Yes, building a simple sandpit for your kids is a very achievable weekend DIY project for most NZ homeowners. In most cases you won't need a building consent, but there are a few practical and safety considerations worth knowing before you grab a spade.
Do You Need a Building Consent?
For a basic, low-level sandpit — think timber edging, sleepers, or a simple frame sitting on or just below ground level — building consent is generally not required under Schedule 1 of the Building Act 2004. However, rules can vary depending on your local council and the specifics of your project (size, any attached structures, etc.). Always check with your local council before starting, just to be sure. You can find general guidance on consent exemptions at MBIE Building Performance.
Choosing the Right Location
Picking the right spot makes a big difference to how much your kids will enjoy the sandpit — and how long it lasts.
- Partial shade is ideal. Full sun means hot sand and sunburnt kids; full shade can lead to damp, mouldy sand.
- Good drainage is essential. Avoid low-lying areas where water pools after rain.
- Visibility from the house — choose a spot where you can keep an eye on young children easily.
- Away from overhanging trees where possible, as leaf litter, sap, and bird droppings can contaminate the sand.
- Level ground makes construction simpler and the finished sandpit more comfortable to use.
Materials You'll Need
Here's a basic list for a simple rectangular timber sandpit, roughly 1.5 m × 1.5 m:
| Item | Notes |
|---|---|
| Timber (treated pine or hardwood sleepers) | Use H3.2 or H4 treated timber for ground contact |
| Weed matting / geotextile fabric | Lines the base to suppress weeds and aid drainage |
| Coarse sand (play sand) | Washed, fine-grained play sand — not builder's sand |
| Screws or coach bolts | Galvanised or stainless to resist rust |
| Optional: sandpit cover | Keeps cats and rain out when not in use |
Treated timber: Make sure any timber in contact with the ground is rated at least H3.2 (above ground, exposed) or H4 (in-ground contact). Check the treatment rating stamped on the timber at Bunnings or Mitre 10. Avoid old railway sleepers or reclaimed timber that may contain harmful preservatives.
Step-by-Step: Building a Basic Sandpit
1. Mark Out and Excavate
Mark your sandpit area with pegs and string. Dig down around 200–300 mm. This gives enough depth for good play without using excessive sand.
2. Improve Drainage
If your soil is clay-heavy (common in many NZ regions), add a 50–75 mm layer of coarse gravel or scoria at the base before laying your weed matting. This helps water drain away rather than pooling under the sand.
3. Lay Weed Matting
Cut geotextile fabric to fit the base and up the sides slightly. This stops weeds pushing through and helps keep the sand clean.
4. Build Your Frame
Construct your timber frame above ground level or partially recessed. Pre-drill and use galvanised screws or coach bolts to join corners. Sand any rough edges smooth — little hands will thank you.
5. Fill with Play Sand
Use washed play sand, not builder's sand or beach sand. Play sand is screened to remove sharp particles and debris. As a rough guide, a 1.5 m × 1.5 m sandpit filled to 200 mm depth needs approximately 450 litres (around 0.45 m³) of sand. Your local landscape supplier or PlaceMakers can help you calculate the right quantity.
6. Add a Cover
A fitted timber lid or a simple tarpaulin cover keeps cats from using the sandpit as a litter box and stops rain from waterlogging the sand. This is one of the most important finishing touches.
Sand Safety Tips
- Always supervise young children in the sandpit.
- Check the sand regularly for foreign objects, animal droppings, or signs of contamination.
- Replace sand if it becomes discoloured, smells unpleasant, or has been heavily contaminated.
- Wash children's hands after play.
- Keep the sandpit covered when not in use.
- WorkSafe NZ has general guidance on keeping children safe around DIY projects and tools.
When to Call a Professional
A simple sandpit is well within most homeowners' DIY abilities. However, consider calling a qualified landscaper if:
- Your backyard has significant drainage issues that need professional assessment.
- You want a more elaborate built-in sandpit with decking, retaining walls, or integrated play structures (which may require building consent).
- You're unsure about ground conditions, buried services (always call Before U Dig on 0800 248 344 before digging), or site drainage.
A professional landscaper can also advise on the best materials for your specific NZ climate and soil type. You can find qualified local landscapers on tradedirectory.co.nz.
Licensed Building Practitioner (LBP)
