The only circumstances in which a borrower with an existing FHA insured loan for a principal residence may obtain another FHA insured mortgage on a new principal residence.
Relocation -A borrower may be eligible to obtain another FHA-insured mortgage without being required to sell an existing property covered by an FHA-insured mortgage if the borrower is:Relocating or has relocated for an employment related reason, andEstablishing or has established a new principal residence in an area more like than 100 miles from the borrower’s current primary residence.
If the borrower moves back to the original area, the borrower is not required to live in the original house and may obtain a new FHA-insured mortgage on a new principal residence. As long as the relocation meets the two requirements above.
Increase in Family Size - A borrower may be eligible for another house with an FHA-insured mortgage if the borrower provides satisfactory evidence thatThe has had in increase in legal dependents and the property now fails to meet the family’s needs; andThe loan-to-value (LTV) ratio on the current principal residence is equal to or less than 75% or is paid down to that amount, determined by comparing the outstanding mortgage balance to a current residential appraisal.
Vacating a jointly-owned Property - A borrower may be eligible for another FHA-insured mortgage if the borrower is vacating (with no intent to return such as divorce, legal separation, etc...) the principal residence which will remain occupied by the existing co-borrower.
Non-occupying Co-borrower - A non-occupying co-borrower on an existing FHA-insured mortgage may qualify for an FHA-insured mortgage on a new property to be their own primary residence.
Please see my other post for more information on obtaining an FHA Mortgage.