Monitoring Heritage Buildings and Places

Monitoring is the act of observing something and keeping a record of it.

The central argument for monitoring can be stated in a single sentence: You cannot recognize, understand, improve or maintain what you do not or cannot measure.

Monitoring is the act of measuring change in the state, number, or presence of characteristics of something. It involves the repeated collection of a specific set or sets of information over time and analysing the results to detect the changes that are occurring. The collection of this information facilitates identification of recurrent problems or fabric susceptible to damage. The problem areas, once identified, can be monitored more intensively and, where appropriate, management action taken.

Before deciding on any monitoring activity, managers must ask themselves the following question: What is the purpose of the monitoring exercise? The more specific the answer to this question, the better will be the results. An unspecific monitoring brief will not provide the anticipated results.

Good and wide-ranging documentation review and preparation should precede any monitoring activity. As much information as possible about the building should be gathered from existing sources before deciding on monitoring activities.

In the case of heritage buildings monitoring involves measuring:

• Changes in the external pressures acting on the property
  
• Changes in the condition of the property
  
• The effectiveness of management actions on conservation of the property's values.
  

Condition monitoring requires:

• a long-term commitment;
  
• a rigorously followed procedure for reporting monitoring observations and
  
• adequate numbers of qualified personnel to carry out the monitoring.

For methodology and forms for monitoring various types of structures and sites, consult New Zealand's 2003 technical paper "Methods for monitoring the condition of historic places"

Basic questions for monitoring heritage buildings include: Is it stable, safe, dry, maintained, documented, regularly inspected, valued by the community, and interpreted? Following are a few examples of monitoring indicators, tools and purpose for heritage properties. Many tools and instruments can help those responsible for the care and maintenance of heritage buildings monitor the condition of those buildings. But in the end, nothing is a substitute for a keen eye, patient assessment, and human logic, all of which will always be needed to conserve the best of the past for the future.

