The most cost-effective approach to Homestar – by far
A simpler, lower-cost way to achieve Homestar standards.
No alternative building systems required.
Set target airtightness in design model and use with standard, familiar construction processes and systems.
Pragma achieved the airtightness levels required for Homestar using a simple, low-cost AeroBarrier approach that integrated easily with standard construction practices. Performance was independently verified by BXG through blower door testing, providing confidence in the result.
Typical airtightness costs were around $3,000–$4,000 per dwelling, with alternative systems typically costing three to four times more to achieve comparable outcomes.
“We were able to hit all our Homestar targets. We’re pretty stoked about how it came out.”
Liam Pugh, Senior ESD Consultant, BXG
Setting airtightness targets at the very start of the design process in ECCHO energy modelling creates a powerful opportunity to value-engineer the entire specification.
As shown in the screenshots, improving airtightness from the default 5 ACH50 to a modeller-set target of 2 ACH50 reduces heating demand from 45.1 to 38.7 kWh/m² and electrical demand from 39.7 to 36.4 kWh/m² with the same set of other specifications.
This uplift in building-envelope performance allows Homestar targets to be met with less reliance on higher-spec or higher-cost measures—such as upgraded glazing, extensive thermal breaks, slab-edge insulation, or additional loft insulation.
By improving performance at the envelope level first, airtightness unlocks simpler, more cost-effective solutions across the rest of the build.
Traditional membrane-based airtightness systems are typically two to four times more expensive than aerosol air-sealing solutions on a per-unit basis.
While some economies of scale can be achieved on repeat projects, membrane systems remain highly labour-intensive and rely on precise installation by multiple trades, often early in the construction sequence when the airtight layer is most exposed to damage. They also introduce non-standard sequencing, extensive taping and junction detailing, and higher material costs due to large surface areas.
Defects are frequently identified late through final testing, increasing the likelihood of rework, programme extension, and cost escalation.
From a cost-certainty and risk-management perspective, membrane systems therefore represent a higher-risk and higher-cost approach to achieving airtightness compared with aerosol air sealing.
Many airtightness approaches rely on perfect installation of unfamiliar systems and remain vulnerable to later trades.
With wraps, membranes, or panel systems:
The target is achieved because it is tested—not assumed.
Unlike other sealing systems, AeroBarrier:
This removes uncertainty for specifiers and assessors—and dramatically reduces the risk of costly remedial work late in the project.
“AeroBarrier achieved exactly what we needed to achieve. We got down to the right amount of air changes for Homestar 6. We couldn’t ask for better.”
Nick Allan, Builder and Director, Nuline
It’s important to distinguish between:
Airtightness systems, such as SIPs panels, Intelligent wraps and membranes and AeroBarrier tighten the building envelope but are not intended to address the operational leakage.
Disclaimer: Actual leakage depends on product selection, detailing, and installation quality. Values in the table are indicative only and not to be relied on for design.
Source: aggregated data from international agencies and industry associations.
| Component | Indicative contribution (ACH50) |
|---|---|
| Rangehoods & kitchen exhausts | 0.2 - 0.5 |
| Bathroom / laundry fans | 0.2 - 0.3 |
| Ceiling access hatches | 0.1 - 0.4 |
| Window & door hardware | 0.1 - 0.5 |
| Trickle vents | 0.05 - 0.2 |
| LED Downlights | 0.05 - 0.15 |
| Electrical outlets | 0.01 - 0.04 |
| Weep holes | ~0.01 |
AeroBarrier helps Homestar projects:
If you want a clear, measurable, and low-risk pathway to Homestar, start with airtightness—and start with Aero.
Some images on this page have been AI-generated by Gemini
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