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Paper presented at 46th ESReDA Seminar on Reliability Assessment and Life Cycle Analysis of
Structures and Infrastructures (May 29th - 30th, 2014) Politecnico di Torino, Turino, Italy
Evidence-based, mission-oriented Corporate Real Estate Management.
Cyp van Rijn (Asset Management Consultancy), Ronald Kollaard, Vincent Faesen, Rene Leeuw (The
Government Buildings Agency, RVB)
Abstract
The Dutch Government Real Estate Agency (RVB, Rijks Vastgoed Bedrijf) is one of the largest
corporate real estate managers in The Netherlands being responsible for approximately 2000
government buildings and terrain of the Ministry of Defence ; from approximately 350 monuments
to buildings of various types like palaces, museums, offices, penitentiary institutions, bunkers,
shelters, airfields and harbours, in total some 12 million gross square meter floor space. The annual
maintenance budget is in the order of some 200 million €. Daily maintenance is managed via 5-7 year
service level agreements; investments and refurbishments are planned over a five year interval.
Every five years the condition of building elements are established by a team of inspectors, using the
Dutch NEN2767 condition assessment norm. A building advisor then has to integrate this information
in a budget proposal in order to cost effectively maintain the overall real estate condition in line with
the mission of the RVB.
To this end we developed a decision support tool (prototype in Excel) in which the RVB management
experts link the building elements to one or more of the mission categories (safety, health, , energy,
environment and quality, SHEEQ). The inspection results are registered under these headings and are
weighted via the Analytical Hierarchy Process with respect to the RVB mission. The advisor, in this
way, easily obtains a ranked list of potential refurbishment candidates. He / she then will allocate
budget, first for obligatory, then for the most critical actions in descending order on single building
elements until the budget limit is reached. In a third round a cost-optimal combination of activities
on the top-ranked total set of building elements will be sought and offered as an advice to the
building owner. The latter may extend the analysis over the portfolio of similar buildings to achieve a
company-wide optimal 5-year budget plan.
The technique has been successfully field-tested, is regarded as an efficient decision support tool
both by the RVB and by building maintenance companies facing the introduction of long-term service
level agreements (main-contracting) and is taught in certification courses for building advisors. It will
be implemented in CONDOR, a commercial building management system.
Introduction.
The Dutch Government Real Estate Agency (RVB) is one of the largest real estate managers in The
Netherlands. The agency is responsible for approximately 2000 government buildings and terrain of
the Ministry of Defence ; from approximately 350 monuments to buildings of various types like
palaces, museums, offices, penitentiary institutions, bunkers, shelters, airfields and harbours, in total
some 12 million gross square meter floor space. The annual maintenance budget is in the order of
some 200 million €. Daily maintenance is managed via a large number of a.o. 5-7 year service level
agreements via a standard specifications and conditions. Larger activities like replacement of building
parts or installations are managed via a rolling 5 year planning forecast.
2
Set policies, steer proces Methodology Report
Analyse, advice &
plan
Report Allocate
ASSET MANAGEMENT
Asset owner Market parties Client, asset owner
RgdBOEI
inspection
Set integral
framework
Define
required
information ->
inspection
Functionality
~ NTA8026
Integral
inspection
report
Cost benefit
analysis
Risk
analysis
Integral
advice report
Policies asset
owner
Assets
portfolio
Requirements
/ preferences
clients
Investment
additional
Investment
client
Investment
owner
feedback
Fig. 1
Like most countries, the Netherlands has legal requirements on fire safety, health, energy
consumption environmental aspects and quality (SHEEQ) of different types of buildings as laid down
in the Building Regulation (Bouwbesluit). The RVB [1]introduced in 2009 the BOEI concept; every five
years teams of certified inspectors are hired-in to evaluate the condition of building elements
according to the Dutch norm NEN 2767 on these legal aspects (B= “brand” -> Dutch for fire, O=
“onderhoud”-> Dutch for maintenance, E= energy, I= information on laws and regulations) on basis
of a standard inventory of building elements. The Dutch norm NTA 8026 offers the required
methodology for the link between physical asset management and these condition measurements. A
hired-in building advisor subsequentially uses these inspection reports to formulate a budget
proposal (integral advice report) in order to cost effectively maintain the overall real estate condition
in line with the mission of the RVB (Fig. 1). As the figure suggests we are dealing here with a very lean
organization of asset owner and clients that has to rely on a large number of market parties that not
only are responsible for carrying out the daily maintenance and renovation activities but also provide
all the required management information on condition of building elements and scenario’s for
planning.
In the past, the RVB had difficulties in forecasting a required budget for major maintenance /
refurbishment / retrofitting as well as the risks of not meeting required building standards. An
integral decision support tool for building management was required.
The decision problem.
Given (restricted) information on the condition of building elements and standard specifications for
(service level) agreements on daily maintenance:
How to provide an overall steering mechanism to secure that the above integral advice
reports allocate available funds cost-effectively to such maintenance / renovation activities
3
that optimally improve the overall building condition with respect to the needs of the user
and the mission of the RVB organisation?
