provisional plan of maintenance in historic buildings
TRANSCRIPT
PROVISIONAL PLAN OF MAINTENANCE IN HISTORIC BUILDINGS
Daniel Nóbrega Tomásio Lopes Soares
Extended abstract
December 2012
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1. INTRODUCTION
The maintenance of historic buildings is a subject which is neither very well-known nor developed in
Portugal, with lack of continuum research when compared with other European countries.
In recent years a philosophy of proactive maintenance has been developed, mainly applied in current
buildings, allowing the detection of problems before they affect the users of the building as well as
reducing costs of corrective actions of maintenance applied during buildings’ service.
This reality cannot be fully transposed to the case of historic buildings, but it helps to motivate and
develop the scientific process associated with maintenance methodologies. In the case of historic
buildings, there are different concerns often related with the ability of these buildings to generate
profits associated with tourism. In recent years there has been a greater awareness of the importance
of heritage and its role in consumer society.
The aim of this work is to create a methodology for proper maintenance of historic buildings, taking
into account their unique characteristics and respecting the issues associated with authenticity. The
maintenance actions will be described through a plan, applied to a case study, with estimated costs for
a timeline of 10 years.
2. SCOPE OF MAINTENANCE AND HISTORIC BUILDINGS
A historic building is defined not only by its architectural nature, but also by its historic testimony.
Therefore it will be a cultural property (classified or in the process of classification), which by its type of
construction and architecture conserves a historic testimony of the region or place where it belongs.
The origins of maintenance are mainly linked to the industrial field, being considered as a means for
technical development, not only from a conceptual point of view but also from the strategic and
management view, factor that will later influence the choice of preventive methodologies applied to
buildings.
In this work it will be important to recognize different possible interventions in buildings in order to
improve performance levels depending on the type of work involved. There are several concepts
which are important to differentiate in each analysis.
Small repairs and occasional intervention with the aim of bringing the building for adequate
performance levels are included in maintenance. Focusing on the topic from the perspective of civil
engineering, the definition of maintenance of buildings is associated to the combination of all technical
and associated administrative actions during the service life to retain a building or its parts in a state in
which it can perform its required functions (ISO 15686, 2011).
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If the state of degradation increases significantly deeper intervention will be needed, prolonging the life
cycle of the building/element. In this case, it is more appropriate to use the with the increase of
intervention degree: refurbishment, renewal, reconstruction (Manso, 2003).
In this context it is also important to define the conservation concept. This can be defined as the first
level of intervention to be applied to the historic heritage, so that it remains in a state of appropriate
preservation, and without existing a profound degradation in its elements. As mentioned in the Venice
Charter (Weaver, 1997), the conservation of a monument implies preserving a framework that is not
out of scale. Wherever the traditional setting exists, it must be maintained, and should not be adopted
any new construction, demolition or modification which will change the relationship of the original
monument.
The existing definitions in ISO 15686 (2011) are usually linked to the concept of life cycle of the
building. That’s the reason why its philosophy and methods of analysis cannot be entirely transported
to the full scope of historic buildings, an area where the lifetime of some materials and elements has
long been exceeded.
i) Portuguese experience:
The sector of construction in Portugal has investing in new construction over the years, within this
sphere (Figure 1) exist a small field but with growing importance, that corresponds to works of
refurbishment in existing buildings. In Portugal this sphere has a value of less than 10% of the total
construction, while in other European countries it is 40 to 50%. The third sphere is concerned with the
conservation and restoration of monuments and historic buildings, the noblest part of the built
heritage: buildings which, besides being constructions, are also cultural goods. The latter sphere
covers less than 1% of total production in the construction sector (Cóias, 2009).
Existing legislation in Portugal over maintenance is outdated, and the only existing regulation is RGEU
(General Regulation of Urban Construction), which has been revised and is waiting for approval,
changing its name to RGE (Regulation of General Buildings). It should be noted that the updated
General construction
Refurbishment of buildings
Heritage conservation
Figure 1 – Representatives spheres of activities in the construction sector (adapted from Cóias, 2009)
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RGEU does not include any article or specificity regarding the maintenance on historic buildings,
although there are several important changes envisaged in the chapter on Maintenance and
Durability.
