of the original church and the Mother’s Room, housed within.
Highlights: Significant water was entering through the balustrade and related copings and cornices, damaging embedded steel, masonry and interior finishes below. SGH designed a long term approach to rebuild the balustrade as a veneer wall system, incorporating backup waterproofing and flashing. The original limestone facade was reused to preserve the building appearance.
Exterior Building Restoration Team:
Project Team for Exterior Building Restoration
Engineer of Record – Simpson Gumpertz & Heger
CM – Shawmut Design and Construction
Mason – Grande Masonry
Roofer – Gilbert and Becker
Attachment Hardware – TriPyramid
Terra Cotta – Boston Valley Terra Cotta
Highlights: Finegold Alexander Architect’s design strategically inserted updated electrical and life safety systems into the existing building fabric to bring the building up to code, while leaving the original interiors virtually intact. Due to extensive water damage, the interior plaster and associate decorative painting were also restored.
Highlights: The restoration created intimacy within The Mother Church Extension’s (TMCX) expansive Auditorium to host a smaller congregation by creating an accessible reader’s platform. Priorities at the interiors included the introduction of modern electrical and life safety systems, the integration of accessibility and the restoration of the Church’s original historic finishes. Fun fact: The interior restoration required 14 tractor trailer loads to create 1.7 acres of planked scaffolding decks, with 2 stair towers at 11 levels high, each to reach the top of the interior semi-domes. BACK
Highlights: A goal of the restoration project was to create a welcoming, accessible entrance for the congregation’s journey through this vast building complex. This included a clear path of travel from the underground parking garage all the way to both Auditoriums through careful planning and the introduction of an elevator within the historic interiors to create an accessible entry from the plaza on the south side of the church, opening up the building on that public face.
Client
Owner’s Project Manager
Architect
Contractor
The First Church of Christ, Scientist
Colliers International
Finegold Alexander Architects
Shawmut Design & Construction
Building Envelope, Structural Engineer Simpson, Gumpertz & Heger (SGH)
and Geotechnical Engineer
MEP/FP Engineer/Life Safety/Lighting Design ARUP
MEP/FP Engineer/Life Safety Altieri Sebor Wiebor LLC
Lighting Design Lam Partners
Geotechnical Engineer Peer Review
Code Consultant
Accessibility Consultant
Historic Preservation Resource Consultant
Local Preservation Consultant
Stained Glass Consultant
GEI Consultants, Inc.
Jensen Hughes
KMA Associates
Ilene R. Tyler
Building Conservation Associates
Sepentino Stained Glass Studio
Cost Estimating Vermeulens
Faithful & Gould
Test Pit Contractor
Specifications
United Civil
Kalin Associates
TMC INTERIOR REFRESH AND UPGRADES
Structural Engineer
Tripi Engineering Services
MEP/FP Engineer/Life Safety/Code Consultant ARUP
Cost Estimator
Acoustical & AV Consultant
Interiors & FF&E
Photography - TMCO interiors
Fennessy Consultants
Cavanaugh Tocci Associates
Stefura Associates, Inc.
Robert Benson Photography
Photography - Both TMCX Interiors and Exteriors Raj Das Photography
› Historical Context
› Plaza Supporting Materials
› Church Building Supporting Materials
BUILDING
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• Restoration & Repair
• Welcome & Integration
Add passive infiltration & rain water storage tanks
Increase area of pervious softscape
Use stored rain water for recharge wells
Re-waterproof & decrease depth of pool
The Mother Church sits at the center of the Christian Science Center Plaza, 13.5-acres that is the largest privately owned, publicly accessible open space in the City of Boston. This renowned building is comprised of two structures: the Romanesque Revival The Mother Church Original (1894) designed by Franklin Welch; and the larger Neoclassical domed edifice, The Mother Church Extension (1906) designed by Charles Brigham & Charles Covery of Boston and Solon Beman of Chicago. Each building represents different architectural styles and materials and were the product of rapid growth in the Christian Science faith. The Church buildings are Landmarked by the Boston Landmarks Commission (BLC), and all preservation work required careful consideration to receive BLC approval.