SUB-
OBJECTIVES
MAIN
OBJECTIVES
MISSION
number of
victims
RVB
mission
Safety
damage to
third parties
welfare
Health
convenience
& comfort
Quality
financial
damage to
user
security
internally
and
externally
Energy
energy
efficiency
emission
Environ-
ment
sustain-
ability
damage to
environment
damage to
owner
Fig. 2
In contrast with industrial asset management we are faced here with two sub-problems:
1. The mission statement in corporate real estate management is rather vague in
comparison with the predefined system requirements in industry; “The RVB
contributes to the successful operation of its customers by providing efficient and
effective housing solutions. With the preservation of monuments the RVB contributes
in the preservation of our cultural heritage” and cannot properly be quantified.
2. There is no clearly defined link between the functions of building elements and that
of the building; preventing the use of reliability block diagrams / fault trees.
The mission statement covers five main objectives (Fig. 2) that can be properly defined and expanded
into sub-objectives. For instance, safety is described as: “This task focuses on activities that
contribute to the safety of people in and around an object. A good security of people is characterized
by the absence of incidents involving personal injury, as well as an adequate social safety in the
operation in and around the object. Bodily injury includes both temporary or (semi-) permanent
impairment of physical health, temporary or permanent disability, with fatal injury as the most
extreme situation.” This objective implies two sub-objectives:
Limiting victims; Limiting both lethal and non-lethal, visible or invisible, physical or
psychological injury, of such a character that medical treatment is necessary.
Limiting damage to third parties: This includes property damage (money and resources),
except the victims, in the vicinity of the property. ("Area" is an elastic concept. Though the
formal responsibility mainly concerns the immediate vicinity of the property, as government
housing organization, we have a greater social responsibility)
In a similar way, the remaining objectives “Health”, “Quality”, “Energy” (consumption), and
“Environmental aspects” are described and subdivided.
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Needs for decision support models.
objective users
DSS model
based on AHP
RVB/ owner
RVB management
Asset manager
Dashboard
Overall Condition
Reporting
Analysis model
Grouping
Risk, action
Cost-benefit,
LCC
Effect
Condition
Activity
Prioritisation
RVB/ owner
Asset manager
Integral building
advisor
Information
model
Elements
Condition score
Database
Reference date
Elements
Score
RVB/ owner
Building inspector
model
In this process we recognise various actors with different needs for information (Fig. 3):
The responsible RVB manager and, potentially, a local asset manager will be interested in
overall information only. They need to be informed if the overall building condition exceeds
prescribed limits whereby the range in allowed condition score will depend on the type of
building (a monument versus a storage shed), the stipulations of the lease contract, the
strategic position of the building in the asset portfolio, the phase in commercialisation (new
versus end of life, plans for disposal), etcetera.
The RVB specialists and the integral building advisor needs more detailed information for
decision-making. They address the influence of condition scores of specific building elements
on the building performance and produce motivated investment plans for major
maintenance / renovation activities.
All these activities are based on a well-defined and updated asset register. This data base
provides information on the time dependency of element condition degradation thereby
improving future decisions in design and maintenance. The data base is filled by the reports
of the inspectors of various disciplines.
Like with all decision support systems utmost care needs to be taken to secure that the different
types of information can be changed only by certified staff.
Ranking the main and sub-objectives.
Given the disparate nature, the rather vague description and the lack of objective measures, we used
the AHP [2] technique to mutually rank the objectives. The AHP technique relies on pairwise
comparison of each objective on a scale from 1 – 9 (Table 1):
These pairwise comparisons are carried out for all objectives to be considered, leading to the AHP
matrix. The eigenvector of this matrix produces weighting factors, summing up to 1. The consistency
of the individual rankings can be checked by calculating the “Consistency Ratio” that compares the
ranked values with purely random judgements.
Fig. 3
5
1
Equal importance.
Two factors contribute equally to the objective.
3
Somewhat more
important.
Experience and judgement slightly favour one over the
other.
5
Much more important.
Experience and judgement strongly favour one over the
other.
7
Very much more
important.
Experience and judgement very strongly favour one over
the other. Its importance is demonstrated in practice.
9
Absolutely more
important.
The evidence favouring one over the other is of the highest
possible validity.
2,4,6,8
Intermediate values.
When compromise is needed
Table 1
In our approach, we first presented the problem statement and the concept of the AHP technique to
the RVB management team after which each team member made his / her individual rankings based
on their role in the team. In a subsequent meeting the individual scores were compared with the
(geometric) group averages which led to a fruitful discussion on the background of the deviations.
Eventually, a group decision was reached such, from that moment on, each objective in Fig. 2 has a
weighting factor that is endorsed by management.
It may well be that in future the RVB management team favours the use of different rankings for
buildings of different category (say, monuments versus office buildings). Next generations of the
management team may have different preferences leading to changes in the weighting factors used
that far. The consequence will be that major maintenance activities from that moment on will be
ranked differently in terms of cost – benefit but the systematics of the approach will remain
unaffected.
Modelling a building.
In industrial reliability engineering the concept of functional decomposition is used to describe a
system and analyse its unit characteristics further via failure mode effect and criticality analyses
(FMECA) and, subsequentially, the system performance by reliability block diagrams (RBD’s) or fault
trees (FT’s ).