Apart from the maintenance of historic buildings in Portugal, it is important to analyze what has been
done in other countries. So the following cases have been described:
ii) International experience:
the Italian experience, which due to its pioneering and conservation model applied to the
territory was the largest contributor to the development of the theme at an european level;
the English experience, with especial importance due its pragmatism addressing the problems
dealing with the conservation of monuments, as well as its experience in implementing
preventive and pro-active strategies in their churches and cathedrals, has been providing
good indications about the financial relevance of this type of approaches.
the Dutch initiative has proved a success in terms of application and financial advantages,
reason why it has been followed by several countries.
3. METHODOLOGY OF MAINTENANCE IN HISTORIC BUILDINGS
Throughout the application of this methodology it should be taken into account some characteristics
that differentiate this type of buildings such as:
heterogeneity of existing monuments, with different periods of construction and different
construction techniques;
cultural appreciation for the zone in which they are involved;
authenticity of unique elements, where the aim is not to replace but to save;
buildings often subjected to daily tours.
The methodology described can be applied to any historic building, taking into account that changes
may be made in the formulations presented, depending on each case study.
A maintenance plan designed specifically for historic properties introduces the concept of preventive
conservation, i.e. we must be especially careful with all interventions made, replacing only what is
essential and preserving what is unique and historic. The purpose is to monitor the performance of the
building, preventing the emergence and deterioration of predictable anomalies. Efficient management
of these routines, organized technically on a plan, allows not only greater longevity of the elements
studied, as improves the building daily functioning, for all those who use or visit it.
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This document provides maintenance management through the identification of future interventions,
who runs them and what their periodicity. In addition, it serves as an important tool for monitoring the
building, allowing control costs associated with maintenance. The maintenance plan assumes a
character both technical (operating instrument) and economic, being possible to estimate financial
needs by programmed actions.
The methodology developed is shown in Figure 2 and is spread over several phases. Initially it will be
presented the preliminary phase, targeted for the study of the intrinsic characteristics of the building
under study and the environment that surrounds it. Then there will be the phase of inspections, where
through various surveys one can divide the building into different facilities, studying the state of
degradation of each one scaling the maintenance actions. Finally, the maintenance plan will be
prepared, accompanied by decision criteria based on rationalization and opportunity.
Figure 3 - Proposed methodology for maintenance on historic buildings
- Description of the historic building
- Changes made to heritage over the time
- Importance of the building to the region
- Characterization of the entities responsible for the
management and maintenance
- What type of maintenance is performed
- What is the current condition of the building
- Study of the environmental conditions of the region
- Human risk factors
- Possible funding problems
- Check for existing maintenance material
- Check for emergency routes
- Gather information on touristic visits
- Floor plans and elevations
- Photografies
- Accessibilities
- Previous interventions
- Physical condition
- State of degradation
- Observed anomalies
- Frequency
- Criteria for priority
- Description of the inteventions
- Material
- Equipment
- Workmanship
Previsional plan of maintenance
- Different scenarios
- Rationalization/means synergy
- Opportunity factors
2 - Inspections
phase and
maintenance
program
A - Survey data
E - Maintenace costs
1 - Preliminary
phase to
development of
the plan
A - Building comprehension
B - Current situation of the building
C - Study of the environment and potential
risks
D - Internal management of the building
3 - Decision - Economic Analysis
Sheets survey
B - Information organizationInspection sheet
nº 1
C - Study of materialsInspection sheet
nº 2
D - Maintenance actionsInspection sheet
nº 3 (criteria)
- Division of the building in facilities
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4. CASE STUDY
At this stage the maintenance methodology presented in the previous chapter will be applied to a
historic building. As a case study will be used the National Pantheon, a building located in the historic
district of Santa Clara in Lisbon, and classified as a National Monument.
