How the Right Blinds and Awnings Can Help You Meet BASIX Requirements
If you're renovating, extending, or building a new home in New South Wales, you've probably already run into the acronym BASIX — and if your project involves new or replacement windows, it's worth understanding early, because the shading you choose can make the difference between a pass and a redesign.
Our blinds and awnings may help you meet BASIX requirements.
The following article is not specific advice - it is general. Please make sure you speak to your own professional. But hopefully it give you a bit more information that help you inform your choices.
What is BASIX, and do I actually need to worry about it?
BASIX (the Building Sustainability Index) is the NSW Government's sustainability standard for new homes and many renovations. It's administered through the NSW Planning Portal and assesses a home against three targets: water, energy, and thermal performance (also called thermal comfort). A BASIX certificate is generated online and lodged as part of your development application — your council or certifier won't approve the build without it.
Does BASIX apply to my renovation, or just new homes?
Both, in most cases. BASIX applies to all new residential dwellings, and to alterations and additions where the estimated cost of works is above the threshold set by the Planning Portal (currently $50,000), as well as new swimming pools and spas over 40,000 litres. If you're adding a second storey, enclosing a verandah, or doing a substantial extension, assume BASIX applies and check the current threshold on the Planning Portal before you lodge your DA.
What does the "thermal comfort" part of BASIX actually look at?
Thermal comfort is about how much artificial heating and cooling your home is likely to need, based on its design and materials. The assessment looks at insulation, glazing (window and door size, orientation, and glass type), ventilation, and — critically — shading. A home with large, unshaded, west-facing glass will need much better (and more expensive) glazing or insulation to hit the same target as a home with the same windows properly shaded.
Why does shading matter so much to a BASIX assessment?
Windows are almost always the weakest point in a home's thermal envelope — glass gains and loses heat far faster than an insulated wall. Shading controls how much direct summer sun reaches that glass in the first place, before it becomes heat inside the house. Effective shading is selective: it blocks the high, hot summer sun while still allowing the lower winter sun to reach the glass and warm the room, particularly on north-facing walls. Get that balance right and a BASIX assessment rewards it; get it wrong — or skip shading altogether — and you'll likely need to upgrade to more expensive double glazing or extra insulation elsewhere to compensate.
How is a shading device actually measured for BASIX?
The Planning Portal's shading guidance measures a projection to the outside edge of the shading feature, including any fixed attachment such as a gutter or awning frame. As a general rule of thumb under the standard ("DIY") assessment method:
| Projection above window head | Shading credit |
|---|---|
| Up to 500mm | Full credit — treated as effective shading |
| 500mm–1500mm | Partial credit (around 50%) |
| Over 1500mm | No credit under the DIY method |
The shading also needs to extend horizontally on both sides of the window by at least the same distance as the projection — a narrow awning that doesn't reach past the window's edges won't get full credit even if its depth is right. For renovations and additions, the allowable range is typically tighter again (commonly capped around 500mm above the window head and 2400mm above the sill). These figures come from the Planning Portal's shading guidance and can vary by method and project, so it's worth confirming the exact numbers for your job with your BASIX assessor.
Can an awning genuinely help me pass BASIX?
Yes — awnings are explicitly recognised as a shading device in BASIX's thermal comfort guidance, whether fixed or retractable. A well-sized external awning over a north-facing window can provide the same shading benefit as a fixed eave, while a retractable model gives you the flexibility to open it up on a mild winter's day and let the sun in — something a fixed structure can't do. For west and east-facing windows, where the sun sits low in the sky and a horizontal awning alone won't fully block it, a drop-arm awning that extends down as well as out, or a vertical screen, typically performs better.
Do external blinds count as shading too?
Yes. External louvres and blinds are also recognised in the BASIX guidance, with one important condition: to get credit, they generally need to completely cover the window when closed. A narrow or partial blind that leaves glass exposed at the edges won't be treated as effective shading. This is one reason external blinds are assessed differently to a simple curtain or an internal roller blind — coverage and fixing matters, not just the presence of a blind.
External shading vs internal blinds — which one actually helps my BASIX result?
