Recommended clearances where manufacturers DO NOT give clear guidance.
- 20mm gap between Cooker-Side & Bottom-Unit-Side
- 150mm gap between Cooker-Side & anything on the Worktop-up-to-
- 610mm gap above any eyelevel gas grill
- 760mm gap between Hob & Cupboard over it
- 50mm gap between Hob-Side & L/R-cupboards within 460mm above
- 50mm gap between Hob-Rear & Worktop-Rear
- 300mm gap between adjacent wall/cupboard/surface to Hob-Side
Clearly the first 3 are about fire.
Clearly the last 1 is about safety (having somewhere to move stuff off
Where a hood is installed above a cooker or hob, the greater of the
separation measurements given in either the cooker or hood
installation instructions should always be used if they are different.
Electric is a bit simpler - although then there is the argument about
FTE vs H07RNF vs H05BBF etc and the cooker actually having an oblong
cable clamp & cable entry hole that can't take 6mm round without
filing metal away which involves standing on your head!
So as stated you actually need the manufacturers instructions. Keep a
copy of those instructions around so you don't end up with a kitchen
being chopped up if it does not comply with the "default".