In the built environment this approach, in fact, is feasible only for building installations where the
system requirements are properly defined (for instance, the required temperature, humidity and
cleanliness of air in a HVAC system[3]) and the (replaceable) units that are required for fulfilling these
specifications are easily defined and its reliability and repair characteristics can be estimated. For civil
structures such a system model is, in general, quite complex and the only information we may use is
a measure of observed condition.
Still, we observe that although most buildings are rather unique from an architectural point of view
they are composed of similar or comparable building elements (sub-parts) which together are
required to fulfil the necessary functions. Hence, we may follow a similar approach of functional
decomposition, grouping, for instance, all components that are required for the structural aspects,
the electricity supply, climate technology, transport of people and goods, … Currently, however, this
clashes with the formulation of SLA contracts that are concluded with individual civil, electrical
installation, heating, air conditioning, …. contractors. This led us to use solely a standard list of
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building elements, part of which is given in Fig. 4, as a basis both for the 5 yearly inspections as well
as for the formulation of the integral maintenance advice report.
Information on condition.
The Dutch standard on condition of building components NEN 2767 [4] uses an ordinal scale of 1 to 6
to represent the development of ageing and wear from an initial “excellent” state to the demolition
phase 6 “ very bad”:
condition
description
1
Excellent - good
2
Good
3
Reasonable - mediocre
4
Mediocre
5
Bad – very bad
6
Very bad
Table 2
These rather imprecise rankings are substantiated (
Fig. 5) by observing a defined deterioration process (say, corrosion) with a description of the “ size”
(ranging from 1 to 4, small to large) and the “ intensity” (1 – 3). It will be clear from the above that
this type of information (ordinal scale, imprecise description) does not lend itself for elaborate
mathematical optimisation procedures.
element
code
desc ription SEL
Integral
replacement
value
160100 Foundation Construction (m2 footprint) -€
170000 Pile foundations (m2 footprint) -€
210000 facade -€
222100 Interior walls -€
231100 Indoor Floor Construction (incl. balcony) -€
240100 stairway inside -€
240800 Ladders and crampons outside 2,780€
270100 roof construction -€
270300 Shed 13,900€
281200 Skeleton Part inside -€
310100 Frames outside 917,500€
310520 Insulating glazing outside 79,620€
313000 doors outside 10,170€
323000 doors inside 40,210€
471100 Roofing flat roof 45,540€
472300 fall protection 10,110€
661100 Lift installation 91,600€
751300 Facade maintenance facility 156,200€
851200 Heat generation unit ( eg boilers ) 40,440€
852110 Rainwater within 10,110€
852400
Combined sewer drain rainwater and wastewater disposal
32,610€
853103 Water pipes fittings accessories 85,630€
853105 protection of drinking water ( eg valve ) 4,160€
853140 Pressure boosting system 8,720€
853213 Electric water heater 5,810€
855200 Cold generation unit central 309,490€
855301 Distributor / collector cooling 20,540€
855303 Pipeline fittings & accessories. cool 47,390€
855306 Expansion Cooling Services 7,900€
856101 Distributor / collector heating 9,480€
856103 Access heating pipeline 147,860€
856109 Expansion heating services 8,000€
856117 Heat emission element 419,640€
857200 Extractors 22,220€
857510 Air handling units (LBKs) 142,180€
857704 Fire damper 32,860€
857714 Ducts, app. and insulation 602,920€
858110 Divide / climate control box 107,420€
861111 Emergency Power Generator 21,360€
861112 Emergency Lighting Unit + cabled. 15,350€
861200 Grounding general 1,160€
861300 Wiring / electrical distribution 202,200€
861420 High Voltage Distribution device 14,150€
861500 (Main) manifold Light / Power 55,870€
861710 Lightning Protection System 53,710€
863140 Light Fixtures 665,250€
864210 Telephone installation 137,880€
864410 Data installation 176,930€
864620 Central antenna system 1,390€
865110 Fire Alarm System 75,210€
865130 Local fire extinguishers 20,480€
865135 Dry fire main 10,740€
865140 Fireproof conduit 55,610€
865210 Burglary Signaling Install. 67,140€
865310 Sun protection installations outside 263,360€
865400 Social alarms 3,890€
867300 Building management system 3,920€
874100 Toilet group 13,649€
Fig. 4
7
Fig. 5
Fig. 6
RVB experts prescribe the type of inspection (B,O,E,I) to be carried out. The observed NEN 2767
conditions are stored (Fig. 6) in the AHP software package. Note that an individual element may
have different scores for each aspect. For instance, the façade scores “excellent” for the aspects
“fire” and “maintenance” but has a ranking 4 (mediocre) for “energy”. These figures are to be
regarded as the final, overall judgement from one of the inspection teams; in the associated report
this figure is substantiated by an extensive description of the observed phenomena.