This is the distinction that trips up a lot of homeowners. Internal blinds and curtains improve comfort and privacy, but by the time sunlight has passed through the glass it's already inside the building envelope as heat — internal coverings can only slow that heat spreading into the room, not stop it arriving. External shading (awnings, external blinds, louvres, eaves, pergolas) intercepts the sun before it hits the glass, which is why it's what BASIX's thermal comfort assessment actually credits. If you're weighing up window furnishings for BASIX purposes specifically, external is what does the work; internal blinds are a comfort and lifestyle upgrade on top.
Does the right shading depend on which way my windows face?
Yes, and it's one of the most common mistakes in a shading design. A single approach applied to every elevation of a house rarely works:
| Orientation | Sun path | What tends to work best |
|---|---|---|
| North | High in summer, low in winter | A fixed or retractable horizontal awning sized to the table above — blocks summer sun, admits winter sun |
| West | Low and intense in the afternoon, year-round | A drop-arm awning or vertical external blind that can close down close to the glass |
| East | Low and intense in the morning | Same approach as west — a drop-arm awning or vertical blind, or adjustable louvres |
| South | Minimal direct sun | Shading usually isn't the priority here — the BASIX gain is smaller |
What features should I look for in a BASIX-friendly awning or blind?
A few practical things make a real difference to how a shading device performs, and to what an assessor will credit:
- Correct projection depth for the window's height and orientation, not just "whatever looks right" — this is the single biggest lever, per the projection table above.
- Full width coverage — extending past both edges of the window opening, not just spanning the glass itself.
- Full coverage when closed, for external blinds and louvres specifically — gaps at the sides reduce or remove the credit.
- Fixing and durability suited to the elevation — a west-facing screen copping direct afternoon sun and weather needs a more robust fabric and frame than a sheltered north-facing awning.
- Adjustability where it helps — retractable awnings and adjustable louvres let you open up for winter sun and low light, which fixed shading can't do.
My BASIX assessment failed on thermal comfort — can adding shading fix it after the fact?
Often, yes, and it's usually cheaper than the alternative. If a home is falling short on thermal comfort, the standard fixes are: upgrade the glazing (double glazing, low-E coatings), add more insulation, or improve shading. Of the three, adding or resizing external shading on the problem elevations is frequently the lowest-cost path to closing the gap, because it doesn't touch the building fabric itself. It's worth asking your BASIX assessor to model the effect of a specific awning or blind size before you commit to a more expensive glazing upgrade.
How do I make sure my shading is right before I lodge my DA?
Get the window schedule (sizes, orientation, head heights) to whoever is fitting your awnings or blinds early, ideally before your BASIX assessment is finalised, so the shading design and the certificate match. If the certificate specifies a certain projection and your installed awning ends up shallower — or narrower than the window — you can end up out of step with what was approved. A council or certifier checking the completed build against the BASIX certificate can query the mismatch.
Frequently asked questions
Do I need BASIX for a small renovation like replacing a few windows?
Not usually on its own — BASIX generally applies once the estimated cost of works passes the current threshold (commonly $50,000) set out on the NSW Planning Portal, or for new dwellings and larger pools regardless of cost. Check with your council or certifier if you're unsure whether your project is captured.
Is a pergola treated the same as an awning under BASIX?
They're assessed under the same shading principles but with different rules — fixed pergolas with battens or sheeting are measured differently to awnings, including a batten-spacing rule and a shading-coefficient requirement for solid roofing. An awning (fixed or retractable) is generally simpler to size correctly.
Will internal blinds or curtains help my BASIX rating?
They help with comfort, glare and privacy, but they're not what BASIX's thermal comfort shading credit is based on, because they act after the heat has already entered through the glass. External shading is what's assessed.
What's the difference between the "DIY" and "Simulation" BASIX methods for shading?
The DIY method uses fixed rules of thumb like the projection thresholds above. The Simulation method models your specific home's performance and can give more flexibility on shading design in exchange for more detailed input — worth discussing with your assessor if your shading doesn't neatly fit the DIY rules.
Can I install a bigger awning than BASIX requires, just to be safe?
You can, but check the projection-credit table first — under the DIY method, going much deeper than around 1500mm above the window head stops adding BASIX credit, and on north-facing windows an oversized fixed awning can start blocking useful winter sun too. Matching the depth to the window, rather than maximising it, usually gives the best year-round result.
Who do I talk to about getting the shading right for my BASIX certificate?
Your BASIX assessor or accredited certifier is the authority on what your specific certificate requires. Awnly can talk through awning and external blind options, sizing and placement for your windows once you know your target — get in touch and we're happy to help.
