Year: 2018 — 2020

Location: Saint Petersburg, Bolshoy Prospekt V.O., 100

Client: StroyTechProekt (general designer)

Scientific advisor: honored architect of Russian Federation A.N. Obolensky

Chief architect/restorer: A.S. Antipova

Chief engineer/constructor: V.V. Pavlinov

Area: 1 370 sq.m.

Status: Under construction / Concept + Project Documentation + Working Documentation + Supervision

AB A4 team: Sergey Markov, Aleksey Afonichkin, Anastasia Medvedeva, Ksenia Maximova, Andrey Nekrasov.

With participation of: Sergey Kanterin, Ekaterina Nikolaeva

The Church of Our Lady the Merciful is situated in the west part of Vasilyevsky Island of St. Petersburg and is historically connected to the Galley Harbor. The church’s construction started in 1889 and consecration took place in 1898.


The project of the church was developed by an outstanding architect, civil engineer V.A. Kosyakov (who also created Kronstadt Naval Cathedral) along with D.K. Prussak; the church’s design was developed in character Neo-Byzantine style with elements of Modern in the interiors. The church of height of 42 meters became the district’s dominant. Around the church a square park was arranged, a metal fence on granite base was set along the Bolshoy Prospect (demolished). Maximum capacity of the historical church was of 1800 parishioners.

G.V. Baranovsky. Architectural encyclopedia of the second half of the XIX century.

Confession architecture. – SPb: editorial office of “Stroyitel’”, 1902 


In 1932 the building of the church was shut and passed onto the order of the scuba diving detachment at Galley Harbor. At that time the parish was adapted to a test chamber, equipped in the church: resque divers were training in the building – the church was partially serving the navy once again. The pressure chamber for diving under the dome with the pipe leading to it were unique for their time and became first in the USSR.



Vasily Antonovich Kosyakov was born in June 1862 in a family of modest wealth. On account of his hard work, persistence and artistic talent, he successfully graduated from Saint Petersburg State University of Architecture and Civil Engineering in 1885. The creative path of V.A. Kosyakov began in his years of institute with buildings in Brest. The major works of the master are created in tradition of Byzantine and Russian styles. The first individually built project of the architect is the Church of Our Lady the Merciful (construction started in 1889). The Kronstadt Naval Cathedral (1902-1913), conceived and implemented as a temple-monument to the heroes of the Russian navy, is considered the most distinguishing project of Vasily Kosyakov.

On December 19, 2012, the Russian Defence Ministry handed the church over to the Russian Orthodox Church. Finalazation of scientific and design documentation for preservation of cultural heritage in 2018-2019 was being carried out considering the data obtained in 2015 by design organization “Gorod” LLC.


A4 Bureau developed the adaptation project of architectural (facade and interior) solutions, along with the masterplan of the church’s terrirory.


Historically, the basement of the church housed stoves and heating ducts; they were dismantled in 1932 in the process of equipping the mentioned training station.


The adaptation project involved establishing a lower baptistery with a font in the basement. Setting up a lower baptistery is a common fashion for reconstructed orthodox churches. On the basement floor there are also recreational rooms and engineering/technological premises for comfortable and modern operation of the church.

Iconostasis details

Artist Ekaterina Nikolaeva



The pattern of the basement floor is typical for V.A. Kosyakov’s works. The restored pattern is based on archival drawings (sketches) of the floor of the upper church and includes details similar to Art Nouveau style.


Lower church is initially intended for the baptism sacred ceremony. For this aim the prayer hall is equipped with a stationary font for adults and a portable font for infants.


The stationary font is of a traditional shape: its sides raise above the lower church’s floor surface while the steps descend along the central handrail-axis. The font is richly decorated with natural Jerusalem stone, marble and smalt. Fencing of the font is made of patinated brass with a character lattice pattern.

The general space-planning solution of the basement was affected by foundations of the four bearing pillows of the church and the architecture of the historical vaults (existing and reconstructed) of the basement floor. The reconstructed iconostasis of the lower church echoes with the iconostasis of the upper church, made in the archeological Byzantine style with chromatic natural stone and incrustation applied.

The vaults’ and partly the walls’ surfaces are designed prepared for further artistic painting. The work on the project was being developed under scientific guidance of the famous architect specializing in Orthodox church architecture - A.N. Obolensky, and together with invited architects and artists of religious structures.