Outdoor kitchen dimensions and clearances

An outdoor kitchen is an indoor kitchen with three assumptions taken away. The floor is not level, because paving sheds water. The cabinets have no toe kick, because they are masonry built off the slab. And the appliance puts out two to three times the heat of the one it replaces. Almost every dimension that differs from an indoor kitchen differs for one of those three reasons; the rest, like everything else in outdoor room dimensions, comes straight across.

The datum: a level counter over a floor that falls#

Counter height outdoors is measured from the finished paving directly in front of the counter to the top of the finished worktop. Not from the slab, not from the threshold, not from an average of the patio. Paving is laid to a fall: 2 per cent (1:50) is usual and 1.25 per cent (1:80) is about the flattest that drains. Over a 10 ft (305 cm) run of counter set truly level, a 1:60 fall drops the paving 2 in (51 mm) end to end, so the counter reads 36 in (91 cm) at one end and 38 in (97 cm) at the other. A 38 in worktop is above comfortable working height for anyone under about 5 ft 8 in (173 cm).

Set the 36 in datum at the end where the work happens, which is the grill, and let the far end run high. Better still, run the island parallel to the fall rather than across it, so the whole counter climbs together. The method for pinning a datum is in how to measure a room properly.

Why 36 in, and the two heights worth breaking it for#

Standing elbow height for a 50th percentile adult is roughly 40 to 43 in (102 to 109 cm), and unloaded work sits 3 to 5 in (8 to 13 cm) below it. That lands at 35 to 40 in, and 36 in (91 cm) is where the industry settled, arriving indoors as a 34.5 in (876 mm) base cabinet plus a 1.5 in (38 mm) top. Outdoors no cabinet module forces it, so the number is a choice made by the same counter and cabinet height logic.

Two departures earn their keep. 32 to 34 in (81 to 86 cm) suits a prep zone, because chopping and anything you press down on wants 6 to 8 in (15 to 20 cm) below the elbow rather than three. 42 in (107 cm) suits a bar, which is a seating height and also screens guests from the grill. The full ladder is in work surface heights by task.

The grill is not at counter height. A drop-in head puts its cooking grate 2 to 6 in (5 to 15 cm) above the worktop, so the cook reaches over a 38 to 42 in surface, not a 36 in one. Check that height against the shortest user.

Depth: 30 in, and why it does not behave like 30 in#

Thirty inches is not a rounded-up 24. It is the smallest depth that takes a 27 in (69 cm) grill head with 2 in (51 mm) in front of the control panel and an inch behind the firebox, and still leaves room for a plate.

Grill widths and the cutout arithmetic#

Built-in grills are sold by their overall hood width, and the cutout is smaller by the mounting flange, typically 1 to 2 in (25 to 51 mm) in total. Get it the wrong way round and the masonry opening is either short or shows a gap.

Cutout height matters too: most heads need 9 to 11 in (23 to 28 cm) of clear depth below the worktop, which is why no outdoor island carries a full-depth drawer bank under the grill.

Clearances: the three that are not negotiable#

Three rules govern, and the strictest applies.

1. The appliance label. A listed grill states its own minimum clearance to combustible construction at the sides, rear and overhead, and that takes precedence over any rule of thumb. Most require a noncombustible enclosure and give a side clearance to combustible walls of 6 to 12 in (15 to 30 cm).
2. The International Fire Code. For buildings with three or more dwelling units, LP-gas and charcoal cooking appliances are prohibited on balconies and within 10 ft (3 m) of combustible construction. Single houses are usually outside that scope, but 10 ft is a sound separation from timber cladding, a fence or a hedge in any case.
3. Overhead. The one that catches people. Many grills state a minimum clearance to a combustible overhead of 30 to 36 in (76 to 91 cm), and some prohibit installation under any combustible structure. A timber pergola is exactly that condition: its rafters sit at 7 to 8 ft (213 to 244 cm), only 4 to 5 ft (122 to 152 cm) above the grate.

If there is a solid roof, there is a hood. Size it as you would indoors and add for wind: grill width plus 6 in (15 cm) each side, against the 3 in used over an indoor range, mounted 36 to 42 in (91 to 107 cm) above the grate rather than 30 in. The reason is the burner rating: a four-burner outdoor grill totals 60,000 to 100,000 BTU/h against 30,000 to 50,000 for a domestic hob, so the plume is hotter and wider at hood height. The capture arithmetic is in range hood sizes and mounting heights.

