| Planner | Ontario Professional Planners Institute (OPPI) | RPP (Registered Professional Planner) | Planning rationale, OLT testimony, policy analysis |
| Architect | Ontario Association of Architects (OAA) | Licensed Architect | Building design for Part 3 buildings (>600 sq m or >3 storeys) |
| Building Designer | Ministry of Municipal Affairs (BCIN) | BCIN (Building Code Identification Number) | Building design for Part 9 buildings (houses, small buildings) |
| Civil Engineer | Professional Engineers Ontario (PEO) | P.Eng. | Grading, drainage, servicing, stormwater management |
| Structural Engineer | PEO | P.Eng. | Structural design, foundation design |
| Geotechnical Engineer | PEO | P.Eng. | Soil testing, foundation recommendations |
| Traffic Engineer | PEO | P.Eng. | Traffic impact studies, parking studies |
| Environmental Consultant | MECP Qualified Person (QP) | QP under O. Reg. 153/04 | Phase 1 and Phase 2 ESAs, Record of Site Condition |
| Ontario Land Surveyor | Association of Ontario Land Surveyors (AOLS) | OLS | Legal surveys, topographic plans, reference plans for severance |
| Arborist | International Society of Arboriculture (ISA) | ISA Certified Arborist | Tree inventory, preservation plans, injury reports |
| Archaeologist | Ministry of Citizenship and Multiculturalism | Licensed (Class 1-4) | Archaeological assessments |
| Heritage Consultant | Canadian Association of Heritage Professionals (CAHP) | CAHP member | Heritage Impact Assessments |
| Acoustical Engineer | PEO (or specialized firm) | P.Eng. or equivalent | Noise and vibration studies |
| Energy Consultant | Various certifications | CET, LEED AP, Passive House | Energy efficiency, Toronto Green Standard |
| Landscape Architect | Ontario Association of Landscape Architects (OALA) | Full Member OALA | Landscape plans for site plan approval |
| Lawyer | Law Society of Ontario (LSO) | Licensed Lawyer or Paralegal | Title searches, OLT representation, agreements, opinion letters |
| Hydrogeologist | Professional Geoscientists Ontario (PGO) | P.Geo. | Groundwater studies, well-head protection |