I agree with @Ray Harrell - you need to understand what is common in your area.In Chicago, I would never recommend a landlord put in unit washer and dryer unless they are already doing a full rehab of the unit. 

It's common to have an illegal basement unit in Chicago but it's obviously a risk.

It may be a tenants in common relationship.

I have never done it but it is fairly common for some to get started house hacking a smaller multi family property. 

Is a standard written notice ok? 

Your purchase agreement should ideally include some sort of verbiage along the lines of "seller will allow access to house with 24-hour notice" or similar.As far as "how" you share this info, here is how I do it.

Bill You should start by contacting the Real Estate Board: There is a recovery fund for consumers who have been damaged by Brokers. http://www.dre.ca.gov/consumers/consumerrecoveryaccount.html  One of the most common reasons for Brokers to get in trouble with the board is for this kind of thing.

Most are in Mpls or St Paul, but you will find some first-tier suburbs with large duplexes.  3-4 plexes are as common as a Vikings Super Bowl outside of the two cities.Within 45 minutes of MSP airport: This will be no problem, everything is within 45 minutes of the airport, especially in multifamily.Areas with a small town/ neighborhood feel are a big plus: South St Paul would have this feel so would Stillwater but that is probably more than 45 minutes from the airport with any level of traffic or bad weather.

But yesterday, I put in my notice and today I've never felt better.

Otherwise I would expect the story above is the most common.