Engineer
Designs foundations and tie-downs, and prepares Building Code evidence if your project needs consent. We can connect you with an independent engineer, optional, at your cost.
THE TECHNICAL DETAIL
See inside the walls before you pay a deposit.
Every material, every test report, published. Here's what goes into an Expanders® building, and where your engineer, plumber and electrician come in.
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[PHOTO: unit mid-installation, frame or panels visible]
EXPLORE THE MATERIALS
Built from the frame out.
[IMAGE: cutaway or exploded diagram – to be supplied]
MATERIAL 1 / 9
Frame
Welded steel chassis and frame. Q235A and Q355B structural steel, main sections 150 × 150mm and 100 × 150mm. Galvanised, then finished with anti-corrosion paint. All-steel construction, no timber framing.
Frame
Welded steel chassis and frame. Q235A and Q355B structural steel, main sections 150 × 150mm and 100 × 150mm. Galvanised, then finished with anti-corrosion paint. All-steel construction, no timber framing.
Walls
[WALL SPEC – CONFIRM: product page says 75mm EPS sandwich panels; disclosure says 16mm PU composite cladding with 60mm EPS core]. Asbestos testing by NATA-accredited labs to AS 4964: no asbestos detected.
Roof
50mm EPS-core corrugated colour-steel roof panels at a factory-set 8.8° pitch. Optional pitched roof upgrade.
Windows
Aluminium (6063-T5) double-glazed windows with fly screens. Current window series independently tested by Intertek to AS 2047-2014, pass.
Doors
Double-glazed aluminium sliding entry door, independently tested by Intertek to AS 2047-2014, pass.
Plumbing
20mm PPR water pipe and tapware carrying WaterMark certification; 50mm and 110mm PVC waste. Final connection on site by an NZ Certifying Plumber / Drainlayer. Hot water system not included, so you can choose one that suits your power supply.
Electrical
AS/NZS 5000.2-certified building cable. Final connection by a registered NZ electrician, who issues the Certificate of Compliance and Electrical Safety Certificate. 6 LED lights supplied.
Floor
Water- and insect-resistant magnesium composite floor with SPC flooring.
Factory
Our manufacturing partner holds ISO 9001 (quality), ISO 14001 (environmental) and ISO 45001 (health & safety) certifications.
Sizes and weights.
- Open dimensions
- 5.94m (W) × 6.42m (L) × 2.5m (H)
- Closed dimensions
- 5.94m (W) × 2.26m (L) × 2.5m (H)
- Floor area
- Up to 36m²
- Weight
- 4,200 kg
- Bedrooms available
- 0–4 bedrooms
- From-price (NZD, GST inclusive)
- $34,000
Set up or packed down in 1–2 days. Opening out needs a minimum crew of 4 for a 20ft and 6 for a 40ft. NZ delivery usually $1,000–$4,000 depending on distance from Christchurch and site access. Typical turnaround around 4 months from order. Prices exclude transport and installation.
Comparing quotes? Ask every supplier these.
A low price only means something if you know what's behind it. Here's what we'd ask, and our answers.
QuestionExpanders®Ask them
Can I read your full product disclosure without giving my email?
Yes. Read the public disclosure.
Ask for it in writing
Have your windows and doors been independently tested? To what standard?
Yes. Intertek, AS 2047-2014
Ask for the report
Is the tapware and water pipe WaterMark certified?
Yes
Ask for certificate numbers
Who does the final electrical and plumbing connection?
Registered NZ electrician and Certifying Plumber
Ask who signs it off
Is there a warehouse I can visit?
Christchurch and Auckland
Ask for the address
Who backs the warranty, and for how long?
Our NZ team. 3-yr structural + 1-yr fixtures
Ask who honours it if they close
Who does what.
An Expander arrives ready to set up, but most projects involve a few local professionals. Here's how it fits together.
Architect / designer
Site plans, consent documentation, and checking planning rules such as minor-unit size limits.
Builder / installer
Site prep, placing and opening out the unit, sealing joins. We don't install directly, but we recommend experienced installers and provide guidance and documentation.
Plumber / drainlayer
Connects water, wastewater and your hot water system, and issues the paperwork.
Electrician
Connects power and issues the Certificate of Compliance and Electrical Safety Certificate.
Your council
Confirms consent and planning requirements for your site. Talk to them before you order.
What we give your team: our manufacturer evidence and test reports to support any consent application. Sub-supplier certificates are available on written request to your council, designer, engineer, plumber or insurer.
Consent, explained straight.
Expanders® are sold as portable buildings. If you plan to live in one full time, your council will usually treat it as a building that needs consent, and consent needs evidence that it meets the Building Code, prepared for your specific site. Planning rules are separate from building consent. Small sleepouts without a kitchen or bathroom can sometimes be exempt, but most of our units include a bathroom. Talk to your council before you order, and we'll help your team with everything we hold.
Read our consent guidance20FT UPGRADES
Make it yours.
Premium exterior cladding
4 colours to choose from — replaces the standard shiny EPS panel
+$2,000
Luxury bamboo fibreboard lining
15 interior finishes — a warm matte alternative to the standard EPS lining
+$2,000
Pitched Roof – 20ft
Traditional roofline with better rain runoff and longer weather life
+$4,900
Veranda
Covered outdoor living — 6 decking finishes
+$4,900
Trailer – 20ft
Road-legal engineered chassis — makes the unit fully mobile
+$12,000
Veranda, requires pitched roof
[AVAILABILITY & PRICE – CONFIRM]
Flashing to expansion joins
[PRICE – CONFIRM]
20ft prices, GST inclusive. Other model upgrade prices: [CONFIRM].
Configure your own
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Your questions, answered.
Is an Expander consented?
Not automatically. Consent depends on your council, site and how you'll use it. See Consent, explained straight above.
Can I live in one full time?
Possibly, but your council will usually require consent. Check with them before ordering.
What foundations suit an Expander?
Commonly concrete slab or pads, concrete, timber or steel piles, or compacted ground where permitted. An engineer or qualified contractor should confirm what your site needs.
Does it come with hot water?
No. You choose a system that suits your power supply, installed by a qualified tradesperson.
Are Expanders® made from shipping containers?
No. They're designed for living and built to fit inside a shipping container for cheap, easy transport.
How does my engineer get your test reports?
Start with the public disclosure. For certificates held on file, email info@expanders.co.nz.
Got the detail you needed?
Get a quote, or send us your questions and we'll answer them in writing.
Step 1 of 2
About your project
About your project
What's it for?
When are you looking to go ahead? *
Where's it going? *
Your address lets our team look at your site on the map — access, space and orientation — so we can recommend the right unit and delivery approach before we call. Your details stay private and are never shared.
Site access for a truck and hiab?
Prefer to talk? Call Taylor on +64 27 210 6839 (South Island & Pacific) or Ross on 027 255 6623 (North Island).