Start with the big boxes. In this example, we have a large opening for a washer/dryer combo unit. For any opening larger than 24", double the 3/4" plywood with glue and screws to provide adequate support for the stairs.
marmara tiny house design (furnished here with four lights houses components?) ... note secondary loft above entry, window options, stainless steel counters, jokul gas heater, combi sink /toilet?! ... the marmara is nearly 3x the size of jay's tiniest houses, with 262 sq ft, 250 sq ft for proposed loft space, 14.75'h if 32"h deck-over-trailer... on wheels is a park model RV, not a travel trailer (wide load /over height requires commercial drivers license to tow in USA); not to ICC code
nice The SHEDsistance: a 204 sq ft tiny house, built by its owners for just $30,000!... by http://www.danazhome-decor.xyz/tiny-homes/the-shedsistance-a-204-sq-ft-tiny-house-built-by-its-owners-for-just-30000/
Nomad’s Nest 5th Wheel Tiny Home on Wheels by Wind River Tiny Homes