element
code
desc ription SEL
Integral
replacement
value
B
CB
O
CB
E
CB
I
CB
160100 Foundation Construction (m2 footprint) -€ 1 1
170000 Pile foundations (m2 footprint) -€ 1
210000 facade -€ 1 1 4
222100 Interior walls -€ 5 1
231100 Indoor Floor Construction (incl. balcony) -€ 1 1 4
240100 stairway inside -€ 1 1
240800 Ladders and crampons outside 2,780€ 1 1
270100 roof construction -€ 1 1
270300 Shed 13,900€ 5
281200 Skeleton Part inside -€ 1 1
310100 Frames outside 917,500€ 1 1 6
310520 Insulating glazing outside 79,620€ 1 1 4
313000 doors outside 10,170€ 1 1 4
323000 doors inside 40,210€ 1 1
471100 Roofing flat roof 45,540€ 1 1 4
472300 fall protection 10,110€ 1 1
661100 Lift installation 91,600€ 3 5 1
751300 Facade maintenance facility 156,200€ 2 1
851200 Heat generation unit ( eg boilers ) 40,440€ 3 1 1
852110 Rainwater within 10,110€ 2
852400
Combined sewer drain rainwater and wastewater disposal
32,610€ 2
853103 Water pipes fittings accessories 85,630€ 2 4 1
853105 protection of drinking water ( eg valve ) 4,160€ 3 1
853140 Pressure boosting system 8,720€ 3 5
853213 Electric water heater 5,810€ 3 4 1
855200 Cold generation unit central 309,490€ 3 5 3
855301 Distributor / collector cooling 20,540€ 3
855303 Pipeline fittings & accessories. cool 47,390€ 2
855306 Expansion Cooling Services 7,900€ 3
856101 Distributor / collector heating 9,480€ 2 4
856103 Access heating pipeline 147,860€ 2
856109 Expansion heating services 8,000€ 3
856117 Heat emission element 419,640€ 3 5
857200 Extractors 22,220€ 3 4
857510 Air handling units (LBKs) 142,180€ 2 3 3
857704 Fire damper 32,860€ 1 3
857714 Ducts, app. and insulation 602,920€ 3 4
858110 Divide / climate control box 107,420€ 3 3
861111 Emergency Power Generator 21,360€ 3 4
861112 Emergency Lighting Unit + cabled. 15,350€ 1 3
861200 Grounding general 1,160€ 2 1
861300 Wiring / electrical distribution 202,200€ 2 4
861420 High Voltage Distribution device 14,150€ 2 1
861500 (Main) manifold Light / Power 55,870€ 3 5
861710 Lightning Protection System 53,710€ 2 1
863140 Light Fixtures 665,250€ 3 2
864210 Telephone installation 137,880€ 3
864410 Data installation 176,930€ 3
864620 Central antenna system 1,390€ 3
865110 Fire Alarm System 75,210€ 4 3
865130 Local fire extinguishers 20,480€ 3 3
865135 Dry fire main 10,740€ 1 3
865140 Fireproof conduit 55,610€ 3 3
865210 Burglary Signaling Install. 67,140€ 3
865310 Sun protection installations outside 263,360€ 3 1
865400 Social alarms 3,890€ 2
867300 Building management system 3,920€ 3 1
874100 Toilet group 13,649€ 1
DEFECT INTENSITY
< 2% INCIDENTAL 2 - 10 % LOCAL
10 -30 %
REGULARLY
30 - 70%
SIGNIFICANT
> 70 %
GENERAL
BEGIN 1 1 1 1 2
EVIDENT 1 1 1 2 3
FINAL PHASE 1 1 2 3 4
BEGIN 1 1 1 2 3
EVIDENT 1 1 2 3 4
FINAL PHASE 1 2 3 4 5
BEGIN 1 1 2 3 4
EVIDENT 1 2 3 4 5
FINAL PHASE 2 3 4 5 6
MAGNITUDE
SLIGHT
SERIOUS
GRAVE
8
If all inspection reports are available and the BOEI condition scores filled in as described above, these
conditions need to be linked with the (sub)objectives. With the previously described lack of system
model this task is performed by an RVB expert and secured in the software.
Fig. 7
Fig. 7 shows an example of such a grouped list of element conditions. Note that an individual
element may result in several, not necessarily identical, inspection scores under the various sub-
objectives.
At this point we can evaluate the list of scores for each sub-objective. Fig. 8 shows, for example, 25
scores under the heading S-O 1.1 “limit # victims”; 16 at condition 1, 2 at condition 2, 2 at condition
3, 3 at 4, 2 at 5 and zero at condition 6. An average representation then is 1.92, although this figure is
debatable since we deal here with ordinal scales; the distribution of the condition scores is more
relevant. This process is repeated for the second sub-objective S-O 1.2 “limit damage to 3rd parties”
with 17 scores.
