Wow that is an extremely limited amount of information you gave for what you are wanting.
First and formost are you wanting it for your single aparmtent or are you asking about a wifi network for the entire building?
Assuming you are wanting it for your appartment:
What service provider are you going to use?
Do you already have any netwokring equipment?
How many devices do you need to connect?
What are those said devices?
How many apartments are there around you?
If you are asking about wifi network for the entire aparment building, you are going to need to consult someone locally. To make it half way reliable it will take someone with expertise to design, install and configure all the equipment; that scale of a wifi network would be a disaster if not done by a professinal.