acquired by the Foundation under the name of one Mr. Samuel Coleridge Peterson
I'm not quite at the point where I will downvote an article on sight for doing this. But I'm getting close. The "SCP" acronym thing appears a lot in older articles, but it makes absolutely no sense in-universe. Why on earth would a secret organization go out of its way to narrow down possible front entities from "anything in the world" to "things what spell SCP"? There is absolutely nothing to be gained from a practice like that, and it's needlessly risky. It's not just you that does this, but it's exceedingly silly.
In light of its proximity to the local community, parents, teachers, and local authorities of the surrounding area are advised to discourage children from accessing the premise of the containment site. Civilians are to be deterred from entering under the excuse of dangerous building conditions.
"In light of" is a little informal for what you're going for here. "Due to" would probably work better.
I'm not sure why you're focusing on discouraging children in particular from accessing this. And if you aim to do that, creating an urban legend (which is what you're going to end up doing with this) about the spooooky house that no one should go to ever is going to lead to the exact opposite of what you're intending.
"Excuse" is also informal. "Under the guise of," "using X as a pretext," "condemned by local authorities as unsafe," etc. etc. There's any number of ways to rephrase that in a more clinical manner. Also, you don't mention how people are to be "deterred". Really, this whole section could have been some variant of "put a fence up around it and have it condemned" and we could have called it a day. I don't usually pay much attention to containment procedures, but when it doesn't look well-developed enough, this section can drag articles down.
At all times, at least two security members for each of Site-2503’s entry points are to remain on site. Anyone who enters SCP-2503-1 without permission is considered lost if reappearance does not take place through SCP-2503-2 within 80 hours.
This seems excessive, and really why are you going to go to the trouble of the first part of your containment if the place is already under 24 hour armed guard with at least (I assume) four guys watching it all the time? And how many people are going into this thing without permission that it merits a mention in the procedures? And how are they sneaking past multiple guards all the time? None of this makes any sense to me.
located within a town community about ██ kilometers north of Burnaby, BC, Canada
"town community" doesn't sound right, you could probably just say "town" or "city" or whatever the political subdivision is. You can also just right "X kilometers north," since "about" sounds imprecise for the context you're using.
Site-2503 is a residential house
You can probably just say "residence". Or even "house". Minor point.
According to Site-2503’s blueprint, the room SCP-2503 inhabits is the master bedroom on the second floor, henceforth referred to as SCP-2503-1.
This is a little confusing; is the spatial anomaly actually indicated on the filed blueprints for the house? If it isn't, you can probably just say that the anomaly is located (not "inhabits" unless it really is a living thing) in the master bedroom.
The presence of SCP-2503 was discovered in 199█
This is another thing that happens a lot (so it's not really limited to you) but doesn't make sense to me. Why would knowing when something happened within a ten-year period be okay, but not the particular year? Why wouldn't you just blackbox the whole year if the date is privileged information?
Noteworthy is the nature of SCP-2503’s inner space
This is an extraneous sentence. There may be some justification for it in-universe (though "noteworthy" is a touch informal), but really, the reader should be able to figure out the fact that a crazy time-bending hallway being in this person's house is "noteworthy".
It is discovered that time and space operate differently within SCP-2503.
"It is discovered" is clumsy phrasing. You can just say that time and space operate differently in the anomaly, though probably in a more clinical manner than that.
Objects that enter SCP-2503 do not age while inside SCP-2503's space but will nonetheless experience a sense of time flow. Due to this nature, the object’s real time “freezes” while inside SCP-2503, and the speed with which it travels within SCP-2503 does not influence the amount of time it experiences.
"Sense of time flow" doesn't really mean anything, and the scare-quoted "freezes" is something that wouldn't show up in a clinical document. "Subjects will perceive the passage of time", "the subject does not experience the actual passage of time", phrases like this are more what the context demands.
At the current point, SCP-2503-2 is the only known exit of SCP-2503-1.
"At the current point" is unnecessary and is also slightly weird phrasing. You can just say "currently."
This experiment was carried out by accident
Then it's not an experiment. Experiments are things that are designed and carried out purposefully to gather data under controlled conditions. While data can be gathered from accidental occurrences, it's poor terminology to refer to something like that as an experiment.
The note is a bit of a different creature, and so my observations are mostly stylistic at this point:
you may demand some monetary reward for your service.
