I'm confused as to what exactly you're asking us to determine from this, but I'll give it a shot.

As far as I can tell, the question is why a door is useless without stairs to use with it. That means the stairs either lead down to a basement entrance, or lead up to an upper floor entrance. Possibly not even that, being simply steps to a patio against someone's door, porch steps, so on.

At least, that's if the question really is as straight forward as that.

Hmmm.. I'm going to guess that the "house" is a "tower". My basis for thinking this is the position of the stairs in relation to the door.

"A door to a house is vital"
Leads me to believe we are moving from the outside to the inside of a house.

"In order for the door to be useful, stairs must follow."
So stairs must come after the door as you enter the house.

"if one does not build stairs then the door is pointless"
Without stairs, the door is pointless because it leads nowhere?

OK nvm, I'm starting to confuse myself.

The house represents us, our consciousness, minds, or 'soul' if you will. It is the thing that makes us what we are. Some may be run-down and unmaintained, eventually collapsing in on itself, while others can even be described as picturesque - large, well maintained, and with the greenest of lawns.

The door obviously represent an entrance into our thoughts, our hopes, our fears. Most people keep this locked and impossible to tell the state of the rooms within. A house beautiful on the outside may be a dark, roach-infested dirt hole on the inside. The door also allows us to channel our thoughts outward and into the busy streets. A person who leaves their door unlocked may either be a very inviting person or somebody who's simply a little naive. A house without a door will eventually rot from the inside out.

The stairs represent the bridge to and from our minds. You can leave the door unlocked, but if no stairs are connecting it to the street, it would still be useless. Similarly, anyone can claim that their mind is open, but without a path inside, it's as good as closed. In other cases, as sad as it may be, somebody could leave their door wide open and wonder why their house is so repulsive that nobody dares to enter, when in fact it is because that they did not take into consideration that nobody could reach the door because it's too high from the ground and there's no stairs leading up to them.

It is vital to stay open for other people (have a house with a door), but no one will enter unless you make your thoughts accessible (build stairs towards the entrance).

Doors and stairs? Someone's in Valentine's mood already :)

I'll just take the lift.

West of House
You are standing in an open field west of a white house, with a boarded front door.
There are no stairs, but there is a small mailbox here.

My blind guess interpretation is that you are playing Zork or some sort of text adventure game? Anyway, if there are no stairs to the tower, ask Rapunzel to lower her hair :-D

The simplest and most literal solution I can think of would be a lighthouse. It could also be a cellar or tornado shelter or mineshaft or some "inverted" lighthouse/tower.

Alternatively, it could be vague philosophical or metaphysical stuff, as others have said. Or it could just be Feng Shui.

The door to the house is your mouth. You need your mouth to eat and live. The stairs connect your mouth to your brain and keep you from running your mouth off.

Thanks a lot for the giveaway. This message tells me: It is not only important to start something, but to also continue what you have done with the logical outcome. Beginning something is just the first step, doing this something better and better and working on it afterwards is what is important. :) I know you probably mean something else, but I do like the message.

A lighthouse? ... Ah, now I see that bevinator already said this. That's the most literal thing I can think of as well.

If it is not straightforward then it looks like some religious theory to me - door (to believe) and stairs (to follow) to heaven :D

I bet it's what you need to do a MC Escher style painting. ;)

It's not religious, and someone was fairly close in this thread.