Remedial Consultant vs Builder Quote: Which Do You Need?

When a strata building leaks, the reflex is universal: get some quotes. It feels prudent, it gives the committee numbers to compare, and it is often the exact move that leads to paying for the same repair twice. This page is about why, and about when the reflex is actually fine. I should declare my position up front: I am an independent remedial architect, so I sit on one side of this comparison. But the argument below is structural, not tribal, and it ends with me telling you when you do not need someone like me.

A quote is an answer to the wrong question

A quote answers "what will you charge to do a repair?" The question a leaking building actually has is "what is wrong?" Those are different questions, and the difference matters because of a simple conflict built into quoting: the person quoting is describing the problem they will be paid to fix.

That does not require anyone to be dishonest. A membrane contractor honestly sees membrane problems, a sealant applicator sees failed sealant, a tiler sees failed grout. Each quotes the repair they sell, scoped from a walk-over, priced to win against the other quotes. Nobody in that process is paid to find the actual water path, and water is a slippery witness: it enters in one place, travels through another, and appears in a third. So the committee compares three prices for three different guesses, picks one, and the building gets a confident repair of a symptom.

Waterproofing is the most common serious defect in NSW strata buildings on the government's own surveys, and the recurring version, the leak that comes back after repairs, is very often this mechanism rather than bad workmanship: the work was done well, on the wrong thing.

What an independent consultant actually does

An independent remedial consultant is paid for the diagnosis and the design, and specifically not for the construction work, so the findings have no thumb on the scale. Done properly, the sequence looks like this (it is the same five steps as on our waterproofing remediation service page):

1. Diagnose the cause. Investigation before opinion: moisture mapping, thermal imaging where useful, dye or flood testing where it earns its place. The output is evidence of where water enters and travels, not an impression.
2. Design the repair. Detail drawings of every junction and termination, specified materials and sequence, and the testing that will prove the work before it is covered. For apartment buildings this is regulated design work: waterproofing is a "building element" under the Design and Building Practitioners Act, so remedial designs must be prepared and declared by a registered practitioner.
3. Tender it like for like. This is where builders come back in, and where quotes become genuinely useful: several specialist remediation contractors pricing the same documented scope. Now the cheapest number means something, because everyone priced the same building.
4. Inspect the hold points. Membrane checks before screed, flood tests before tiles, junctions before finishes. Waterproofing fails invisibly; the hold points are the only time failure is cheap to see.
5. Document completion. Test results, photos, as-builts, warranties. This is what supports a bond claim, a warranty action or a future sale. Undocumented remediation is invisible the day the scaffold comes down.

I want to be precise about the relationship with builders here, because this page is not builders-versus-consultants. The remediation builders I work with are skilled specialists, and the good ones prefer working to a proper design, because it protects them too: a documented scope means fewer disputes, fewer surprises, and a defensible record of what they built. Independent design plus specialist construction is a partnership. What it removes is only the conflict of one party both defining and selling the problem.

When a builder quote alone is the right call

Honesty cuts both ways, so: not every leak needs a consultant.

• The cause is obvious and single. A failed shower screen seal, one cracked pipe, a blocked balcony outlet backing water up over a threshold. If the diagnosis is genuinely trivial, engaging a consultant is ceremony.
• The stakes are small and contained. One wet cupboard in one unit with a clear source does not need a five step process.
• A trusted specialist has already found the real cause, demonstrated it (shown you the test, not just the opinion), and the repair is modest. Good contractors do this, and when they do, let them fix it.

The dividing line I give committees: recurring leaks, multiple symptoms, multiple units, structural hints (spalling, rusty staining, magnesite), or any repair costing serious money, get diagnosed independently first. One-off, small, demonstrated problems get fixed by the person who demonstrated them. And if the building is under warranty or inside its defect bond window, independent evidence is worth even more, because it feeds the claim as well as the repair. The responsibility side of that is covered in who pays for waterproofing defects.

The money question, answered straight

Committees worry a consultant is an extra cost on top of the repair. The frank version: on a small job, it is. That is why small jobs should skip it. On a real remediation, the design fee is usually a small fraction of the construction cost, and it buys the three things that decide whether you pay once or twice: the right problem, comparable prices, and verified work. The most expensive waterproofing repair in any building's history is the one it does twice, with scaffold both times.

If your building is at the "getting quotes" stage right now, it costs little to pause and get the diagnosis question answered first. A Class 2 waterproofing consultation is a fixed $660 including a diagnostic site visit, and it ends with an honest recommendation, including, sometimes, "this one is simple, let your contractor fix it."