I was reminded on a recent trip home to Norway what an amazing resource we have in our forests and I was also very proud to think despite the demand we place on our forests we now have twice as much wood in our forests than we did 100 years ago.

Norwegian industry relies heavily on timber for both its home market and exports, so we’re lucky that our indigenous trees grow in pace with demand. In Norway though we don’t take our supply for granted. For every tree we fell we plant 2 in its place. That way both our industry and our impact on the environment is sustainable.

Official UN/ECE statistics show that European stocks of unharvested trees are growing at a rate of 252 million cubic metres a year. That would be enough to build 21 million homes.

Forest management and sustainability

In fact the use of wood in manufacturing is a great help to the environment. Trees absorb and lock-in the harmful greenhouse gas, carbon dioxide. Even when the tree is cut down and turned into something else the CO² remains locked-in. Meanwhile with 2 more trees growing in the original tree’s place, double the CO² is being absorbed.

Some people say, “Why not just leave trees in the ground as well as planting more trees?” That sounds like a great idea but actually, just like us humans, as trees grow older they slow down. Trees absorb CO² and through the process of photosynthesis oxygen is created as a waste product. It is known that younger trees are more efficient at this. Therefore, the constant harvesting and replanting of trees is more beneficial in reducing carbon dioxide and increasing the supply of oxygen than simply leaving mature trees standing.

Timber – the ‘green’ choice

Using timber as a construction material is environmentally sound. Timber is not only bio-degradable but the energy required to manufacture a timber window is incredibly just one fifth of that to manufacture a comparable PVC product.

Choose timber windows and doors and you’ll not only own something of beauty, you will also sleep easy in the knowledge that you have chosen responsibly for the environment.

So what’s the truth about hardwood?

The fashionable hardwood is Oak and so I’ll use Oak as my reference point throughout this post.

Take a small square of untreated Oak and a similar piece of Pine and bury them side by side in the garden. The likelihood is that after a few years the Pine will be showing some definite signs of decay whereas in comparison the Oak should look in much better shape. So there’s the answer, Oak takes longer to rot than Pine and so it’s reasonable to assume for that reason alone that Oak is the better building material.

Note that the experiment above uses untreated wood and we tend not to test our products by burying them in the ground, after all, their job is to withstand the weather. A good quality slow grown treated softwood will resist rotting for a very long time and of course 2-3 coats of factory applied paint will provide a tough outer shield against the elements. Therefore in terms of durability, modern processes and materials make softwood as reliable as hardwood.

Oak is the most popular hardwood choice. The colour and look of Oak is certainly wonderful as an interior finish but one little known characteristic of Oak is that it can occasionally twist. All timber used in our factories is dried, conditioned and treated before being machined. This process stabilises the material which is vital to ensure minimal movement in the finished product. All Broxwood windows are precisely engineered and so if twisting does occur this can lead to problems when operating the window or door.

Twisting is of course a rare occurrence with Broxwood products so don’t let that put you off choosing Oak. What might put you off though is the cost. Oak for instance will add approximately 20% to the cost of windows which excludes the additional cost for adding matching window sills. This often leads to another dilemma. Understandably when a customer orders Oak they don’t intend to hide it but it’s still vitally important to protect Oak from the punishing British climate. Varnish coatings are not as durable as modern paints and require annual maintenance. So to keep within the terms of the Broxwood warranty all external facing surfaces must be factory painted. This does allow the internal facing surfaces to be finished with a lacquer without compromising the warranty.

If your reason for specifying hardwood is because you live in a particularly wet climate such as the west coast of Scotland, we would instead recommend aluminium cladding. Alu-clad windows are made using treated timber with the addition of an aluminium shell on the exterior surface. The cladding provides the ultimate protection against the worst weather and requires minimal maintenance.

Alu-clad can be used in combination with any wood. Standard Broxwood windows and doors are manufactured using Nordic Red Pine but Oak, Larch, and Mahogany can also be specified.  So for the ultimate in protection and beauty you could combine Oak with alu-clad.

In conclusion: if it’s durability you’re looking for then a correctly manufactured softwood window or door will perform extremely well in comparison to a hardwood product. If it’s aesthetic appeal you’re looking for then sure a hardwood such as Oak will look fantastic but ideally you’ll still need to paint the exterior facing surfaces to keep within your warranty. If you’re looking for a product to withstand your local climate then consider aluminium cladding for the ultimate shield against the elements.

For individual advice please feel free to email or call on 01738 444456.

In the UK today, standard practice in construction is to specify preservative treated timber for external use. But as I previously stated, there are many examples from the past – where houses and other buildings constructed from preservative-free timber are still performing well after hundreds of years. Look at Norwegian Stave churches as an example.

Designers in the past did not have access to preservative treatment, so they developed alternative means to ensure the longevity of their timber structures. They relied on appropriate design and detailing; and on using the correct species of naturally – treated timbers.

The design approach

The use today of preservatives is a necessary evil for many manufacturers but it comes with a cost to the environment and often only compensates for poor quality materials and design.

Wind and water will always attack our houses, so clever window and door designers looked to an example of another product routinely exposed to the weather – the car. Modern principles of car design maintain that – If you can’t stop water getting in, make sure it can get out. Cars on the roads these days rust less than they did 20 years ago, not just because of additional rust-proofing, but by applying the basic design principle that water should not become trapped inside panels.

High quality factory finished timber windows and doors from Broxwood are also designed to withstand the weather. Just like modern car design, any water that penetrates the frame structure is safely drained away through internal channels. So efficient is the design, that I’m confident our products could be supplied untreated with minimal impact on product life expectancy.

So why do we treat our products against rot?

Despite my confidence I wouldn’t blame potential customers for choosing alternative treated products so until there’s a real trend against preservatives Broxwood will continue to use them for additional peace of mind. However, the growing importance of environmental responsibility will drive our industry to examine alternative approaches to timber preservation. When that time comes I believe we will already be prepared with our advanced designed products of today.

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.

In conclusion

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.