Yes, in most cases a NZ homeowner can dig a fire pit or outdoor fireplace base themselves — it's a straightforward manual excavation job that doesn't require a licensed tradesperson. That said, there are real considerations around building consents, underground services, fire safety rules, and soil conditions that you need to work through before you pick up a spade.
Do You Need a Building Consent?
This is the first question to answer. Under the NZ Building Code and the Building Act 2004, some outdoor fireplaces and fire pits are exempt from building consent under Schedule 1, but others are not. As a general guide:
- A simple in-ground fire pit (a hole in the ground with no permanent structure) is typically exempt.
- A freestanding outdoor fireplace or chiminea placed on a base is usually exempt if it meets size and setback thresholds.
- A built masonry outdoor fireplace (e.g., brick or block construction) may require consent depending on its size and your council's rules.
Schedule 1 exemptions can be interpreted differently by different councils, so always confirm with your local council before starting work. You can read more about consent requirements at MBIE Building Performance.
Locate Underground Services First
Before you dig anything — even a shallow hole — you must identify what's underground. Hitting a buried power cable, gas line, or water pipe is dangerous and potentially fatal.
- Contact Dial Before You Dig (0800 248 344 or dialbeforeyoudig.co.nz) to get utility plans for your property.
- Check with your local council for any stormwater or drainage lines.
- Look for surface clues: inspection covers, meter boxes, and conduit runs.
WorkSafe NZ has clear guidance on excavation safety — even shallow residential digging carries risk if services aren't located first.
How Deep Do You Need to Dig?
The depth of your excavation depends on what you're building:
| Feature | Typical excavation depth |
|---|---|
| Simple in-ground fire pit | 200–400 mm |
| Gravel/sand drainage base for a fire pit | 150–300 mm |
| Concrete pad for an outdoor fireplace | 100–150 mm (plus sub-base) |
| Footing for a built masonry fireplace | 300–600 mm+ (check with engineer) |
For a basic fire pit, you're usually digging 200–400 mm down and lining the pit with fire-rated materials. For a concrete pad under a freestanding outdoor fireplace, you'll typically excavate 100–150 mm and fill with compacted gravel before pouring concrete.
If you're building anything substantial in masonry, consult a builder or structural engineer about footing depth — especially on clay or sloping ground.
Choosing the Right Location
Where you place your fire pit matters for safety and compliance:
- Setbacks from structures: Most councils and fire safety guidelines recommend a minimum of 3 metres from any building, fence, or overhanging tree. Check your council's district plan for specific rules.
- Avoid slopes: Digging on a slope increases the risk of collapse and drainage issues.
- Drainage: Ensure the base won't pool water. A layer of compacted gravel beneath your fire pit helps with drainage.
- Wind direction: Consider prevailing winds so smoke doesn't blow toward your home or neighbours.
Some areas in NZ have open-air fire restrictions or bans during dry periods. Check with your regional council or Fire and Emergency NZ (FENZ) before lighting any fire.
What Tools Do You Need?
For most residential fire pit excavations, basic hand tools are sufficient:
- Spade and mattock for loosening and removing soil
- Tape measure and string line to mark out the shape
- Spirit level to check your base is flat
- Wheelbarrow for removing spoil
- Compactor plate (hire one) if you're laying a concrete pad
If you're dealing with hard clay, rocky ground, or a large footprint, hiring a mini excavator for a day is a practical option and saves a lot of effort. You can find qualified local excavator operators on tradedirectory.co.nz if you'd rather leave the machine work to a professional.
Soil and Ground Conditions
NZ soils vary enormously — from free-draining volcanic soils in Auckland to heavy clay in Waikato and expansive soils in Canterbury. Heavy clay can make hand digging very hard work and may shift seasonally, which can crack a concrete base over time. If you're unsure about your soil type, a local builder or geotechnical engineer can advise. BRANZ is also a useful resource for understanding NZ building ground conditions.
Fire Safety Rules
Once your fire pit is built, you still need to follow fire safety rules:
- Never leave a fire unattended.
- Keep a bucket of water or a hose nearby.
- Check for fire season restrictions with your regional council or FENZ before lighting up.
- Avoid burning treated timber, plastics, or rubbish — this is both a health hazard and often illegal.
When to Call a Professional
While the digging itself is DIY-friendly, call in a qualified tradesperson if:
- You're building a permanent masonry outdoor fireplace that may require consent and a proper footing design.
- Your ground is rocky, waterlogged, or on a significant slope — a mini excavator operator will do the job safely and efficiently.
- You need a concrete pad poured and want it done to a professional standard.
- You're unsure about underground services in your area.
- Your project triggers a building consent — you'll need a Licensed Building Practitioner (LBP) involved in restricted building work. See Licensed Building Practitioners for more information.
You can find experienced local excavators, concreters, and builders on tradedirectory.co.nz.
Licensed Building Practitioner (LBP)
