At one time, it was the prevalent trend for people to style their houses according to a certain template with one certain color palette and similar furnishings and accessories.

I called on retail bicycle stores to sell them bicycle parts and accessories.

John gives good advice.When planning any building like this, check with the local planning and development commission to make sure this is doable before you spend any more time or resources on it.Here in seattle all single family lots allows a second accessory dwelling, sometimes called a mother-in-law.

In my experience, the difference in rental rate will range from $50-75 for a low end unit, to $100-125 for a mid to upper-mid range unit for basic furnishings and minimal accessories.

The city wouldn't let me convert the main house to a duplex due to the accessory unit.

Other things also tend to fall into them, such as toys-crayons-bits of paper, barbie doll accessories, etc.

Additionally you can find things like lots with multiple homes on them or a property with an accessory dwelling unit over a garage for extra income.Are you willing/able to move to SLC or Provo anywhere in between?

Ikea has lots of small accessories and items that make life at home much easier (hooks, storage solutions, organizing rooms and spaces, etc) I have personally never seem a house with those attributes but I think it can also be a niche

@James Freeman Since you need a 4 bedroom, I would recommend that you look into the possibility of building an ADU, Accessory Dwelling Unit, to help supplement your current income.

I was going through the checklist PDF provided by Hayward city (https://www.hayward-ca.gov/services/permits/accessory-dwelling-unit) and one of the requirement says Are you the property owner and do you reside on the property?