Weep holes performance solution in the Northern Territory
When the drawings cannot meet the Deemed-to-Satisfy Provisions for weep holes, a performance solution shows the design still meets the Performance Requirement. Fixed fee, 72 hours, one revision included.
Send your drawings → Get an instant quote
A certifier replies within one business day with what the job needs and a fixed fee, GST shown.
The requirement
NCC 2022 Volume One Performance Requirement F3P1 (weatherproofing) with masonry to AS 3700, and for houses Volume Two H1D5 masonry via the ABCB Housing Provisions clause 5.7.5 (weep holes).
The Deemed-to-Satisfy Provisions require open perpend joints (weep holes) in the course above flashings and damp-proof courses, over lintels and at the base of cavities, at set spacing, so water that crosses the outer leaf drains out rather than into the building.
When the drawings need a performance solution
Rendered or painted masonry where visible weep holes are refused, bushfire-prone sites where weep holes need screening to AS 3959, retrofits where a slab edge or a paved terrace covers the drainage course, heritage facades, and cavity-wall details with proprietary drainage systems.
What we write
We show how the wall still meets F3P1: where the water goes, how the cavity drains, and what the alternative detail does that the open perpend would have done. That may be a proprietary cavity drainage product, a modified flashing detail with concealed outlets, or a screened weep hole system, each with the manufacturer's evidence and the exposure of the wall taken into account.
The solution follows the NCC's own process for a Performance Solution (A2G2): the Performance Requirement identified, the Assessment Method stated, the evidence set out, and a conclusion a certifier can adopt. One revision is included when the assessor or the authority asks for more.
What the certifier needs to see
- Wall sections at every flashing, lintel and slab edge with the drainage path drawn
- Product data for any cavity drainage or screened weep hole system
- Bushfire attack level where the site is bushfire prone
- The assessment against F3P1 and the maintenance the detail relies on
Who accepts it in the Northern Territory
In the Northern Territory a performance solution is accepted as part of a building permit issued by a registered building certifier, then the occupancy permit, under the Building Act 1993 (NT). The NCC is adopted in full, so the solution is written to the NCC's Assessment Methods and it is the building certifier who adopts it. We write it so the certifier can adopt it as it stands.
Fee
- $4,400 inc GST ($4,000 + GST) per performance solution, one revision included
- Delivered in 72 hours from a complete drawing set; 24 hours at +50%
- Further revisions $1,100 inc GST ($1,000 + GST); a redesigned element is a new solution
- Fire-engineered solutions are scoped and quoted separately
Get an instant quote now
Answer a few questions and the fee is on the screen, GST shown, before you give us your name. Accept it and send the drawings.
Something larger, or Class 2, 3, 4 or 9c? Send it through and a certifier replies with a fixed price inside a business day.
Questions
Can weep holes be left out of a rendered wall?
Not under the Deemed-to-Satisfy Provisions. A performance solution can justify concealed or alternative drainage that does the same job, with the evidence a certifier needs.
Is this a structural question?
No. Weep holes are weatherproofing. The structural masonry design to AS 3700 is separate, though the two details sit on the same drawings.
What is the difference between a performance solution and a BCA report?
A BCA report assesses the whole design against the Deemed-to-Satisfy Provisions and lists the non-compliances. A performance solution resolves one of those non-compliances by showing the design meets the Performance Requirement another way.
How long does it take?
72 hours from a complete drawing set, or 24 hours at +50%. The clock starts when we confirm the set is complete.