“Built-in” or “In-built”

Question

Is there any difference between using in-built or built-in? Is one more correct than the other, or does it depend on the context, or ”house style”?

This oven comes with a built-in extractor fan.

This oven comes with an in-built extractor fan.

Answer 1

This is one of those ones where Google, whatever faults it might have, does tell you something significant:

"built-in extractor fan"      643,000 results
"in-built extractor fan"          137 results

Subjectively, from the first ten results, it looks like the "in-built" hits are largely from the UK. I've never even heard of an "in-built extractor fan".

Just at a guess I would think that "in-built" would go with "ability", so I tried it on Google:

"built-in ability"  216,000 results
"in-built ability"   75,500 results 

Answer 2

Actually, this is written "inbuilt" and not "in-built".
It is an old (1923) chiefly British synonym for built-in.

• Constructed as part of a larger unit; not detachable: a built-in cabinet.
• Forming a permanent or essential element or quality: a built-in escape clause

Example:

"Of course, even the most able driver in the most dynamically competent car can sometimes find his or herself in a situation where a collision is inevitable, so with this in mind the Spark was designed with high levels of passive safety inbuilt from the outset."

—Automotive Headlines