Designing to the Maximum: How a 1,400mm Louvre Span Unlocked $60,000 in Savings at Darcy Road Public School
Safetyline Jalousie louvre windows are engineered differently to conventional louvre systems — and that difference has real consequences for project cost, program, and performance. At Darcy Road Public School in NSW, our team identified an opportunity to configure the specified louvre windows in a way that better reflected what our system can do. The result: 31 fewer windows, better ventilation performance across every window type, and $60,000 in savings, with the architectural intent of the project fully intact.
The Safetyline Jalousie Difference: Engineered for 1,400mm
Unlike traditional glass-on-glass louvre systems, which are constrained by the weight and fragility of the glazed blade, Safetyline Jalousie uses an aluminium louvre bearer that supports each blade along its full length. This engineering allows each bay to span up to 1,400mm — compared to the 1,000–1,200mm typical of conventional systems, without any compromise to structural integrity, weather performance, or blade operation.
That structural difference translates directly into how a window schedule is configured, costed, and built. A wider bay means:
- One window unit where there would previously have been two — fewer units, less framing, less hardware
- Less fixed framing between louvre blades, which directly increases the free air percentage of each opening
- Faster fabrication — a single 1,400mm bay is more efficient to produce than two narrower bays of the same total area
- Faster installation — fewer components per opening reduces handling and labour time on site
- Lower cost per m² — reduced configuration complexity improves the economics across the whole package
One 1,400mm Safetyline Jalousie bay where there would otherwise be two narrower windows. Same glazed area. Less framing, less hardware, better airflow — and a meaningfully lower cost.
Identifying the Opportunity at Darcy Road PS
As part of our involvement on the project, our team looked at the louvre window schedule through the lens of what our system is capable of. It is something we do as a matter of course — understanding the specified windows and identifying where our 1,400mm span capability can be applied to achieve the same design outcome more efficiently.
At Darcy Road PS, that process revealed a clear opportunity. By configuring the louvre bays to take full advantage of our maximum span, the project could achieve the same glazed area and the same façade intent with fewer, wider bays — delivering stronger ventilation performance and a lower overall cost. The window count moved from 226 to 195 units, free air performance improved across every window type, and the package came in $60,000 under where it would otherwise have landed.
The drawings below illustrate the change in louvre bay configurations for key window types. The architectural design of the façade is unchanged — what shifted was how the louvre bays were arranged within each opening to make the most of what our system can span.
Window Type WAT02 — Before & After
Original | 900mm bays | 51% free air
Total Free Air Area: 3.96m²
Optimised | 1,400mm bays | 68% free air
Total Free Air Area: 5.23m² (+17%)
WAT02: Moving from 900mm bays to 1,400mm bays eliminates intermediate framing and increases free air from 51% to 68% — with no change to total glazed area.
Window Type WAT03 — Before & After
Original | 24% free air
Total Free Air Area: 1.9m²
Optimised | 50% free air
Total Free Air Area: 3.92m² (+26%)
WAT03: The most significant improvement on the schedule — free air area nearly doubled from 24% to 50% by consolidating bays to 1,400mm.
Window Type WAT04 — Before & After
Original | 24% free air
Total Free Air Area: 2.52m²
Optimised | 36% free air
Total Free Air Area: 3.8m² (+12%)
WAT04: Wider bay configurations reduce frame count and increase the proportion of louvre blade coverage across the elevation.
Compliance: Meeting Every Requirement, Then Some
For any NSW school project, the compliance requirements are non-negotiable. Every louvre bay configuration was assessed against:
- NCC / BCA — natural light and ventilation provisions
- NSW Education Facilities Standards and Guidelines (EFSG) — classroom daylight and air quality requirements
- Free air area calculations for each window type, confirmed against the project’s design requirements
The optimised bay configurations not only met every requirement — they exceeded the ventilation performance of the original window schedule across all four window types:
Window type WAT03 saw the most significant result: free air area nearly doubled, from 24% to 50%. This is a direct consequence of removing the fixed framing between narrower bays — wider spans with a continuous aluminium louvre bearer allow substantially more unobstructed blade coverage per opening.
The Cost Outcome
$60,000 saved — representing a 4–5% reduction on the louvre package. No reduction in glazed area. No compromise on compliance. No change to the architectural intent — just a smarter configuration made possible by how our system is engineered.
The saving was driven by reducing the total window count from 226 to 195 units. Thirty-one fewer windows to manufacture, deliver, coordinate, and install — each one a modest saving in time and cost that accumulates into a result the whole project team can point to.
For Architects: Specifying Louvres to Their Full Potential
When louvre windows are part of a façade or ventilation strategy, the configuration of each bay has a direct bearing on free air performance, daylight penetration, and cost. Safetyline Jalousie’s aluminium louvre bearer system allows bays to span up to 1,400mm, which changes what is achievable compared to narrower conventional configurations.
In practical terms, this means fewer mullions interrupting an elevation, higher free air percentages per opening, and a window schedule that can often be simplified without any reduction in glazed area. For projects that need to satisfy NCC ventilation provisions, EFSG classroom requirements, or specific free air area targets, the wider span can be the difference between meeting the minimum and exceeding it.
Our team works directly with architects and façade consultants during the specification and procurement process to identify where our system’s capability can add value — whether that is through free air performance, simplified bay counts, cost, or a combination of all three. Where opportunities exist, we can model the numbers, confirm compliance outcomes, and prepare the technical documentation required for certification, before the schedule is finalised and priced.
The earlier we are involved, the more scope there is to influence the outcome — for your client’s budget as much as for the performance of the façade.
For Builders and Project Managers: Fewer Windows, Faster Program
Thirty-one fewer windows on a school project is a tangible program advantage. It means:
- Fewer line items to procure, coordinate, and schedule for delivery
- Fewer components to receive, check, and manage on site
- Fewer installations per elevation — each one a direct saving in labour time
- A simpler window program from tender through to practical completion
On a project of this scale, those savings compound quickly. The $60,000 outcome was not achieved through value engineering or specification reduction — it came from configuring the louvre bays to take full advantage of how the Safetyline Jalousie system is built. Wider bays, fewer units, lower cost per m², and a faster install. That is a result worth pursuing on your next project.
The Best Time to Have This Conversation is Now
The earlier we are involved in a project, the more scope there is to add value. Once a window schedule has been tendered and priced, the opportunity to influence cost and performance narrows significantly. If you have an upcoming project where Safetyline Jalousie louvre windows are being considered, we would welcome the chance to work alongside your team from the start.
Our team will:
- Review the louvre specification against our 1,400mm span capability
- Identify where wider bay configurations can improve free air performance and reduce unit counts
- Confirm compliance with NCC, BCA, and any applicable Education or Government design guidelines
- Provide a clear cost comparison before the schedule goes to tender
There is no obligation. If the opportunity is there — as it was at Darcy Road PS — you will have the numbers to take it forward with confidence.
Send us your schedule. We’ll find the efficiencies.
