while true; do echo -n "Give me the code of that house: "
     read code ; 
     namef=$(awk NR==1'{print $5}' apartments_file)
     if grep -q " $code $" apartments_file; 
              then echo "There is already a house named $namef with that code." ;
                   echo -n "Please try again: ";
     else echo "Apartment name: $name with code $code" >>    apartments_file; 
     echo "Apartment name: $name with code $code added successfully." 
     break 
       fi ;  
     done ;
    break ;

[simeon@localhost project]$ cat apartments_file
Name of the apartment:  "house1" with code :: 90 
Name of the apartment:  "house2!" with code :: 80 
Name of the apartment: "rush hour" with code :: 100 
Name of the apartment: "fly away" :: 10 
Name of the apartment: "flying high" :: 20 
Name of the apartment: "into the summer sky" with code :: 50 

and some output of the script:
**********************
Adding a new apartment...
**********************
Give me the name of the apartment house: same_house_testing
Give me the code of that house: 90
There is already a house named "house1" with that code.
Please try again: Give me the code of that house: 90
There is already a house named "house1" with that code.
Please try again: Give me the code of that house: 100
There is already a house named "house1" with that code.
Please try again: Give me the code of that house: