Income tax exemption for additional rooms construction?

Dear Sir,

I have built a house by taking house loan in 1997 in Bangalore and availed the income tax exemption available  during that time. I am a  central PSU employee and  planning to go for additional rooms construction in 2 nd floor of the same house which I have occupied since 1997.I am planning to go for house loan(Rs 5.0lakhs for 5 years term ).Can I avail the income tax  exemption benifits of principal  repayment and  house loan interest under section 24(b).

Please clarify.

Thanks in advance.

from

manjuks