Vacant Dwelling policy with RenovationThere are multiple companies writing either option in my area.

I bought a lot in Rock Hill with a small stream next to it and is not buildable. 

My goal is to rent it out and over time had a guest house in the backyard for an extra revenue stream.

It's zoned R2 which is a multi-dwelling zone.

Thurston County Code.20.34.020 - Limitations on accessory uses.Parking or storage of ... major recreational equipment in residential and rural districts, including but not limited to ... camping trailers, travel trailers, motorized dwellings, recreational vehicles, .... are subject to the following limitations: Such equipment shall not be used for living, sleeping, or other occupancy associated with residential uses when parked, or stored on a residential lot, or in any other location not approved for such use.

As agents, we see a steady stream of first-time homebuyers in Denver and Colorado Springs who have no experience with renovations who want to replicate their favorite HGTV show. 

The neighbors LOVE them - the investors are like janitors of the neighborhoods -  they turn ugly dwellings into beautiful homes, making the other properties values to go up in $$$.

A vacant dwelling policy? 

With a working sump pump and dehumidifier you will probably have a nice dry basement of it's not actually a constant stream. 

And we have just begun plans for a 650 sqft, 2BR/2BA (with 1-car garage) Accessory Dwelling Unit (ADU) in place of our garage.