This is the question? And the answer goes a long way into determining how a property should be listed (advertised) and presented to home buyers. More over, it maybe more important to determine how viable the property is then for the prospective buyer.

First one needs to understand how something that is, today, considered to be nonconforming or illegal by code and or ordinance can also be legal (or permitted to remain).

Will first assume that at sometime the building was legal. This may address your question with some of those ramblers in Bloomington.

Nonconformance typically occurs when codes and or ordinances are added or changed by a regulatory body (ICC or Federal, State, County, or City government). These changes will have altered, added or removed definitions to requirements. In this case, sleeping area (may not just affect bedrooms) egress windows.

Legaly Nonconformances arise as a solution by any one of the regulatory bodies to allow an existing legal structures to remain legal. There are often conditions placed, as to how long these nonconforming instances may remain. Conditions such as change in ownership, change in use (such as converting a church into a single family home), or some improvement threshold to the structure; while possibly allowing for maintenance (repair and replacement) to continue a noncorformity.

It is therefore necessary to do a little homework to better understand the implications for the use (and future) of this structure. Same question would be: Can the existing structure ever be brought up to code, if altered?

Just remember, that these issues, and how they are enforced, will vary by jurisdiction.

Happy property hunting.