Indicators	Tools	Purpose
Building Drainage	Hygrometer recording levels of moisture in basement, stains on foundations, walls and ceilings, downspouts and roof drains.	To determine where and how much moisture penetrates into the building.
Building Graffiti and vandalism	Visual observation, inventories	To plan clean-up or to strengthen security measures.
Building Interior temperature variations	Thermometers	To determine if and when heat/cold may affect materials and finishes, collections and living conditions or comfort.
Building Interior relative humidity variations	Hygrometers	To determine if and when condensation may occur inside the building or create conditions favorable to algae and fungus growth.
Building Maintenance techniques	Survey maintenance crews and maintenance work	To determine if maintenance techniques or lack of have adverse impact on building conservation of materials and values.
Building Movement	Structural movement: permanent survey stations can be established independent of the site and readings taken on a regular basis to a set of permanent markers fixed onto the building surface using high precision total station survey instruments. As a rule of thumb, a monitoring system should be at least ten times more accurate than the lowest threshold.	To determine if building or parts of building are moving.
Building Materials: Surface erosion	Surface erosion: the surface can be mapped either using digital close range photogrammetry or laser scanning to establish a digital terrain model (dtm). This process can be repeated and quantitative analysis made possible using specialized software for depicting surface change. It would be essential to carry out accurate control measurements so that all dtm’s could be georeferenced (overlapped precisely).	To determine location and quantity of erosion of building materials.
Building Materials: Moisture content	Moisture meters	Moisture meters are used to measure the percentage of water in a given substance. This information can be used to determine if the material is ready for use, unexpectedly wet or dry, or otherwise in need of further inspection. Wood and paper products are very sensitive to their moiture content.
Building Movement: Cracks	Plaster patch, glass plate & epoxy resin, 3-point brass pins survey	To determine if parts of building are still moving and in what direction.
Building Multiple information data gathering	There are now available a number of ‘matchbox’ sized data loggers. These are small enough to be positioned inconspicuously within buildings and are accurate and user friendly. They generally measure temperature, relative humidity (RH), dew point, vapour pressure, lux, ultra violet (UV) and timber moisture content.	To gather data on various environmental conditions with a single sensor.
Building Past conservation treatments	Various types of laboratory and site tests and observations.	To determine the effectiveness of past treatments.
Building Safety	Building Code inspectors, architects, engineers.	To determine public safety measures in case of emergencies (fire, water, earthquakes, riots, demonstrations).
Building Security	Local police, security experts, reports from site guards	To determine level of protection of building and contents.
Building Structure	Resistograph	To determine deterioration of structural timber elements.
Building Surface temperature variations	Temperature sensors	To determine the level of protection of the building and its contents.
Building Ultra Violet levels	UV sensors	To determine if levels will affect textiles, paintings, colours.
Building Water infiltrations	Visual observations	To prepare remedial actions.
Economy Dollars in craft sales	Interview craft shop owners	To prepare remedial actions
Economy Dollars spent by population in the area	National Statistics	To determine economic impact of monument and site on local economy.
Economy Dollars spent by tourists	Interview local businesses, visitor surveys	To determine economic impact of monument and site on local economy over time.
Economy Grants received from outside sources	Survey businesses, organizations	To determine contribution by international community to monument.
Education Amount of education literature produced	Number of publications, number of copies sold, Dept. Of tourism, publishers	To assess level of population`s understanding.
Education Number of students taught	Interview with school children and principals	To assess level of student’s understanding; they are the next generation who will have to care for it.
Environment Acid rain levels		Calcareous materials and metals are especially affected by acid rain. Monitoring levels will help to determine acceptable threshold.
Environment Changes	Aerial photography & aerial remote sensing, color & infrared photography	To monitor & mitigate environmental changes, vegetation type, variety and health and water pollution.
Environment Dust pollution	Dust deposition sensors, airborne particulate sensors (light)	Top determine what and how much dust is deposited and to determine how best to mitigate if a problem arises.
Environment Light	Photometric sensors, Blue wool standard, solar radiation sensors (pyrometer)	To determine the total amount of visible light affecting the fading of certain materials, the total amount of solar energy heating a building or materials.
Environment Noise levels	Decibelmeter	To determine levels of noise from traffic, mousic, crowds, vendors, restaurants, business establishments and plan remediation to problems.
Environment Ozone levels	O3 Analyzer	To determine levels of this color fading oxidant.
Environment Pollution levels and pollutants	Various technologies	To determine the presence and level of pollutants that may affect the monument or the people.
Environment Seismic activity	Seismic sensors, national & international statistics and data	To determine if conditions are below established thresholds.
Environment Smells	HS detectors	To improve quality of visitor experience.
Environment Soil moisture	Soil moisture sensors	To determine level of moisture at building foundations.
Environment Sulphur dioxide	Pulsed Fluorescence SO2 analyser	To determine levels and causes of sulphur dioxide, that causes deterioration of stone and metals.
Environment Waste management & disposal	Visual observations, waste disposal staff or company, site manager	To manage visual appearance of building & site, cleanliness, visitor experience.
