Some Buyers do not care whether they are in an HOA governed community or not, and others specifically ask for one or the other. In Denver, if a home was built after the mid-90's, it most likely is in an HOA governed community. (With the exception of homes that have been scraped and re-built)
So what's the difference?
In an older neighborhood without an HOA, you can have trailers, campers and utility trailers parked in the driveway or on the side yard.
WITH an HOA, this is not allowed. Some will allow you to put some in the back yard behind the fence, but they cannot be seen over the top of the fence.
In an older neighborhood without an HOA, you can paint your home whatever color you choose.
WITH an HOA, there are usually colors selected for the community, and you have a choice of certain colors.
In an older neighborhood without an HOA, you can have chickens (if the municipality allows this) and a maximum of four, but no roosters.
Most HOAs state there are no chickens allowed.
In an older neighborhood without an HOA, you can park your panel truck with your company name out front or in the driveway.
WITH an HOA, many times this is not allowed, and quite a problem in some cases.
In an older neighborhood without an HOA, you can add onto your home, add a covered patio, or add a shed without approval. (There will be City approval needed.)
WITH an HOA, all these additions will need to be sent through the architectural committee of the HOA before it will be approved.
In an older neighborhood without an HOA, you pay for your own trash, and usually there are no community amenities.
WITH an HOA, the trash and recycling is included in the fees, and sometimes there is a community pool and tennis courts.
With patio homes and attached properties, there is usually an HOA, and amounts vary with the size of the community and amenities included.
Most HOAs are to help maintain the beauty of a neighborhood, therefore keeping the home values preserved. I remember years ago trying to sell a home where their neighbor had painted their home FUCHSIA, and absolutely would not repaint. My seller even offered to pay for the whole home to be repainted, and he said if he touched his home, he would call the police. Sadly, the home never sold. There are those HOAs that act like a separate police department, and pick on everything/everyone throughout the community.
It is wise to read ALL the rules and regulations to be sure you can live with the HOA, as they do all differ.