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In the context of building construction industry, the phrase means that 'a building will tend to be defective if the designer or the architect in charge fails to plan well'. Design defects often require corrective measures such as maintenance during the post-occupational stage.
A lot of buildings have been erected in Malaysia nowadays to meet the rising demands of both private and public sectors. It is assumed that many errors will arise during design and construction phase which will result in higher maintenance costs in the later stage.
Generally, the increase in the maintenance cost is caused by the defective designs. The increased maintenance cost often used as an excuse for building owners for not carrying out maintenance on their buildings. This resulted in deterioration of the building which may cause it to be collapse or demolished.
Therefore, it's essential for the maintenance aspects to be put into consideration during the design stage. This is because improper decisions made during design and construction stage might place a heavy burden on the maintenance costs of the building and also its life cycle.
1.1 Problem statement
The study by Building Research Establishment showed that 58% of defects were caused by design defects, 35% from wrong installation techniques, 12% from inferior materials and 11% from unexpected user requirements (Seeley, 1987). It showed that improper designs decisions will yield lower construction quality and in turn, causes defects during the life span of the building.
Gibson (1979) found that poor decisions made during design stage that lead to occurrences of defects during post-occupational stage can be avoided. Large chunks of maintenance expenditures can be cut down provided that the design and construction defects are known and reduced.
In United Kingdom, about 20% of the average annual expenditure of building repairs is used on defects caused by designs and construction. According to Gibson (1979), cutting down on the design and construction defects will reduce the maintenance expenditure. This statement was supported by Assaf et al., 1996 which stated that the maintenance expenditure can be lessen by reducing the numbers of defective designs.
Arditi (1999) points out that the influence of design on the maintenance of buildings is greater than ever before. He further elaborates that issue of building maintenance is a universal one and its consideration at the design stage is of great importance on the future performance of the building.
A study of Foo (1989) highlights the issue of faulty design as, in recent years many defects, premature maintenance and failure are occurring in relatively new building. Che-Ani et al (2009) states that newly built structures are subjected to intensive maintenance nowadays and sometimes require revised design and reworks.
Hence, it can be deduced that maintenance can be reduced if there is a good building design which takes into account the maintenance considerations in the later stage. There is a mutual relationship between design and maintenance where satisfactory design is known as requiring less maintenance.
This research was conducted to raise awareness among local architects and building designers of the importance of incorporating the need of building maintenance during design stage.
1.2 Research Objectives
This research designed to meet the following objectives:
To study the implications of design defects on building maintenance
To recognize the defects that is affecting building maintenance
To recommend ways to improve building maintenance
To recommend ways to deal with the defects
1.3 Research Scope
This research report aims to study the implications of design defects on building maintenance. The study will be carried out either building within around University of Malaya or within the Klang Valley, Malaysia. Emphasis is given for building that is maintained by in-house maintenance or employed maintenance contractor.
The literature review will be conducted in four stages, which are:-
A review will be adopted through topic related literatures such as reference books, articles in the refereed and normal journals, seminars and conference papers. The referred literatures will be ensured its reliability, validity and originality before it is being included in the research. All references will be cited accordingly to its sources.
Data collection will be done through questionnaire and interview. Questionnaire will be given out to the building occupants, maintenance staff of the building and also maintenance contractors (if there is any) assigned to carry out maintenance work at the building. The same also applies to the interview session in order to obtain information regarding the dilapidation condition of the building.
Data analysis will be done through suitable computer software such as Microsoft Excel and Statistical Package for the Social Science (SPSS). The data will be evaluated and examined. Tables and charts will be produced by converting statistical value through statistical analysis
The findings obtained are summarized and the results evaluated. The outcomes then will be compared to the initial objectives. The conclusion will tie the result of the research to the objectives, and subsequently determine if the is relevant to the problem statement.
CHAPTER 2: BUILDING MAINTENANCE
The definition in BS 3811: 1993 (BSI, 1993) stated that the definition of maintenance is as follow:
The combination of all technical and administration action, including supervision actions, intended to retain an item in, or restore it to, a state in which can perform at its required function.
According to the definition in BS 3811: 1993, there are two processes envisaged as building maintenance, they are:
Retaining - work carried out in anticipation of failure which is usually referred to preventive maintenance and
Restoring - corrective works carried out after failure which is usually referred to corrective maintenance.
