Lastly, Oregon building code currently considers triplexes to be commercial real estate, meaning they must have sprinklers and more robust firewalls; there's currently some momentum to change that at the state level, but you know how fast/slow these things can be.

--Computer Network, server, router, switch, fire wall; all the back end fully managed.

These are townhouses built side by side, sharing a firewall in-between.

For a dryer vent, often a handyman can handle it, unless ducting through a firewall, roof, or unusual type of material.

Feel free to PM me.We are a avid fan of using LLCs to hold our property for a number of reasons: 1) The liability issue, so we hold about $5 million (approx 20 to 50 SFHs) per LLC as a way to place a firewall between all of our holdings; 2) We use it as a way to concentrate our holdings for easier tax filings (ie, our FL LLC only holds FL property); 3) Investor ownership to allow each investor to be segregated in what they actually own.

We brought the common wall with the adjoining unit (along the kitchen and bathroom) up to current fire code (on this side):Due to our proximity to the property line and the neighbouring building, we also covered the rear external wall with resilient channel and 5/8" fire rated drywall to allow us to use vinyl siding, versus more expensive non-combustable siding solutions, when we re-clad the building.In addition to using rock wool (Roxul Safe-n-Sound) insulation in our fire walls, we installed it in all bathroom walls, the bathroom ceiling and in the "TV wall" and walls and ceiling surrounding the laundry space to provide sound deadening. 

They are using a conventional loan and the appraiser is saying the ceiling needs to be a firewall.

Partner and liability as a "lender" goes away entirely.Liability as a member is limited to members, your LLC is the member, not you, that's another firewall, top that with liability coverage.

The City may be requiring 36" exit widths, fire walls, fire doors, ceilings; emergency lighting, exit signs, the parking, a new water service, the energy code compliance, separate thermostats.The City will feel that if you are making money on income property then they will have no problem making you spend money in the name of life safety.  

Before you tear the drywall ceiling out in the basement make sure your firewall requirements will be sufficient with what's left.. are you exposing plumbing and electrical?