If you are hired by someone to build a house on land they own or lease, you must charge them GST/HST on the labour and material you provide when building the house. Your client may qualify for a rebate of some of the GST or the federal part of the HST paid on labour and materials, but they must apply for the rebate. You cannot apply for it on their behalf.
For more information, see Guide RC4028, GST/HST New Housing Rebate.
Also, a provincial new housing rebate may be available to your client for owner-built houses for some of the provincial part of the HST paid to build or substantially renovate their primary place of residence that is located in Ontario or BC. For more information, see Ontario new housing rebate for owner-built housing or BC new housing rebate for owner-built housing.
Note
Revenu Québec administers the GST/HST new housing rebate program in the province of Quebec. If your business is located (or you build or sell a house) in Quebec, visit the Revenu Québec Web site.