The description of the building and its surroundings will be done initially, followed by previous
interventions and data collection. After that the monument will be divided in facilities, and the
campaign inspections will start.
4.1. Preliminary phase to development of the plan
The National Pantheon, located in the Lisbon, occupies the building originally intended for the church
of Santa Engrácia, hosting the tombs of the great figures of Portuguese history. The current
guardianship of the building belongs to the Institute for Managing the Architectural and Archaeological
Heritage (IGESPAR), a public body within the Ministry of Culture, with responsibilities for the
architectural and archaeological heritage in Portugal.
This building is a key reference in the profile of the city (Figures 4 and 5), offering privileged views
over the old town and the Tagus River.
This ancient church, severely damaged by a storm in 1681, was completely rebuilt by architect João
Antunes. The death of the Royal Architect, in 1712, resulted in the virtual abandonment of the work,
deprecated by King D.João V. After the extinction of the religious orders in 1834, the church served as
a depository of war material and as factory of clothing and footwear. The works lasted so long that
gave rise to the popular expression "works of Santa Engrácia" to designate something that takes a
long time to finish. The building eventually receives its dome only in 1966.
Figure 4 – National Pantheon, view from Tagus River
Figure 5 – National Pantheon, aerial view
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It is a building with classical architecture assimilated to the Baroque, Greek cross plan with three
chapels, central quadrangular space and four towers at the corners. The structure is characterized by
having sturdy resistant masonry walls.
The recent dome (1966) is characterized by a totally different type of construction, with reinforced
concrete structure coated with stone as can be seen by Figures 6 and 7.
Figures 6 and 7 – Dome construction by the DGEMN, 1964
4.2. Inspections phase and maintenance program
Previous operations performed on the monument were monitored by the former General Board for
National Buildings and Monuments (DGEMN), and the existing documents were passed to the
Information System for Architectural Heritage (SIPA). A research conducted on this platform met some
old building plants and an elevation, this information was completed and transposed into digital form,
this way is possible to have an architectural and functional survey of the building, easy to use, which
enables the measurement of elements in an expeditious manner.
As described in the presentation of the methodology in Chapter 3, should be created a complete list
identifying all the maintenance elements existing in the historic building under study.
In order to implement this system in maintenance plans for historic buildings the Italian standard for
facilities management (Lobo de Carvalho, 2007) has been adapted, consisting on an alphanumeric
code, with two parts: the identification of the element in context of the constructive system (in text
characters) and its functional location and sequential numbering (in Arabic numerals).
Figure 8 – Example of the maintenance elements codification
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In the example of Figure 8 the coding of the maintenance element is made by specifying its class (in
textual characters), followed by its spatial location and numbered sequentially (in Arabic numerals), in
this example refers to simple glass element (Gl) from the technological class Window (WIn), located
on the facade 026, number 2.
After verifying the compatibility of the collected data with the code presented, the inspection phase has
begun through inspection sheet nº1 (extract in Table 1). The information presented here is just an
example. Around 500 maintenance elements along all facades and roofs of the monument have been
collected in this study.
Table 1 – Extract from the inspection sheet nº1
Cost center
Area Group cod. Class cod. Element Quantity
(un/m/m2) Date
Complete element code
Façade Vertical str. (EXw) Exterior wall (Sm) Stone masonry 816,0 m2
19.11.12 EXwSm 001-1
Façade Vertical str. (EXw) Exterior wall (Sw) Stonework 21,5 m2
19.11.12 EXwSw 001-1
Façade Vertical str. (EXw) Exterior wall (Sw) Stonework 91,0 m2 19.11.12 EXwSw 001-2
After identified all the maintenance elements on the facades and roof, starts the evaluation phase of
the state of degradation.
The most serious anomalies observed in the front facade are associated with disruption of masonry;
the principal cause for the problem is the absence of anti-bird protection. This facade has three stone
statuary (as opposed to other facades that have none), serving as a local of pigeons aggregation, a
factor that accelerates the degradation in these areas (Figure 9).
