The project addressed the following specific issues:
Maintenance of the retaining wall. The retaining wall of variable height from 4 to 3 m, made of natural stone and partially plastered, was in poorly stable conditions. The existing wall was demolished and rebuilt in a length of 35 m, the new wall with structural functions is built in reinforced concrete and later covered with stones from the dismantling of the pre-existing wall. The final form reproduces exactly that of the original wall.

The tiles that cover the upper part of the wall (covered with stone) have great historical value, since some of them have rock art engravings (cupels). The original covers of the wall were numbered, dismantled, preserved and later replaced in their original position and sequence. The perimeter of the square was delimited by 8 tall trees. The trees were transplanted during the work and replanted at the end of the work.

Paving and channeling of rainwater. The original clay pavement has been removed and a new one made of Saltrio stone has been laid. The proposed pavement allows preserving the unitary and material aspects of the square. The 10 x 10 cm stone cubes were placed in parallel rows, following the direction of the steps of the church patio. The new pavement is waterproof and is grouted with cement mortar.

Rainwater is collected through a system of grids placed at the entrance to the plaza and then introduced into a channel dedicated to a mechanical pre-purification system (2 oil separators and 2 sand traps); once treated, the water is channeled and reintroduced into a natural receptor.

Furniture. A fountain was placed near the pedestrian staircase next to the churchyard. The fountain was made with an ancient block of Arzo marble, the water comes out of a brass faucet, recovered from the old fountain, and is screwed to a brass spout, supported by an IPE 100 natural oxidized steel profile. stone seats have been placed in the fountain, made up of large blocks of stone from Moltrasio, recovered from the excavated material from the square. The same type of seats was used at the entrance. Some of the boulders were also used for the construction of the stair steps under the retaining wall.

Text provided by the architect.

The project was started by the Patriziato di Arzo who commissioned an initial study on the potential of the area in 2012. From the very start the project was supported by ERS-MB (Ente Regionale Sviluppo Mendrisiotto e Basso Ceresio, the Regional Development Institute for the Mendrisiotto and Basso Ceresio districts), and was able to count on the patronage of the Mendrisiotto Turismo (Mendrisiotto Tourism Board) and Fondazione Monte San Giorgio (Monte San Giorgio Foundation).

The project for the redevelopment of the area and for the re-use of the buildings focussed on three areas: the educational trail (a path that leads to the ancient quarries in the wood above), the natural amphitheatre (a project for the reuse and promotion of the great disused Cava Caldelari approximately 4,500 square metres of rich natural diversity; the quarry workshop (the conversion of the ancient sheds where marble was processed into workshops and exhibition spaces).

The Educational Trail – Above the current marble quarry there are a number of old, now disused quarries. The project entails organising and marking a pedestrian route (an educational trail) to the disused caves revealing the different quarrying techniques (chisel, helical wire) and the various types of stone that were exctracted (red Macchiavecchia, Rosso Arzo, Broccatello). At the start of the trail a new building houses the public conveniences. The concrete slab is made from inert materials specially obtained by crushing marble, and the surface has been polished to reveal them. The building that houses the public conveniences is entirely built from marble blocks and its translucent canopy is supported by HEB steel beams. The doors are made from oxidised metal grills. The structure is lit from above and naturally ventilated from the open band between the roof and walls. The washbasin was made from an ancient hand-quarried block of marble. The walls were built from blocks of marble with different surfaces and finishes.

The Natural Amphitheatre – The former Cava Caldelari is an area of great significance in terms of geology and paleontology, as well as for its flora and fauna. The project known as “Natural Amphitheatre” has been developed in collaboration with the environmental engineering firm Oikos 2000 and involves the organisation of spaces to make them accessible while preserving particularly significant natural environments, by creating specific biotopes that capitalise on the natural features of the site. The project has cleared an area that was cluttered with quarrying detritus, now replace by four rows of seats made from marble blocks, arranged in a semi-circle. The steps can be used as seating and allow the staging of public events.A timber walkway was built in locally sourced black locust wood to extend the footpath across the marshland area along the quarry face. The trail leads to an area characterised by some imposing reinforced concrete walls (the base of the old crushing plant) which have been made safe by the addition of a railing made from rebars.

This area – know as the baluardo panoramico (the belvedere) overlooks the quarry and has been fited with three tables made of marble slabs. A stair made from timber and marble connects the trail to another footpath above it. Two new biotopes were also ceated:a small pond where rainwater from the area is collected and a biotope for small animals – a mound of piled marble blocks that recreates the habitat that has been removed to build the seating.

The Quarry Workshop – The quarry workshop project reuses and upgrades the ancient buildings of the original production facility, which consists of two discrete volumes: the main building (known as the marble shed) and a secondary building that organises access and circulation.

The elevation of the main building faces on to the cantonal road and is entirely built from marble blocks. This unique feature is highlighted by a new roof cover that emphasises the material and construction technique. The new roof has no drainage gutter and is set back from the plane of the facade, so that rainfall drips onto the marble blocks, enhancing their colour. The openings in the original facade (a door and three windows) were sealed with marble slabs to give the elevation material uniformity: the facade appears as a single large block of marble in which the traces of the original facade are etched. The old roof cover has been replaced. However, the unique, original timber truss of the marble shed has been retained. To ensure the static safety of the roof, the ancient truss is now flanked by two new steel trusses. The main volume of the building that organises circulation has been covered with a new roof, clad in marble slabs.

All other volumes are covered with corrugated transparent polycarbonate panels which allow spaces to be lit zenithally. New public conveniences were built with floors made by alternating strips of Arzo marble, grey Macchiavecchia and Alp green marble; the washbasin was carved from an ancient block of Arzo red marble extracted manually, with a chisel.The two original steel doors were restored and reused, as were two ancient wooden doors inside the building. The workshop spaces have been retained, and the original machinery for handling stone has been restored. Inside the ‘marble barracks’ an ancient Hatz diesel engine from 1925 operates a flywheel which in turn activates a helical wire. The wire is connected to the outside by a system of upright base supports and flywheels, and is used to demonstrate the technique for cutting marble with a helical wire.
Text provided by the architect.

On the inside, structural consolidation work was carried out: in the basement, new walls were built and a new reinforced concrete slab (10 cm thick) was cast inside the original masonry; on the upper floors, the existing slab was replaced with a new one in reinforced concrete and metal beams, the surface of which was sown with porphyry aggregates from Cuasso al Monte and limestone from Moltrasio (Sasso di Caprino) and then smoothed.

The back wall of the original building was removed to gain space for the construction of the exposed concrete staircase, thus adding more rock surface to the interior of the building. Two new reinforced concrete walls and a new reinforced concrete slab were then built, which in addition to covering the new connection further consolidated the original building by connecting it entirely to the rock behind.

In the basement a bathroom was introduced which is separated from the corridor by a 3.5 cm thick curved concrete wall, on the upper floor the door connecting to the outside was changed into a window facing south and the existing roof was replaced. Everything else was left in its existing state or restored.

Externally, the façade of the building, which was also damaged, was restored, bringing back the original pictorial decorations and a new terrace was added to the existing one. The surface of both terraces was paved with re-used stones (Porfido di Cuasso al Monte, Sasso di Caprino, granite slabs and strips of white marble obtained from the re-use of ancient slabs with the names of the streets of the city of Lugano).

The original parapets have been maintained and modified to comply with the law; the new ones, also internally, are in rough oxidised iron.

Text provided by the architect.