Bespoke Timber Windows Specifications

Our Bespoke timber windows are designed with a range of innovative design features that combine traditional aesthetics with modern technology. This product is ideally suited to conservation projects such as the renovation of grade 2 listed buildings, Conservation area's.and Bespoke projects.


The below specification details are a minimum standard  we look to achieve on our  windows/doors. Any Bespoke profile of cill, frame thickness, finish and ironmongery options are available together with your choice of timber sash option. Traditional butt hinges and casement stays, or modern high security espagnolette locking systems are also available.

To BS 644 ,  Our glazed window/door designs are tested to BS6375 Part 1  Min whole product  U value of 1.6 for windows & 1.8 for doors,  They are designed to achieve minimum BS6375 Part 2 ratings of  Air 600pa, -  Watertightness 150pa - Wind-load 1200pa  class 3 for outstanding weather resistance to cope with most British climate conditions. 


BS 6375, Part I and Part 2: 
Air permeability BS EN 12207: 2000, 600Pa (Class 4)
Watertightness BS EN 12208: 2000, 300Pa (Class 7A)
Wind resistance BS EN 12210: 2000, 2000Pa (Class 5)
Exposure category BS 6375: Part 1: 2004,  2000. 
BS 6375; Part 2; 1987
BS 7950: 1997 


Performance; BS 6375, Part I 
Air permeability BS EN 12207: 2000, 600Pa (Class 4)
Watertightness BS EN 12208: 2000, 150Pa (Class 4A)
Wind resistance BS EN 12210: 2000, 1200Pa (Class 3)
Exposure category BS 6375: Part 1: 2004,  1200

Because our windows and doors are hand made to order, we work with you to ensure you get the desired performance characteristics for your specific project.

Locking System

Our Stormproof, or flush casement windows  can also utilise mushroom bolts and/or shootbolts. Our standard espagnolette locking systems have achieved more than 7.4Kn which is more than double the requirements of BS7950. They have also been endurance tested to 40,000 operations and have been salt spray tested for 500 hours by the BBA.

Friction Stays

We utilise the benefits of two different friction stays in our timber flush casement window range. All our top hung windows and side-hung egress windows use a hinge that is manufactured in the UK and available as austenetic for enhanced corrosion resistance. For our heavier side hung sashes, we use a heavy duty hinge ensuring that the product will perform for many years to come.


Our internal design team are able to tailor our product to suit the most extreme exposures. Our  timber windows benefit from a full dry gasket glazing system available as externally or internally beaded. The dry gasket glazing system ensures any moisture penetrating the external glazing seals has an escape route and therefore eliminates standing water from the rebate, significantly reducing the risk of rot, warping etc.

Energy Efficiency

We can design an manufacture to any Uvalue specification required and  our close links with Buildcheck  allow us to quickly simulate both whole frame u-values and window energy ratings should projects require this. All our timber windows come with full CE markings and declaration of conformity.

 Please contact our sales team to discuss further.

Adam Irving,
31 Oct 2013, 03:45
Adam Irving,
30 Oct 2013, 13:41
Adam Irving,
31 Oct 2013, 04:01