Chanter (2007) mentioned organisational aspects such as administration and supervision is being stressed based on building maintenance definition which reflects an increasing trend of initiation, financing and organization in building maintenance besides mere physical maintenance work.
Alner and Fellows (1990) and Horner et al (1997) suggested that building maintenance is to ensure that building is in safe condition and safe to be occupied, meets all the statutory requirements and to maintain the value and quality of the building by carry out necessary work.
In other way, Horner et al (1997) quoted from Seeley (1976) defined building maintenance as "work undertaken in order to keep, restore or improve every part of a building, its services and surrounds, to a currently accepted standard, and to sustain the utility and value of the building". This definition has been supported by Piotrowski (2001) as he highlights that building maintenance is to retain the building in a proper condition.
A more functional definition proposed by White (1969) which termed maintenance as "a synonymous activity which controls the condition of the building so that it patterns lies within specified regions". The definition suggests that maintenance is a positive activity, which is controlled and planned in order to achieve a defined end result. The term "specified regions" also can be interpreted as "acceptable standards" and would be determined in an identical fashion.
RICS (1990), Bon and Pietroforte (1993), and Kherun et al (2002) states that building maintenance as the work undertaken to keep, restore and improve every part of a building either by improvement, refurbishment, maintenance and repair works.
2.2 Types of maintenance
Seeley (1987) quoted from BS 3811 states that building maintenance is divided into two major types which are planned maintenance and unplanned maintenance. This has been supported by Swallow (2007) and Kothamasu et al (2006) which also agreed that maintenance is divided into planned or proactive and unplanned or reactive maintenance. Horner (1997) points that there are few alternatives strategies and decisions available to the management that needs to be considered in maintaining a building. They are:
These strategies are put into good use when deciding whether to repair or replace an item and to carry out periodic maintenance at fixed intervals or upon requests from the users. Figure 2.1 shows the types of maintenance stated by Seeley (1987) which is also supported by Swallow (2007) and Kothamasu et al (2006) while Figure 2.2 shows the three types of maintenance strategies stated by Horner et al (1997).
Maintenance or Proactive
Maintenance or Reactive
Reliability Centered Maintenance
Condition Based Maintenance
Constant Interval Maintenance
Age Based Maintenance
Time Based Maintenance
Figure 2.1: Types of Maintenance
(Source: Seeley, 1987; Kothamasu et al, 2006; Swallow, 2007. Retrieved on November 5, 2010)
Carried out based on condition of item
Use condition monitoring tools
Figure 2.2: Maintenance Strategies
(Source: Horner et al, 1997. Retrieved on November 5, 2010)
2.2.1 Planned Maintenance
According to BS 3811, planned maintenance is defined as the "maintenance organised and carried out with forethought, control and use of records to a predetermined plan while unplanned maintenance is the maintenance carried to no predetermined plan". Planned maintenance is a routine maintenance which does not wait for the equipment to fail before commencing the maintenance operations. Planned maintenance is divided into two types which are preventive maintenance predictive maintenance. Cruzan (2009) states that there are some degree of similarities between preventive maintenance and predictive maintenance except that the former is time-based and latter is condition-based.
Benjamin (1994) and Kothamasu et al (2006) states that preventive maintenance involves restoration work that implement regularly or at predetermined intervals to prevent or reduce sudden failure of facilities. This is agreed by Horner et al (1997) which states that preventive maintenance tasks are performed at fixed intervals which based on operating time of the facilities according to a predetermined plan intended to reduce the probability of occurrence of failure.
According to Ruta and Graff (1997), preventive maintenance is to effect repairs before a failure or breakdown likely to occur, to eliminate or reduce actual failures or breakdowns and to reduce cost through managing work and downtime and offering greater utilization of any facility. This has been supported by Lewis (1999) who suggests that preventive maintenance involves periodic inspections which reveal any problems that might lead to the failure of facilities and fix it before any major repairs are required.
On the other hand, Rushlow and Kermath (1994) states that preventive maintenance is a systematic and routine maintenance process designed to extend the life of the building materials, components and systems. This has been agreed by Cruzan (2009) as he suggests that preventive maintenance is a scheduled program of regular inspections, adjustments, lubrications or replacement of worn or failing parts in order to maintain an asset's function and efficiency. The usage of the term "scheduled" and "regular" is intended to keep minor problems from escalating into major problems through periodic inspections regardless of the need.
