Dimensions 4 / 6 / 3.5

Roof

Chimney

Door cut-out + keep shape (cube)

Door knob (cylinder 8)

Windows cut-out + delete shape (cube mirrored)

Steps

Enable Viewport settings : Cavity / Both

Set dimensions 4 / 6 / 3.5

Set Z : 1.75

Extrude roof, merge at center (M)

Separate roof (P) and light scale on Y

Extrude roof along normals (Enable Offset Even option)

Bevel top roof edge and extrude sides along normals (O.2)

Create chimney : scale down, scale Z, Extrude top, Inset, extrude down

Create Loop cut on bottom of house for flooring (CTRL + R)

Select base face loop and extrude + scale out

Prepare a door cut-out shape and apply transformations to Door and House (CTRL + A)

Use Difference Boolean to cut door then delete excess mesh in house door.

Inset front face of door (disable Boundary option) and light extrude inside

Create door knob with a 8 sided cylinder, scale down and place on house

Create window cutout cube and place at proper depth

Set Origin point to 3D cursor (RIGHT-CLICK) (3D Cursor should be at world origin)

Mirror modifier along Y axis and boolean modifier on cubes

Delete cubes

Separate left window bottom face

Inset face, vertical loop cut x2 and scale down along Y axis (Use option tab)

Horizontal loop cut x2 and scale down along Z axis

Dissolve faces on the inset

Extrude created frame outwards

Delete other cut-out bottom face in house and mirror window to other side

Add two loop cuts to house base and scale down along Y

Extrude out to create upper step

Knife in the middle (SHIFT) and extrude bottom half to create bottom step