Any watertight gap in worktops or tiles in regards to kitchens and bathrooms will usually need a sealant line.
Real Marble worktops that are over a certain thickness (typically over 30mm) are made from separate pieces of marble fitted together at the corner so the vein would NOT match along the edge.
Worktops less than 20mm would be made from the same piece and therefore would match round.
Adding a full height glass wall to a room requires fixings, either connected to the ceiling/floor like the image to the left, or using a shower screen frame, which most shower enclosures are supplied with
Size and spacing of steps is important to make them realistic in the space. For dimensions and sizes see here: https://www.dimensions.guide/collection/stairs-stairways
For references of various types see here: R:\05_REFERENCES\01_PRODUCT_TECHNICAL_SPECIFICATION\03_REAL_WORLD_REF_IMAGES\_MISC\STAIRCASES
Fireplaces are a classic example of needing to use reference images in order o construct. This is especially important for using certain materials and certain finishes which normally wouldn't work in a fireplace environment.
See real world reference images here: R:\05_REFERENCES\01_PRODUCT_TECHNICAL_SPECIFICATION\03_REAL_WORLD_REF_IMAGES\_MISC\FIREPLACES
A classic mistake to make with radiator models is either fitting them to walls without any piping, or using piping that seems illogical to the location of the radiator.
See here reference images of correct radiator piping and fixings:
R:\05_REFERENCES\01_PRODUCT_TECHNICAL_SPECIFICATION\03_REAL_WORLD_REF_IMAGES\_MISC\RADIATOR FIXINGS