Because weight is such an issue, the furniture is constructed using 42mm x 19mm pine to form a frame, which is covered in 4mm ply. The top of the sofa is 9mm ply to support weight. The cupboard doors were ordered and made to fit the holes once the frame was built. Lots of fiddling getting them in as nothing ends up being square.
We bought a few sheets of laminate for the kitchen and covered up the pine. The bench top is 8mm mdf with an edge fixed on to make it look thicker (it's well sealed to keep the moisture away). An old sofa was used as a donor for the cushions and the spare material was used to cover the sofa fronts.
All held together with various combinations of PVA glue, screws, and a nail gun.
Pine frame. The baskets are for storage accessible from the sofa front, with the spaces inbetween accessible from the top
The sofa front is covered, and 'magnetic doors' hide the baskets.
The black lids are the access points into the hidden cupboards. 3mm ply is covered with foam / material to keep the sofa cushions off the wallpaper
Pine frame for the kitchen.
Fridge in with extra insulation. 3mm white mdf lining the cupboards
8mm bench top
Splashback and cupboards / surrounds laminated
More doors fitted
Pantry slide out fitted to make use of awkward deep cupboards
Finished storage cupboard