Update on crypt restoration works

September 2020 update

The Crypt of St. Agnes
Short resumé of the work done
from March 2017 to August 2020

Final report on Santa Agnese in Agone’s Crypt restoration

August 2020 update


The restoration of the chapel of the martyrdom of Saint Agnes

A stone’s throw from the entrance of the Crypt, on the left, the marble altar representing the martyrdom of St. Agnes, lies framed by two marvellous frescoes in early Christian style, representing the Virgin with Child and St. Cecilia, and a masterfully frescoed ceiling with a Tetramorph in blue and gold.
Both the ceiling and the frescoes on the walls are seriously attacked by humidity and time and require immediate conservative restoration. In particular, the fresco depicting the Virgin and Child is in a truly critical condition and we must intervene before the irreparable happens and a masterpiece of nineteenth-century wall art is lost.

It is not easy to find financiers eager to save a work of art. Do you want to “adopt a fresco” by financing the restoration of a wall? Contact us at info@santagneseinagone.org !

Otherwise any extra help will help us to restore the Crypt, the place of the martyrdom of Saint Agnes!

Donations can be made using the links in this website or by bank transfer:


  • Chiesa Sant’Agnese in Agone – Piazza Navona
  • IBAN:           IT76 H030 6905 0201 0000 0060 870
  • BANK:     Intesa San Paolo

Thank you!!

July 2020 update

The restoration of the frescoes in the crypt continues successfully.

Video Player

Video Player

Video Player


June 2020 update

Restoration work on the frescoes has begun.

January 2020 update

Experimentation to control and stabilize the environmental parameters of temperature and humidity in the largest environment in the Crypt has been going on for a year.

Currently the temperature is stable at about 15-16°C while humidity is falling to about 65-70% (RH). As an example we report the graph of the relative humidity of the last months in which the trend of the values of humidity that tends to fall:

Following these positive results, the Superintendence of the Ministry for Cultural Heritage (MIBACT) was contacted to verify the state of the crypt environments in the area where the plants being tested are active.

Arch. Pesoli of MIBACT has therefore noted the actual reduction in humidity and temperature stability, confirming that, at first glance, the walls and paint surfaces are much drier. It was therefore suggested, under these conditions, to carry out a restoration on a portion of the surface in the experimental area. She identified herself once in the central area of the test area.

By the month of January, restoration work will begin on this portion of the crypt. If it is successful, the restoration will be completed in the largest part of the crypt, experimenting with the systems as they are considered suitable to guarantee the thermo-hygrometric conditions necessary for the restoration and maintenance of the painted surfaces.

We will then move on to reclaim and restore the smaller but at the same time more valuable environments because they are the very place where the martyrdom of the young St. Agnes took place.

In January, in order to confirm the reduction of water in the masonry and therefore on the painted surfaces and to allow the partial restoration, the CNR IREA carried out measurements with the georadar in the areas of the Crypt already analyzed before the experimentation. The aim is to show the effective reduction of water in the masonry thanks not only to the air conditioning and environmental remediation system but also to the system that avoids the capillary rising of the water.

Below are some images of the surveys carried out:

As soon as the results of the measurements and the first images of the partial restoration are available, they will be published on this web page to update all benefactors and faithful interested in the progress of the restoration of the Crypt.



29 July 2019

Restoration Activities – Summary


The activity for the restoration of the Crypt of Santa Agnese in Agone began with a historical and scientifical research aimed to evaluate its conservation status. The Crypt of Sant’Agnese in Agone is located in Piazza Navona, in the historic center of Rome, where since the 1st century A.D. the Stadium of Domitian was located. The Crypt is the only surviving part of the primitive church built on one of the fornices of the Stadium, right on the site of the martyrdom of the thirteen year old girl Agnese, which took place in 305 A.D. The Crypt is currently closed to tourists because, after its last renovation in 1893, it was subject to natural catastrophic events (floods of the Tiber river, intense rains, etc.) that ruined the ancient frescoes on the walls and ceiling.

The Crypt is located at 12 meters above sea level, while the ground floor of Piazza Navona is 15 meters above sea level. The aquifer is located between 8 and 10 meters above sea level. Furthermore, under Piazza Navona, an ancient network of water drainage channels was identified at 13 meters above sea level.


This information allows us to state that the presence of water is due to:

  • Adsorption from the internal environment;
  • The capillary rise of water from underground;
  • The descent of water (due to rain).

Radar analysis were performed on different surfaces of the Crypt in order to determine the presence of water. As shown in the following images, the presence of water up to a height of 50 cm from the floor is evident. This is due precisely to capillary rising phenomena.
The chemical and morphological analyzes showed the presence of calcium sulphate on the frescoes that led to exfoliation, efflorescence and detachment of frescoes from the plaster.
Given these results, the planned interventions are:

  • Promote ventilation;
  • Limit access to rainwater;
  • Check the humidity and temperature;
  • Sanitizing indoor air.