Another definition by Lee (n.a.) states that preventive maintenance is a maintenance is based on replacing, overhauling or remanufacturing an equipment at a fixed interval. This has been agreed by Cruzan (2009) as he points out that tasks performed after breakdown of equipment is considered as repair which are expensive and time consuming. Normally, the failure to implement preventive maintenance on facilities will eventually end up adopting expensive and time consuming repair.
Advantages of preventive maintenance
According to Raymond and Joan (1991), preventive maintenance can reduce maintenance costs by avoiding the cost of consequential damage. Cruzan (2009) also agrees with the statement which opines that preventive maintenance helps to lengthening the life of equipment or facility, reducing the long term cost of owing the equipment and also reducing the expenses of hiring outside contractors.
Cruzan (2009) points out that one of the advantages of preventive maintenance is that it keeps the equipment life longer by implementing scheduled maintenance on regular basis so that any detected problems can be solved easily. This has been agreed by Rushlow and Kermath (1994) as they state that regular servicing and minor repairs through planned preventive maintenance extends building's useful life by interrupting the natural process of deterioration.
According to Horner et al (1997) quoted from Raymond and Joan (1991) states that the implementation of preventive maintenance can improve the health and safety of the building occupants. This has been supported by Cruzan (2009) as he states that a simple preventive maintenance programme of scheduled inspections and repairs may keep the building occupants' complaints at bay.
On the other hand, preventive maintenance can reduce the building downtime or the out of service period of the building so that the habitability of the building can be increased (Raymond and Joan, 1991). Rushton (2007) highlighted that one of the advantages of preventive maintenance is that it can reduce emergency breakdowns or downtime and also reduce the time required for critical shutdowns or overhauls.
According to Cruzan (2009), predictive maintenance is used to keep equipment in good condition and fix problems before the equipment fails. This has been supported by Mobley (2002) which points out predictive maintenance is a process of monitoring the situation of the facilities in an attempt to detect any incipient problems and to prevents catastrophic failure. The idea of predictive maintenance is that regular monitoring of the actual facility condition, operating efficiency and other indicators of the operating condition will provide the data required to ensure maximum interval between repairs and minimize the number and cost of unscheduled failure.
As stated by Cruzan (2009) earlier on, the predictive maintenance is condition-based. The predictive maintenance tasks are scheduled after there is any occurrence of wear factor in the facility. This has been agreed by Ahuja and Khamba (2008) as predictive maintenance is often referred to as condition based maintenance. Ahuja and Khamba (2008) quoted from Vanzile and Otis (1992) states that predictive maintenance is initiated in response to specific equipment condition or performance deterioration.
Mobley (2002) quotes that predictive maintenance is a condition-driven preventive maintenance program which uses direct monitoring of the condition, system efficiency, and other indicators to determine the actual mean-time-to failure instead of relying on average life statistics to schedule maintenance activities.
Kelly and Harris (1978) states that predictive maintenance is carried out in response to a significant deterioration in a unit as indicated by a change in monitored parameter of the unit condition or performance.
Advantages of predictive maintenance
According to Cruzan (2009), predictive maintenance can minimize unscheduled breakdown of the facilities and ensure that repaired elements is in an acceptable condition. This has been supported by Kothamasu et al (2006) as he states that one of the advantages of the predictive maintenance is the prior warning of impending failure and increased precision in failure prediction. Mobley (2002) also agreed as he suggests that predictive maintenance reduces the number of unexpected failiures and provides a more reliable scheduled preventive maintenance tasks.
Kothamasu et al (2006) states that predictive maintenance also aids in diagnostic procedures as it is easy to associate the failure to specific components through the monitored parameters. This is agreed by Hornel et al (1997) as he points out that planned predictive maintenance is carried out by monitoring the building's elements and services in order to identify which components requires maintenance before major breakdown happens.
Mobley (2002) points out that predictive maintenance eliminate unnecessary problems which in turn extend the life span of the facilities. This has been supported Piotrowski (2001) as he states that predictive maintenance helps to increase the life span of the facilities and its availability.
2.2.2 Unplanned Maintenance
According to Seeley (1987) quoted from BS 3811, unplanned maintenance is a type of ad hoc maintenance which is carried out to no predetermined plan. Kothamasu et al (2006) went on to elaborate that unplanned maintenance is classified as legacy practice. According to Swallow and Shallow (2007), unplanned maintenance is normally associated with inadequate routine maintenance, ineffective replacement programme, lack of proper inspections on planned basis and inadequate data to enable the preceding items to be properly carried out. Unplanned maintenance is divided into corrective maintenance and emergency maintenance.
