A bathroom upgrade rarely means just one thing. For some Whanganui homeowners it’s a single leaking toilet that finally needs replacing. For others it’s a full retile with a new vanity, a walk-in shower, and everything in between. At MB Plumbing, we see the full range, and the right approach depends on whether you’re repairing, replacing, or installing from scratch.
Here’s what’s involved in each part of a bathroom upgrade, and what’s worth knowing before you start.
Toilets: Repairs, Replacements, and New Installs
Most toilet problems start small. A cistern that keeps running, a wobbly pan, or water pooling at the base are common calls, and they’re often caused by a worn flush valve, a failing wax or rubber seal, or fixings that have loosened over time. These are usually straightforward repairs that don’t require replacing the whole unit.
Replacement becomes the better option once a toilet is cracked, repeatedly failing, or simply old enough that parts are hard to source. It’s also worth knowing that every toilet sold in New Zealand must carry a WELS water efficiency rating, so replacing an older single-flush model with a modern dual-flush unit can meaningfully cut water use without any change to how the bathroom looks or feels.
New installs, such as adding a second toilet or repositioning one during a renovation, involve connecting into the drainage and water supply system. This is where the work shifts from a DIY-friendly repair into regulated plumbing territory, which we cover further down.
Vanities: More Than Just a Style Upgrade
Vanities get treated as a purely cosmetic choice, but the plumbing behind one matters just as much as the style in front of it. Water supply lines, the waste trap, and the connection back to the drainage system all need to line up correctly with the new unit, especially if you’re moving the vanity to a different wall or changing from a single to a double basin.
Timber and timber-look vanities are popular in Whanganui bathrooms, but they sit in one of the wettest parts of the house. Splashback sealing and correct waste connections matter more here than they would elsewhere, since ongoing dampness around the base of a vanity is one of the more common causes of swelling, staining, and mould we’re called out to address.
Showers: Repairs, Replacements, and Waterproofing
Showers are usually the highest-stakes part of a bathroom upgrade, because they combine plumbing, waterproofing, and daily heavy use in one small space. Leaking mixers, poor water pressure, and tired shower boxes with failing seals are the most common repair calls we get across Whanganui homes.
A full shower replacement, or converting to a walk-in or frameless design, is a bigger job that depends heavily on getting the waterproofing right. Bathrooms and other wet areas fall under Building Code clause E3, which sets out the requirements for keeping moisture out of walls and floors so it doesn’t cause hidden damage over time. A shower that looks finished but wasn’t waterproofed to this standard is one of the most expensive mistakes to fix later, since the damage is usually inside the wall or floor before it becomes visible.
Shower performance is also tied to your hot water system. If a new shower is leaving you with lukewarm water or poor pressure, the issue is sometimes the shower itself and sometimes the hot water system behind it, particularly with older cylinders that weren’t sized for a higher-flow shower head.
Do You Need a Building Consent for a Bathroom Upgrade?
Straightforward like-for-like replacements, such as swapping a toilet, vanity, or shower for a comparable unit in the same position, are generally exempt from needing a building consent under Schedule 1 of the Building Act 2004.
Once you start moving plumbing lines, changing the layout, or altering wet area waterproofing, the job is more likely to need consent from Whanganui District Council. A good plumber should be able to tell you which category your upgrade falls into before work starts.
Why the Work Needs to Be Done by a Licensed Plumber
Sanitary plumbing work, including most toilet, vanity, and shower installs, is regulated under New Zealand law. Only practitioners registered with the Plumbers, Gasfitters, and Drainlayers Board can legally carry out this kind of work, and using an unlicensed tradesperson can also void your home insurance if something later goes wrong.
This isn’t just a compliance formality. Incorrect drainage falls, poor sealing, or a badly connected water supply line can cause damage that takes months to show up, long after the job looked finished.
Getting It Right the First Time
Bathroom upgrades often touch several trades at once: plumbing, waterproofing, tiling, and sometimes gasfitting if you’re adding a gas continuous-flow unit. Coordinating that as one project, rather than several separate callouts, is usually faster and avoids the risk of one trade’s work undoing another’s.
At MB Plumbing, we’ve handled bathroom upgrades across Whanganui homes for over 40 years, from a single toilet repair to a full bathroom fit-out. If you’re planning an upgrade, big or small, get in touch and we’ll talk you through what’s involved.
Phone: 06 345 7111
Email: info@mbplumbing.co.nz