This seemed strangely formal and out of place considered with his plea to take the message to his family. Not necessarily an error of writing, but it scanned weird to me when I read it.
The reason I am writing is to prepare for the worst case scenario and to record down details of my misfortune.
"Record down" is an odd choice of phrase from what I imagine a highly-educated person like this would sound like. This sentence also seems more like something I'd see in an essay, rather than a last message to loved ones.
I should probably begin with how I ended up in my current state
Again, this is a little formal, and it conjures up thousands of internet creepypastas with the whole "it all started when" thing.
Nonetheless, your case may be different, and so here’s my story if you wouldn’t mind keep reading.
This sentence doesn't scan properly with the "wouldn't mind keep reading" and again, it sounds like something typed up on NoSleep. I mean, he's imagining that someone may come along and find this note after ending up in the same inexplicable situation that he's in. Is he really worred about that hypothetical person finding a note that may pertain to their situation, and then going "boooring" and just tossing it aside?
At some point, I just blacked out completely, but before that I do remember asking Will and Kevin to get me home in case I get too shitfaced. It now looks like they didn’t do as they were asked.
Notes of realism and minor details are what make a piece feel real to a reader and convince them to suspend their disbelief. In this case, no. I'm in a field where alcohol is pretty much a job requirement, and getting blackout drunk at work functions is not something that people really do. If they do get to that point, it's because they have some profound problem and they're about to self-destruct. Your character does not come across as such a person, and if they were drugged or something like that, they would probably have noticed that that was unusual for them to not remember what happened the night before and remarked upon that. Stuff like this is preventing me from believing this person as a real character.
There’s also no way to tell time in this god-forsaken place
The "god-forsaken" bit is where the narm starts creeping into this.
My instinct is telling me to go towards the light (let’s hope that isn’t the last bad pun I pull).
That's…not a pun so much as a garden-variety joke, and also this is really dissonant in terms of the tone that you're trying to set here.
So I suppose it’s time to write down another entry. Unlike the previous ██ times
Why is that redacted?
I’ve been purposely ignoring that 9927 in fear of this…IN FEAR OF THIS!
Narm intensifies. He's really repeating "in fear of this" again and bolding and underlining it in a written account?
But I am no God – hell I’m not even a sadhu or a sage!
Sort of a weird observation for a middle aged Canadian white guy in the suburbs to make.
I haven’t seen one myself, but think it is what you call a “drone.” It’d be one of those things Ji Da that one guy who I roomed with during my sophomore year in college (it’s been too long) – he’d be all thrilled about it 'cause he’s in engineering.
So he's modern enough to have hung out with people who've worked on stuff like drones before, but he's still speaking about it like it's an esoteric particle collider or some such? Weird style here.
Can’t believe it has been 7 years since my last entry. I have become inert. By age, I should have died.
He's young enough to have had a small child when he went in, but he should be dead within seven years? Huh?
I felt nostalgic and overwhelmed with emotions - anger and sadness, hope and despair, a grim pessimism coupled with an ironic optimism.
If I'm to buy that this guy has been changed by his experiences of continually walking for redacted-hundreds of years, he's going to need to sound a little bit different than this. This is the same character with some dialogue that's clearly trying to sound world-weary and insightful, but not really succeeding.
I don’t know. I feel disgusted with what my immediate reaction was. It was neither grief nor angst, but avarice.
That makes very little sense. Why would this guy, supposedly so detached from self and humanity that he can look back on his former writings and be reminded of a person he used to be, who has no material needs since he doesn't need to eat or drink or rest, feel the need to scavenge stuff as his immediate reaction?
I’m writing this with only so little sanity left within me …and I must admit that I'm approaching the border of madness.
I don't necessarily buy into "show not tell" as a commandment of writing. But if you're trying to portray a character that is losing their mind, surely there are more artful ways of doing that than straight-up having him say "I only have a little bit of sanity left". This strikes me more as someone's PC from a Call of Cthuhlu game than a literary character.
Upon this path I walk alone and now only to become blind to all but solitude.
You might be able to get away with this line with proper character development and context. Maybe. Here it's just making me cringe.
but it’s too impressionable to be written off like that
I don't think that's what "impressionable" means.
The journal, upon recovery, was luckily in good condition
"Luckily" is poor tone since we're now back into clinical documentation.