d13 thin double glazing

HD13 & 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 HD13 Thin Double Glazing will cut your energy loss between 74-78%, compared with single glazing:

Ug (W/m2K)
Histoglass HD13 1.5
Histoglass HD13/1.3 1.3
Single glazing 5.8


Technical information

HD13 HD13/1.3
Inner pane: 3mm Low-E float 3mm Low-E float
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 and may, therefore, not be 13mm overall anymore and become HD12/13.

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.

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 thickness.

Rebate depths

  • For HD13 in new frames, the rebate should be 22mm (for D13/1.3, it should be 23mm)
  • The width of the glazing bar should be 24mm
  • See HD13’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

  • To maintain our 7-year warranty, we supply Kawo Elastokitt bedding compound with all our glazing orders. Whilst this can also be used as a putty finish, we recommend linseed putty / glazing bead to achieve a more traditional look and feel.
  • Within the thin double glazing units, the aluminium spacer bar is supplied as standard in either black or white. However, to match your window frames, we can supply other RAL colours on request for an additional charge.


HD13 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.