Miele KM 7999 FR Operating And Installation Instructions page 73

Safety distance to niche cladding
If niche cladding is installed, a minimum safety distance must be maintained
between the worktop cut-out and the cladding, since high temperatures can alter
or damage these materials.
If the niche cladding is made from a combustible material (e.g. wood), a minimum
safety distance  of 50 mm must be maintained between the worktop cut-out and
the cladding.
If the niche cladding is made from a non-combustible material (e.g. metal, natural
stone, ceramic tiles), the minimum safety distance  between the worktop cut-out
and the cladding will be 50 mm minus the thickness of the cladding.
Example: 15 mm thick niche cladding
50 mm – 15 mm = minimum safety distance of 35 mm
Flush-fit installation
a Masonry
b Niche cladding dimension x = thickness of the niche cladding material
c Worktop
d Worktop cut-out
e Minimum safety distance to
combustible materials 50 mm
non-combustible materials 50 mm – dimension x
Installation
Surface-mounted installation
73