Pilkington Spacia™

Pilkington Spacia™ 

Ultra-thin energy-efficient vacuum glazing


The width of single glazing. The warmth of double glazing.

Our revolutionary Pilkington Spacia™ vacuum glazing technology provides unrivalled thermal performance in an ultra-thin unit that fits seamlessly into listed and conservation properties. This innovative unit allows the character of the property to be retained as it can be used with the original frames. It can also be used as secondary glazing and where aesthetics are important in a new or modern property.

How It Works

Pilkington Spacia™ consists of an outer pane of low-emissivity glass and an inner pane of clear float glass, with a vacuum rather than air or gas between the two panes of glass. The result is excellent thermal performance from a unit only fractionally as thick as a standard doubled glazed unit.

Below are some images of recent projects at Repton school, Derbyshire (Courtesy of Gowercroft Joinery)
and St Gerard's School, Ireland (Courtesy of Energlaze - Ireland North or South). 

To find out more about these projects click HERE


Supplier Information

We have a number of  Pilkington Spacia™  suppliers throughout the UK & IRE:

Grosvenor Restorations Ltd

9 Grosvenor Close, Lichfield, WS14 9SR

Contact: Tony Dee 

Email: Tony.grl@outlook.com

Gowercroft Joinery

Cotes Way, Alfreton, DE55 4QQ

Contact: Andrew Madge

Tel: 01773 300510

Email: andrew@gowercroft.com

WM Mallen Joinery

Black Lane, Kelso, TD5 8RW

Tel: 01573 420 452

Email: wmallenjoinery@btconnect.com

Energlaze - Ireland North or South

Contact: Peter Campbell

Email: peter@energlaze.ie


The world’s first commercially available vacuum glazing. This extremely thin glazing can be fitted in old style fine frames, maintaining the original appearance of older traditional buildings whilst providing good thermal insulation.

  • Thermal performance equal to or better than that of most low-e double glazing but in the same thickness as single glass
  • Four times better thermal insulation than single glazing
  • Provides the opportunity to improve energy efficiency in older properties, including listed buildings and properties in conservation areas. 
  • Suitable as a replacement for single glazing in old frames, retaining the appearance of historic buildings and meeting the requirements for conservation areas
  • Suitable for other applications where use of thinner, low-weight glazing is desirable, such as sliding box sashes, secondary glazing, or as part of a triple glazed ‘super-window’
  • Offers good acoustic performance for reduced noise
  • Proven solution; installed successfully in the UK and used in Japan for over a decade
  • Offers reduced levels of internal condensation compared to single glazing




Are there glazing guidelines?

Yes, please see the Literature tab. Pilkington Spacia™ at 6.5 mm is slimmer than conventional units which means there are more glazing options and opportunities.


Can I see a sample?

Yes, samples are available however, since they are rather expensive, we ask for details about your project. The best way to obtain one is to email us via our Contact form


Can it be made to any size or shape?

Many shapes can be produced, but to do so two straight edges forming a right angle are required. Please see the examples below.

The size limits are: 

Maximum 1350 x 2400mm Clear
Maximum 1200 x 1800mm Sandblasted
Minimum 200 x 350mm


Can it be used to comply with building regulation document N - low level glazing?

Pilkington Spacia™ is not an impact-resistant glass classified to BS EN 12600. It can however have a film applied or be modified on site to achieve the required classification.


Can it be used to comply with current building regulations concerning energy efficiency?

Yes. As part of a SAP calculation for new buildings Pilkington Spacia™, in an appropriate frame, can meet or improve upon the limit window U-value or 2.0 W/m²K. Pilkington Spacia™ can also be used for replacement windows that require a WER (Window Energy Rating) of band C or above or a window U-value of, at worse, 1.6 W/m²K. Certain buildings that are restricted in their glazing options have special consideration for energy efficiency. They can benefit from using Pilkington Spacia™ where traditional glazing is inappropriate and single glazing does not provide the thermal comfort of a modern home.


Can Pilkington Spacia™ be putty glazed?

Yes. It is compatible with most glazing compounds with the exception of those containing acetic acid.


Can you see the spacer bar?

Pilkington Spacia™ vacuum glazing doesn’t use spacer bar technology, and therefore can be easily glazed into steel, wood and secondary glazing window systems, both new or old with the same visual appearance as single glazing.


Does the product come with a warranty?

Yes. The standard warranty is 10 years.


How do you stop the 2 panes of glass touching each other?

There is a grid of micro spacers within the unit keeping the glass surfaces apart. They are 0.5mm diameter and 20mm apart, and when viewed in transmission at a distance of 1-2 meters they become imperceptible.


How does the performance of the product compare with other Pilkington low-e products?

Pilkington Spacia™ is far from a compromise on performance. Just compare the figures in this table, which shows that it is four times more thermally efficient than single glazing.

Max size: 2400mm x 1,350mm Min size: 350mm x 200mm. Sandblast max size: 1800 x 1200mm.

The above table is determined in accordance with EN410 and EN673.


How long does it take from placing and order to delivery?

The standard lead time is 12-14 weeks; a 4-5 week delivery is available via air freight but this does obviously increase the cost considerably.


Is there an obscure version?

Yes there is a sandblasted version with the obscure facing into the cavity. The maximum size is 1800 x 1200 mm and the obscure version is currently the same price as the clear version.


Tell me about the air extraction point

Pilkington Spacia™ uses vacuum technology and the point at which air is removed is covered by a small cap on every unit. The black protection cap is 12mm in diameter and set 50mm in from two edges of the glass and should not be removed.  The cap is not intrusive and tends not to be noticed once glazed.


What will it cost?

The price is available on application. There is a minimum area charge 0.3m² per pane. For orders above 4m², and as an approximate guide the cost will fall between £200 - £350m² depending upon volume, sizes and quantities.

Note - the smaller the order the more expensive the glass per m², as small orders attract a disproportionate level of transport costs.