I’m writing this because I made several avoidable mistakes during our kitchen and bathroom renovation. If you’re planning something similar, I hope our experience helps you ask the right questions before you order anything or become too attached to a layout.
By the time anyone asked where the kitchen waste pipe was going, I had already chosen the pendant lights.
I had also spent an unreasonable amount of time comparing two almost identical shades of cupboard paint. The kitchen layout was saved on my phone, the bathroom tiles were picked, and I could picture exactly how everything would look.
Then the plumber came round.
The kitchen sink was moving from the outside wall to an island. In the bathroom, I wanted the shower on the opposite side of the room. Both floors were concrete.
I had treated those changes as if I were rearranging furniture. Move this over there, open that up and put something nicer in its place. It hadn’t occurred to me that moving the things above the floor meant figuring out what had to happen underneath it.
Where would the new pipes run? What was already buried in the slab? How much of the floor would need to be opened? And who was supposed to work all of that out before the new kitchen and bathroom went in?
Those questions affected the renovation far more than the finishes I had spent weeks choosing. They also taught me that concrete cutting and drilling shouldn’t be treated as a last-minute demolition job. It needs to be considered while the layout is still being planned.
That was the lesson I learned the hard way.
Table of Contents
The island sink changed the whole plan
I wanted to wash up facing the room instead of staring at a wall. It seemed like a perfectly reasonable thing to want from a new kitchen.
What I hadn’t worked out was how the sink would connect to the drainage from its new position. I assumed the plumber would sort that out when the kitchen went in.
He needed to establish the route and drainage levels much earlier. Because the house had a concrete slab, getting the waste pipe to the island could mean cutting a trench through part of the floor.
Before anyone started marking the concrete, the builder also needed to understand what was already there and whether there were any structural or service-related constraints. My clean kitchen render didn’t answer any of those questions.
I remember standing in the room, trying to reconcile the island in the picture with the possibility of a trench running across the floor. I had budgeted for the sink and tap. I hadn’t properly understood the work involved in connecting them.
We went back over the layout while there was still time to change it. The island stayed, but only after the people doing the work had confirmed that the services could reach it.
That conversation should have happened before I became attached to every detail.
Then the bathroom joined in
The bathroom had its own version of the same problem.
Moving the shower made the room look more spacious on paper. But where it could go depended on the drainage route, the levels available and how the floor would be repaired and waterproofed afterwards.
I had been thinking about where I wanted to stand. The plumber was thinking about where the water would go.
There was also a difference between cutting a trench through the floor and drilling an opening through concrete. I had used “drilling” to describe almost everything because I didn’t know what else to call it.
The contractor explained that floor sawing could define the section that needed to come out for the plumbing trench. Core drilling was different: it created a circular opening for a pipe or another service.
Even the hole size had to come from the person installing the pipe. It might need room for a sleeve or sealing system as well as the pipe itself.
These felt like small details compared with choosing an entire bathroom. In reality, they were the details that decided whether the bathroom could be installed as planned.
One small change nearly put the opening in the wrong place
Somewhere between those conversations, I moved the kitchen island again.
Only slightly. Enough to improve the walkway, I thought. I sent the updated drawing to the cabinetmaker and carried on with my day.
The plumber still had the previous version.
Fortunately, we caught it before the floor was marked out. It was an uncomfortable moment because I could see how easily my small layout improvement could have put the pipe opening in the wrong place.
After that, the builder kept one current plan, and changes had to reach everyone whose work depended on them. The final positions were checked on site before the cutting was booked.
I also stopped assuming that “the trades will work it out” was a complete plan. They could solve the practical problems, but they still needed everyone to be working from the same decisions.
Being in Margaret River added another complication: availability. Some contractors cover jobs across Bunbury, Busselton, Dunsborough and the wider South West, so the builder wanted the concrete work discussed before locking in dates with the plumber and cabinetmaker.
Until then, I’d assumed the builder would call someone to cut the concrete once everything else was sorted. I hadn’t realised that concrete cutting and drilling specialists could be involved earlier, while there was still time to check whether the layout was practical.
We went through both rooms again with the drawings, looking at where the equipment would need to go, which sections required opening and how the concrete would be removed. For the first time, I understood what had to happen between the old layout coming out and the new one going in.
There was still one change I hadn’t thought through properly: widening the opening into the next room.
The wider opening had to wait
I wanted the kitchen to feel more connected to the adjoining living area. In my head, widening the opening was one more demolition job.
The builder brought me back to the structural questions.
Because the proposed opening involved concrete, the engineer had to confirm whether it was possible and what support or strengthening it would need. Wall sawing might be used to form the approved opening, but the cutting contractor wasn’t the person who could approve the structural change.
The engineer also wanted the concrete checked for reinforcement and embedded services before the opening was finalised. That was when I learned what scanning could and couldn’t tell us. It could help show what was inside the concrete, but it wasn’t permission to cut through whatever it found.
That took the opening off my list of quick decisions. I still wanted it, but I understood why the engineering and investigation had to come before the cutting was booked.
We also had to confirm the finished size of the opening, including space for the frame and finishes. The rough opening shown during planning wasn’t automatically the final dimension the cutting contractor needed.
By that point, I was beginning to realise how many renovation problems start with one person assuming someone else has already checked the details.
The house became a worksite before it became a new kitchen
I had pictured the disruption as noise and a bit of dust.
The practical arrangements started before any cutting. The equipment needed a clear route into the house. Furniture and stored items had to move. Floors we were keeping needed protection, and we had to work out which parts of the house would be unavailable.
I had been hoping to keep using the place almost normally. That expectation needed adjusting.
I also learned that the dust problem was more serious than protecting the furniture. Cutting and drilling concrete can release respirable crystalline silica, including particles too small to see, so the contractor needed proper controls to protect the workers and anyone nearby.
My idea of shutting a door and cleaning afterwards was nowhere near a plan.
Where water was used to help control the dust, there was concrete slurry to collect and clean up. That mattered because slurry allowed to dry can become another source of silica dust.
I started asking more useful questions. Where would the equipment go? What needed clearing? How would the work area be separated? Who was responsible for the slurry and clean-up?
Those answers affected our daily lives far more than the choice of tap finish ever did.