Figure 9 – Agglomeration of pigeons in the statuary of the main facade
This situation should be corrected as quickly as possible; in certain areas are already visible pecking
zones from the pigeons, and the droppings at the place act as chemical aggression factor. It is
advisable to place networks anti-pigeon areas in the statuary, and a system of plate needles in the
upper region of the masonry.
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It should be noted that although the symmetry of the building and the apparent similarity between all
walls, the several facades presents different anomalies.
Due to the geographical location of the building and the surrounding environment, the lateral facades
contain anomalies related to human presence. The south facade features plenty of graffiti, a situation
that makes the stone cleanness more expensive (Figure 10). The north facade is close to Campo de
Santa Clara, venue that hosts the flea market twice a week, this facade is currently used as a public
toilet (Figure 11), a situation that causes several anomalies related to urine in contact with the stone.
Figure 10 – Graffiti zone in the South facade
Owing to the special nature of the place, it would be advisable to limit the access to this area of the
monument, for example installing a fence that reduces access to this place.
In the roof areas the major defects are associated with the existing stormwater drains. In the terrace
area there is a single gutter that surrounds the entire building (Figure 12) and discharges into several
downpipes. It’s possible to see through the inspections that most of the downpipes are blocked (many
of them do not have drains pine cones), that’s the main reason why the water remains in coverage as
shown in Figure 13.
The rainwater drainage systems existing on the roof should suffer cleaning interventions within a short
time.
Figure 11 – Accumulation of urine in the North facade
Figure 12 – Single gutter that bypasses the entire
terrace
Figure 13 – Gutter full of water, already visible parasitical vegetation
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The anomalies registered during the inspections should be pointed in the inspection sheet nº2 showed
in Table 2.
Table 2 – Extract from the inspection sheet nº1
Element code Element name
Degradation state of the facility Observed anomalies Possible causes
WA R B R
EXwSm 001-1
Stone masonry X Dirtiness Lack of cleanliness
EXwSw 001-1
Stone work x Black stains Accumulated dirt, grubbiness
Key: WA=Without Anomalies; R= Reasonable; B=Bad; R=Ruin
After this phase the classification of the criteria associated with facilities belonging to historic buildings
was elaborated.
It should be noted that the criteria "Cultural Value" (main criterion for differentiation between historic
buildings and current buildings) will adopted low values in some elements of the monument. Despite
being a XVII century building, the various reconstruction and extension of the works meant that much
of the building is from much recent construction.
Figure 14 – Monument division
The bottom of the monument is from the XVII century, while the upper part was constructed only in
1964 factor that causes the difference value (Figure 14).
According to the present Equation 1 the calculating of the scaling ratio relative to all elements existing
in the building has been made. On the Table 3 is presented as an example of the scaling ratios.
Low cultural value
Significant
cultural value
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(1)
Table 3 – Example of scaling index of the main facade
Facility code DS CV RF AC Weighted
index Relative
index Cost
center
EXwSm 001-1 2 2 2 3 33 0,77 Facade
EXwSw 001-1 3 2 2 3 38 0,88 Facade
EXwSw 001-2 3 2 2 3 38 0,88 Facade
WInGl 001-1 1 1 3 1 19 0,44 Span
Key: DS=Degradation state; CV=Cultural value; RF= Relation to other facilities; AC= Accessibility
(2)
Table 4 - Scheduling actions
Type of action
Maximum time until the next
intervention
Immediate ≥ 0.90 Immediate
Short-term 0.40 ≤ < 0.90 5 years
Long-term < 0.40 From 5 to 10 years
This type of scheduling actions will be very important for the next phase of the methodology, which
consists in preparing the provisional plan for maintenance. The maximum time for interventions is
described on the Table 4.