These results are aggregated at the objective level “safety” using the (AHP) weighting scores
1
0.7 for
S-O 1.1 and 0.3 for S-O 1.2, respectively. This leads to a weighted number of scores
(
of 22.6, a similarly weighted average of
1.86 and weighted number of individual scores of 15.1, 1.4, 1.7, 2.7, 1.7 and 0 for the categories 1 –
6. Repeating this process for the remaining objectives, we are in a position to aggregate these scores
1
The AHP weighting factors in this paper are for illustrative purposes only.
element
code
desc ription SEL
Integral
replacement
value
B
CB
O
CB
E
CB
I
CB
SUB-OBJEC TIVES
RANKING
D1.1
limit # victims
D1.2
limit damage
to 3rd parties
D2.1
convenience &
comfort
D2.3
wellfare
D3.1
limit financial
damage to
owner
D3.2
limit damage
to owner
sec urity
internally
externally
D4.1
energy
effic iency
D4.2
emission
D5.1
durability
D5.2
damage to
environment
160100 Foundation Construction (m2 footprint) -€ 1 1 0.27 1 1 0
170000 Pile foundations (m2 footprint) -€ 1 0.09 0 1 1
210000 facade -€ 1 1 4 2.54 1 1 4 4 1 1 1 4 4 4 1
222100 Interior walls -€ 5 1 1.10 5 1 1
231100 Indoor Floor Construction (incl. balcony) -€ 1 1 4 2.38 1 4 4 1 1 1 4 4 4
240100 stairway inside -€ 1 1 0.09 0 1 1
240800 Ladders and crampons outside 2,780€ 1 1 0.03 0 1
270100 roof construction -€ 1 1 0.39 1 1 1 1 1
270300 Shed 13,900€ 5 0.46 0 5 5
281200 Skeleton Part inside -€ 1 1 0.39 1 1 1 1 1
310100 Frames outside 917,500€ 1 1 6 3.42 1 6 6 1 1 1 6 6 6
310520 Insulating glazing outside 79,620€ 1 1 4 2.47 1 1 4 4 1 1 1 4 4 4
313000 doors outside 10,170€ 1 1 4 2.38 1 4 4 1 1 1 4 4 4
323000 doors inside 40,210€ 1 1 0.27 1 1 1
471100 Roofing flat roof 45,540€ 1 1 4 1.19 1 1 1 4 4 4
472300 fall protection 10,110€ 1 1 0.18 0 1 1 1
661100 Lift installation 91,600€ 3 5 1 1.39 0 3 3 5 5 5
751300 Facade maintenance facility 156,200€ 2 1 0.27 0 1 2 2
851200 Heat generation unit ( eg boilers ) 40,440€ 3 1 1 0.96 0 1 1 1 3 3 1 1 1 1
852110 Rainwater within 10,110€ 2 0.19 0 2 2
852400
Combined sewer drain rainwater and wastewater disposal
32,610€ 2 0.33 0 2 2 2
853103 Water pipes fittings accessories 85,630€ 2 4 1 0.27 0 1 2 2
853105 protection of drinking water ( eg valve ) 4,160€ 3 1 0.37 0 1 3 3
853140 Pressure boosting system 8,720€ 3 5 1.39 0 3 3 5 5 5
853213 Electric water heater 5,810€ 3 4 1 1.26 0 1 3 3 4 4 4
855200 Cold generation unit central 309,490€ 3 5 3 3.09 0 5 5 3 3 5 5 5 3
855301 Distributor / collector cooling 20,540€ 3 0.28 0 3 3 0 0 0
855303 Pipeline fittings & accessories. cool 47,390€ 2 0.19 0 2 2
855306 Expansion Cooling Services 7,900€ 3 0.28 0 3 3
856101 Distributor / collector heating 9,480€ 2 4 1.08 0 2 2 4 4 4
856103 Access heating pipeline 147,860€ 2 0.19 0 2 2 0 0 0
856109 Expansion heating services 8,000€ 3 0.28 0 3 3
856117 Heat emission element 419,640€ 3 5 2.88 0 5 5 3 3 5 5 5
857200 Extractors 22,220€ 3 4 2.36 4 4 3 3 4 4 4
857510 Air handling units (LBKs) 142,180€ 2 3 3 2.25 2 3 3 3 3 3 3 3
857704 Fire damper 32,860€ 1 3 0.49 1 3 3
857714 Ducts, app. and insulation 602,920€ 3 4 1.17 3 3 4 4 4
858110 Divide / climate control box 107,420€ 3 3 1.84 3 3 3 3 3 3 3 3
861111 Emergency Power Generator 21,360€ 3 4 1.47 4 4 3 3 3
861112 Emergency Lighting Unit + cabled. 15,350€ 1 3 0.49 1 3 3 3
861200 Grounding general 1,160€ 2 1 0.48 1 1 2 2 2
861300 Wiring / electrical distribution 202,200€ 2 4 1.37 4 4 2 2 2
861420 High Voltage Distribution device 14,150€ 2 1 0.48 1 1 2 2 2
861500 (Main) manifold Light / Power 55,870€ 3 5 1.76 5 5 3 3 3
861710 Lightning Protection System 53,710€ 2 1 0.48 1 1 2 2
863140 Light Fixtures 665,250€ 3 2 1.61 3 3 3 3 3 2 2 2
864210 Telephone installation 137,880€ 3 0.17 3 3
864410 Data installation 176,930€ 3 0.17 3
864620 Central antenna system 1,390€ 3 0.17 3
865110 Fire Alarm System 75,210€ 4 3 1.11 4 3 3
865130 Local fire extinguishers 20,480€ 3 3 0.90 3 3 3
865135 Dry fire main 10,740€ 1 3 0.49 1 3 3
865140 Fireproof conduit 55,610€ 3 3 1.17 3 3 3 3
865210 Burglary Signaling Install. 67,140€ 3 0.17 3 3
865310 Sun protection installations outside 263,360€ 3 1 1.37 3 3 3 3 1 1
865400 Social alarms 3,890€ 2 0.53 2 2
867300 Building management system 3,920€ 3 1 1.39 3 3 3 3 3 1 1 1
874100 Toilet group 13,649€ 1 0.09 1 1
9
Fig. 8
at building level. The building reaches an overall score of 2.7, 35 % of the observed conditions are at
the level 1 “Excellent – good”, but we also note some 25% at level 3 “Reasonable – mediocre” and
some 2 % at the level 6 “Very bad”.
