Many of Canada’s tax treaties follow Article 5(3) of the OECD’s model tax treaty, which provides that a resident of the foreign treaty country (Forco) will have a permanent establishment (PE) in Canada – and will thus be taxable in Canada – if Forco has “a building site or construction or installation project” in Canada that lasts more than twelve months.  In 2016-0655701E5, the Canada Revenue Agency (CRA) expressed its opinion that a project involving the decommissioning of oil & gas platforms in Canada’s offshore area would constitute a construction project in Canada under Article 5(3) of the applicable treaty (see page 4).  The CRA further said that: (1) several sites or projects can be regarded as a single unit if they form a coherent whole both commercially and geographically; and (2) a particular site does not cease to exist if work is only temporarily discontinued (see page 5).  These are questions of fact, which must be determined having regard to all the circumstances.  The CRA also said it would consider applying Canada’s general anti-avoidance rule if Forco is involved in a contract-splitting arrangement in order to avoid having a taxable PE in Canada.