Duncan is a Partner in Simpson Grierson's Resources and Infrastructure Department, which is comprised of the local government and environment, construction, and commercial property workgroups.  Duncan's expertise extends across a range of industry sectors, including resource management, local government, and energy law.

He provides advice to a wide range public bodies on matters including resource consents, designations, declarations, heritage orders, water consent orders and district and regional plan submissions and references.  He also acts for developers on resource consents and designations.  These have involved a variety of issues including heritage protection, oil and gas exploration, marine farms and forestry development.

He has also advised on several large infrastructure development projects involving pipelines, substations, roads, fibre optic cables, landfills, treatment plants and transmission lines.  He regularly advises on issues relating to the Electricity Act including land access and compensation.

Duncan advises insurance companies, local bodies and others in the areas of professional indemnity and public liability insurance.  He also advises insurance companies in relation to policy drafting and interpretation, cross-border insurance bond issues, international insurance treaties, underwriting agreements and international re-insurance arrangements. 

• Telstra Saturn Submarine Cable Project
• State Highway 1 Upgrade in Paremata
• Eastern Taupo Arterial Project for Taupo District Council
• Fort Dorset Development, Seatoun, Wellington for Globe Holdings
• Kapiti Urban Roading Project for Kapiti Coast District Council
• Transmission Gully Roading Project for various local authorities
• Oil and Gas Exploration Consents in Wairoa, Gisborne and Napier for Westech
• BP Service Station Redevelopments in Wellington and Christchurch
• Contaminated site remediation projects for various local authorities

• Resource Management Law Association - Member
• New Zealand Institute of Surveyors - Honorary Life Member
• Brookers' Building Act - Co-author
• Brookers Resource Management - Co-editor