The Church selected Simpson Gumpertz & Heger as the building envelope and structural engineer for the building exterior, while Finegold Alexander Architects served as the architect for the building interiors, including electrical upgrades, life safety systems, significant accessibility modifications and the redesign of ancillary spaces, all while preserving and restoring the Church’s original historic finishes. Shawmut Design and Construction served as the construction manager, tasked with implementing the preservation work, restoring the building to its original vision while leaving behind no trace of the invasive work that was completed.
The recently completed renovations spanned eight years, with a completion date of 2024. The project is a first-rate example of groundbreaking preservation work, due to the impressive scale of the domed
structure; the difficult logistics required to remediate the ornate building fabric; the innovative engineering solutions used to rebuild the original Guastavino and terra cotta tile semi-domes and replace the terra cotta and steel framed cupola; and the significance that this iconic building has for Boston and beyond. In this model of preservation practice, leadership and teamwork was displayed in the coordinated efforts of the client, engineers, architects and consultant groups required to tackle this massive project. The preservation and restoration work on the Church edifices—which took place before, during and after the Covid-19 pandemic—created and enhanced opportunities for community not just for the Christian Science congregation, but also for the neighborhood residents, Boston citizens and visitors.
CONSTRUCTION OF TMCO
DESIGNED BY FRANKLIN WELCH
ROMANESQUE REVIVAL STYLE
NEW HAMPSHIRE GRANITE
EXTERIOR WITH SLATE ROOF
CONSTRUCTED IN ONLY 13 MONTHS
1906
CONSTRUCTION OF TMCX
DESIGNED BY CHARLES BRIGHAM & CHARLES COVERY OF BOSTON AND SOLON BEMAN OF CHICAGO
NEOCLASSICAL STYLE WITH BYZANTINE ELEMENTS
LIMESTONE & GRANITE EXTERIOR W/TERRACOTTA
CONSTRUCTED IN 23 MOS.
1918
SEMI-DOME
RESTORATION AT TMCX
1950 DOME
RESTORATION AT TMCX
TO ADDRESS SIGNIFICANT LEAKS AT BOTH NORTH AND SOUTH SEMI-DOMES
ALL TERRACOTTA ON BOTH SEMI-DOMES WAS REMOVED AND REPLACED
THE TERRACOTTA CLADDING ON THE CENTRAL TMCX DOME HAD SYSTEMATICALLY FAILED
CUPOLA AND ALL TERRACOTTA ON THE MAIN DOME WERE REMOVED AND REPLACED
1978
MASTERPLAN AND STONE PORTICO ADDITION
DESIGNED BY ARALDO COSSUTTA
PART OF THE PEI COBB FREED MASTER PLAN TO PROVIDE THE ADMINISTRATIVE HEADQUARTERS OF THE WORLDWIDE CHRISTIAN SCIENCE CHURCH WITH A MORE OPEN AND WELCOMING ENVIRONMENT
2011 LANDMARKS DESIGNATION
SIGNIFICANT AT THE LOCAL, STATE AND NATIONAL LEVELS
ASSOCIATION WITH DISTINGUISHED ARCHITECTS OVER THE SPAN OF A CENTURY
MONUMENTAL DESIGN FOR ENTIRE CITY BLOCK PROVIDES OPEN SPACE FOR ADJ.NEIGHBORHOODS
PHASE 1
COMPLETED: APRIL 2016
Timber pile foundation repairs
PHASE 2
COMPLETED: DEC 2017
Exterior envelope repairs
Electrical rewiring
Life safety upgrades
Interior plaster repair and decorative painting
3 MAY 2019JULY 2020
Exterior envelope repairs
PHASE 4 JAN 2018MAY 2019
Exterior envelope repairs
5 FEB 2020AUG 2021
Exterior envelope repairs
AUG 2021APRIL 2022
Exterior envelope repairs
AUG 2021DEC 2023
Interior plaster and stone repair
Decorative painting
Life safety upgrades
Accessibility and Congregation
Experience Improvments
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