PHPD asks Frank Buckley, Managing Director, Mumford & Wood, about the main characteristics of timber windows and examines if colour is becoming more of a factor for housebuilders?
Q: What do you believe are the key benefits of timber windows?
There are many but importantly British homeowners have an intrinsic appreciation of the natural beauty of wood: how it looks, feels and performs. And of course timber is the only truly sustainable option for high quality joinery.
Some interesting and valuable research was carried out a few years ago on behalf of the Wood Window Alliance (WWA), an affiliate of the British Woodworking Federation and of which Mumford & Wood is the founding member. In this in-depth, 2-year study by Heriot Watt on Service Life Planning (SLP), Whole Life Costing (WLC), Life Cycle Assessment (LCA) and Global Warming Potential (GWP), four commonly used materials in fenestration frame manufacture were analysed: timber, modified timber, aluminium clad timber and PVC-U. The results showed that timber windows are greener; will last longer; are better value and have a negative value in relation to global warming.
Taking the green debate, when substituting a single timber frame for a PVC-U frame, approximately 160kg CO₂e is saved over the expected 60 year life of the window making it carbon neutral. Multiply this by several windows in an average size house and the savings can be measured in tonnes.
We all like to invest wisely and over a lifetime timber is proven to offer the lowest cost option. Made to the exacting standards of the WWA our timber windows have an expected life of between 56 – 65 years or more.
Timber-based windows have a negative value impact on global warming potential. This great result for timber is due to the carbon storage effect of this natural resource during its growth phase; by converting timber into products ensures carbon is locked away for the life of the tree and in the products it is used to create.
When you add all these benefits together I feel better knowing that we are making a positive contribution to environmental factors for the benefit of the planet.
Do your timber windows have Secured by Design (SBD) accreditation? Does this extend to bi-folding doors?
Almost all of the products in the Conservation range meet SBD
accreditation including the newly designed sliding sash which meets Approved Doc Q – Security standards. Our tried and tested timber windows now carry additional security features required for the new build sector.
To the untrained eye the Conservation sash window looks no different to its predecessor and of course there is the natural advantage that timber offers better strength to weight ratios than any other frame material so the innovative new features our technicians have created will give an unwelcome visitor a run for his money.
Bi-folding doors are no exception and with the popularity of open plan kitchen cum family room featuring large areas of glass our open-out Conservation Bi-folding doors are SBD accredited for total peace of mind.
The company has recently introduced the Classic range of double glazed windows. What are the key elements of this range?
The new Classic range offers a full suite of timber windows and doors that feature a slim panel double glazing system. This effectively reduces sight lines which is more in keeping with window replacement or upgrade in heritage projects and conservation areas. Classic products are available with a choice of profiles and feature individual 12-14mm units with true bars and a traditional external putty faced finish. There’s also a choice of glass – Victorian and Crown glass – that will achieve the natural appearance of hand-blown glass with reduced reflection.
Is colour becoming more important for window specification on new homes and can you achieve any colour required by a housebuilder?
Yes, definitely. We offer a full palette of RAL and Heritage colours; green has been very popular but now grey is taking over. But we do have demand for brighter more vibrant colours such as burgundy which was specified for A House For Essex. We also offer a dual-colour option: normally a colour to the external face and either white or stain to the interior which gives more freedom for interior design coordination. Regardless of the longevity of our products homeowners never need to worry about changing the colour scheme to ensure the décor remains on trend. You can’t do this with PVC-U or aluminium. We deliver our products to site with three coats of high grade micro-porous paint or stain, as standard, which ensures that our windows will look better for longer. When maintenance is required we also offer our own branded paint which is colour matched to the original order.
From what type of timber are Mumford & Wood windows manufactured and is the material sustainably sourced?
We use engineered Siberian larch in our core specification. Because of the location of these forests, growth is very slow producing timber with exceptionally tight growth rings. It is their closeness that results in an exceptionally dense material which is naturally durable and able to withstand testing climatic conditions. The timber we use has a density of more than 600kg/m³ and needs no further treatment to resist fungal or insect decay. Compared with European redwood this material has a lower density of 510kg/m³ which is classified as nondurable and must be treated with a preservative to give it longevity; this secondary coating process has environmental implications and it is only a surface coating. Accoya also needs to be treated.
Timber has the wonderful advantage that it can be naturally replaced – there are more trees planted today for every tree that is harvested. We are hugely committed to sustainable sourcing with all of our timber being FSC and PFC certified. Chain of Custody is available on request. Certification is also a requirement of the WWA and as a member we are fully compliant.
