Quick answer
A workable kitchen island needs 900mm of clear aisle on every side at an absolute minimum — 1m is comfortable, 1000-1200mm on the main working side — so your room should be around 3.6m wide minimum. Allow 600mm of bench width per seated stool. MTN Kitchens designs and installs islands to suit Auckland homes.
Everyone wants an island. It's the first thing out of most people's mouths when they sit down to plan a kitchen. And fair enough, a good one is the best thing you'll add to a room. It's bench space, it's storage, it's where people lean while you cook, it's where the kids do homework. But an island is also the easiest thing to get wrong, because it's the one piece of joinery that has to work from all four sides, and the room either has the space for it or it doesn't. There's no fudging clearances after the cabinets are in.
The numbers an island lives or dies by
We've built and installed something north of 2,000 kitchens out of our East Tamaki workshop over 23-odd years, a fair chunk of them with islands, in everything from Ponsonby villas to spec homes in Flat Bush. The pattern is always the same. The island that looks great on the plan is too big for the room, or it's the right size but someone forgot the waste needs to get under the floor, or it's been squeezed into a galley where a peninsula would've done a better job for less money. This guide is the stuff we actually measure to before a sheet of MDF gets cut.
Key points
- Leave 900mm minimum clearance around an island, 1000-1200mm on the main working side. Under ~3m of room width, you usually can't have one.
- A usable island is roughly 1200mm long minimum; for seating, allow 600mm of width per stool and 300mm of knee overhang.
- Plumbing or a hob in the island means waste, water and ducting under the floor or in a bulkhead — cheap on a slab pour, expensive as a retrofit.
- A peninsula gives you 80% of the island for less money and less floor space — it's the right call more often than people think.
- Waterfall ends look sharp but add cost (more stone, mitred joins) and aren't structural — decide if you're paying for the look.
The clearance numbers, and why they're non-negotiable
An island lives or dies on the gaps around it. Get them wrong and the kitchen feels cramped no matter how nice the joinery is, and you'll knock hips on the corners every day for the next fifteen years. We work to a clear floor space of 900mm as the absolute minimum on any side someone walks through. That's measured from the face of the island to the face of the opposite cabinetry, with doors and the dishwasher shut, and crucially with handles factored in. A 900mm gap becomes 850mm the second you fit chunky bar handles both sides.
On the main working run — the side facing the cooktop and sink wall — push that to 1000mm, and 1100-1200mm if two people cook together or anyone uses a mobility aid. The reason is simple: that's the side where the oven door drops down, the dishwasher tray pulls out, and someone's bent over the lower drawers. 900mm there and you can't open the oven and stand behind it. On the back side, where it's just a walkway or seating, 900mm holds up fine, and 1000mm if stools are tucked there because a seated person eats into the gap.
A wrinkle worth flagging: the Building Code doesn't dictate kitchen island clearances in a standard house the way it governs, say, stair geometry, so nothing forces your hand on paper. The numbers above are trade convention, learned from two decades of kitchens that got them wrong. If you're doing a universal or accessible layout, you're looking at 1200mm clear to allow a wheelchair to turn and pass, and that single number often decides whether the island survives the design at all.
How big the island itself needs to be
Below a certain size an island stops being an island and becomes a table you can't move. We won't build a freestanding island much under 1200mm long by 600mm deep — below that the bench space is too narrow to prep on and the cabinet underneath barely holds a bin. The sweet spot for most Auckland homes is somewhere between 1500mm and 2400mm long, and 900mm to 1100mm deep if you want storage or a sink on both faces.
Depth is where people underthink it. A 600mm-deep island gives you one row of cabinets accessed from one side — fine, but you've used a lot of floor for a single bank of drawers. Go to 900mm deep and you can fit cabinets one side and an overhang for stools the other, or shallow storage both faces. Past 1100mm deep and you can't reach the middle of the benchtop to clean it. Depth isn't what forces a stone join, though — standard engineered stone slabs run around 3000 x 1400mm, so it's tops past 3m long, or waterfall ends eating into the slab, that push you into a second slab and a join. Plan the island to fit a slab and you save a join and the cost that comes with it.
| Island size (L x D) | Realistic use | Room width needed (900/1000mm aisles) |
|---|---|---|
| 1200 x 600mm | Prep + bin, no seating | ~3.2m |
| 1500 x 900mm | Prep + storage + 2 stools | ~3.6m |
| 2100 x 1000mm | Sink or hob + seating + storage | ~3.9m |
| 2400 x 1100mm | Double-bank storage, sink, 3-4 seats | ~4.2m+ |
Seating: the maths people get wrong
Seating is the number one reason islands grow past what the room can take. Everyone wants four stools. Few rooms have space for four stools done properly. The rule we use: 600mm of bench length per person, and 300mm of clear knee space under the overhang. Two stools comfortably is 1200mm of run plus the cabinet that's behind them. Four stools properly is 2400mm of clear seating frontage, which is a big island before you've added any cabinet returns.
