The process of SEA was introduced under European Directive 2001/42/EC ‘the assessment of certain plans and programmes on the environment’.
Although the Directive does not make use of the term "strategic environmental assessment" or SEA it is often referred to as the SEA Directive.  For convenience, the term SEA is used in the context of this project to mean an environmental assessment which complies with the Directive.
The requirements of the SEA Directive are transposed into domestic law through the Environmental Assessment of Plans and Programmes Regulations (Northern Ireland) 2004 (S.R. 280/2004).  

The SEA Regulations (Northern Ireland) requires environmental assessments to be carried out for a range of plans and programmes likely to have significant effects on the environment, including those produced for energy and which are subject to preparation and or adoption by and authority at a National level.    

The objective of the SEA Directive, which has been integrated into relevant domestic legislation, is "to provide for a high level of protection of the environment and to contribute to the integration of environmental considerations into the preparation and adoption of plans and programmes with a view to promoting sustainable development". This objective is consistent with the general thrust of Government policies on sustainable development.
The Directive and SEA Regulations defines the "environmental assessment" as a procedure comprising five key stages:

• preparing an Environmental Report on the likely significant effects of the draft plan or programme;
• carrying out consultation on the draft plan or programme and the accompanying Environmental Report;
• taking into account the Environmental Report and the results of consultation in decision- making;
• providing information when the plan or programme is adopted and showing how the results of the environmental assessment have been taken into account;
• Monitoring