According to Horner et al (1997) quoted from David and Arthur (1989), corrective maintenance is maintenance which takes place in ad hoc manner in response to breakdowns or user requests. This has been supported by Kothamasu et al (2006) who states that corrective maintenance is the restoration process which is being performed after failure has occurred intended to restore the item so that it can perform at its required function.
Cruzan (2009) states that corrective maintenance is known as "reactive maintenance" or process of fixing or correcting something that is already broken and it is opposes to preventive maintenance which prevents problems before corrective maintenance is necessary. This type of maintenance is the most common type of maintenance done in most facilities and it cannot be eliminated even with the existence of effective preventive maintenance program.
According to Dhillon (2002), corrective maintenance refers to an unscheduled maintenance or repair carried out to return the facility to a defined state after perceived maintenance deficiencies.
The corrective maintenance can be divided into 5 major categories as stated below (Dhillon, 2002):-
The failed item is restored to its operational state
This element of corrective maintenance is concerned with disposal of non-repairable material and use of salvaged material from non-repairable equipment in the repair, overhaul, or rebuild programs
Involve restoration of an item to a standard as close as possible to original state in performance, life expectancy, and appearance.
Involves restoration of an item to its total serviceable state as per maintenance serviceability standards, using the "inspect and repair only as appropiate" approach.
Servicing is needed because of the corrective maintenance action.
Horner et al (1997) points out that corrective maintenance can be considered as one of the most expensive maintenance as the failure of one of the building element can yield catastrophic effect to other elements and the element can occur at any time which brings a lot of difficulties to both occupants and maintenance staffs.
According to by Seeley (1987) quoted from BS 3811, emergency maintenance is the "maintenance necessary to put in hand immediately to avoid serious consequences" and sometimes refer to day-to-day maintenance. This statement is supported by Kothamasu et al (2006) as he points out that emergency maintenance is defined as the maintenance that is supposed to be carried out immediately to avoid serious consequences such as breakdown or downtime.
Cruzan (2009) states that emergency maintenance involves effort that should be done immediately to curb maintenance issues that put facility and people at risk from further harm. Emergency maintenance has the largest cost per job as the appointment cost of outsource contractors is extremely high for emergency response and normally there is no time for contract tendering for emergency work which can result in higher costs.
2.3 Maintenance needs
According to Seeley (1987), the prime aim of maintenance is to preserve a building in its initial state, as far as practicable, so that it effectively serves it purpose. On the other hand, Rozita (2006) points out that building maintenance is to maximize the aesthetic and economic values of a building as well as increase the health and safety of the occupants.
Some of the purposes of maintaining buildings are (Seeley, 1987; Magee, 1988; Alner and Fellows, 1990):
Retaining value of investment.
Maintaining the building in a condition in which it continues to fulfil its function.
Presenting a good appearance.
Ensure that building and its services are in good condition.
Ensure that building is fit for use.
Ensure that building meets all statutory requirements.
Carry out work necessary to maintain the value and quality of building.
Perform daily housekeeping and cleaning to maintain a properly presentable facility.
Complete major repair based on lowest life-cycle cost.
Identify design and complete improvement projects to reduce and minimize total operating and maintenance costs.
Operate facility in the most economical while providing necessary reliability.
Provide for easy and complete reporting and identification of necessary repair and maintenance work.
Monitor the progress of all maintenance work.
Perform accurate cost estimating to ensure lowest cost solutions to maintenance problem.
Maintain a proper level of material and spare parts to support timely repairs.
Accurately track the costs of all maintenance work.
Schedule all planned work in advance, and allocate and anticipate staff requirements to meet planned and unplanned events.
Monitor the progress of all maintenance work.
Maintain complete historical data concerning the facility in general and equipment and components in particular.
Continually seek workable engineering solutions to maintenance problems.
2.4 Consideration of maintenance in design stage
Maintenance and design are habitually considered as if the two activities are unrelated. Maintenance is often regarded as self-contained and therefore leading to risk of undesirable divorce from other related functions. Nowadays, designers were not fully aware of the consequences of their designs after they completed their designs. Designers usually realize their mistakes or bad decisions that were taken during design stage only through post occupational survey or users' feedback (Chanter and Shallow, 2007 and Che-Ani et al, 2009). This is supported by Ramly et al (2006) as they points out that designer is always free from any of his faults once the building had been issued the certificate of fitness as designer won't be asked to bear the cost of the maintenance associated with the design faults.