Jobs Number of current jobs in area	National tourism statistics	To be able to compare from year to year and assess impact of monument on job creation.
Jobs Number of dollars spent in creating quality jobs	Survey local businesses (for full time jobs, well paid, good working conditions etc.)	To assess impact of monument on creation of quality jobs.
Jobs Number of jobs created over time	National tourism statistics	To assess impact of monument on job creation.
Jobs Number of jobs for development	Regional / Local statistics	To assess impact of monument on job creation.
Jobs Number of jobs for servicing	Regional / Local statistics	To assess impact of monument on job creation.
Materials Lime plaster deterioration	Photographic survey, visual inspections for cracks, stains, detachments, loss, salts	To determine maintenance program, replacements, repair & conservation techniques.
Materials Mortar deterioration (bedding)	Core sampling, core wetness sensors	To determine structural stability & integrity, conservation & injection techniques.
Materials Mortar deterioration (pointing)	Survey cracks, loss, adhesion, cohesion, tests for characterization, resistance water absorption, vapour transmission	To determine maintenance program, replacements, repair & conservation techniques.
Materials Stone accretion deposits	Visual observations, chemical analysis, photography	TYo determine maintenance program & cleaning techniques.
Materials Stone corrosion of anchors	Radiography	To determine when and how to intervene.
Materials Stone discoloration	Photos, photos with color scale	To select tests and test areas to determine causes of discoloration.
Materials Stone preservatives & consolidents	Tests to determine levels of water repellence, waterproofing, vapour transmission, mechanical resistance	To determine maintenance program, replacements, repair & conservation techniques.
Materials Stone staining	Observation, colour photography	To determine cause and cleaning method
Materials Stone water absorption	Rilem tube & lab water absorption tests	To determine stone mechanical resistance especially to freeze-thaw cycles, water absorption may introduce salts in the stones.
Materials Stone weather resistance	Sodium sulphate crystallization test, thin sections analysis	To determine level of stone resistance to weather.
Media Amount of coverage internationally	Square cm of international newspaper or magazine articles and hours of foreign radio or TV. Content should be analyzed by academics in literature	To determine quantity & quality of media coverage, perceptions by international visitors, protection of site values.
Media Amount of coverage nationally	Square cm of national newspaper or magazine articles and hours of national & local radio or TV. Content should be analyzed by academics in literature.	To determine quantity & quality of media coverage, perceptions by national & local visitors, protection of site values.
Meteorology Amount of precipitation / period of time
Meteorology Floods & flash flooding	National statistics	Flash flooding carries with it debris, soils and stone that erode and crack monuments.
Meteorology Levels of relative humidity	RH sensors	When RH is higher than 70%, this is optimal condition for growth of micro-organisms. To determine level of comfort for visitors.
Meteorology Variations in temperature / period of time	Thermometers	To determine impact of visitors, building materials, fauna and flora.
Meteorology Wind amount & dfirection / period of time	Various wind tracking instruments	To determine wind direction and intensity over time. Dominant winds affect rate of wetness & dryness of materials, wind borne particles may erode materials.
Site Capacity	Visitors statistics, interview site personnel and maintenance crews	To determine maximum number of visitors
Site Drainage	Site observations, photography, mapping techniques	To identify potential flodding areas or damage to structures and buildings' foundations
Site Erosion	Aerial photography
Site Use and occupation by people and animals	Visual observation	Manage site use
Site Type of vegetation	Visual observation, historical photos	Roots and branches may damage monuments, keep moisture in areas that should be dry.
Site Visual intrusions	Photographic records, visual observation	To manage incompatible developments, litter, special pollution, signage.
Social Cultural values (shifts, changes etc.)	Surveys, analysis of media and publications	To manage changes in traditional life ways, crime.
Social Social impacts	Surveys	To manage impacts unacceptable to the local population and sustain those that are favourable and welcomed.
Traffic Number and type of vehicles / period of time	Highway Dept., local police Dept. (license plates identification), Surveys	To determine volume of vehicles during specific periods, capacity for traffic and parking, who parks where, levels of pollution, to plan for additional roads & parking lots, to better manage vehicle traffic.
Visitors Number	Hotel occupancy, airline, Dept. Of Tourism, tourism center records, government statistics, visitor surveys, ticket sales	To support funding request, annual statistics, relative importance of site.
Visitors Number in specific areas of site	Counting on site, electronic sensors at entrances & strategic places	To alert site management to degradation of the visitor experience due to overcrowding, to provide statistics needed to plan for visitor services within site, to alert managers to potential degradation of material fabric that might be reduced by heavy visitor traffic in a given area.
Visitors Number of days tourists spend in the area	Survey local businesses, hotels, transport agencies, regional statistics bureau	To extend visitor stay in the region.
Visitors Origin	Airlines, trains, car rental agencies, origin maps in various businesses	To support investments in marketing strategy.
Visitors Type	Register books, hotels, restaurants	To support investments in marketing strategy, to plan for new resources and facilities.
Volunteers Number of volunteers hours	Number of meetings and participants	To determine amount of support from population and interest in protecting and sharing this resource.
Volunteers Number of volunteers involved in programs	Contact local groups and associations	To determine amount of support from population and interest in protecting and sharing this resource.