A trullo (plural, trulli) is a traditional Apulian dry stone hut with a conical roof. Their style of construction is specific to the Itria Valley, in the Murge area of the Italian region of Apulia. Trulli were generally constructed as temporary field shelters and storehouses or as permanent dwellings by small proprietors or agricultural labourers. Their golden age was the 19th century.
From the casedda to the trullo 
The Italian term il trullo (from the Greek word τρούλος, cupola) refers to a house whose internal space is covered by a dry stone corbelled or keystone vault. Trullo is an italianized form of the dialectal term truddu used in a specific area of the Salentine peninsula (i.e. Lizzaio, Maruggio and Avetrana, in other words outside the Murgia dei Trulli proper) where it is the name of the local agricultural dry stone hut. Trullo has replaced the local term casedda (pl. casedde) (Italian casella, pl. caselle) which was used by locals in the Murgia to call this type of house.
A stonemason specializing in the building of trulli is a trullisto or trullaro in Italian. The corresponding dialectal term is caseddaro (caseddari in the plural), i.e. builder of casedde.
The style of construction is specific to the Itria Valley, in the Murge area of the Italian region of Apulia. Trulli may be found in and out of Alberobello, and in the areas around Locorotondo, Fasano, Ostuni, Cisternino, Martina Franca and Ceglie Messapica.
The Murgia is a karst plateau. Winter rains drain through the soil into fissures in the strata of limestone bedrock, and flow through underground watercourses into the Adriatic. There is no permanent surface water, and water for living purposes must be trapped in catchment basins and cisterns. The surface forms a landscape of rolling hills and ridges punctuated now and again with dolines and other forms of enclosed depressions characteristic of karsts.
The trullo is essentially a rural building type. With its thick walls and its inability to form multi-story structures, it is wasteful of ground space and consequently ill-suited to high density settlement. However, being constructed of small stones, it has a flexibility and adaptability of form which are most helpful in tight urban situations.
In the countryside, trullo domes were built singly or in groups of up to five, or sometimes in large farmyard clusters of a dozen or two dozen, but never for the occupancy of more than a single rural family.
Depending on the area, the building material used could be either hard limestone or calcareous tufa.
Traditionally trulli were built using dry stone masonry, i.e. without any mortar or cement. This style of construction is also prevalent in the surrounding countryside where most of the fields are separated by dry-stone walls.
In Alberobello, the structural walls of a trullo are laid directly on the bedrock, after removal of the topsoil when necessary. Their width varies from 0.80 metres to 2.70 metres (a measure recorded in the Trullo Sovrano). Their height (from ground level to where the vault starts) ranges from 1.60 metres to 2 metres. Their exterior facing has a 3 to 5% batter.
Underground cistern 
The stones needed for starting to build a trullo were provided by digging a cistern (cisterna), an absolute necessity in an area devoid of water. The cistern was capped with a lime-mortared barrel vault or dome which in many cases supported the floor of the house.
The trullo may take on a circular or a square plan. The circular trullo is mostly a temporary shelter for animals and their fodder, or for the peasant himself.
The trullo that is part of a grouping of three, four or five follows a squarish plan. It may serve as a kitchen, bedroom, animal shelter, store room for food or tools, oven, cistern as the case may be.
In Alberobello, groupings did not exceed two trulli as evidenced by 19th-century notarial deeds.
The roofs are constructed in two skins: an inner skin of limestone voussoirs, capped by a closing stone, and an outer skin of limestone slabs that are slightly tilted outwardly, ensuring that the structure is watertight. The roof stones can be taken away without compromising the stability of the rest.
In Alberobello atop a trullo's cone there is normally a hand-worked sandstone pinnacle (pinnacolo), that may be one of many designs - disk, ball, cone, bowl, polyhedron, or a combination thereof, and is supposed to be the signature of the stonemason who built the trullo.
Whitewashed symbols 
Additionally, the cone itself may have a symbol painted on it (as shown in the picture of the trulli in Alberobello.) Such symbols may include Christian symbols such as a simple cross, a cross on a heart pierced by an arrow (representing Santa Maria Addolorata, i.e. Our Lady of Sorrows), a circle divided into four quarters with the letters S,C,S,D in them (for Sanctus Christus and Sanctus Dominus according to one source, but more likely the initials of Santo Cosma and Santo Damiano, the two saints the local basilica is dedicated to) and quite a few others.
