Maintenance of Windows - 3
The previous articles revealed high maintenance costs resulting from hardware and the need for some strategies to deal with these. The costs revealed by the previous articles were based on outsourced reactive maintenance and lower costs could be achieved by other strategies.
The Berry study (Berry - 2000) revealed some authorities had very low maintenance costs and these were attributed to 'a very carefully written and controlled specification using high quality components". The right specification will minimise the total cost of the window if all the correct factors are included in the specification. A specification or other selection procedure, which concentrates on the initial cost of the window, will almost certainly lead to a more expensive 'total cost of ownership'. In the long term, the initial manufacturing cost of a window is a relatively small cost, yet this has been the primary concern of specifiers. The low incidence of reported manufacturing concerns is indicative of improving manufacturing quality standards. Using certified manufacturers is no guarantee of purchasing a good window but it increases your chances and provides reassurance that the manufacturer is serious about quality. The base manufacturing cost is important but should not overshadow the true total cost of the window.
One method of reducing the cost of maintenance is to get the job done correctly in the first place. Compulsory Competitive Tendering (CCT) drove specifiers in the wrong direction and projects were often given to the cheapest tender - leading to the use of companies that were not adequately certified or who used poor project and labour controls. Can anyone think of a better method to increase maintenance costs?
Correct installation will allow the window to function correctly, optimise the product life and improve the energy efficiency. The specifier can save on installation costs but it is certain that they will pay for the savings with increased concerns throughout the life of the window. Despite this, general experience shows that the majority of initial quality concerns with windows relate directly to installation - the 40% of the concerns identified by the Berry study that are related to 'ease/adjust/lubricate' are probably due to failure to fit or glaze the product correctly. Use only high quality installers, be prepared to pay for them and manage the project to reduce long-term costs.
The high incidence of 'ease/adjust/lubricate' may show that tenants were unwilling or did not have the knowledge to carry out any essential maintenance. High impact tenant information programmes could reduce the cost of low-level maintenance to a large degree given some willingness of tenants to undertake even basic lubrication.
The Berry study revealed several different models for maintenance and these ranged from totally outsourced programmes to 'in-house' maintenance. The study showed that outsourcing is more expensive but there it is doubtful if the 'in-house' costs included all the relevant costs. The maintenance of PVC-U windows by skilled or semi-skilled DLO / DSO operatives appears to be cheaper but this is still operating in a totally reactive environment.
Prevention is always better than cure and at the current cost levels there is a strong argument for preventative maintenance. This can be carried out on a regular schedule at a fixed price (or by a defined staff) to reduce the unit visit cost and to prevent concerns arising. Contracted preventative maintenance would provide reduced cost per visit and a fixed cost that could be negotiated and allocated at the start of the Best Value process.
The real question is: 'Does preventative maintenance reduce the overall cost of the window?' In many ways this is the wrong question. It is analogous to education - if you think education is expensive then figure out the cost of ignorance. In the same way, if you think the cost of maintenance is expensive then work out the cost of neglect. Simple, but regular, hardware adjustment and lubrication will prevent costly failure and replacement.
A part of the preventative maintenance question is the exact definition of what windows and hardware are installed. The last 20 years have seen a range of systems and hardware installed in houses and it is not true to say that a PVC-U window is a PVC-U window. Authorities were forced to accept varying manufacturers and installers during the CCT years and even if records have been kept of what was originally installed then very few authorities have records of changes made during essential maintenance. The simple question 'Do you know the type and details of the window and hardware installed in each house?' would be difficult (if not impossible) for most authorities to answer. Preventative maintenance could become a nightmare with the varying products, systems and hardware installed across a given housing stock. The cost of maintenance (preventative or reactive) will naturally rise as the number of variants in the housing stock increases due to material/hardware availability problems and product confusion.
Under these conditions, a possible outcome of Best Value could be consolidation in the sourcing of windows installed in a given Local Authority. Best Value may be to simply select a single 'best' system and remain with this forever. At the same time, the authority could require the system supplier and hardware manufacturers to provide a guarantee of continued supply of vital parts for continuity of sourcing. This should be relatively easy to achieve given the purchasing powers of most authorities. The initial installation cost could be higher but the reduction in maintenance costs and the ease of repair could easily justify the initial higher costs.
The cost of maintenance will not go away and the initial work shows not only that the costs are surprisingly high but also that they will probably get worse. The introduction of Best Value instead of Compulsory Competitive Tendering may change the landscape but only if the cost of maintenance is included as part of the true cost of the window.
Berry - 2000: Berry, Simon. 'Maintenance of PVC-U double glazing - choices for Local Authorities'. M.Sc. Dissertation in Building Care, Oxford Brookes University, December 2000.*
Berry - 1999: Berry, Simon. 'PVC-U - the hidden maintenance in double glazing products'. Unpublished. Copies available from Tangram Technology Ltd. (firstname.lastname@example.org)
The Window Maintenance series is designed to raise awareness of a critical subject in the area of window technology. It is being published in Fenestra Journal on a monthly basis and published here after the Fenestra publication. The series is
Part 1: The Changing Landscape
Part 2: Measuring the hidden cost
Part 3: Reducing the hidden cost - Strategies for the future (This section)
Last edited: 11/03/10
© Tangram Technology Ltd. 2001
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