Shopping Cart

Wooden Window Alliance – Flawed research? Can Wood Windows cost less than UPVC?

The WWA Press Release demonstrates wooden windows are cheaper than UPVC over their whole life

The WWA in April 2012 issued a press release stating that:

New research shows cost-effectiveness of wood and wood composite
Highlights of new research undertaken by Heriot Watt University show that wood,
modified wood (Accoya™) and aluminium-clad wood windows, designed and
manufactured to Wood Window Alliance standards, have a lower Whole Life Cost
than equivalent PVC-U windows over the 60-90 year design life of a building.

The full press release has been pulled from their site – presumably due to it’s flaws. It is however available here: New-research-shows-cost-effectiveness-of-wood-and-wood-composite-windows_April-2012.

Now, I just frankly didn’t believe this. it would be wonderful if it were true, and would provide significant justification for buying wooden windows, but to my mind it warranted further investigation. Let us have a look at the actual report:

The Report

The full report on which the press release is based is available Final report SLP WLC and LCA. The report is dated June 2013, more than a year after the press release was published.

On page 12 we find the following table:WWF Maintenance Costs

This means that the report has based the cost of repainting your window depending on whether it is Accoya or plain softwood, at £24 or £20. Now I don’t know about you, but I think that’s utterly unrealistic in June 2013. In a normal house half the windows will require scaffolding or ladders to reach. If you used ladders and not scaffolding, you may be able to clean windows for £20 / window, but you certainly can’t actually paint them for that. My enquiries suggest that around £200 / window average would be a more realistic estimate of painting costs.

So in conclusion, we have a report published by a pro wooden window trade federation, which contains a completely unrealistic figure for painting windows, and then draws a hard to believe conclusion that wooden windows are cheaper to own than UPVC. It did indeed appear too good to be true.

Lessons from the WWA report

Quite apart from the obvious lesson to only undertake paid research if you are allowed to publish real results, with real figures (Yes, I have worked as a scientist, and have undertaken commercial research, at the very august institution attributed to this work, so I am aware of the potential for a conflict of interest), there are actually some lessons to be learnt from this research:

  1. The total cost of ownership is massively influenced by the periodic maintenance requirements.
  2. If you can’t reduce the cost of the maintenance (that’s determined by the real world cost of scaffolding and painters time), you can make a BIG difference to the total cost of ownership by increasing the intervals between maintenance.
  3. Whilst the study above hasn’t looked at this, I suspect you would minimise the cost by synchronising the re glazing requirements with the repainting requirements. All double glazing panels require periodic replacement, and that would be an ideal time to repaint, if you can make the paint last that long in the first place. Scaffold once, maintain twice if you like.
  4. Why aren’t hardwood windows compared? Is it the ease with which modern plantation softwood can be marked FSC? Do I care? My perception of softwood windows has always been: ‘a silly economy only ever perpetrated by someone who is a builder or seller of a house’, so why no comparison with hardwood.


To my mind this single discovery had completely undermined the report. Armed now however with the significance of the maintenance interval to the whole life cost of the window, I carried on my research to find my new windows. Click here to return.