Architectural Glass

Insulated glass (DGU)

An insulated glass unit, or DGU, is two glass panes separated by a sealed gap of air or argon. ARG builds them in-house from Saint-Gobain clear and coated glass.

Also called Insulated glass, Double glazed unit, IGU, Double glazing.


Insulated Glass (DGU) — specifications
SourcingProcessed in-house
Saint-Gobain coated glassSKN series[as heard] — awaiting written confirmation
Saint-Gobain coated glassPlanitHerm series[as heard] — awaiting written confirmation
Saint-Gobain's code name for clear glassPlaniClear[as heard] — spelling awaiting written confirmation

ConstraintHard-coated glass can only be used in an insulated unit, and must be converted within 30 days, or the glass is damaged.[as heard] — awaiting written confirmation from ARG

Insulated (DGU) configurations we make

Clear + air + clear Clear + Air gap + Clear
Clear + argon + clear Clear + Argon + Clear
Coater + argon + clear Coater + Argon + Clear
Clear + clear Clear + Clear
Example insulated (DGU) configurations
Configuration Build-up Typical use
Clear + air + clear Clear + Air gap + Clear The baseline unit — two clear panes with an air-filled cavity, and the usual starting point for a quote.
Clear + argon + clear Clear + Argon + Clear The same clear panes, with argon rather than air filling the cavity. Only the fill changes.
Coater + argon + clear Coater + Argon + Clear Brings a Saint-Gobain hard-coated pane — a coater — into the unit alongside an argon fill. The coated glass is the layer the one-month conversion rule applies to.
Clear + clear Clear + Clear A plain two-pane combination, named by ARG as a build the unit can also be made in.

What is an insulated glass unit?

An insulated glass unit is two panes of glass held apart by a spacer around their edges and sealed, so the cavity between them is closed off from both the room and the weather. That cavity is filled with air or with a gas such as argon. Because heat has to cross the cavity as well as the glass, the assembly behaves as one building component rather than as two loose sheets.

That is the general description of the product, and it is true of any maker’s unit. What ARG adds is the build — we assemble the units in-house, choosing the pane on each side of the cavity to suit the job.

Is insulated glass the same as a DGU?

Yes. ARG puts it plainly: insulated glass and DGU glass are the same product under two names. DGU stands for double glazed unit. The same thing is also written IGU (insulated glass unit), and in general trade usage it is simply called double glazing.

If you arrived here searching any of those four terms, this is the page you wanted. We keep them on one page on purpose, because splitting them would create two thin pages describing one product and leave a buyer wondering which of the two ARG actually makes.

Which build-up should you ask for?

Read the configurations on this page as a ladder rather than a menu. The clear-air-clear unit is the baseline: two clear panes, an air cavity, nothing else. Swapping the air for argon keeps the same glass and changes only what sits between the panes. Bringing in a coated pane — a coater, in trade shorthand — changes the glass itself. A plain clear-plus-clear combination is available as well. [as heard]

What this page deliberately does not print is how each build-up performs. U-value, solar factor and light transmission are the glass maker’s numbers, published on the glass maker’s datasheets, and we hold none of those in our own records. A number we cannot source is a number we will not print.

What is the difference between SKN, PlanitHerm and PlaniClear?

SKN series and PlanitHerm series are Saint-Gobain coated glasses, and ARG describes both as carrying a hard coating. PlaniClear is different in kind — ARG describes it as Saint-Gobain’s code name for clear glass, not a coated product. So in a build-up, a coater layer means an SKN or a PlanitHerm pane, and a clear layer means PlaniClear. [as heard]

One honest note on the naming. The PlaniClear spelling was given to us on a spoken call and we have not yet matched it against a Saint-Gobain document held in our own records, so treat it as provisional until we confirm it in writing.

Why must hard-coated glass go into a unit within one month?

This is the most commercially useful thing to know about coated DGU glass, and it is why coated glass is not something to buy early. ARG states that the hard-coated glasses — the SKN and PlanitHerm series — can only be used inside a DGU, and must be converted into one within one month, or the glass is damaged. [as heard]

Plan the order around it. Coated glass and unit fabrication want to be one job, not two purchases separated by a wait. Buying coated stock ahead of a site date to hedge a price means a clock starts running the moment it lands in the rack.

What ARG needs from you to quote

Final unit sizes in millimetres, and which of the configurations above you are considering. If you are not sure of the build-up, send the drawing on WhatsApp and we will come back with one.

Source Product specifications stated by ARG on 13 August 2026. Marked [as heard] — recorded from a spoken call and awaiting written confirmation from ARG. Confirm any figure with us before you specify against it.

Common questions

Is insulated glass the same thing as a DGU?

Yes. ARG states that insulated glass and DGU glass are the same product under two names. DGU stands for double glazed unit, and the same thing is also called an IGU or double glazing.

How long can hard-coated glass be stored before it is made into a unit?

One month. ARG states that hard-coated glasses such as the SKN and PlanitHerm series must be converted into a DGU within one month, or the glass is damaged, as heard on the call of 13 August 2026 and awaiting written confirmation.

Which Saint-Gobain glasses does ARG use in a DGU?

The SKN series and the PlanitHerm series, both hard-coated, and PlaniClear, which ARG describes as Saint-Gobain's code name for clear glass.

Ask ARG for a quote on WhatsApp →