The working aisle, and what the lid does to it#

NKBA sets the indoor work aisle at 42 in (107 cm) for one cook and 48 in (122 cm) for two, measured counter face to counter face, not to the cabinet below. Outdoors, our recommendation moves both up a step: 48 in (122 cm) as the working minimum, 54 in (137 cm) where a walkway crosses.

The reason is mechanical. A 36 in (91 cm) lid rotates up and back on a hinge at the rear of the firebox, sweeping an arc of roughly 18 in (46 cm) radius. Open, it stands 16 to 20 in (41 to 51 cm) above the counter and finishes 4 to 8 in (10 to 20 cm) behind the counter's rear face, so a grill backed onto a wall needs that gap or the lid never opens fully. On the working side, nobody stands within arm's length of an open lid over a hot firebox, so the cook stands 6 to 10 in (15 to 25 cm) further back than at a hob.

Forty-two inches of aisle minus that stand-off leaves under 32 in (81 cm) of clear passing width behind the cook, below the 36 in (91 cm) that walkway and circulation widths sets for a primary route. Forty-eight leaves 38 in, which works. The indoor version of the same arithmetic is in kitchen island clearances.

Island length: adding it up rather than guessing#

The NKBA landing rule is the whole calculation. A cooking surface needs 12 in (30 cm) of counter on one side and 15 in (38 cm) on the other; a sink needs 15 in (38 cm) on each side of the bowl. Applied literally:

• Grill only: 36 + 12 + 15 = 63 in, plus a 1.5 in (38 mm) overhang each end gives 66 in (168 cm). Build 6 ft (183 cm) and both landings get 15 in.
• Grill and sink: a 15 in (38 cm) bowl with 15 in each side adds 45 in (114 cm), giving 108 in, or 9 ft (274 cm).
• Grill, sink and an undercounter fridge: 24 in (61 cm) of fridge plus 15 in of landing adds 39 in (99 cm), giving 147 in, a little over 12 ft (366 cm). Fridge sizes and ventilation gaps are in wine fridge and beverage centre dimensions.

Twelve feet of counter with a 48 in aisle and a row of stools takes roughly 150 sq ft (14 m2) before a dining table is drawn, which is most of a terrace. Test it against patio sizes and layouts before the masonry is ordered, and run the aisle through the kitchen island fit checker.

Stools, overhang and the stone that cantilevers#

Overhang follows counter height, fixed by knee geometry rather than fashion: 12 in (30 cm) at a 42 in (107 cm) bar, 15 in (38 cm) at a 36 in (91 cm) counter, 18 in (46 cm) at a 30 in (76 cm) table. Allow 24 in (61 cm) of counter per stool as a minimum and 30 in (76 cm) for comfort, so a 120 in (305 cm) island seats four comfortably. Stool heights against each counter height are tabulated in bar stool and counter stool heights, and the same per-person allowance drives outdoor dining table sizes.

One structural point bites only outdoors: a 12 in (30 cm) cantilever in 30 mm (1.25 in) granite is at the limit of what stone does unsupported, and freeze-thaw cycling is unforgiving of stone already working hard. Beyond 10 in (25 cm) of unsupported overhang, set steel brackets at 24 to 36 in (61 to 91 cm) centres under it.

Frost, roofs, fuel and the 600 mm module#

Frost. Where the ground freezes, the island wants a footing below frost depth or it moves relative to the paving and opens a joint along its base, which often pushes the design towards a framed and clad island.

A roof. A solid roof turns the grill into an appliance needing mechanical extraction. An open pergola extracts nothing, and most manufacturers still treat its rafters as a combustible overhead.

Fuel. Natural gas needs a supply sized for the burner rating and fixes the grill in place forever. LP keeps the island movable at the cost of an undercounter compartment and a cylinder change every few months.

The module. Grill widths are an imperial family (24, 30, 32, 36, 42, 48 in) even in metric markets, so a kitchen set out on 600 mm modules will not take a 36 in grill without a modified opening.