I am working on planning a small apartment layout. I have limited space for laundry, so I was going to use a stacking unit in a niche. If I put the electrical and water on one side, and vent it out the back (probably), would a 36" x 36" space be the appropriate size, so all the hookups could be done, but not waste space?
If you want to know for sure, choose the combo now and read the installation manual. (You can almost always find the manuals online.) The manual will tell you exactly how much space you’ll need, where the vent will need to be and so forth.
Check the electrical code. There are restrictions on having electrical power too close to water faucets in many locations.
You may also need a certain amount of clearance for the drier for cooling. Installation instructions would tell you this. The space might need to be somewhat bigger than to actually fit the drier.
You can get recessed laundry outlet boxes so nothing sticks out of the wall.
https://www.plumbingsupply.com/washing-machine-outlet-boxes.html
Dennis
We put a full sized over under unit into a closet in the bathroom that’s 40" wide and 38" deep. Tight fit, but there’s an inch or two leeway side to side. There are smaller units that should be able to fit into a 36" x 36" space. You will need some other storage space nearby for detergent bottles and whatnot.
Standard size for w/d units in the US is 27" x 30". You need a few inches in the back (for power and/or venting), so you should be OK, but you will have no room for storage. I would not go any smaller.
A friend built walls around his laundry area. He used a small closet door to minimize expense. Years later, I helped him rip out one of the walls when he had to replace his washer and it was bigger than the doorway.
Have seen a lot of closet laundry rooms, built more than a few. Very common now with starter homes having laundry on the upper floor / with the bedrooms. Door should be 32" (code here) so the problem above does not arise. For size, 27 W x 30 as John says is pretty typical, some stacking models are smaller. Most front loading units have stacking kits, height should not be a problem. Many dryers have optional side venting but typical is back and at the bottom, but I would take a good look at where your exhaust duct because you can probably not do anything about the placement of the existing wall hood. Ducting should be hard pipe rather than flex and fastened with metal tape rather than screws wherever possible.
Recessed wall boxes for plumbing and exhaust are pretty standard now. These make final installation much easier. Two inch waste pipe and vent is now standard to reduce vent clogging issues caused by too much suds. Really best to check with local municipality for code requirements though.
A cabinet for supplies and a shelf for laundry baskets should be planned for. Also choosing the units and confirming door swing and hook up placements before layout is best practice.