According to Nor Haniza et al (2007), the actions of design and the consequences of their actions can be termed through the Newton's third law which states that 'For every action there is a reaction. This can be interpreted as 'there will be a consequence for every design decision made during the design stage'. This is supported by Seeley (1987) who states that maintenance can be positively or negatively influenced during the design stage. Seeley (1987) further elaborates that good maintenance practice begins from the single stroke of designer and skilful design can reduce the amount of maintenance work and also make it easier to perform.
Design team usually neglects the importance of maintenance considerations and it's important to reduce the big gap between design and maintenance. Maintenance should be considered right from the design stage in order to prevent the unplanned maintenance during post occupancy stage as design faults are expensive mistake in term of occupants' life and the restoration cost (Seeley, 1987 and Che-Ani et al, 2009). RICS (1990) claims that building designs should be considered as the design of the auto in order to reduce the gap between design and maintenance. This is done by providing a copy of manual which contain building design and product used in that design to each occupant.
Design plays an important role in determining the condition of the building after completion, especially the defects and maintenance. Design also indirectly influences the performance and physical characteristics of building and its durability to withstand against environmental condition, social interfaces such as graffiti and vandalism. As a result, the link between design and maintenance should not be interpreted as only increased cost involved in restoration, but it also need to consider the effect of design on structure and material installed as well as the life cycle of each component of building (Ramly, 2006).
It is emphasised that maintenance should be taken as an integral part of the whole design process and not only after the completion of construction process. Designer should contribute significantly to the reduction of maintenance problems during post occupancy stage by putting into considerations these questions when designing each component or part of the building (Seeley, 1987):
How can it be reached?
How long can it be cleaned?
How long will it last?
How can it be replaced?
Che-Ani et al (2009) quoted from Peacock (1986) points out that designers fail to reduce the numbers of maintenance which in turn causing costly unplanned maintenance in building mainly due to these factors:
unsatisfactory detailing in design,
incorrect selection of materials and components,
lack of standardization in design and,
fail to appreciate how the structure is used and maintained.
CHAPTER 3: BUILDING DEFECTS
According to Andi and Minato (2003), building defects can be defined as defective where it does not conform to the acceptable level of quality as required by owners, contractors, or applicable codes/regulations. Meanwhile, Watt (1999) states that a defect may be considered to be failing or shortcoming in the function, performance, statutory or user requirements of a building, and might manifest itself within the structure, fabric, services or other facilities of the affected building. When an inspection or survey is being undertaken, the set of requirements for the particular building type or use will help to set performance benchmarks against which the building can be measured. Where a performance benchmark is not achieved, this indicates a defect or deficiency, the severity of which is gauged by reference to the benchmark.
The rigorousness of a building defect and the related levels of damage, deterioration or decay currently present or expected to affect the building and its occupant are similarly related to the perceptions and expectations of the owner and occupier, and to various other stakeholders with interests in the well-being of the property. The defect, or the action required to reduce or remove its effect on the building, will typically be ranked according to a pre-determined set of priorities for repair, maintenance or other works to improve either performance or capability.
The various elements and associated service installations that make up a building, together with the contents that allow it to be used and enjoyed, are susceptible to various forms of defect and fault. Past and present research has helped to identify the principal causes, yet many of the problems relating to poor-quality design, construction, repair and maintenance continue to reduce the utility and value of the existing buildings.
Nature of Building Defects
Research into the technical quality of the design and construction of new housing some years ago revealed 955 different kinds of faults in low-rise, mainly two-storey, housing (Bonshor and Harrison, 1982). Just under half of these were judged to have originated on site, slightly fewer in design, and with a small remainder related to materials and components. Others significant factors included inadequate design information and poor site practices (Watt, 1999).
Most building defects are avoidable and they occur, in general, not through a lack of basic knowledge but by non-application or misapplication of it. Knowledge seems to become mislaid from time to time. Those with long memories and those whose business it is to make a particular study of building defects are often struck by the re-emergence of problems which have been well researched and documented.
Certain basic properties of materials, such as their ability to move through changes in temperature and moisture, seem to be overlooked and a rash of difficulties occurs. A call goes out for more research but, in truth, all that is usually needed is a good system for the retrieval of information, a better procedure for its dissemination and, most important, the realization that information search is desirable (Ransom, 1987).
