The Supreme Court recently ruled in the case of R v Paterson, 2017 SCC 15, that police cannot search your home without a warrant simply because it would be impractical to obtain one. Warrantless entries must be compelled by urgency, immediate police action to preserve evidence, or officer and/or public safety. The decision highlights the importance of the section 8 right against unreasonable search and seizure of the home.
The facts of the case unusual. Paterson agreed to let the police enter his residence in order to surrender several marijuana roaches with the police telling him they would treat it as a "no case" seizure (meaning they would seize them to destroy them, but not charge him). Once inside the residence, the police observed firearms and drugs and arrested Paterson. The issue was whether the warrantless entry by the police was a violation of Paterson's section 8 rights. The Court found that in this case, the Crown could not satisfy the requirement to prove exigent circumstances to allow the warrantless search.
The Court noted "In this case, the police had a practicable option: To arrest the appellant and obtain a warrant to enter the residence and seize the roaches. If, as the Crown says, the situation was not serious enough to arrest and apply for a warrant, then it cannot have been serious enough to intrude into a private residence without a warrant."
Link to the case: https://scc-csc.lexum.com/scc-csc/scc-csc/en/item/16484/index.do
Link to news article on the case: http://www.theglobeandmail.com/news/national/supreme-court-throws-out-drugs-and-guns-conviction-over-lack-of-warrant/article34340844/