The symbols now visible on a row of trulli in via Monte Pertica (cross, pierced heart, host with rays radiating from it, tree, dove symbolising the Holy Spirit, crescent with a cross) were painted only in the late 20th century and the early 2000s when the roof cones were redone.
The quaint symbols which grace the trullo-like cones of bungalows at the Hotel dei Trulli in Alberobello first appeared in the late 1950s, when the hotel resort was built.
The vast majority of trulli have one room under each conical roof, with additional living spaces in arched alcoves. Children would sleep in alcoves made in the wall with curtains hung in front.
A multiroomed trullo house has many cones representing a room each.
Along with its exterior wall, a trullo's interior room and vault intrados were often rendered with lime plaster and whitewashed for protection against drafts.
The trulli used as dwellings all have an open fireplace complete with a flue (hidden in the masonry) and a stone-built chimney stack (rising high above the roof). Because of their design, trulli are difficult to heat: the walls are too thick and warm air will rise up the interior cone. An alternative heating solution was to use a central brasero with embers in it (a specimen can be seen in Alberobello's Museo del Territorio).
The thick stone walls and dome of the trullo, pleasantly cool in the summer, tend to become unpleasantly cold during the winter months, condensing the moisture given off by cooking and breathing and making it difficult to feel warm even in front of the fire. The inhabitants simply leave the doors open open during the day to keep the interior dry, and live more outdoors than in.
In trulli that were used as stables, the troughs the animals fed from can still be seen.
Owing to the concentration of houses, trulli have few openings outside their doorway and a small aperture provided in the roof cone for ventlation. As a result, it can be quite dark inside.
Some trullo houses have had their perimeter walls substantially raised so that their cones can be hidden from view, making the buildings look like ordinary houses.
A number of conical roofs have a truncated top with a round hole in it covered by a movable circular slab. Access to the hole is by an outside stairway built into the roof. These trulli were for grain, hay or straw storage.
There are many theories behind the origin of the design. One of the more popular theories is that due to high taxation on property the people of Puglia created dry wall constructions so that they could be dismantled when inspectors were in the area.
In available historical records from the mid-14th century to the late 16th century, the area of Alberobello is referred to mostly as a selva (i.e. "forest") and occasionally as a land from which grazing animals were excluded. Evidence is lacking as to the existence of dwellings in the area prior to the 17th century.
A Plan of the Territory of Mottala drawn by Donato Gallerano in 1704 reveals the existence of a nucleus of trulli in the midst of a large wood, making up the initial settlement of Arbore bello.
In a geographical map drawn by Giovanni Antonio Rizzi Zannoni in 1808, one can see the selva of Alberobello and, in the midst of it, a clearing with a settlement of scattered houses that bears a striking resemblance to the present-day urban pattern.
In an 1897 photograph of the rione Monti (the district of the Mounts), the trulli are far less densely packed than today, being surrounded by enclosed gardens.
The urban trulli still extant in Alberobello today date from the 18th, 19th and 20th centuries. After having undergone a process of densification in the first decades of the 20th century, the trulli settlements started being deserted in the second half of the 20th century.
The rural trulli, on cheaper land, ceased to be built when the cost of labour began to rise in the twentieth century. The sheer expense of handling the hundreds of tons necessary for a single house became prohibitive.
Trulli as tourist attraction 
Today the surviving trulli are popular among English and German tourists and are often bought and restored for general use. However, anyone wishing to restore a trullo needs to conform with many regulations as trulli are protected under the United Nations Educational, Scientific and Cultural Organization (UNESCO) world heritage law.
Since the beginning of the century, a large number of trullo houses have been restored and converted into second homes or self-catering cottages. In 1999, rebuilding a trullo roof would cost about 3 million liras (about 1,500 euros), in 2009 the cost rose up to 15,000 euros.
In late twentieth century, the Monti district in Alberobello was largely a derelict area when a local crafstsman, Guido Antionetta, came up with the idea of buying up a few dozen abandoned trulli, installed in them modern kitchenettes, a few pieces of wooden furniture and cast-iron bedframes with a view to renting them out as mini apartments for the night for less than rooms cost at local hotels. He even painted good luck symbols on the roof of each trullo.
In the Alberobello region, local residents who still live in trulli only do so because they cannot afford to move out or because they provide bed and board for tourists in their trulli.
See also 
Notes and references 
- Benito Spano, La Murgia dei trulli, chapter VII of La casa rurale nella Puglia, 1970, p. 184, note 2.