Causes of Defects
A building may be defined as an imperfection deficiency or fault in a building element or component which adversely affects its functional performance or appearance. Some defects are the natural consequence of ageing and normal use but many premature failings can be traced to a lack of proper skill and care. A BRE study concluded that over 90 per cent of building defects could be explained partly or wholly as the result of readily identifiable faults in design or construction which could have been foreseen and hence prevented. Broadly, the causes may be attributed to the following (Lee, 1987):
Inadequate brief. It is often said that defects start on the drawing board but in some cases they can originate at an even earlier stage. For example, the brief may lay down totally unrealistic cost limits or fail to give vital information on the functional requirements of the building. Usually there is no indication of the likely period of use or of the client's attitude towards maintenance.
Faulty design decisions. The most common faults may be grouped as follows:
Failure to follow well established design criteria in the choice of structural system and selection of materials.
Ignorance of the basic physical properties of materials, e.g. failing to make allowance for the differing thermal and moisture movements of materials used in combination.
Use of new materials or innovative forms of construction which have not been properly tested in use. This is often the result of uncritical reliance on manufacturers' literature quoting simulated laboratory tests.
Misjudgement of user and climatic conditions under which the material will have to perform.
Complex details which have a low probability of successful execution on an open building site.
Poor communications between different members of the design and construction teams.
The fault may be traceable to component manufacturers, specialist subcontractors and consultants as well as the main designer. A less obvious design fault is the failure to consider the case with which components can be maintained and eventually replaced. For example, little thought is given to the standardization of components in order to reduce the need to carry a large variety of spare parts or to ensuring that access can be easily gained for servicing and cleaning.
Construction method. The conditions under which construction takes place are often far from ideal and, coupled with an emphasis on speedy completion, can result in careless and skimped work. Although the BRE study mentioned earlier showed that only a small proportion of defects were attributable to faulty materials it is apparent that some manufacturers of do-called high technology components have little awareness of the rigours of a building site or the standards of accuracy achievable under such conditions. Thus, whilst the materials may be perfect on leaving the factory they can quite easily be damaged in transit, loading and unloading, unsuitable conditions of storage on site and hoisting and placing in position, many such defects could be avoided by ensuring greater care at all stages in the process, proper training of operatives, and closer supervision. To tackle this problem the construction industry is beginning to introduce the quality assurance techniques developed in other industries such as Quality Assurance (QA) groups and circles (QC). Essentially these techniques consist of setting down appropriate inspection procedures and specifying levels of acceptance and rejection together with methods of sampling and testing the performance characteristics.
User activities. Defects may be caused by unintentional misuse through a lack of information on the correct mode of use, or by deliberate acts of vandalism. The solution is to provide the designer with more information on the degree of severity of use so that a better match can be made between the robustness of the fittings and finishing and the condition of use. Also, certain defects may be related to the social attitudes and financial circumstances of the user, for example, condensation is affected by the amount of money spent on heating and ventilating, and the occupancy pattern.
Maintenance. Incorrect identification of the true cause of a defect, and inappropriate remedial work, will not only do nothing to rectify the original defect but may substantially worsen the condition of the building. Similarly, lack of care in carrying out repairs and inspections may be the cause of defects in previously satisfactory elements, e.g. walking on unprotected felted flat roofs can drive the gravel into the felt, causing splits and cuts leading to premature leaking. The life of building elements and components can be extended considerably by adopting a planned maintenance approach so that problems can be identified in their early stages and preventive maintenance carried out to avoid early failure.
Current training in design needs to concentrate in what to do rather than what not to do. A similar situation exists in training in construction techniques, where the craftsman is instructed how best to undertake a particular operation but, to a lesser extent, in the dangers of deviation from an accepted technique. Understanding of the likelihood of defects through inadequate design or construction is taught implicitly rather than explicitly. The level and nature of defects in building construction currently encountered suggest that more guidance is required on the avoidance of failures. A need is seen, too, for such guidance to be a positive part of a training curriculum. It seems better to aim at identifying the principal defects and their causes which, if wholly eliminated, would prevent the great majority of the defects which currently occur, save occupants of buildings much annoyance and discomfort, and reduce the national bill on maintenance and repair by scores and, possibly, by hundreds, of millions of pounds annually.