The overhang is the bit that gets value-engineered out and then complained about. For legs to fit under, you need 300mm of clear knee room. A standard 600mm-deep cabinet plus a 300mm overhang gives a 900mm-deep island — which loops straight back to your room width. People want the slim island and the comfy seating, and you can't always have both. If the stone overhangs more than about 300mm unsupported, it needs steel flat bar or brackets underneath, especially in 20mm engineered stone, or it'll crack at the join over time. That's a detail, not an afterthought.
Bench height vs bar height
Two heights work for island seating. Bench height (around 900mm, same as the benchtop) takes a 650mm stool and keeps one continuous surface — cleaner look, easier to wipe down, and the prep area and eating area are one. Raised bar height (around 1050-1100mm) takes a 750mm stool and hides the prep mess behind a lip, which families with kids tend to like. The raised section costs more — it's a second benchtop level and extra framing — and it eats into the at-a-glance openness people want from an open-plan kitchen-living space. We build both; just know the trade-off before you choose.
Running services to an island: the real cost driver
This is where island budgets quietly double. The minute you put a sink or a hob in the island, you're running services across the room to a piece of furniture sitting in the middle of the floor. Power for a hob or sockets is the easy one — a sparky drops a sub-floor run or chases it through the slab. Water and waste are the ones that bite, because waste needs fall, and you can't give a waste pipe fall through a concrete slab that's already poured.
On a new build over a timber sub-floor, it's straightforward — the plumber sets the waste, water and the dishwasher line before the floor goes down, and it's a couple of hours of work. On a slab, the services have to be cast into the pour, which means your island position is locked before the concrete truck arrives. Get this coordinated early; it's a classic source of variations and RFIs when the kitchen plan lands after the slab's down and the waste stub is a metre from where the sink now needs to be.
If you're putting a hob in the island, you've also got ventilation to solve. A ceiling rangehood or a downdraught extractor, and a downdraught needs its own ducting run under the floor, which is the same slab problem again. Most of the time we steer clients toward keeping the cooktop and rangehood on the wall and using the island for the sink, prep and seating — it's cheaper, the extraction works better ducted to the wall, and you're not staring at a rangehood hanging in the middle of your open-plan room.
A worked example: a Te Atatu renovation
When to drop the island idea
Here's a real-shaped scenario we see often. A 1970s brick-and-tile in Te Atatu Peninsula, owners knocking out the wall between kitchen and dining to open it up. Resulting room is 3.8m wide where the island would sit. They want a 2400mm island with a sink and four stools. Let's run the numbers the way we would on a measure.
Room is 3.8m. The sink and cooktop wall carries a 600mm cabinet run, so a 900mm-deep island leaves 3800 minus 600 minus 900 - 2300mm to split between two aisles, measured face to face. Give the working side 1100mm and the seating side gets 1200mm, enough for stools. Go 1000mm deep and both aisles land at 1100mm, which still clears the numbers above — so that depth is on the table too. We kept it at 900mm because the extra 100mm behind the stools does more for the room than 100mm of bench depth does. But the house is on a slab. The sink means cutting the slab for waste, or — what we actually recommended — moving the sink back to the wall run and making the island prep, storage and seating only. That dropped the plumbing cost out entirely, kept the four stools (2400mm gives 2400 of frontage, four at 600 each, tight but it works), and the budget went into a waterfall end in engineered stone instead of into a concrete cutter. Better kitchen, same money.
Nine times out of ten the island people sketch is 200mm too big and has a sink in it that's going to cost them four grand in concrete cutting. Move the sink to the wall, lose nothing, save a fortune.
