The Queen v. Mitosinka, 78 DTC 6432, [1978] CTC 664 (FCTD) -- summary under Principal Residence

The taxpayer rented out 1/2 of an unusual structure which was analogous to a duplex but which had a common basement and a window connecting the adjoining kitchens. In light of the facts that the building "could, and did, house separate families, who had separate facilities, and paid for separate services," only 1/2 of the building was held to be the "housing unit" of the taxpayer. The Minister's allocation of 1/2 of the underlying land to the taxpayer's principal residence was not shown to be unreasonable.