Why do some Apartment Buildings in Pennsylvania. have Fire alarms and or Sprinklers and similar buildings do not? its a very long convoluted story

An Engineer  friend of mine is looking to move and as a child he had a very bad experience with a fire where he lived. So he is always looking when he decides to find a new place to move into a fire safe apartment as his job takes him around Pa. to various long term job sites. He often wonders why some apartment buildings are well prepared safety wise with Fire Alarm and or sprinklers, yet similar size and types of apartment buildings of the same age have no safety features at all.
Well we got into this discussion one evening and I explained to him a very convoluted story as to how Pennsylvania. Building Codes  have evolved and why the disparity.
it starts in 1985 when  the Pa. Fire & Panic act was passed which required all apartment buildings to install Fire Alarm systems.

http://www.pacode.com/secure/data/034/chapter50/chap50toc.html

 But there is a catch like my community of Penn Hills had.

When Jack Mason now retired became Fire Marshal in Penn hills in the late 70's  He told me how  Penn Hills  basically was still following state codes from the 1920's he observed these metal buckets in hallways  in some apartment buildings which where rounded on the bottom and filled with sand in some buildings. which in 1920's was all that was required for fire protection a bucket of sand. why the round bottom this was done so it had to be hung up and not set on floor and forgotten or blocked in or used for something else.

   You can imagine his shock when he realized codes in the town had not been updated since the 1920's the only apartment buildings under that code at the time which required fire alarms where over 3 story's and then it was only pull stations and bells.Like Wellington Arms  in Penn Hills which I retrofitted with full  smoke detection systems in  late 1980's

So Jack got the council to push thru and enforce the BOCA Code which stands for Building Officials Codes Administration.   Now known as ICC /IBC Which was a good thing Penn Hills now had a unified code where structures would be safely built. But  still only apartment buildings over 3 story's had to have fire systems but now they had to have firewalls and proper fire rated doors etc. and such to improve fire safety and fire systems  when required had to meet NFPA72 regulations .

https://en.wikipedia.org/wiki/International_Building_Code

But this is where the catch came in when the new Pa.  Fire & Panic Act came into being community's which where following the BOCA code did not have to follow the new state code  or they could enforce both codes.  While Monroeville and Mt Lebanon chose to do both community's like Pittsburgh and Penn Hills chose to stay with BOCA only  and did not want to put the extra burden on apartment owners which meant those apartment buildings where grandfathered and did not have to have fire alarms installed. Which is why even today with the new Uniform Construction Code you still find Apartment Buildings with no or very old  fire alarm system.
How ever when buildings are sold now and new owners take over they must be upgraded or if there is major additions or reconstruction. So it will be decades before you see some buildings retrofitted with fire systems. While all new apartment  construction requires a system of some type depending on number of units dictates what must be used which can include sprinklers.
 But even thou the Fire & Panic Act came into being and was enforced in many community's it was still a mix match of systems and products. Yes back then it was legal to use a Burglar Alarm panel with a Fire Loop  in it to provide fire protection to a small apartment building as the Fire & Panic Act
was not state enforced and approved.  The state instead  gave the power to review plans and  enforce the code  to local community's to enforce and if the official felt a Burglar Alarm panel was good enough to protect a property so be it as NFPA72 which sets standards for how fire system must be installed  was not adopted as part of the Fire & Panic Act.  I found and changed out many such system in apartment buildings and business over the years but the thinking back then was it was better to have a couple smokes tied off a burglar panel than have nothing at all.So you find all kind of systems Pre UCC codes of 2005 if the community was also not enforcing BOCA Codes so you never know what you are going to find as back then if AHJ said it was legal it was legal which caused problems when I was quoting systems to NFPA72 standards and others where not and where half the price I was putting in. These cheaper systems where far inferior systems but it was legal in non BOCA Community's.
Then when it came to buildings requiring sprinklers this also was where many compromises where done. Some community's like Penn hills said instead of having to retrofit buildings and put in sprinklers when occupancy changed  that if you put in a full fire system and then added limited sprinklers off the domestic water supply in storage rooms and basements you did not have to fully sprinkler a building.
 So of course you find all kinds of deviations to these property's as well.

So thankfully we now do have a fully enforced even code state wide all new construction must follow and as structures are knocked down and new ones built they all must follow the new codes. But it will be decades before it has all evened out and even now there are community's not enforcing the new state codes and even Pa.UCC code is a mix and match of ICC and IBC as the whole code was not adopted by Pa.  and so it goes.