Pilkington Spacia™

Pilkington Spacia™


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).

To find out more about these projects click HERE

Pilkington Spacia™ Gallery

Watch our latest Pilkington Spacia™ Video

Supplier Information

For more information on our Pilkington Spacia™ suppliers who offer a range of supply & install services and the manufacture of bespoke Timber Windows  -  Click the Logos below:

Areas Covered:
Scotland & Northumberland

Areas Covered:
Kent, Sussex and London
Europe - France and Belgium

Areas Covered:

Areas Covered:
Central England

Gowercroft Joinery

Award winning timber windows and doors of exceptional quality. We are a premium quality, full service, UK manufacturer of joinery products with extended guarantees. Designing, manufacturing and installing windows, doors, garden rooms and internal fittings for new build, renovation and heritage projects.

Our Heritage window and door ranges featuring Pilkington Spacia™ glass have won and been shortlisted for a number of national awards, as well as being installed in significant listed buildings across the country.

Installation Service Offered: Full windows and doors featuring Pilkington Spacia™ glass. Glass and glazing is provided on a supply only basis.
Installation Area covered: Nationwide
Supply available: Commercial and Domestic
Supply area covered: Nationwide
Website: www.gowercroft.co.uk/
e-mail: info@gowercroft.com
Telephone: 01773 300510

Name of Distributor: ENERGLAZE UK Ltd

Head Office: Suite 40, Edwin Foden Business Centre, Moss Lane, Sandbach, Cheshire, CW11 3AE

London Office: 601 International House, 223 Regent Street, London W1B 2QD

Services: ENERGLAZE UK Ltd specialise in retrofitting energy-efficient glazing products into existing window frames. To date we have retrofitted over 5000 homes with Pilkington products. We are the current agents for Pilkington Spacia™ and specialise in retrofitting this ultra-thin double-glazing into existing timber sash windows.

Areas covered: UK Nationwide
Supply: We offer a supply only and or a supply and install service throughout the UK
Website: www.energlaze.co.uk
e-mail: info@energlaze.co.uk
Telephone: 0845 8621801 or 0161 5050626


ENERGLAZE specialise in retrofitting energy-efficient glazing products into existing window frames. To date we have retrofitted over 5000 homes with Pilkington products. We are the current agents in Ireland both North and South for Pilkington Spacia™ and have successfully completed over 300 installations into existing timber sash windows.

Installation Area covered: Republic of Ireland and Northern Ireland.
Supply available: We offer a supply only and supply and install service throughout the island of Ireland.
Website: www.energlaze.ie
e-mail: info@energlaze.ie
Telephone: Rep of Ireland +353 (01) 9011635 Northern Ireland +44 (0)2890995666

WM Mallen Joinery

Wm Mallen Joinery, established in 1983, based in Town Yetholm in the Scottish Borders, is predominately a joinery business that specialises in sash and case windows. Over the last 20 years, Wm Mallen joinery has built up the business to focus on the refurbishment and replacement of sash and case windows alongside the development of a draft proofing system which can be used in conjunction with the windows and doors.

Website: wmallenjoinery.co.uk/
e-mail: wmallenjoinery@btconnect.com
Telephone: 01573 420 452

Grosvenor Restoration Ltd

Specialist in the renovation and performance upgrading of period sash and casement windows
Full installation service in Staffordshire, Shropshire and the West Midlands
Installation service only available for Domestic Customers
Supply only service from a line between Staffordshire & Midlands and North London
Supply only available for both domestic & commercial customers

Website: www.grosvenorrestoration.co.uk
e-mail: tony.grl@outlook.com
Telephone: 07830 095189

Glass Services

Established in 1995; Glass Services has been grown to become one of the largest independent processors and distributers of flat glass products in the south east of England.

We work closely with the joinery and restoration trades to supply high quality glass products and are proud to offer Pilkington Spacia™ as an industry leading solution to thermal performance in heritage glazing.

Supply available: Commercial and Domestic
Supply area covered: UK - Kent, Sussex and London, Europe - France and Belgium
Website: www.glassservices.co.uk
e-mail: sales@glassservices.co.uk
Telephone: 01233 632245


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
  • Suitable as a replacement for single glazing in old frames, retaining the appearance of historic buildings and meeting the requirements for conservation areas
  • Four times better thermal insulation than single glazing
  • 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’
  • Pilkington Spacia™ achieves higher levels of sound insulation than conventional glazing
  • 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: 2400 mm × 1500 mm. Min size: 335 mm × 120 mm. Pilkington Spacia™ Opaque max size: 1800 mm × 1200 mm.
The above table is determined in general accordance with EN 410 and EN 673 with the exception of the U value for Pilkington Spacia™ which has been measured in accordance with EN 674.


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. Although the cap comes in black as standard, silver is also available on request.


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 - £300m² depending upon volume, sizes and quantities, as packaging and delivery costs need to be included. Please contact the Pilkington Spacia™ dealerships with any enquiry as these costs can vary. Note - the smaller the order the more expensive the glass per m², as small orders attract a disproportionate level of transport costs


What acoustic performance does this product provide?

A comparison of the sound insulation data of Pilkington Spacia™ compared to that of single and double glazing is provided in the table below:

Note: The values for single glazing are generally accepted values for generic products taken from EN 12758. They are conservative values that can be used in the absence of measured data. The values for Pilkington Spacia™ and insulating glass units have been measured in accordance with EN ISO 10140 and Rw (C; Ctr) determined in accordance with EN ISO 717-1.