At this stage of the work, apart from the scaling operations already estimated, it is important to know
the periodicity that must be defined between each intervention. This information should be gathered
through technical catalogs, professionals with experience in maintenance and technical literature
directed to historic buildings.
Once collected all the necessary information has been possible to build the provisional program of
maintenance actions for the National Pantheon in Lisbon. In Table 5 is shown a representative form of
the plan for maintenance of the main facade.
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Table 5 - Representative form of the provisional plan of maintenance
After the development of the plan should exist a stage dedicated to the economic analysis. This way
it’s possible to study several intervention scenarios. It is important at this stage of the work to make a
rationalization/synergy of available means, trying to make a maintenance based in opportunity (e.g.
association of works taking in account the high cost of scaffolding assembly on the facades).
Table 6 – Provisional plan in associated costs for the main facade
5. CONCLUSIONS
To make the implementation process of maintenance plans (theme that has undergone major
developments in current buildings) is necessary to take into account the specificities associated with
historic heritage, including the different attributes of each building - each monument usually presents
unique characteristics - as well as issues relating to authenticity, a practice that in the past was not
privileged.
This work intended to develop a methodology for maintenance that could be applied to any historic
building, the ultimate goal is the development a provisional plan for maintenance actions and cost
estimates for each analyzed building.
Routine
Facility Code Type Pontual Month Anual Quinquennial Decennial Man power Equipment Total cost
Stone masonry EXw Sm 001-1 Cleaning x 2 workmen Eq. water jet 951,0 m2 14,76 €/m2 14.036,8 €
Stonew ork EXw Sw 001-1 Cleaning x 2 workmenEq. manual
brushes112,5 m2 14,98 €/m2 1.685,3 €
Glass WInGl 001-1 Substitution x x 1 workman Eq. Glass 6,0 m2 36,05 €/m2 216,3 €
Facilities codification Periodicity Means Costs
Quant. Price
Main Facade
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Facade 19.110,2 €
Span/Porthole 1.489,0 € 1.900,4 €
Stonework 8.802,7 €
Systems 420 € (a) 24,3 € 31,0 €
Scaffolding 11.246,0 €
Anual costs: 420,0 € 0,0 € 0,0 € 0,0 € 40.672,2 € 0,0 € 0,0 € 0,0 € 0,0 € 1.931,4 € 0,0 €
(a) Anti-pigeons system 3.911,2 €Anual average costs to main facade:
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The application of the maintenance methodology created was implemented without much difficulty on
the case studies. However it was found that its application is both laborious and long, since each
building has been subject to several visits to complete the inspection sheets. The software used for
the calculation of the index of the maintenance elements needs was Microsoft Excel, which revealed
to be suitable for obtaining the required results.
The three inspection sheets drawn up to perform the visual inspections have allowed the collection of
nearly 500 elements in the monument. The data collected were applied to the hierarchy formula
previously developed and provided good results.
The application of the methodology developed on the historic buildings made it possible to obtain the
following data:
A list of building anomalies;
A provisional maintenance plan with needs for 10 years;
The maintenance associated costs for 10 years.
REFERENCES
Manso, A. (2003), Refurbishment and conservation of buildings: costs evaluation and recent
developments. 2º International Symposium of pathology, durability and refurbishment of buildings,:
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ISO 15686-1 (2011), “Buildings and constructed assets - Service life planning - Part 1: General
principles and framework”, International Organization for Standardization, Swiss.
Cóias, V. (2009), Rehabilitation: the best way to sustainable construction; article present in “Banca e
Ambiente”, page. 2. Lisbon.
Rodrigues, R. (1989) Building Maintenance - Analysis and exploration of data on a residential park,
Thesis to obtain the Master’s Degree, FEUP, Oporto.
Flores, I. (2002), Maintenance strategies – Current building’s envelopes, Thesis to obtain the Master’s
Degree, IST, Lisbon.
Lobo de Carvalho, J. (2007). Heritage Conservation - Policies for Economic Sustainability. Thesis to
obtain the PhD Degree, IST, Lisbon.
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