The advisor uses this information in his/her integral advice report, in three subsequent steps:
1. The building owner needs to adhere to building regulations and will normally agree a
minimum condition level in the lease for a specific type of building. Any violation of this type
needs to be solved or further negotiated. The advisor will use the software package to easily
observe such intolerable conditions. This will lead to a first set of indispensable maintenance
activities, the costs of which form a lower threshold.
2. The advisor will observe a multitude of conditions that warrant improvement. Rather than
following his own technical insight, the advisor now is forced to use a ranking that is provided
by the software package; the importance of a given NEN condition score depends on:
a. The number of sub-objectives that are involved.
b. The relative value to the RVB mission as expressed by the AHP weighting scores. For
each element:
c. If the advisor proposes one of these activities he has to add the costs to the budget
which normally shows a ceiling that determines the total financially accepted scope
and thus provides a cut-off point.
d. Note that the ranking at condition scores is a starting point only for a more detailed
analysis that is required in the in the integral advice report. The advisor has to
TOTAAL
OVERALL SCORE
2.80
21.1
2.80
% # of condition 1 34.6
% # of condition 2 9.0
% # of condition 3 25.6
% # of condition 4 19.2
% # of condition 5 9.4
% # of condition 6 2.3
OBJECTIVES
O1
SAFETY
O2
HEALTH
O3
USABILITY
O4
ENERGY
EFFICIENCY
O5
ENVIRONMENT
WEIGHTING FACTOR 0.30 0.30 0.12 0.04 0.20
SCORE 1.86 3.71 2.23 3.69 2.99
weighted number 22.6 14.0 47.5 19.7 14.4
average 1.86 3.7 2.2 3.7 3.0
w. # condition 1 15.1 1.0 13.2 2.7 2.7
w. # condition 2 1.4 0.0 9.9 1.0 1.0
w. # condition 3 1.7 5.0 23.6 2.0 1.7
w. # condition 4 2.7 5.0 0.0 9.0 5.9
w. # condition 5 1.7 2.0 0.8 4.0 2.6
w. # condition 6 0.0 1.0 0.0 1.0 0.7
SUB-OBJECTIVES
S- O1.1
limit # victims
S- O1.2
limit damage
to 3rd parties
S- O2.1
convenience &
comfort
S- O2.2
wellfare
S- O3.1
limit financial
damage to
owner
S- O3.2
limit damage
to owner
security
internally
externally
S- O4.1
energy
efficiency
S- O4.2
emission
S- O5.1
durability
S- O5.2
damage to
environment
WEIGHTING FACTOR 0.70 0.30 0.50 0.50 0.50 0.30 0.20 0.70 0.30 0.65 0.35
SCORE 1.92 1.71 3.71 3.71 2.30 2.30 1.95 3.65 3.79 3.65 1.75
number 25 17 14 14 57 50 20 20 19 20 4
average 1.92 1.71 3.71 3.71 2.30 2.30 1.95 3.65 3.79 3.65 1.75
#condition 1 16 13 1 1 15 13 9 3 2 3 2
#condition 2 2 0 0 0 12 11 3 1 1 1 1
#condition 3 2 1 5 5 29 25 8 2 2 2 1
#condition 4 3 2 5 5 0 0 0 9 9 9 0
#condition 5 2 1 2 2 1 1 0 4 4 4 0
6
#condition 6 0 0 1 1 0 0 0 1 1 1 0
0.00
weighted number
average
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
1 2 3 4 5 6
Building condition, % total score
10
describe the link between observed / in near future expected conditions and the
risks of not meeting functionality or building standards. A total lifecycle cost
evaluation has to be provided.
3. The advisor will use this crude list to evaluate a more integral evaluation. In practice the
execution of one specific activity may lead to the opportunity of executing another activity at
much lower costs. For instance, if one replacement requires the use of scaffolding, he may
study other activities that could benefit from the then existing scaffolding and thus can cost-
effectively be executed.
Fig. 9 Example of ranking
The ranked list (Fig. 9) shows that the replacement of all window frames, at a cost of € 917500, leads
to the most significant contribution since they score “very bad” (condition 6) w.r.t. energy and image.
The cold generator unit is a second candidate, followed by replacement of all radiators (heat
emission element). Obviously, the selection of candidates requires more information than these
simple numbers. Take the window frames with an investment of around 1 million euro, they will last
for another 30 – 50 years; will the building be used that long? Are other measures available that,
although not bringing the condition back to 1 but say to 3 commercially more interesting?
