PHOTOGRAMMETRY AND SURVEY PROCEDURES FOR THE ANALYSIS OF VENETIAN VILLAS:
THE CASE STUDY OF VILLA ZENO BY ANDREA PALLADIO
Clemente di Thiene - Francesco Guerra - Luigi Fregonese - Luca Pilot - Caterina Balletti
CIRCE, Istituto Universitario di Architettura, Venezia, Italy
Commission V, Working Group 4
KEY WORDS: K007 Architecture, K061 Design, K142 Model, K176 Close_Range, K235 Test
ABSTRACT
one of the most significant aspects of the architectural heritage of the Veneto region is the Venetian Villa. This project originates from
the necessity of standardization which will regulate techniques and adjust procedures in order to analyse and catalogue their preservation.
Different approaches are necessary for the comprehension of a historical building and the measured survey is essential for two particular
reasons - the first being the knowledge of the building’s composition, its geometry, its proportions; the second being the possibility for
the spatial location and representation of datums (historical information, building materials, stratification of layers, quality of conservation
...). Measured survey is therefore contemporarely the representation of the material text of the villa and the most adequate support for
the informations acquired through different investigations and various analytical techniques.
The primary objective is to establish a vade-mecum for a project planning of the operations to be repeated for all villas, a preliminary
standard support for different successive specific examinations. The mean with which all information have been catalogued is through
the CD-ROM (an instrument suitable for the integration of scholarly programs of investigation) where the technical report of the survey
work can be found with all the topographical and the photogrammetrical datas, the program of digital photogrammetrical restitution
(monoscopic and stereoscopic) using the orientation parameters (supplied by the CD-ROM) permitting the restitution of those elements
that other scholars claim important in their research.
The Istituto Regionale Ville Venete, the public agency set up in
order to facilitate the financing of the preservation of this very
significant aspect of the architectural heritage of the Veneto region,
in 1994 has commissioned a test study on villa Zeno located at
Donegal di Cessalto (Treviso).
This villa built for Marco Zeno by Andrea Palladio (1508-1580)
the most famous venetian architect, is a very peculiar case. The
project is published in Palladio's Quattro libri dell'Architettura
(Venice, 1570) but the villa has never been lived in and has
experienced radical transformations in different periods; there is
also the belief that the variance of its construction is due to the
opposing ideas of the owner and the architect.
The villa needs a thorough restoration but the historical
informations and the archivial documentation are insufficient; there
is then the necessity to undertake the process of cognition of a
historical building from the material text; a point of view where
measured survey plays a fundamental role.
The test had to face three different purposes:
1. to set up the technical operations for the acquisition of the
essential metrical informations necessary to document the formal
model of the villa - i.e. its geometry and proportions - integrating
topographical survey and photogrammetry in order to obtain the
most complete description of the building; to be followed by the
exploration of the most suitable methods for a efficient
representation of the distinctive character: from classical
projections (horizontal and axonometrical), to computer solid mod-
elling:
. to document the decayed preservation of the building,
. to analyse the geometrical configuration,
. to study the distinctive stylistic elements,
. to lay the foundations for subsequent analytical chronological
examinations;
2. to draft a program of interaction with other investigations to
define standardized procedures for a closer examination in occasion
of subsequent important works of restoration.
The first phase (spring 1995) has accomplished:
. the topographical survey to set up the vertexes, the reference
nets, the control points for the photogrammetrical models and
verify the existing measured drawings,
. the rectification of the south and north facades to make plainly
visible the decayed conditions and to underline the
characteristical architectural elements,
. the geo-physical investigation using the Ground Penetrating
System (G.P.R.) method with the aim of identifying possible
underground structures and to determine their position,
. the stratigraphical analysis aimed to examine the succession of
modifications and their relationship in chronological terms.
The second phase (winter 1995-96) has accomplished:
. the detailed survey of the entire building (the preexisting survey
was not reliable) with special attention to those parts structurally
more significant (vaults, disjointed walls, ...),
. the enlargement of the area examined with G.P.R. and the
ascertainement through excavation of the recorded reflection,
. the investigation on more numerous sites with stratigraphical
analysis. Several specimen have gone through chemical and
physical tests.
As far as the architectural measured survey is concerned the
drafting produced till now corresponds to:
. plan of the first and second floor,
. three longitudinal sections and one transversal,
. rectified prints of the north and south facade.
The confrontation with the design produced by Palladio in his
Four books of the Architecture and with the set of prints produced
by Ottavio Bertotti Scamozzi at the end of tne XVIIIth century
gives way to a some considerations that can be summerized as
follows:
. Palladio's illustration reproduces correctly the typology of the
building but the proportions do not correspond,
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
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