Eileen P. K. Costello

Partner Admitted to the Ontario Bar: 2002

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  • Bio
  • Awards & Recognition
  • Professional Involvement
  • Representative Matters
  • Selected Speaking Engagements
  • Selected Publications
  • Insights
  • Education

Eileen is a member of the Aird & Berlis Municipal & Land Use Planning Group, as well as a member of the firm’s Executive Committee. She assists clients with acquiring development approvals for a broad range of projects and advises municipalities on all aspects of the statutory and regulatory scheme which governs land development and regulation in the Province. 

Eileen’s outgoing personality and natural story telling abilities make her a convincing and relatable advocate. Eileen’s commitment to her community and to the broader precepts of city building give her a well-rounded – and particularly effective – approach to her clients’ matters. 

She appears regularly before municipal authorities and administrative tribunals. Eileen also appears before the Superior Court of Justice, the Divisional Court and the Court of Appeal in respect of leave motions and appeals from the Ontario Land Tribunal (formerly the Local Planning Appeal Tribunal), by-law interpretation matters, and matters under the Ontario Heritage Act.

Eileen is the author of The Ontario Heritage Act and Commentary and regularly advises private property owners and municipal governments in respect of property designations, Heritage Conservation, Districts and property standards bylaws to address designated properties.

Eileen is an active citizen in her community and sits on a number of non-profit boards. This, together with her young family, provides perspective and meaning to her work on behalf of clients.

Awards & Recognition

  • Recognized in Chambers Canada as a top practitioner in Real Estate: Zoning/Land Use (Ontario)
  • Recognized in The Best Lawyers in Canada for her expertise in Municipal Law
  • Recognized in The Canadian Legal Lexpert Directory as a leading practitioner in the area of Property Development

Professional Involvement

Professional Activities

  • Member, Women’s Leadership Initiative (WLI) Championship Team, Urban Land Institute Toronto
  • Board of Directors, Ontario Heritage Trust
  • Vice Chair of the Board, Canada Ireland Foundation, Chair of The Corleck Construction Committee


  • Canadian Association of Heritage Professionals
  • Canadian/Ontario Bar Association (Municipal Law Section and Administrative Law Section)
  • Community Heritage Ontario
  • Irish Canadian Chamber of Commerce
  • Urban Land Institute (ULI)
  • Heritage Toronto

Community Involvement

  • Chair of the Program Committee, Ontario Heritage Trust (2024)
  • Chair of the Board of Governors, The Corporation of Massey Hall & Roy Thomson Hall (2016 – 2019)
  • Member, Board of Governors, The Corporation of Massey Hall & Roy Thomson Hall (2010 – 2016)
  • Director, Ireland Park Foundation (2011 – 2016)
  • Board of Management, Fort York National Historic Site (2007 – 2011)
  • Co-Chair, Fort York Citizenship Committee (2009 – 2011)
  • Mentor, Pathways to Education (2005 – 2007)

Teaching Engagements

  • Instructor, Ryerson University Graduate Program in Planning (2008 – Ongoing)

Representative Matters

Represented Homestead Land Holdings Ltd. in connection with two proposed high-rise buildings in downtown Kingston at an Ontario Land Tribunal Hearing and successfully resisted a motion for leave to appeal at the Divisional Court.

Advised client in its co-venture acquisition of commercial development site for a purchase price of $29 million.

On behalf of a private developer was successful in obtaining approval at the Ontario Municipal Board for a mixed use/commercial development on lands in the former City of Scarborough (now Toronto). This development proposal, which was resisted by the City of Toronto, represented one of the first challenged employment land conversion cases in the City of Toronto.

Obtained zoning approvals and negotiated heritage easement agreement to facilitate redevelopment of industrial lands in Toronto for successful commercial development. 

Negotiated a Heritage Easement Agreement on behalf of a university with the City of Toronto, thereby permitting the unencumbered redevelopment of the site for a student centre.

On behalf of a municipality, provided a legal opinion and on-going strategic advice with respect to the preparation of a Heritage Conservation District under the Ontario Heritage Act.

Successful appeal of City of Toronto refusal of an OPA and rezoning to permit a 29-storey condo development in the downtown area of Toronto. 

On behalf of an association of wine growers, providing ongoing advice with respect to the impact of various planning instruments proposed by the local and regional municipalities. Represent the association in on-going dealings with various levels of government.

On behalf of a private landowner, was successful in having high density commercial and residential development approved by the Ontario Municipal Board in the area known as the Park Lawn Block in Toronto.

On behalf of a cottage area municipality, successfully resisted a motion for leave to appeal to the Divisional Court from an Ontario Municipal Board decision upholding an interim control by-law.

Successfully defeated applications for aggregate extraction operations (pit/quarries) on behalf of a rural municipality. 

Selected Speaking Engagements

Speaker, "Bill 23 Changes to the Ontario Heritage Act," The Six-Minute Municipal Lawyer 2023 (Law Society of Ontario, Virtual Event), May, 2023.

Speaker, "Ontario Heritage Act," A Deep Dive: Analyzing the Legislative Changes of Bill 23 (Webinar), March, 2023. 

Panellist, MOD Developments City-Building Discussion, October 2022.

Guest speaker, Virtual REALPAC Law in CRE Course, September 2021.

Master of Ceremonies, LandPRO Conference, March 2020.

Instructor, Ryerson University Graduate Program in Planning, 2008 – Ongoing.

“Legal Issues in Property Development - Managing The Approval Process & Mitigating Risk,” Real Property Investment Certificate, November 2015 and April 2017.

“Legal Issues in Property Development - Managing The Approval Process & Mitigating Risk,” Ryerson School of Business Management, January 2017.

"Discussions on the Heritage Act," Canadian Association of Certified Planning Technicians Professional Development Conference, October 2009.

Co-presenter with Leo Longo, "Five Things Real Estate Lawyers Need to Know About the New Ontario Heritage Act Regime," The Law Society of Upper Canada's 5th Annual Real Estate Law Summit, April 2008.

Co-presenter with Leo Longo, "Legal Opportunities and Constraints to Heritage Preservation and Conservation," Heritage Ontario Conservation Conference, June 2008.

"Ontario Heritage Act," OBA 2008 Institute Municipal Law Program, February 2008.

"The 'New' Building Code Act," Aird & Berlis LLP's New and Emerging Municipal Issues and Legislation Conference, June 2005.

Selected Publications

"Ontario Heritage Act & Commentary," published by LexisNexis, February 2010.

"Amendments to the Ontario Heritage Act,” TechTalk, Ontario Legislative Update, Fall 2005.

"The New Ontario Heritage Act," Digest of Municipal and Planning Law, Issue 6 (2d), June 2005.

Co-Author with Robert G. Doumani, "Some Legal Issues Concerning Affordable Housing as a Municipal Capital Facility."

Co-Author with N. Jane Pepino, "Conversion, Demolition & Substantial Renovation of Rental Units - A Review of Official Plan Policies, Critical Caselaw and Current and Emerging Policy Considerations," December 2003.


  • LLB, University of Toronto, 2001
  • M.Sc.Pl., Urban and Regional Planning, University of Toronto, 1998
  • BA (Hons), Urban and Economic Geography, Queen's University, 1996