People in the UK like timber windows and doors, yet many have switched to PVC. Why? Well, according to many salesmen, PVC doesn’t rot like wood, it’s cheaper and of course it doesn’t need painting. Sounds great but before you rush off to place your order, in this, my first blog post; I’m going to challenge that wisdom.
I am a Norwegian living in the UK. In Norway we have lots of woodland and extremely cold winters. So, over the years we’ve become pretty adept at using our plentiful natural resources to keep us warm; but more importantly as an efficient building material.
Throughout Norway very few homes feature PVC windows. This is because wood, by its very nature is a natural barrier to the cold. When cleverly designed and engineered into a window or door, and combined with double or triple glazing, it far outperforms PVC windows and doors. So why is PVC so popular in the UK? The story is complex, but for many the experience of rotten timber windows relates to those installed in houses after the Second World War. Have you ever noticed how many houses built over a century ago still have their original windows? This is because they were made using well seasoned, high quality timber. By stark contrast, many buildings built during the post war period were constructed using inferior materials. Consequently timber gained itself a bad reputation.
So what’s the modern day truth?
Currently around 12 million windows of all types are sold each year in the UK, with timber windows accounting for 30% of that market. 57% of timber windows sold in Britain are used by the public sector and 42% by the private; 86% of these in refurbishment projects and 14% for new build applications. (Figures from FSC website.)
Whilst Norwegian windows and doors have always used high quality materials, over the last 10 years in particular, the evolution of timber windows in terms of quality, durability and design has been dramatic. Factory finished and treated against rot, with frames which are fully protected from water and UV light; modern high-performance timber windows can have finish guarantees for up to 10 years, and rot free guarantees for up to 30. Dual sealing and factory glazing helps to maximise the life of a unit, and sophisticated design details further lengthen the life of the timber.
Comparing this to PVC units, The National Building Federation’s Standards in Quality and Development gives PVC windows a lifespan expectancy of 20 to 25 years; where as it gives vacuum treated softwood windows 25 to 35 years. According to the Green Builders Digest, ‘Well designed and well maintained timber windows can and do last the lifetime of the building in which they are installed’.
Maintenance is the challenge for many people, but no material is maintenance-free, despite claims by PVC salesmen. Developments in timber window design and finish has created products that minimise water retention, damp penetration, and with micro-porous paints that allow wood to breathe; all contribute to a low maintenance product. Peeling and blistering paint is a thing of the past. Factory-finished windows need not be repainted for up to 8 years. Thereafter 5 to 8 year painting cycles is the norm. Modern finishes also minimise the preparation times. Unlike PVC, your factory finished timber windows and doors can be made to an exact shade of colour to suit your project and property. So, while it remains true that timber windows need some maintenance, modern high performance windows make that maintenance exceptionally easy.
While the initial cost of timber windows can be higher than that of other materials, the ‘whole-life’ cost which timber delivers in terms of maintenance, durability and environmental impact, makes it excellent value for money.
To substantiate the value for money claim The National Housing Federation finds softwood cheaper, both in terms of initial capital costs and life cycle costs over a period of 30 years. Figures from its reports, ‘Standards in Quality and Development’, put the cost of buying, fitting and maintaining a softwood window frame at between £149 and £199 over 30 years. In contrast a PVC frame will cost between £257 and £275.
A further cost advantage to wood windows is the ability to repair and restore them. According to TRADA, the Timber Research and Development Association, wood can be readily repaired, refreshed and maintained without special components, skills or equipment.
Finally, timber is, of course, a natural insulator which when combined with the glazing system, (air, argon or krypton filled), insulating glass and draught sealing, has no difficulty in providing windows which meet current requirements of a U-value of as low as 0.6W/m2K.
Sourced from managed forests, mostly from my homeland of Scandinavia; timber is an environmentally friendly, thermally efficient, good looking and low maintenance material. All of which is, happily, a far cry from the poor reputation created by cheap, poor quality softwood windows and doors of the recent past.
For me, all of the above makes really good sense, and when it comes to windows and doors, nothing looks and feels as good as wood.