The following systems are used to manage and control the climate in the Crypt:

  • Air conditioning systems located near existing openings.
  • CNT (Charge Neutralization Technology) systems for neutralizing the electric charge of water on the floor in contact with the walls (to avoid capillary rising).
  • Environmental sanitization systems based on the use of a cold plasma to break down volatile organic compounds (VOC), atmospheric particulate and many varieties of viruses, bacteria, molds and fungi that could further damage the frescoes.

The operation of these systems will provide a favorable environment for the conservation of the frescoes so that we can proceed following the consolidation phase and a careful restoration of the pictorial surfaces. The sanitation and environmental remediation activity follows the flow shown in the following diagram:


At the beginning of October 2018 in the largest room of the Crypt the first plant was installed to start the first experiment in order to evaluate the effectiveness and efficiency of sanitizing and reclamation (see image on the left). It is assumed that at the end of 2019 good results will be achieved. Together with this plant, a neutralization system of the electrolytic charge of the water was also installed to avoid the effect of the capillarity of the water coming from the subsoil (see the side image: rising water).

October 31, 2018

On October 31, 2018, the first experimentation of the “Great” plant for environmental rehabilitation was officially opened within the Crypt of the Church of S. Agnese in Agone.

The system was optimized by the RIELCO staff, as follows:

  • H24 thermo-hygrometric machine working
  • 25% operating regime
  • plasma treatment performed from 8:00 to 20:00
  • Air recirculation at night from 8.00pm to 8.00am
  • Always present dehumidification
  • Air renewal only during the day.

Finally, the sensors for monitoring the temperature and relative humidity have been configured and set up appropriately and the CNT system has been installed to avoid the capillary rise of water.

Once these activities were completed, the door of the Crypt was closed and the seals were applied in the presence of CNR-IREA, CNR-IMC, RIELCO, MIBACT and of the Rector of Santa Agnese.

The CNR will carry out periodic control analyzes to evaluate the actual functioning of the machinery, and to optimize it in relation to the results of the analyzes, in agreement with the MIBACT (Ministry for Cultural Assets and Activities).

Chronological analysis of the activities carried out for the environmental rehabilitation of the Crypt of S. Agnese in Agone in Rome

Edited by Ing. Luca Mazzola

2003 technical report – thermohygrometric analysis (May-October 2002 period) by Eng. Romanelli, Arch. Bianchi and Dr Corsi. (Acquired by the Rector) Targets:

  • Identify the relationship between internal microclimate and the external climate through the rotation of the seasons
  • Measure the moisture content of the masonry
  • Evaluate if there are thermohygrometric exchanges between environment and walls.

March 2017 – Start on the recommendation of the Rector S. Ecc. Rev. Mons. Paolo Schiavon of the Technical-Scientific-Pastoral Commission for the Restoration of the crypt of S. Agnese in Agone.

From April to June 2017 – activity of historical and technical-scientific analysis of the Crypt and intervention solutions:

  • Historical analysis of the Crypt
  • Study of the floods of the Tiber and their impact on the state of the Crypt
  • Analysis of the geological and hydrogeological aspects of the subsoil
  • Georadar measurements for estimating the water present inside the walls and in surfaces.
  • Micro Micro-chemical and micromorphological investigations on plasters and pictorial layers (SEM, EDS, TGA, XRD, DTA, FTIR)
  • Analysis of masonry materials
  • Conclusions and suggestion of how to proceed with the rehabilitation and environmental conditioning of the crypt before proceeding to the restoration of the frescoes on the indication of scientific results.

June 2017 – Meeting of the Restoration Commission for the presentation of the activities carried out and for the unanimous decision to proceed with the environmental rehabilitation of the Crypt as a priority.

From July to October 2017 – Identification of the requisites required for environmental rehabilitation (confirmed by the Arch Gabriella Marchetti, the Arch. Barsottini (MIBACT) by the Architect Strinati (member and expert of the Restoration Commission) and requested from three potential suppliers technological solutions, timing and costs.

October 2017 – Meeting of the Restoration Commission for the decision to entrust the environmental rehabilitation of the Crypt to Rielco Impianti srl. To protect the Rectory Church of S. Agnese, the CNR (as technical manager of the Rector) will follow from the scientific point of view, the environmental rehabilitation activity of Rielco. The CNR has suggested a two-year experimentation plan to verify the two plants installed in a scientific and rigorous manner, according to established methodologies of investigation in the field of scientific research.

November 2017 in July 2018 – Drafting and stipulation of contracts between Rettoria Chiesa di S. Agnese in Agone and:

  • Rielco Impianti srl

September 2018 – Installation of the Grande facility in the largest area of ​​the Crypt.

October 2018 – Start of experimentation.


September 4th, 2018

The activities for the renovation and restoration of the Crypt of Santa Agnese in Agone, during this first 9 months of 2018, has had as object a careful and detailed legal analysis, which led to the stipulation of 4 contracts: one with Rielco Impianti Co. Ltd., which will provide the implants for the environmental rehabilitation of the Crypt’s spaces, and another two contracts with two different institutes of CNR (National Research Council) which will have to verify both the efficiency of those plants and the fulfilment of their performance conditions. The last contract has been stipulated with the Engineer whom will provide to coordinate the Security in course of performance.

