Maintenance of Windows - 1

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Simon Berry - Letchworth Garden City Heritage Foundation

Robin Kent - Tangram Technology Ltd. 

  The changing landscape - CCT to BV

Local authority purchasing is currently in transition from Compulsory Competitive Tendering (CCT) to Best Value (BV). The Government's definition of Best Value is: 'a duty to deliver services to clear standards - covering both cost and quality - by the most economic, efficient and effective means available' (www.audit-commission.co.uk). 

CCT ensured tight control of the price of refurbishment contracts but the results often sacrificed much of the overall quality desired and took little account of costs after initial contract completion. As part of the Best Value policy, authorities must publish annual performance plans to report on past and current performance as well as identify forward strategies and review all of their individual functions over a five year period.

Best Value is not the lowest initial purchase price but the 'total cost of ownership'. To calculate what really is Best Value requires knowledge of the total life cost of the product and this is especially true where the contract is effectively 'design and operate' and the specifier does not simply pay for the initial installation.

The maintenance cost

Windows are often seen as a fixed part of the building fabric that are specified, fitted and then forgotten, but there is more to the cost of a window than the simple first cost. The true cost components of a window include factors that are rarely, if ever, considered. This is particularly true with the 'maintenance cost' and if we start to consider this then perhaps we can get a better view of what really is Best Value.

A recent study (Berry - 2000) provides an estimate for the total UK cost of window maintenance for local authorities as at least 24 million per year but this could be as high as 48 million pounds per year - the true answer is that we don't know because of the lack of reliable information. The Berry study looked at the maintenance of PVC-U windows but the results and lessons to be learned apply to all frame materials.
There is no such thing as a 'maintenance-free' window and the best that can be achieved is a 'low-maintenance' window. Whatever the frame material, windows have a maintenance requirement.

All windows need regular cleaning to prevent dirt build-up and all hardware needs regular cleaning, lubrication and inspection to ensure continued operation. These costs can be estimated and must be included into the total cost to provide a 'total cost of ownership' and to enable decisions to be made on what really is 'Best Value'. Maintenance costs are also largely 'hidden' in expenditure budgets and generally are not considered as part of the assessment of capital projects. For true 'Best Value' assessment these need to be considered.

The concept of Best Value can also be applied over the complete housing stock and not simply over those that are included in the current capital works budget. The latest products may provide Best Value in isolation but may not be the best when the long-term effects are considered. New, products that are incompatible with existing housing stock will increase maintenance costs for existing stock and there is a strong argument for consistency of product specification rather than specification of the latest products. At the very least upgrading of specifications requires backwards compatibility and some consideration of the existing 'legacy' housing stock as well as that being considered as part of the capital works budget.

The Berry study

The Berry study (Berry - 2000) examined the maintenance requirements of a group of 5 Local Authorities across the UK and the strategies in each authority for dealing with the maintenance of PVC-U windows. The results and cost implications were staggering.

An initial survey was made in December 1999 (Berry - 1999) for one local authority with a housing stock of approximately 10,500 dwellings. Over a six-month period (July to December 1998), there were a total of 1080 individual calls and 1200 repairs were carried out but 269 of these repairs were free of charge as they were still within the manufacturer's guarantee period. The remaining 811 repair requests were chargeable to the authority at a cost of 54,000 (or 67 per visit).

The maintenance cost for this single authority is well over 100,000 per year or in the region of 10 per house per year in the housing stock. This Authority's computer database can monitor these costs very accurately but this is not the case in many authorities and the cost of maintenance can only be estimated.

The complete breakdown of the logged repairs over the six-month period is given below:

PVC-U Window & Door repairs (July - December 1998)

Window repairs

 No.

Door repairs 

 No.

Cills 

3

Cills

0

Ease/adjust/lubricate

213

 Ease/adjust/lubricate

214

Glazing 

72

 Glazing

7

Handles

96

 Handles

57

Hinges/friction hinges

29

Hinges/friction hinges

14

Locks

50

Locks 

220

Loose frames

8

Loose Frames 

14

Seals (gasket)

26

Seals (gasket) 

50

Trims (+ silicone)

16 

Trims (+ silicone) 

6

Lost keys 

Door chains (OAPs)

4

Restrictors/child locks

24 

Letterbox/letter plates

29

Trickle vents

7

Sandwich panels

4

 

 

Vandalism/abuse

16

 

 

Weatherboard 

15

Total

548

Total

532

Grand Total (repairs) 

1080

The largest maintenance loads are in the areas of 'ease/adjust/lubricate' and in the general area of 'hardware'. 

'Ease, adjust and lubricate' represents nearly 40% of the recorded repair concerns and these are often due to poor initial fitting or inadequate quality control during the contract. Improved control of the fitting process and the use of approved installers could reduce the maintenance costs by up to 40%. Concerns with hardware (handles, hinges, locks, restrictors/child locks and trickle vents) also represent nearly 40% of the recorded repair concerns. Improved specification of hardware could also reduce the maintenance costs by up to 40%.

These concerns will be present irrespective of the frame material because similar installation practices and similar hardware are used for all frame materials. It is of interest to note that none of the repairs involved failure of the PVC-U system profile. Frame failure, whilst important if it does occur, is the least of the Local Authorities concerns in the long term.

The important questions are:

References:

Window Maintenance

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 (This section)
Part 2: Measuring the hidden cost
Part 3: Reducing the hidden cost - Strategies for the future

Last edited: 20/05/15

© Tangram Technology Ltd. 2001

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