Fig. 10 condition window frames from 6 to 3
Fig. 10 shows the window frame condition change from 6 to 3 (say, using double window frames).
The overall building score (Fig. 11) improves from 2.8 to 2.7 at maybe half the original costs.
desc ription SEL
Integral
replacement
value
B
CB
O
CB
E
CB
I
CB
SUB-OBJECTIVES
RANKING
D1.1
limit # vict ims
D1.2
limit damage
to 3rd parties
D2.1
convenience &
comfort
D2.3
wellfare
D3.1
limit financial
damage to
owner
D3.2
limit damage
to owner
sec urity
internally
externally
D4.1
energy
effic iency
D4.2
emission
D5.1
durability
D5.2
damage to
environment
Frames outside 917,500€ 1 1 6 3.13 1 6 6 1 1 1 6 6 6
Cold generation unit central 309,490€ 3 5 3 2.85 0 5 5 3 3 5 5 5 3
Heat emission element 419,640€ 3 5 2.64 0 5 5 3 3 5 5 5
facade -€ 1 1 4 2.35 1 1 4 4 1 1 1 4 4 4 1
Insulating glazing outside 79,620€ 1 1 4 2.28 1 1 4 4 1 1 1 4 4 4
Indoor Floor Construction (incl. balcony) -€ 1 1 4 2.19 1 4 4 1 1 1 4 4 4
doors outside 10,170€ 1 1 4 2.19 1 4 4 1 1 1 4 4 4
Extractors 22,220€ 3 4 2.16 4 4 3 3 4 4 4
Air handling units (LBKs) 142,180€ 2 3 3 2.11 2 3 3 3 3 3 3 3
(Main) manifold Light / Power 55,870€ 3 5 1.76 5 5 3 3 3
Divide / climate control box 107,420€ 3 3 1.69 3 3 3 3 3 3 3 3
Light Fixtures 665,250€ 3 2 1.52 3 3 3 3 3 2 2 2
Emergency Power Generator 21,360€ 3 4 1.47 4 4 3 3 3
Wiring / electrical distribution 202,200€ 2 4 1.37 4 4 2 2 2
Building management system 3,920€ 3 1 1.34 3 3 3 3 3 1 1 1
Sun protection installations outside 263,360€ 3 1 1.33 3 3 3 3 1 1
Fireproof conduit 55,610€ 3 3 1.17 3 3 3 3
desc ription SEL
Integral
replacement
value
B
CB
O
CB
E
CB
I
CB
SUB-OBJECTIVES
RANKING
D1.1
limit # vict ims
D1.2
limit damage
to 3rd parties
D2.1
convenience &
comfort
D2.3
wellfare
D3.1
limit financial
damage to
owner
D3.2
limit damage
to owner
sec urity
internally
externally
D4.1
energy
effic iency
D4.2
emission
D5.1
durability
D5.2
damage to
environment
Frames outside ? 1 1 3 1.72 1 3 3 1 1 1 3 3 3
Cold generation unit central 309,490€ 3 5 3 2.85 0 5 5 3 3 5 5 5 3
Heat emission element 419,640€ 3 5 2.64 0 5 5 3 3 5 5 5
facade -€ 1 1 4 2.35 1 1 4 4 1 1 1 4 4 4 1
Insulating glazing outside 79,620€ 1 1 4 2.28 1 1 4 4 1 1 1 4 4 4
Indoor Floor Construction (incl. balcony) -€ 1 1 4 2.19 1 4 4 1 1 1 4 4 4
doors outside 10,170€ 1 1 4 2.19 1 4 4 1 1 1 4 4 4
11
Fig. 11 Results at building level.
Fig. 12 Replacing cold generation unit and radiators
If we leave the window frames at the existing condition but spend some 730 k€ on replacing the cold
generation unit and the radiators (Fig. 12) the overall building score (Fig. 13)improves from 2.80 to
2.5 but the owner still has to live with window frames that do not meet current requirements on
energy consumption.
Fig. 13 Results at building level.
The building advisor will discuss these alternatives with the RVB upon which the latter will take
specific decisions. The resulting change in element condition codes will be recorded in the database.
Conclusions and further work.
1. In comparison with industrial maintenance, Corporate Real Estate Management in general
lacks both quantified and measurable requirements at system level, proper system modelling
and information on failure behaviour of system components.
