French doors look simple from the outside: two hinged leaves, mostly glass, meeting in the middle. The buying decision is more involved than that. The frame system, the sightline, the glass spec, the hardware, the threshold and the install detail all change how the door feels in everyday use and how it performs in a Perth summer.
This guide covers what Perth homeowners need to know before committing to double glazed French doors, drawn from the relevant Australian Standards (AS 2047 and AS 1288) and the building physics behind each design decision. Use it to read a quote critically.
What Are French Doors and Why Perth Homeowners Choose Them Over Bifold
A French door is a pair of hinged leaves meeting at the centre of the opening without a fixed post. Both leaves are largely or entirely glazed. They share a common frame and typically swing inward, occasionally outward. The meeting point of the two leaves is called the meeting stile, and in a double glazed configuration one leaf carries an astragal, a rebated overlap that bridges the centre join and carries a compression seal.
Perth homeowners choose French doors over bifold for three reasons. First, they seal better. A bifold relies on a track and a series of perimeter pile seals; a French door compresses against the frame at multiple points when locked, which is why hinged doors tested to AS 2047 achieve higher water penetration resistance ratings than bifold systems of similar quality. Second, they cost less for the same width. A 1800 mm French door pair has two leaves and one lock; a 1800 mm bifold has three or four panels and the hardware adds up. Third, they age differently. A French door has hinges and a lock to maintain; a bifold has tracks, rollers, multiple hinges and concealed flush bolts that all need regular cleaning and lubrication, particularly through Perth’s dusty late summer.
What French doors do not do well is large openings. Past about 1800 mm, the leaves get heavy, the hinges work harder, and the operation becomes less pleasant. For openings wider than that, a bifold or a lift-and-slide is usually the right answer. Both door types sit alongside lift and slide and sliding options in the Penot Double Glazing doors range, so the comparison can run on a single quote.
Inswing vs Outswing: Which Suits Most Perth Floor Plans
Inswing is the dominant residential configuration in WA and across Australia. The door opens into the internal space, which keeps the external threshold simple and lets weather seals compress against the external frame stop and sill when closed. The downside is that internal clearance has to be maintained. A French door pair at 1800 mm wide will swing into a 900 mm arc per leaf, which is enough to clash with furniture in a tight living room.
Outswing French doors appear in two situations. The first is where the internal room is too small to absorb the door swing, which is common in heritage cottages and small additions. The second is for energy efficiency: wind load from outside presses the closed leaf harder against the seal, which can improve infiltration performance on exposed elevations. Outswing requires different hinge specifications, including tamper-resistant or concealed hinges since the hinge pins sit on the external face. The flashing detail at the head of the frame is more complex too, because the head stop sits on the outside.
Penot Double Glazing’s Bayswater showroom carries both configurations. The conversation usually starts with a sketch of the room and the surrounding furniture, then heads to a frame system that suits the floor plan rather than the other way around.
How Sightline Width Changes the Feel of the Opening
Sightline is the visible width of the aluminium frame member seen from outside when the door is closed. Narrower sightlines mean more glass and a more contemporary look. Wider sightlines look more traditional and accept thicker glass with less engineering.
Australian aluminium systems for double glazed French doors fall into two bands. Standard residential systems run approximately 65 to 80 mm at the stile and rail. Architectural slim-profile systems run approximately 45 to 65 mm, with premium architectural aluminium systems sitting at this end. Slim profiles also accept larger insulated glazing units, up to 24 mm IGU thickness in many cases, which is the sweet spot for thermal performance.
Two practical points. The astragal at the centre adds 20 to 40 mm of visible frame to whichever leaf carries it, which is why a French door pair never has the same visible-glass percentage as a fixed window. And the wider the leaf, the wider the stile and rail need to be to handle the door’s own weight in the hinges, so sightline and panel size are linked.
Glass Choices for Perth French Doors: SHGC, Low-E, Toughened, Laminated
All glass in an external door must comply with AS 1288:2021, which requires Grade A safety glass (toughened or laminated) on any door pane and on side panels within 300 mm of the door at heights below 1200 mm. This is a legal minimum, not an upgrade.
The Perth-specific decision sits on top of that minimum.
Solar heat gain coefficient (SHGC). For west or unshaded north-facing French doors in Perth, this matters more than U-value. A solar-control soft-coat low-e double glazed unit can reduce SHGC to 0.20 to 0.40, where a clear standard double glazed unit sits around 0.70 to 0.75. The lower number means less radiant solar load through the glass on a hot afternoon. Our guide to U-values, SHGC and window energy ratings in WA explains the numbers in detail.
