Material Futures - Part 1




The Way Behind

This series looks at what may be coming in terms of window materials for the future. Like all future gazing, it is bound to be inaccurate but hopefully it will stimulate thinking about where the industry could go and what you can do about it. New materials such as pultrusions, thermoplastic pultrusions, ABS/ASA composites, recycled materials with cellulose extenders and even PVC-U in other forms present both opportunities and threats to the existing industry. Failing to plan for these developments could well be the equivalent to planning to fail in the future.

The current attitudes

In the PVC-U sector of the window industry it is accepted wisdom that PVC-U will remain the main material for window construction for the future and there is a real complacency towards any threat from competing materials. This assumption is so ingrained that the Technical Manager of a leading systems company has been reported as stating that PVC-U is undoubtedly the best material and that there is no viable competition in the field of window frame materials. When the technical people start saying that then it is really time to worry!

Similar reactions come from other manufacturers. Consider the proposition “What if there was a magic aluminium patio door that did everything you needed. Would you be interested?”. The Marketing Manager of another major PVC-U systems supplier replied “No! We are PVC-U processors”. They define themselves primarily in terms of the material they process rather than in the function they serve. In any case real “PVC-U processors” make things other than windows!

A similar narrow reaction would have been found in the companies making slide rules during the late 1960’s (it is a sure sign of your age if you can remember what a slide rule is). During the late 1960’s these companies saw themselves as “slide rule manufacturers” and spent enormous efforts developing new slide rules with extra functions, developing methods for engraving thinner lines and other slide rule technologies. When “electronic calculators” were developed, the slide rule people considered them inferior and dismissed the technology as unworthy of investigation. The existing investment in “slide rules” was considered to be more important that speculative investment in electronics. How many of the slide rule manufacturers made the transition into calculators – None! They defined themselves in terms of their product (the slide rule) and not in terms of the market they were really in. They were actually “providing means for calculations” but they didn’t realise that until it was too late and their extinction was inevitable. They were not the only ones of course, the list could also include drawing board manufacturers, buggy whip manufacturers and many others.

Many PVC-U systems suppliers would be better placed for the future if they defined themselves as “providing window solutions” rather than as “PVC-U processors” and if they regarded their current investment in plant as a means to an end rather than the end itself. It is a small difference in words but a large difference in attitude. The alternative is to be like a frog in water. It is said (not that I’ve tried it) that if you drop a frog in hot water then it will rapidly jump out again. If you put the same frog in cold water and slowly heat the water then the frog will remain there until it is well and truly boiled. Conditions sometimes change so slowly that by the time we realise what is happening it is too late.

The current market and capacity

The current market capacity for PVC-U outstrips the current demand and consolidation is taking place daily at all levels of the supply chain. It is estimated that the over-capacity exceeds 40% at virtually all levels of the industry. The market demand is also forecast to decrease as the bulk of the windows suitable for replacement are replaced - the future for the industry is one of excess capacity and shrinking demand unless new strategies and growth areas are found quickly. The effects of over-capacity rapidly become critical as demand is reduced. Robert Palmer has recently suggested that a part of the solution lies in replacing the replacements but even this could be threatened by a new technology.

At the systems supplier end of the market we see sales, mergers, take-overs and closures on an almost daily basis. Consolidation of the industry is taking place rapidly and the leading systems suppliers are rapidly gaining market share through acquisition. The same consolidation pressure is making itself felt at the fabrication end of the market where the driving forces of competition for market share, changing consumer behaviour and over-capacity have combined to considerably reduce margins. The fabricator response has been to improve manufacturing techniques, improve management skills and to look for economies of scale. In the early 1980’s a large window manufacturer was making 200 windows per week - now a large manufacturer (the super-fabricators) are making 2500 windows per week and growing bigger. There is still growth for individual fabricators but the market will never return to the growth and price levels of the 1980’s.

Price pressure in the industry is intense and in prices in the market are down to about 50% of the early 1980’s prices, even ignoring the effect of inflation. In real terms the prices have dropped even more and the product being sold for these prices has improved in terms of security, quality and performance.

Consolidation is likely to continue because the long-term erosion of real price levels has reduced profitability and capacity has outstripped demand.

The current materials

Before reviewing the new materials it is necessary to look at the strengths and weaknesses of the existing materials to see what competition they must face.


PVC-U is the dominant material in the market place and currently has the most to lose to the development of new materials. It is also the “material to beat” for new materials developments.

PVC-U Windows



  • Low maintenance load.
  • Unaffected by moisture.
  • Good thermal insulation.
  • Low mechanical strength/weight.
  • High thermal expansion.
  • Raw materials cost volatility.  



  • New finishes to provide colour options.  
  • Environmental pressures.  


Timber is undergoing a renaissance due to initiatives being lead by the British Woodworking Federation. The two important sectors, softwood and hardwood, have different strengths but new materials could outflank both sectors at the same time!

Timber Windows



  • Easily modified on site.
  • Good thermal and sound insulation.
  • End-user can repair and maintain.
  • Appearance can be modified by consumer.
  • High maintenance load for end-user if not treated correctly.
  • Moisture expansion can give interference problems on opening lights.



  • Improvements in surface coating techniques.
  • Use of composite materials / layer techniques to give lower cost and more efficient usage.  
  • Growth of other materials in new-build sector.
    Materials price and environmental issues for hardwoods.  


Aluminium has suffered from the growth of PVC-U in the domestic sector. The mechanical strength/weight ratio has enabled the retention of a substantial commercial market and any new material will find it hard to displace aluminium from this market.

Aluminium  Windows



  • High mechanical strength/weight.
  • Low maintenance load.
  • Unaffected by moisture.
  • Fire resistance.
  • Low thermal insulation unless combined with other materials.
  • Raw material costs.



  • Composite windows with good thermal properties and attractive finishes.  
  • Revival of wooden windows (with improved surface coatings).  


Steel is concentrated mainly in the commercial sector where the particular mechanical strengths of the product are best utilised. New materials will take considerable time to displace steel in this area.

Steel Windows



  • High mechanical strength/weight.
  • Slim sight lines.
  • Fire resistance.  
  • Low thermal insulation unless combined with other materials.
  • Maintenance load.  



  • Excellent security and mechanical response.
  • Door products using high mechanical strength.  
  • Continued inroads by alternative materials.  

 So where do we go from here?

The existing materials meet the requirements well but all have areas where new materials can have substantial advantages. In new materials and new product development the advantage often lies with the attacker - they have less to lose and more to gain! The traditional materials are both well established and have well-developed distribution chains but this does not make them immune to new materials. In fact, the seeming strengths of the existing materials make them complacent and the threats may be all the more dangerous for this.

The Material Futures series is designed to look at some of the possible materials that could be used for window frames in the future. The series is:

Part 1: Material Futures - The Way Behind (This article)

Part 2: Material Futures - The Way Ahead

Part 3: Material Futures - The New Composites (1)

Part 4: Material Futures - The New Composites (2)


Last edited: 11/03/10

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