Why Your CIRDs Are Probably Failing the Building Commission's Test

If there's one finding that dominates Building Commission audit reports, it's this: "Design practitioners have not provided sufficient information in drawings."

Insufficient detail in Complying Industry Regulated Designs (CIRDs) is the single most common non-compliance finding. It's not close. And the reason it's so common is that most practitioners don't realise how high the bar actually is.

The Standard: Could a Builder Build From This Alone?

The test the Building Commission applies is deceptively simple: could a competent builder construct the building element from your regulated design, without needing to contact you for clarification?

If the answer is "well, they'd need to call me about the penetration details" or "they'd need to check with the supplier about the application method" — your CIRD fails the test.

This isn't an aspirational standard. It's the legislative requirement under the Code of Practice (Schedule 4 of the DBPR 2021). And it's what auditors are checking every drawing against.

The 7 Most Common Deficiencies

1. Missing Falls to Drain

Waterproofing drawings that show membrane extents but don't specify drainage gradients. The builder knows where the membrane goes, but not which direction the water flows. A floor plan showing "waterproofing to this area" without 1:60 or 1:80 fall indicators to a floor waste is incomplete.

2. Unspecified Products

"Apply waterproofing membrane to AS 4654.2" is not a specification. It's a reference to a standard. The CIRD must name the specific product, system, or equivalent — including primer, membrane type, reinforcement, and number of coats where applicable. A builder can't procure "to the standard." They procure a product.

3. No Penetration Details

Every pipe, conduit, or service that passes through a waterproofed surface is a potential failure point. Auditors expect to see drawn details showing how each penetration type is treated — puddle flanges, clamping rings, or proprietary sealing systems. A general note saying "seal all penetrations" is not a detail.

4. Missing Movement Joint Interfaces

Where different building elements meet — slab-to-wall junctions, expansion joints, control joints — the CIRD must show how the membrane or system transitions across the joint. This is where most waterproofing failures occur in practice, and it's where most drawings are silent.

5. No Termination Details

Membranes must terminate somewhere. The CIRD must show where and how — minimum heights, mechanical fixing, chase details, or turn-up extents. "Membrane to extend up wall" without a dimension or termination method is a deficiency.

6. Generic Notes Substituting for Drawn Details

A common shortcut is to include a "General Notes" sheet that references standards, product data sheets, and manufacturer specifications — without actually drawing the details. Notes are supplementary information. They are not a substitute for drawn construction details. If the builder needs to read a product data sheet to understand how to install the system, the CIRD lacks sufficient detail.

7. No Coordination With Other Disciplines

A waterproofing CIRD that doesn't account for the structural engineer's movement joint layout. A facade design that ignores the structural fixing details. A fire engineer's solution that contradicts the architectural drawings. The Commission checks whether designs from different practitioners actually work together.

What Good CIRDs Look Like

A CIRD that meets the Building Commission's standard typically includes:

• Plan views showing membrane extents, fall directions, and drainage points with gradients
• Section details at every change in condition — slab edge, hob, step-down, penetration, junction
• Product specifications either on the drawing or in a companion specification document referenced by drawing number
• Penetration details — at least one typical detail for each penetration type (floor waste, pipe penetration, overflow)
• Movement joint details — showing membrane continuity or treatment at each joint type
• Termination details — with dimensions, minimum heights, and fixing methods
• A complete title block — title, drawing number, revision, date, practitioner name and registration number

The Real Problem: Industry Culture

The reason CIRD deficiencies are so widespread isn't that practitioners can't produce detailed drawings. It's that the industry has operated for decades on the assumption that the builder will figure it out, or the supplier's rep will be on site, or the certifier will ask if they need more detail.

The DBPA changed the rules. The design practitioner is now accountable for the sufficiency of their design, independent of what happens on site. The drawings must stand on their own. That's a cultural shift, not just a technical one — and it's the cultural shift that most of the industry hasn't fully made yet.

The practitioners who recognise this and adjust their drawing standards now will be the ones who pass audits cleanly. The ones who keep producing the same level of detail they've always produced will keep getting the same findings.