- Vocabulaire italien-français de l'architecture rurale en pierre sèche, in L'architecture rurale, CERAR, Paris, 1979.
- Anthony H. Galt, Far from the Church Bells: Settlement and Society in an Apulian Town, Cambridge University Press, Cambridge, 1991, xiii + 276 p., p. 19.
- Edward Allen, "Stone shelters", the MIT, 1969, third printing 1974, 210 p., p. 84.
- Edward Allen, "Stone shelters", op. cit., p. 84.
- I pinnacoli, trullinet.com : "Lo spessore dei muri dei nostri Trulli va da un minimo di 80 cm. fino ai 270 cm del TRULLO SOVRANO."
- Edward Allen, "Stone shelters", p. 80 : "If a cistern had been dug, it was capped with a lime-mortared barrel vault or dome which in many cases supported the floor of the house."
- Desplanques Henri, Deux études sur la maison rurale dans le Mezzogiorno : C. Colamonico, O. Baldacci, A. Bissanti, L. Ranieri, B. Spano, La Casa rurale nella Puglia, et M. Cataudella, La Casa rurale nel Molise, in Annales de géographie, année 1972, vol. 81, n° 446, p. 473-475.
- Angelo Ambrosi, Raffaele Panella, Giuseppe Radicchio, a cura di Enrico Degano, Storia e Destino dei Trulli di Alberobello - Prontuario per il restauro, Schena Editore, 1997, pp. 65-66.
- I PINNACOLI: Principalmente sono scolpiti in pietra e rappresentano la FIRMA del Mastro trullaro che li ha edificati e che molto spesso coincideva con l'appartenenza della famiglia.
- See "The trulli or casedde of Alberobello, province of Bari, Italy, through old postcards and photos: The changing face of via Monte Pertica in the Monti district (1950-2010)," pierreseche.com, January 20th, 2011.
- See "Les trulli ou casedde d'Alberobello (province de Bari, Italie) à travers les cartes postales et photos anciennes: l'hôtel des trulli," pierreseche.com, July 1st 2011.
- Edward Allen, op. cit., p. 82.
- Edward Allen, op. cit., p. 81-82.
- The Trulli of Puglia, lifeinitaly.com.
- Paula Hardy, Abigail Hole, Olivia Pozzan, Puglia & Basilicata", Lonely Planet, 2008, 248 p., p. 124 : "However, (...) due to the compact nature of the Rione the trulli have few windows and can be quite dark."
- Edward Allen, "Stone shelters", op. cit., fig. 16 & pages 110-111.
- Angelo Ambrosi, Raffaele Panella, Giuseppe Radicchio, a cura di Enrico Degano, Storia e Destino dei Trulli di Alberobello - Prontuario per il restauro, Schena Editore, 1997, p. 12 : ci sembra opportuno osservare che nessuna testimonianza precedente al sec. XVI suggerisce la presenza nel luogo della 'silva de Arbore bello' di un insediaménto umano [in Italian, sec. XVI refers to the century starting in 1600].
- Angelo Ambrosi et al., op. cit., p. 12.
- Angelo Ambrosi et al., op. cit., p. 12.
- Luigi Mongiello, Genesi di un fenomeno urbano, Quaderni dell'Istituto di disegno, Facoltà di Ingegneria - Università di Bari, 1978, 109 p., p. 81: Il Bertacchi ha publicato nel 1897 una fotografia del rione "Monti" sulla quale è possibile effetuare alcune constatazioni. Le costruzioni a trullo, oggeto della ripresa fotografica, esistono ancora, immutate, ma non sono più contornate dagli spazi recintati e coltivati ad orto, inoltre, il nucleo abitato non presenta la saturazione attuale.
- Dans les Pouilles, la folie des « trulli » fait revivre un patrimoine UNESCO, lepoint.fr, 28-5-2009.
- The Land of Point & The White City, reidsguides.com.
- Trulli House, heelitay.it: "The only reasons people still live in them is that they are too poor to move out, or that they entertain tourists as hosts of a trulli B&B."
|Wikimedia Commons has media related to: Trulli|
- Main characteristics of a trullo
- The trullo and its history
- Entry for "The Trulli of Alberobello" on the UNESCO World Heritage Website
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- History and construction techniques of Apulian trulli
- holidays in Puglia
- Trulli & Alberobello English Video
- Il trullo