Maximize Project Profitability with Cost Control
Discover how effective cost control, managing variations, and procurement tracking can protect profit margins in waterproofing projects. Learn strategies to ensure your projects remain profitable from start to finish.
EDUCATIONAL
Sumit Kumar
8/7/2026
You finished the job.
The waterproofing was completed, the builder is happy and the final invoice has gone out.
Then you look at the numbers. The project was supposed to make a decent margin, but the profit isn't where you expected it to be.
So where did the money go?
It doesn't always disappear because the original tender was wrong. Quite often, the margin is slowly lost after the job has already been won.
Winning the tender is only the starting point
Most waterproofing contractors put a lot of attention into getting the price right. You measure the drawings, check material costs, consider labour, add your margin and submit the tender. Once the project is awarded, however, the focus naturally moves to getting the work installed.
That is where commercial control can start slipping.
A project can lose margin through:
Additional work that isn't tracked
Material costs exceeding allowances
Unexpected preparation
Extra site visits
Scope changes
Unrecorded variations
Programme delays
Costs that aren't allocated to the correct project
Each issue might seem small. Together, they can materially change the profitability of a job.
Your tender should become your project benchmark
Once the project starts, your original tender is no longer just a historical document. It becomes your benchmark.
For example, if your tender allowed for 1,200m² and the project information later indicates 1,340m², that difference deserves attention.
It may affect:
Membrane quantities
Accessories
Labour
Preparation
Installation time
Programme
Overall project margin
The important part isn't simply knowing that the quantity changed. It's identifying the change while there is still time to do something about it.
Variations need to be captured when they happen
One of the easiest ways for waterproofing contractors to lose money is to complete additional work first and worry about the paperwork later. The site needs to keep moving, so the work gets done. Then another issue comes along. A few weeks later, someone is trying to remember what changed, who instructed it, which drawing was involved and how much additional work was completed. The longer you wait, the harder that conversation becomes.
A better process is simple:
Identify → Record → Price → Approve → Track.
You don't need a mountain of paperwork. You need a reliable commercial trail that connects the change on site to the additional cost.
Procurement can quietly change your margin too
Your tender might have been based on supplier pricing available at the time. But what happens when the actual purchase cost is higher? If that difference isn't monitored, the project margin takes the hit. The same applies when additional materials are required because of changes, wastage, detailing or site conditions. Regularly comparing project costs against your tender allowances gives you an early warning. Instead of discovering the result at the end, you can see where the project is heading while you can still manage it.
The owner shouldn't have to know everything from memory
This becomes more important as a waterproofing business grows. When you're running a handful of projects, you may have a good feel for what's happening on each one. As the number of jobs increases, that becomes harder.
You need to be able to quickly answer:
Which projects are performing?
Which jobs are exceeding allowances?
What variations are outstanding?
Where has the scope changed?
Are procurement costs tracking against the tender?
Which project needs attention?
That's the role of proper commercial control. It gives the business owner visibility without requiring them to personally chase every piece of information.
This is where a QS becomes more valuable than an estimator
An estimator helps you win the work. A QS can help you understand what happens to the money after you win it. For a waterproofing contractor, that can mean connecting the original tender with:
scope → procurement → progress → variations → costs → claims → final result.
That connection is where a lot of the commercial value sits. You don't necessarily need another full-time employee to achieve it. For many waterproofing businesses, project-based QS support can provide the commercial capability required when the workload or project complexity increases.
Profit should be protected before the job finishes
The biggest mistake is waiting until the project is complete to ask whether it made money. By then, the opportunity to correct most problems has already gone. Strong commercial control gives you visibility while the project is still moving. Because the goal isn't simply to win more waterproofing work.
It's to make sure the work you're winning is actually worth winning.
How AQUOSYNC can help
AQUOSYNC provides specialist waterproofing QS support across New Zealand and Australia, including tender preparation, takeoffs, BOQs, supplier pricing, scope review, procurement support, variations, payment claims, EOT support and project cost control. Whether you need support on one complex project or ongoing commercial assistance across multiple jobs, AQUOSYNC can work alongside your existing team without requiring you to build a full internal QS department.
If you're winning more waterproofing work but finding it harder to keep control of the commercial side, talk to AQUOSYNC about your next project.
