As a first time home buyer of a newly constructed home, there are some special rebates you can qualify for.  Among these are:

Home Buyers’ Plan (RRSP)

The Canadian Home Buyers’ Plan (HBP) is a program that allows you to withdraw up to $20,000 from your registered retirement savings plan (RRSPs) to buy or build a qualifying home for yourself or for a related disabled person. In general, the plan allows a one time withdrawal of up to $20,000 from an RRSP and is repayable in 15 years, by once a year equal payments (for a total of 15 annual payments).

For more information...
Home Buyer Plan - Outline and Conditions

GST/HST New Housing Rebate

Also available to Home Buyers is the GST/HST New Housing Rebate for purchases of new or substantially renovated homes.

For more information...

Home Buyers’ Plan
http://www.cra-arc.gc.ca/tax/individuals/topics/rrsp/hbp/menu-e.html

GST/HST New Housing Rebate
http://www.cra-arc.gc.ca/tax/business/segments/construction/builders-e.html