The municipality might require that you install a "fire wall" between the units.

Every webserver, firewall, router, modem in everyone's house.

This is a originally  built ranch duplex with basement and a firewall between the units and all the comps were with old houses converted to duplexes.

It's more for first time investors in the multifamily space. but we do run into plenty of firewall issues at single-family residences as well, so I think it's valuable to have a little information or reminder about that and understand potential solutions

I think the fact that the numbers have to flush all the way through, the amount of variables, the number of subs, permitting, fire wall ratings, asbestos tests, lead tests, knob and tube wiring, walls not being square, projecting the ARV, market changes, and having it all cash flow at the end... is a lot to handle for most investors. 

Of course, between the units I will have a firewall, but the bedrooms and bathrooms I’m thinking what would be workable. 

Have a "firewall" (fire retardant drywall) all the way up between the units.2.

Amazon plumbing fixtures are really poor in quality.Amazon electrical fixtures are pretty decent.Amazon cabinet and door hardware is decent and better priced.We do LVP throughout the entire house.The firewall is not as intimidating as it may seem.

Depending on the circumstances, you may need to create a PSA to detail the transaction between the two entities if you're trying to keep the entities firewalled. 

.✔ It provides an extra liability firewall—the AMLP owns the LLCs, preventing direct lawsuits against you.✔ Keeps operations separate from property ownership—reducing legal risks from tenant disputes.✔ Strongest legal structure in Texas—LLCs roll up into the AMLP, keeping your name off public records.📌 Best Setup for Maximum Protection in Texas:1️⃣ Each rental property in its own LLC – Shields assets from each other.2️⃣ An Asset Management Limited Partnership (AMLP) – Owns the LLCs and manages them, keeping liability separate.3️⃣ Bridge Trust® for high-net-worth investors – If you scale up, this structure protects your entire portfolio from lawsuits.Final TakeawayWhile an LLC isn’t required to rent a property, it’s one of the best ways to protect yourself from lawsuits.