
WCTNZ® is proud to be the official distributor of Sun-Mar™ composting toilets in the Realm of New Zealand (New Zealand, the Cook Islands, Niue, Tokelau and the Ross Dependency)
In 1971 Hardy Sundberg of Sun-Mar™ developed the world’s first self-contained composting toilet.
For the first time a self-contained toilet could be put in a bathroom and would evaporate liquids and compost solids.
The next big technical breakthrough came in 1979 when Hardy developed his third generation toilet which incorporated a rotating drum as the composting chamber. This was a three chamber design which used separate chambers for composting, evaporating, and compost finishing. Now the environment for each function could be optimized individually.
In keeping with the family tradition, a Sundberg still leads Sun-Mar’s™ research and development effort. Sun-Mar™ remains the world leader in composting toilets. Each model is designed to fill a specific need, and each is distinguished by innovative design, superior technology, and Sun-Mar’s legendary quality.
The way a Sun-Mar™ works is not only unique, it is also elegantly simple. Common sense tells us that the best way to compost is to use a drum. Luckily for Sun-Mar™, their many international patents ensure that only Sun-Mar™ can take full advantage of the benefits a drum offers for mixing and aeration.

All Sun-Mar™ Composting Toilet Systems are certified against the "AS/NZS 1546.2:2008 On-site domestic wastewater treatment units – Waterless composting toilets" standards.
Featured products
SM-EXCS
The Sun-Mar™ Excel is a best-selling, high-capacity Bio-drum composting toilet, known for its reliability, simple operation, and NSF-certified performance.
$3,760.43 excl GST excluding shipping
SM-EXCN-FT
The Sun-Mar™ Excel NE is a high-capacity, non-electric composting toilet, perfect for off-grid living, offering reliable, self-contained waste management.
$3,394.35 excl GST excluding shipping
SM - GTG
Sun-Mar™ GTG is a durable, reliable composting toilet, ideal for tiny homes and certifiable for RV Self-Containment.
$1,545.22 excl GST excluding shipping
CP 24x650g
24 x 650g briquettes of coco peat - a great growing media and an ideal bulking agent for certain types of composting toilet systems.
$117.39 excl GST excluding shipping
CP 5x5kgs
Bulking agent for the composting toilet systems to improve performance 5kgs 100% coco peat compressed bricks (comes in 5 pack) for a total of 25 kgs.
$108.98 excl GST $100.81 excl GST excluding shipping
PM Y-HG-100L
100L bale of peat moss - a great growing media and an ideal bulking agent for certain types of composting toilet systems.
$48.70 excl GST excluding shipping
PM Y-HG-50L
50L bale of peat moss - a great growing media and an ideal bulking agent for certain types of composting toilet systems.
$31.30 excl GST excluding shipping
WCT-SM GTG WMx
The GTG WET Mix is the most effective way of managing the solids chamber of all urine diversion composting toilets.
$28.70 excl GST excluding shipping
WCT-SM GTG C-PK
Getting the best out of your Urine-Diversion system the Sun-Mar GTG Care Pack will give you all the consumables necessary to have an odour-free experience with environmental merits!
$41.74 excl GST $38.61 excl GST excluding shipping
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