Know what matters
Know what applies to your project.
Check the conditions below before you finalize the scope. Every answer connects to an official source.
London lists HVAC systems, furnace duct alterations and rooftop HVAC replacements among permit-required work. Its exemption list includes a higher-efficiency replacement furnace; classify the actual scope before applying an exemption.
Source · City of London
Before you apply for a building permit · Residential permit triggers, exemptions and review timelines
Verified Oct 1, 2026Open official sourceMake a start
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Plan ahead
Fees and timing
From reading to doing
Your next steps.
- Record the scope: existing and proposed equipment capacity and fuel.
- Gather: changes to ducts, vents and combustion air.
- Compare the exact scope with this municipal statement: London lists HVAC systems, furnace duct alterations and rooftop HVAC replacements among permit-required work. Its exemption list includes a higher-efficiency replacement furnace; classify the actual scope before applying an exemption.
- Ask which documents, fees and inspections apply to this exact scope; keep the written response with the project records.
- Resolve approvals before committing to a construction start date.
Trace the evidence
Official sources behind this guide.
These are the source documents linked in the rules above. Check the municipal authority for current requirements before submitting a project.
- City of London
Before you apply for a building permit · Residential permit triggers, exemptions and review timelines
Source verified Oct 1, 2026
A little more clarity
Common questions.
What should I ask before starting a heating and ventilation project?
Is this an equipment replacement or a heating-system alteration, and which building, fuel and electrical approvals are separate?
Does this approve my property-specific project?
No. The published general guidance is verified; zoning, exact scope and other approvals still need to be resolved for your property.
Do you need a permit for heating and ventilation in London?
London lists HVAC systems, furnace duct alterations and rooftop HVAC replacements among permit-required work. Its exemption list includes a higher-efficiency replacement furnace; classify the actual scope before applying an exemption.