The emphasis is on quality, both in terms of materials used and the use of traditional sections, jointing and construction methods.


Our premium windows are constructed of high quality timber using Grade A Accoya, Sapele or European Redwood. The Accoya is a top quality pine that goes through a proprietary, non-toxic acetylation process that modifies the wood to its core.

Accoya is guaranteed for 50 years.
Hardwood, where we mainly use Sapele, is guaranteed for 25 years.
Softwood, where we mainly use European Redwood, is guaranteed for 10 years.

For the full warranty details, please download our Product Warranty

Please view the video below if you would like to learn more about the process or visit our Accoya page.

The resulting performance benefits of this process are:


Swelling and shrinkage are reduced by 75% or more, preventing sticking of doors and windows.
Less movement in the timber means that paint and varnishes will last 3 to 4 times longer, greatly reducing maintenance costs.


The most durable wood possible, even more durable than teak, which makes it ideal for exterior windows and doors.

Long Lasting

Tested to last more than 50 years above ground and 25 years in the ground.


The responsible procurement of wood plays a fundamental role in positioning Accoya as an environmentally compatible product. All Accoya wood is produced from well managed sustainable sources including FSC, PEFC and other regionally certified woods.

Mould and Insect Barrier

Accoya wood is indigestible to insects and micro-organisms, increasing its resistance to decay.
It is also resistant to wood destroying fungi, making it virtually rot-proof.

Energy Efficient

Accoya offers improved thermal insulation over other commonly used timber species. It is 17% more thermally efficient than typical softwoods and 40% more than typical hardwoods. We have documentation to show that the Herald Windows can achieve a whole window value of 1.4 w/m²k which is equivalent to an A rated window.

This is achieved by the combination of:

The use of Accoya which is significantly more thermally efficient than normal timbers used.
Extensive draught stripping on the staff beads, parting beads, meeting rail and top and bottom of sashes, together with easy slide seals to the edge of the sashes.
High specification glass units comprising warm edge spacers, heavy inert gases and thermal softcoat glass.

Paint Finishing

If required, your windows can be finished in any RAL colour with three coats of a very high grade Tecknos paint system, with coarse, medium and fine sanding between coats resulting in a very fine finish.
Teknos Logo

These paints help to control the inherent properties of different timbers and keep them looking beautiful for years. They minimise discolouration, maximise durability and protect against problems such as blue stain and mould.

The Teknos topcoats and primers have been developed for durability and protection against wood discolouring funghi and UV-light.

To learn more about Teknos please download the brochures below:

Teknos Overview
A Guide To Teknos Coatings Solutions
Teknos Translucent Colours
Teknos Forest Inspiration External Translucent Coatings

Ironmongery & Sash Window Balancing

Traditionally the sashes would be balanced with our plastic coated lead weights. We would also be happy to supply the window with spring balances if required.

Our premium quality ironmongery comprises a locking sash fastener and restrictor locks for maximum security, 2 sash lifts and pulleys, all available in brass, polished chrome or brushed stainless steel.