Glazing Options


Secondary Glazing can bring additional benefits to your home by upgrading from standard 4mm or 6mm glass.


Choose Pilkington K Glass™ improve further the thermal benefits secondary glazing can bring.


Or for noisy environments choose Stadip Silence laminated glass which significantly reduces external noise due to the Acoustic dampening interlayer.


Benefits of Upgrading to Secondary Glazing with Pilkington K glass

Pilkington K Glass™ can be used in secondary glazing, with the Pilkington K Glass™ as the inner pane with the coating facing the air gap between the two panes. Although the coated surface will have to be cleaned occasionally, it is generally protected by being in the cavity and washing with clean soapy water or a clear window cleaning solution should maintain it in good condition.

As with any secondary glazing, there is a risk of condensation on the inner surface of the outer pane, unless the air gap has some ventilation to the outside, possibly just through gaps in the existing window.

NB. A secondary glazed window using Pilkington K Glass™ does not give sufficient insulation to meet the requirements of Part L England and Wales and Part J Scotland but will offer a noticeable thermal improvement over existing single glazed windows when full replacement double glazing is not practical.

The following table shows how choosing secondary glazing with Pilkington K Glass™ can offer extra thermal performance over standard clear glazing.


U Value Ratings


Fitting Secondary Glazing to Existing Single Glazed Primary Windows

U Value

Thermal Improvement

Existing 4mm Single Glazing

5.8 W/m2k


Secondary Fitted with 4mm Clear Glass

2.8 W/m2k

51% Improvement

Secondary Fitted with 4mm Pilkington K Glass

1.8 W/m2k

69% Improvement


Fitting Secondary Glazing to Existing Single Glazed Primary Windows

U Value

Thermal Improvement

Existing 28mm Pilkington K Unit (No Argon)

1.7 W/m2k


Fitted behind existing Pilkington K Unit (No Argon)

0.9 W/m2k

47% Improvement


All values calculated using Pilkington Spectrum Program version 3.0.1 and are centre pane glass values

Assumes Secondary is fitted 60mm from primary window

What is Stadip Silence Glass?

SGG STADIP SILENCE contains a special acoustic interlayer which not only bonds the glass but also acts as a dampening core between the glass panes, preventing sound frequencies vibrating from one pane of glass to the other.

Normal windows have a `resonant frequency`, at which they vibrate more significantly reducing their acoustic insulating performance. Stadip Silence Glass in secondary windows will considerably reduce the passage of sound frequency.

Additional benefits are its full compliance as a security and safety glass with the benefit of UV filtration helping protect furnishings from fading.

SGG STADIP SILENCE is ideal for any application in the home where there is a need to insulate against excessive noise levels. It is particularly effective against traffic noise when used in windows facing onto busy roads.

When combined with Secondary Glazing, if full double glazing replacement cannot be achieved, you will notice a considerable difference compared to your existing single glazed window.




Creates more peaceful interiors by reducing noise pollution from air, road traffic, general street noise and noisy neighbours.

Is a safety glass and can be used in safety critical locations.

Its interlayer is transparent and colourless, meaning SGG STADIP SILENCE resembles ordinary glass, with excellent optical quality.

Sources of Noise


Noise is any sound that is unwanted, usually because it distracts or disturbs us. Noise can come from a variety of different sources but there are usually two forms;



These are sounds which travel in waves through the air and enter our ears. Airborne noise can travel from outside a building to inside.


  • Traffic noise
  • Children playing
  • Music



These are sounds that are transmitted via vibration through a physical structure such as a conservatory roof.

  • Rain
  • Hail


Sound can be characterised in different ways but primarily in terms of intensity and frequency;


- The sound intensity describes how soft or loud the sound is (db). A low db value indicates a soft sound- a high db value a loud sound.


- Frequency (or pitch) describes how high or low pitched the sound is (Hz).

What is acoustic laminated safety glass?


Acoustic glass consists of a minimum of two sheets of glass bonded together by at least one interlayer, known as a PVB (Polyvinyl Butyral), providing protection against noise sources whilst maintaining the safety and security properties of standard laminated glass.


How does acoustic laminated glasswork?


The special PVB interlayer used in SGG STADIP SILENCE between the two panes of glass absorbs sound, helping to keep both unwanted noise out or to keep noise in.


The result


Stadip Silence Glass absorbs and weakens the sound, helping to act as a barrier to both airborne and impact noise, making a home, hotel room or office a much quieter place.