TOTAAL
OVERALL SCORE
2.71
21.1
2.71
% # of condition 1 34.6
% # of condition 2 9.0
% # of condition 3 27.9
% # of condition 4 19.2
% # of condition 5 9.4
% # of condition 6 0.0
weighted number
average
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
1 2 3 4 5 6
Building condition, % total score,
windows from 6 to 3
element
code
desc ription SEL
Integral
replacement
value
B
CB
O
CB
E
CB
I
CB
SUB-OBJECTIVES
RANKING
D1.1
limit # vict ims
D1.2
limit damage
to 3rd parties
D2.1
convenience &
comfort
D2.3
wellfare
D3.1
limit financial
damage to
owner
D3.2
limit damage
to owner
sec urity
internally
externally
D4.1
energy
efficiency
D4.2
emission
D5.1
durability
D5.2
damage to
environment
310100 Frames outside 917,500€ 1 1 6 3.13 1 6 6 1 1 1 6 6 6
855200 Cold generation unit central 309,490€ 1 1 1 0.64 0 1 1 1 1 1 1 1 1
856117 Heat emission element 419,640€ 1 1 0.56 0 1 1 1 1 1 1 1
210000 facade -€ 1 1 4 2.35 1 1 4 4 1 1 1 4 4 4 1
TOTAAL
OVERALL SCORE
2.50
21.1
2.50
% # of condition 1 40.5
% # of condition 2 9.0
% # of condition 3 24.3
% # of condition 4 19.2
% # of condition 5 4.7
% # of condition 6 2.3
weighted number
average
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
1 2 3 4 5 6
Building condition, % total score
replacing cgu and radiators
12
2. The mission of the Dutch Government Real Estate Agency (RVB) can be subdivided in five
main objectives (safety, health, quality, energy and environmental aspects); some of which
can be further divided in sub-objectives. Using the AHP pairwise comparison technique the
members of the responsible RVB management team defined subjective rankings that express
their views on the individual importance of these items.
3. Information on the condition of many building elements is obtained from five yearly
inspection reports where teams of hired-in certified inspectors score elements in four
categories (“fire”, “maintenance”, “energy”, “laws and regulations”) with condition numbers
according to an existing Dutch norm N2767 subsequent to a detailed inspection report.
4. A hired-in building advisor subsequentially uses these inspection reports to formulate a
budget proposal (integral advice report) in order to cost effectively maintain the overall real
estate condition in line with the mission of the RVB using a newly developed software
package. In this package the AHP scores are used as weighting factors for decision support;
RVB experts prescribe the link between condition scores and sub-objectives.
5. The new package provides a transparent overview of these conditions at building element
level and determines their effect on the sub- and main mission objectives. The building
advisor easily identifies compulsory actions (elements for which the condition clashes with
rules or contract stipulations) that form the lower basis of a multiannual maintenance
budget. He/she may easily rank elements in terms of contribution to the mission objectives
and use this ranking in identifying a series of cost-effective maintenance solutions. The
budget ceiling for a given object in a given time period provides a natural cut-off point.
Having such a list, a third optimization round will identify combinations of maintenance
activities for which the costs of combined execution provides a cost-effective opportunity.
6. The package covers the needs of all involved parties.
For RVB management it calculates an overall building performance (dashboard
function) that may be used to classify building categories and functions as a key
performance indicator; deviations of which can easily be reported.
For RVB experts and building advisors it provides decision support on cost-effective
maintenance following the mission of the RVB (the analysis function).
The condition scores of inspection results and implemented maintenance activities
are properly registered in the database.
7. This AHP approach is now used on a trial basis in the RVB organisation and is taught at
university courses the advisor has to follow in order to become certified. First results are
promising; the advices produced are sometimes unexpected compared with a traditional
purely technical approach but are understood and accepted by building experts and
contractors.
8. The charm of the method lies with its structure and integral character. It allows the RVB
management to steer activities by changing the AHP weighting factors for different classes of
buildings or different political situations without sacrificing the structured approach. It
ensures that all building elements are properly taken into account with respect to the
mission of the RVB independent from cultural or purely traditional technical preferences. By
using this system, the RVB will automatically build up a reliable data base on the time
dependent behaviour of building elements and thereby contributes to a learning
organisation.
13
9. This concept is planned to be integrated with a commercial building maintenance
information system (Condor) making this new approach available to the corporate real estate
market as a whole.
In the meantime the AHP concept has successfully been used in another decision support tool EPI-
CREM [5], in this case for energy performance optimisation. The AHP approach in obtaining
consensus between disparate parties (principal versus building contractors) also showed to be
effective in system oriented contract management. In one case, 18 (competing) contractors took part
in AHP rankings at three organisational levels; business management, contract manager and contract
administrator. The outcome of this study was that parties agreed that the original number of 176
risk factors could be aggregated to 6 only and 24 conditions / terms into 15; definitions and
objectives were adapted and KPI’s for service level agreements mutually accepted.
References.
[1] Rgd, "RgdBOEI: inspecties nieuwe stijl (RgdBOEI: inspections new style)," ed:
www.rgdboei.nl.
[2] T. L. Saaty, The Analytic Hierarchy Process: Planning, Priority Setting, Resource Allocation.
New York: McGraw-Hill, 1980.
[3] C. F. H. van Rijn, R. G. Kollaard, and C. M. van de Sande, "Technical lifetime of HVAC
installations, an opportunity or a threat for installation contractors?," presented at the 44th
ESReDA seminar on Asset Management Stakeholders and Risk Assessment Methodologies,
Porto, Portugal, 2013.
[4] NEN, "Conditiemeting - Deel 1: Methodiek " vol. NEN 2767-1:2011, ed: Nederlands
Normalisatie Instituut, 2011.
[5] I. Gursel Dino, R. Leeuw, S. Sariyildiz, and R. Stouffs, "Method for Energy Performance
Integration in Corporate Real Estate Management," Journal of Performance of Constructed
Facilities, pp. 286-302, 2014.