Island vs peninsula: making the call
A peninsula is an island attached to a wall or a cabinet run at one end. It does most of what an island does — bench space, seating on one side, a divide between kitchen and living — but it only needs clearance on three sides instead of four, and services run along the connected end instead of across open floor. For a lot of Auckland rooms, especially terraced housing and townhouses where the kitchen is part of a narrower open-plan strip, the peninsula is simply the better engineering.
The honest test is room width. Under about 3m of width, you can't fit an island with workable clearances both sides, full stop — a peninsula or an L-shape or galley layout is the answer. Between 3m and 3.6m, an island is possible but tight, and a peninsula often gives a roomier result. Past 3.6-4m, the island comes into its own. We'd rather tell you a peninsula is right than build you an island you have to sidle around.
- One less side to walk round: that floor goes back to the dining table or the walkway.
- Water and waste run along the connected end, so nobody is cutting a trench across your slab.
- Want seating but limited width: a peninsula seats on the open side without needing a second aisle.
- The bench itself can run longer, because the space a fourth aisle would have eaten goes into joinery instead.
- It still splits the kitchen off from the living end, which is most of what people wanted the island for.
Waterfall ends and the finish details
A waterfall end is where the benchtop material runs down the side of the island to the floor instead of stopping at a standard edge. It's the look of the moment and it does look sharp, particularly in a veined natural or engineered stone where the grain can be mitred to run continuously around the corner. But understand what you're paying for: it's more stone (a whole extra panel per end), a precision mitred join, and for book-matched veining, careful slab selection. It is a finish choice, not a structural one — the island stands up fine without it.
Waterfalls work best on islands you see from the living side — the panel hides the cabinet carcass and gives a solid, furniture-like end. On a budget, a panelled end in 2-pac lacquer or melteca matching the doors gives you a clean finish for far less, and most people can't tell from across the room. We build all three — standard edge, panelled end, full waterfall — and we'll price them side by side so you can see exactly what the look costs before you commit.
Power and the practical extras
Even an island with no sink wants power. A double socket on the end or set into the bench means you can use the island for appliances and charging without dragging a cord across the room — and on a kitchen for resale appeal in Auckland, a powered island reads as a properly thought-out kitchen. Pop-up socket towers exist but they're a maintenance item; we usually fit a discreet socket into the waterfall end or the side panel. Don't forget bin pull-outs, a deep pot drawer, and if there's room, a second prep zone — an island is wasted if the underside is just empty doors.
Frequently asked questions
What's the minimum room size for a kitchen island?
As a rule, around 3.6m of room width is where an island starts to work comfortably with a cabinet plus clearances both sides. Below 3m you really can't fit one with safe walkways — a peninsula is the answer. Between 3m and 3.6m it's possible but tight, and we'll tell you honestly whether it'll feel right or just feel jammed in.
Can I put a sink or cooktop in the island?
Yes, but it drives the cost. A sink needs water and waste run to the middle of the floor; on a poured slab that means cutting concrete, which is expensive. On a new build it's set before the floor goes down and costs far less. A cooktop adds ventilation. Often the smart move is keeping the sink and hob on the wall and using the island for prep, storage and seating.
How much overhang do I need for stools?
Allow 300mm of clear knee room under the bench and 600mm of length per person. Two stools is about 1200mm of frontage, four is 2400mm. Overhangs past 300mm in stone need steel support underneath so they don't crack.
Is a waterfall end worth it?
It looks excellent and lifts the whole kitchen, but it's a cost choice — extra stone, a mitred join, and careful slab selection for veining. It's not structural. A matching panelled end in lacquer or melteca gives a clean look for much less if the budget's tight. We price both so you can decide.
Island or peninsula — which is better?
A peninsula gives most of the benefit of an island but only needs clearance on three sides and keeps services short along the connected end. For narrower or terraced-house kitchens it's usually the better call. The island wins in genuinely wide, square rooms over about 3.6m.
How long does it take to install?
For a standard single kitchen we're on site 5-7 days start to finish, island included. Stone benchtops are templated after the cabinets are in and fitted a few days later, so the island top usually lands toward the end of that window.
If you're weighing up an island, send us the room dimensions — just the width and length of the space and a rough idea of where the sink and cooktop sit — and tell us whether it's a renovation or a new build, and whether you're on a slab. We'll tell you straight whether an island works, what size fits, and where the money goes, and we'll have a trade-priced quote back to you within 24 hours. One contract, one invoice, supplied and installed from our own East Tamaki workshop. If you're a builder or developer running multiple units, send the count and we'll price the lot.