Toughened vs laminated. Toughened glass is heat-treated to be four to five times stronger than annealed glass; when broken it fractures into small relatively harmless cubes. Laminated glass is two panes bonded with a PVB interlayer; when broken the fragments stay bonded to the interlayer. For French doors facing a pool, an alfresco, or street noise, laminated outer glass is usually the right choice. It improves acoustic performance and resists forced entry better than toughened, which shatters completely on impact.
Standard IGU configurations. The common Australian configurations for French doors are 4 mm glass / 16 mm cavity / 4 mm glass (24 mm total unit), or 6 mm toughened / 12 to 16 mm cavity / 6 mm toughened (24 to 28 mm total) for security or acoustic upgrades. A 24 mm unit is the upper bound for most residential aluminium systems; premium architectural systems can accept wider units.
Multi-Point Locks and Hardware for External French Doors
Multi-point locking is the standard security specification for external double glazed French doors in Australia. A 4-point hinged door mortice lock is the volume product in the WA residential market. Lifting the lever engages locking rods at the top and bottom of the door into the frame, then turning the key engages a throw bolt securing the rods and the latch.
A multi-point lock has a benefit beyond security. Four engagement points create a tighter seal, which reduces drafts, rattles and air infiltration significantly over single-deadbolt locks.
The inactive leaf, the one without the lock, is secured at the top and bottom with flush bolts mortised into the stile. The active leaf latches and locks against the astragal on the inactive leaf. This is why French doors should always be specified with the active leaf clearly identified at order time.
French Doors vs Bifold Doors: Side-by-Side Comparison
| Attribute | French Door (pair) | Bifold Door |
|---|---|---|
| Panel count | 2 | 2 to 6+ |
| Typical max clear opening width | ~1800 mm | Up to ~6400 mm (commercial bifold) |
| Seal quality | High, compression at multiple points when locked | Moderate, perimeter brush and pile seals |
| Water resistance per AS 2047 | High | Moderate to high (AU bifold systems test to 150 Pa residential and up to 450 Pa commercial spec) |
| Glazing area | High, around 90%+ if full-height sash | High but framing at each panel reduces aggregate glass |
| Hardware complexity | Multi-point lock + flush bolts | Multi-point deadlocks + flush bolts per panel |
| Best use case | Openings up to 1800 mm, courtyards, garden access | Alfresco connections over 2400 mm |
| Relative cost | Lower for equivalent width | Higher, scales with panel count |
| Maintenance | Hinge lubrication, seal inspection | Track and roller cleaning, multiple hinge points |
Sources: AGWA Guide to Residential Installation 2020, AU industry bifold specification data. For a deeper look at lift-and-slide as the third option, see our lift and slide vs bifold guide.
Standard Sizes and When Custom Is Worth It
Standard size ranges for double glazed aluminium French doors in Australia:
- Pair width: 1200 mm, 1500 mm, 1800 mm most common
- Height: 2040 mm to 2400 mm standard; above 2400 mm is custom, with architectural systems going to 3000 mm
- Per-leaf width: 600 mm to 900 mm standard
Custom sizing is available from any quality aluminium fabricator and is the norm for architectural projects and replacement projects where the existing opening dictates the dimensions. Custom sizes typically extend the lead time; the supplier confirms at quote stage.
Custom is worth it when the standard pair would force you to compromise on either the floor plan (forcing a wall move to accept a standard opening) or the look (an off-the-shelf 1800 mm pair where 1650 mm would suit the room better). The price premium is usually 15 to 25 per cent over standard sizes.
Typical Price Ranges for Double Glazed French Doors in Perth
For a standard 1800 mm aluminium double glazed French door pair in Perth, 2026 indicative pricing:
| Spec | Supply only | Supply and install |
|---|---|---|
| Standard double glazed, standard hardware | $2,500 to $4,500 | $3,500 to $6,500 |
| Thermally broken frame, low-e glass, multi-point lock | $4,000 to $6,000 | $5,500 to $8,500 |
| Premium with acoustic laminated outer, custom finish | $6,000 to $9,000+ | $8,000 to $12,000+ |
Drivers of price: frame finish (powder-coat colour, woodgrain foil), glass upgrade (low-e adds approximately $200 to $500 per door, acoustic laminated adds $300 to $800), thermal break in the frame (adds material and labour cost), and hardware choice. The Penot Double Glazing cost guide for Perth covers what each spec change does to the bottom line.
