for me, pag ibig is like a savings account. mayron talagang interest if you avail of a loan. but the nice thing is that, as mentioned by sir jay, you can get back all your contributions, plus your employers' contribution, when you retire or leave the country or if you have a house and lot already which was acquired by means other than through pag ibig loan. meron pang interest yong account mo.
kaya, be sure na your employer is remitting your contributions properly. to be sure that your pag ibig account is updated, mag salary loan ka naman paminsan minsan just to be sure na walang problema ang yong account.