d13 thin double glazing

D13 & D13/1.3: 13mm Thin Double Glazing

Starting at 13mm, our Thin Double Glazing is ideal for period properties and historic buildings. Designed to fit period windows, it offers all the benefits of double glazing. Visually, it’s hard to tell the difference from the original single-glazed panes.

We offer 2 variants of 13mm-thick Thin Double Glazing: D13 and D13/1.3 (the latter has a slightly wider cavity and slightly slimmer outer pane, offering excellent thermal insulation). Both types fully comply with BS EN 1279 standard and come with a 7-year manufacturer’s warranty. Read more about the benefits of Histoglass Thin Double Glazing.

Thermal Insulation

Using Histoglass D13 Thin Double Glazing will cut your energy loss by around 67%, compared with single glazing:

Ug (W/m2K)
Histoglass D13 1.5
Histoglass D13/1.3 1.3
Single glazing 5.8


Technical information

D13 D13/1.3
Inner pane: 3mm 3mm
Cavity/spacer bar: 6mm (gas-filled) 7mm (gas-filled)
Outer pane: 4mm 3mm
Ug: 1.5 (W/m2K) 1.3 (W/m2K)
Noise reduction: 34dB (with test certificate)
Weight: 17.5kg/m2. 15kg/m2.

Review our technical documents relating to Thin Double Glazing. Please note that having your glass toughened will slightly increase thickness.


Glass types

  • The inner (interior) pane is always float glass with a low-emissivity coating.
  • The outer (exterior) pane can be chosen from float glass or any of our historic glass types
  • Both inner and outer panes can be specified as toughened and laminated glass, depending on the glass type.
  • Toughened glass is always 4mm thick, so it will affect your unit’s dimensions.


Maximum pane sizes

Square 1100x1100mm (approx)
Rectangular 700x1400mm (approx)
Note that the maximum size for any pane made from cylinder glass is 800x800mm.

The above is for D13. For D13/1.3, please contact us.


Rebate depths

  • For use in existing frames, the rebate should be at least 21mm wide and 9mm deep
  • For D13 in new frames, the rebate should be 21.5mm (for D13/1.3, it should be 22.5mm
  • The width of the glazing bar should be 23-24mm
  • See D13’s optimal dimensions
  • For clearance, we recommend 1.5mm on all 4 sides (so 3mm in both the width and height)
  • Create an additional seal by allowing the paint to overlap onto the glass by 1-2mm.


Specification & installation

  • We recommend using putty to obtain the look of single-glazed units. We supply a specially developed, non-linseed-based sealant and putty to guarantee the highest possible quality.
  • The aluminium profile comes in white or black as standard. Other RAL colours can be supplied on request for an additional charge.


D13 still not suitable?

If Histoglass Thin Double Glazing isn’t suitable for your windows, take a look at our MONO single-glazing. Available in a variety of authentic period glass types, MONO delivers substantial thermal and acoustic insulation benefits.