FINEO Vacuum Glazing for Traditional Timber Windows

Improving the thermal performance of an older property does not necessarily mean replacing its original timber windows.

FINEO is a very slim vacuum-insulated glazing system that can offer significantly improved thermal performance while retaining much finer glazing proportions than conventional double or triple glazing.

For suitable windows, this can make it particularly useful in period properties where preserving existing timber joinery and traditional sightlines is important.

G S Haydon can assess existing timber windows, advise whether FINEO is appropriate and undertake the joinery and glazing work required for suitable projects.

What Is FINEO Glazing?

FINEO consists of two panes of glass separated by a very small vacuum cavity.

Because the insulating performance comes from the vacuum rather than a conventional gas-filled cavity, the overall glazing unit can remain much thinner than standard double glazing.

FINEO glazing has a published Ug value of 0.7 W/m²K, providing thermal performance comparable with modern triple glazing while allowing much slimmer glazing details.

This can be particularly useful where thicker sealed units would require substantial changes to an existing window.

Retrofitting FINEO into Existing Timber Windows

One of the main reasons we are interested in FINEO is its potential to upgrade good existing joinery.

Traditional timber windows can often remain structurally sound for many decades. Replacing the complete window simply to improve the glass can therefore mean losing joinery that still has considerable useful life.

Where the existing frame and casement are suitable, we may be able to adapt the glazing rebates and install FINEO while retaining the majority of the original window.

The condition, construction and glazing details of the window need to be assessed first. FINEO will not be appropriate for every frame or every property.

Our timber window repair and restoration service explains more about our approach to retaining existing joinery where practical.

FINEO for Period and Historic Properties

Period windows often rely on narrow glazing bars and fine timber sections for their character.

Installing conventional double glazing can sometimes require thicker bars and deeper rebates, changing the appearance of the window.

Vacuum glazing provides another option where improved insulation is required but maintaining finer proportions is important.

FINEO also produces heritage glazing designed specifically for historic buildings, with glass options intended to reproduce some of the visual characteristics of older glazing.

For listed buildings, any alteration to historic windows should be considered in relation to the significance of the building and any consent requirements. The fact that glazing is slim does not automatically mean it will be acceptable in every listed property.

FINEO or Slim Double Glazing?

FINEO vacuum glazing and conventional slim double glazing are different products.

Slim double-glazed units use two panes of glass with a narrow sealed cavity between them. FINEO uses a vacuum between the panes, allowing high thermal performance from a much slimmer construction.

There are circumstances where either solution may be appropriate.

Our slim double glazing page explains the alternative options we use for new and existing timber windows.

The best choice depends on the window, the required appearance, budget, glazing-bar dimensions and any planning or conservation considerations.

New Timber Windows with Vacuum Glazing

FINEO does not have to be limited to refurbishment work.

It can also be considered for new bespoke timber windows where traditional proportions are required alongside improved thermal performance.

This can be particularly relevant to flush casement and sliding sash windows for period properties.

Designing the window around the glazing from the outset allows the rebates, glazing bars and surrounding joinery to be developed as one complete specification.