This activity was led with the assistance of Luigi Maniscalco, lawyer (Lucente International Lawyers), whom – together with engineer Luca Mazzola, for the technical part – is taking care of the interests and the contractual position of the Rectory of Santa Agnese in Agone.

This delicate step of drawing-up and analysis of contracts, is finished at the end of July with the stipulation of the contract necessary to rule the contractual relationship between the parts. During the first half of September the rehabilitation plants have been installed, to the presence of the representatives of CNR’s institutes and of the representatives of Superintendence of Arts. All the operations have the objective of guarantee the environmental rehabilitation of Crypt’s spaces, in order to protect it as an asset of cultural and historical interest.


(started in September 2018)

Schedule of the operations
(click on this link for the pdf file)


  • Installation of the first implant in the big area by Rielco.
  • Verification of the performance indexes (of environment and walls) before the CNR’s experimentation.


  • Start up of the implant.
  • Verification of the performance indexes (of environment and walls) during and after the CNR’s experimentation.
  • Test of the big area’s implant.


  • Installation of the implant in the two little areas by Rielco.


  • Start up of the Implant.
  • Verification of the performance indexes (of environment and walls) during and after the CNR’s experimentation
  • Test of the little areas’s implant.


  • Definitive putting into service of the implants.
  • Start up of the visits into the rehabilitated Crypt in line with the established visitation protocol.

Meeting of the working committee for restoration
of the crypt of Sant’Agnese in Agone:
current actions and progress report”

16 October 2017


  • Selection of a company for air conditioning and correction of environmental conditions;
  • Report from National Research Council on analyses of the walls and on preliminary tests concerning choice of new air conditioning systems;
  • Time plan for preliminary tests of air conditioning systems in one or two parts of the crypt, followed by installation in the entire crypt;
  • Progress report on virtual tour and rendering of the crypt;
  • Functional and cost analysis of ‘touch-screen totems’;
  • Publication of activities;
  • Identification of funding and donation sources.

“Second meeting of the Technical-Scientific-Pastoral Committee
for the Restoration of the Crypt of Sant’Agnese in Agone”

19 June 2017

Results from the first research stage – Luca Mazzola, Engineer, reporting:

The analyses conducted demonstrate that a range of interrelated causes are responsible for the ongoing deterioration of the crypt. Among these are:

  1. Current positioning and configuration of ventilation openings;
  2. The historic system for rainwater collection and drainage;
  3. High humidity levels, accompanied by surface condensation;
  4. Insufficient ventilation for the entire complex.

Given that any attempts to reduce the problems by direct action on the wall structures (e.g. insulation, isolation from moisture sources) would be extremely difficult and costly, the more reasonable solution is to find systems for management of the crypt climatic conditions. Engineer Mazzola advises non-invasive systems of micro-climate monitoring and management, applying the latest technologies for air conditioning and purification. Such developments would include:

  1. Air conditioners, installed near the existing openings, for ventilation and heat exchange;
  2. Dehumidifiers, for reduction of absolute humidity and moisture in the wall structures;
  3. Charge neutralisation technology (CNT) systems, to neutralise ionic charges in water sources at the base of the rising damp, thus interrupting capillary action;
  4. Air purification systemsusing cold atmospheric plasma, i.e. generation of plasma for reduction of organic volatile compounds, atmospheric particulates, viruses, bacteria, mould, fungi.

Engineer Mazzola reported that the analytical and feasibility studies had thus far been provided without charge by the EMASST, in their role as major sponsor for restoration and renewed use of the crypt of Saint Agnes.


Click below for the full research report on the crypt project:

First meeting of the Technical-Scientific-Pastoral Committee
for the Restoration of the Crypt of Sant’Agnese in Agone

14 March 2017

Proposal for first research stage.

Engineer Luca Mazzola reporting

Proposed actions:

Elemental analysis

Using mass spectrometry (destructive-type analysis) – identifies presence of elements and mass/charge relations;

XRF (x-ray fluorescence) (non-destructive) – uses high-energy gamma and x-ray irradiation for identification of types and quantities of atoms, which serves for further identification of moulds, bacteria, etc. (does not provide information on how the atoms are bound, i.e. information on molecular or crystalline structures).


Molecular analysis

Using Raman spectroscopy (non-destructive) and EDX (destructive analysis) for molecular identification; both techniques use electromagnetic radiation, which interacts with the electrons of the molecules ‒ analysis of the resulting diffusion patterns permits identification of molecules and crystalline structures;

Objective: identification of pigments compatible with the original materials of fresco execution.


Surface analysis

Using optical and electron (SEM, TEM – destructive) microscopy and THz radar techniques (non-destructive technique)

Objectives: Identification and mapping of surface properties, current condition, degradation phenomena (cracks, material degradation, moulds, etc.);

Analysis of subsurface damage (within the depth of the fresco structures) and between the fresco and wall structures.


Expected results

  • Report on the original painting materials and methods, including dating and authentication;
  • Report on the current state of conservation/degradation;
  • Identification of any prior restoration works;
  • Recommendation of possible bio-cleaning methods and improvements for visibility of the artworks;

Recommendation of multifunctional nano-materials for use as protectants and consolidants.