What the Installation Process Looks Like
Five stages run from first contact to install completion. Consultation: a site visit measures the opening and assesses surrounding finishes, orientation and access. Specification and quote: frame system, sightline, glass spec by orientation, hardware, finish. The quote should specify the IGU configuration (e.g., 4/16/4 with low-e on surface 3), the SHGC value, the lock model and warranty terms. Ask about IGU seal, hardware and installation warranty terms at the quote stage. Manufacture: frames extruded and joined, IGUs sealed, hardware factory-fitted, finish applied. Installation: existing opening prepared, frame set plumb and level, flashings dressed, door hung and adjusted. A French door install typically takes a day per opening with two installers. Handover: operating instructions, keys, warranty documentation and an AS 2047 compliance summary, supplied as standard by any AGWA member.
For the wider view across a multi-opening project, see our guide to replacing old windows in Perth.
Common Mistakes Perth Buyers Make When Ordering French Doors
- Choosing inswing without checking the room. A 1800 mm pair swings into a 900 mm arc per leaf, which clashes with furniture in tight rooms. Outswing is the answer, not a smaller pair.
- Clear standard glass on west-facing doors. West-facing doors catch low-angle afternoon sun for hours in summer. Without low-e and a low SHGC, the room behind them becomes uncomfortable from late afternoon onward.
- Skipping the thermal break on the frame. A premium IGU in a standard aluminium frame loses much of its energy benefit through the frame. Thermally broken drops the frame U-value from around 6.6 to around 2.2 W/m²K.
- Forgetting the screen. Hinged flyscreens, retractable screens and integrated screen systems suit different configurations. Decide at quote stage, not after install.
- Treating the lock as an afterthought. A multi-point lock is the AU standard for security and seal compression. A single-point deadbolt trades away the seal performance the rest of the door is paying for.
Where Penot Double Glazing Fits
Penot Double Glazing is a full AGWA member based at 92 Beechboro Rd S, Bayswater WA 6053. French doors are supplied as part of the standard double glazed range, with options for slim architectural sightlines, thermally broken frames, solar-control low-e and acoustic laminated glass, and multi-point hardware as the standard WA market specification. Every door is supplied compliant with AS 2047 and AS 1288. Penot Double Glazing offers a 10-year warranty on frames.
If you are sizing up French doors against a bifold or working out which glass spec suits a west-facing courtyard, a free in-home consultation walks through the choices on the actual opening. Compare options across the wider double glazing Perth range, book a free in-home assessment, call 1300 121 603, or visit the Bayswater showroom at 92 Beechboro Rd S.
How Much Do Double Glazed French Doors Cost in Perth?
For a standard 1800 mm aluminium double glazed French door pair in Perth, supply-only pricing is broadly in the range of $2,500 to $4,500 depending on frame finish, glass spec and hardware. Premium spec with thermally broken frame and solar-control low-e glass sits at the upper end. Supply and install adds approximately 30 to 55 per cent over supply only. These are 2026 indicative ranges, confirm with a quote.
Can You Put French Doors into an Existing Opening?
Often yes, where the existing opening can be modified to take a hinged frame with an appropriate threshold and lintel. The frame structure, sill height, floor finish and surrounding cladding all affect how straightforward the installation is. A site measure is the only way to confirm. The free in-home consultation covers exactly this assessment.
Do French Doors Seal Better than Bifold Doors in Perth?
Yes. A French door with a multi-point lock compresses against the frame seal at multiple points around the leaf, giving high water and air seal performance. A bifold relies on perimeter brush and pile seals that are less tightly compressed. AS 2047 tested water penetration ratings on hinged French doors are generally higher than equivalent bifold systems, though premium commercial bifolds are tested to 450 Pa.
What Glass Should I Use for West-Facing French Doors in Perth?
Solar-control soft-coat low-e double glazed unit with the lowest available SHGC, typically 0.20 to 0.40. West-facing French doors in Perth catch low-angle afternoon sun that no eave blocks effectively. The low SHGC reduces radiant heat gain into the room. Combine with laminated outer glass if the doors face an alfresco or pool area for acoustic and security benefit. Our guide to managing large glass openings in Perth covers the wider thermal picture for west-facing rooms.
