Most commercial HVAC contractors look at permit data the wrong way. They monitor new applications, hoping to catch projects before they are awarded — but new applications are already competitive. Everyone with access to the same feed sees the same list. The real opportunity lives in permits that are 60 to 120 days old and still open.
This is the logic behind aged permit data for HVAC, and it is more nuanced than it appears.
Why aged permits create warm leads
When a commercial building permit is applied for in Calgary or Edmonton, the owner or GC has declared intent to build. But intent and execution are not the same thing. A significant portion of commercial permits — particularly in the $100K–$750K range that represents most commercial fitout and renovation work — are applied for before the GC has fully assembled the trade package.
Permits in this range often go through a period of 45–90 days where the building permit is applied for (or even issued), but the HVAC sub-trade contract has not been finalized. The GC is either still getting quotes, waiting on the building permit to be issued before firming up sub-trade commitments, or dealing with delays on the owner side. That 45–90 day window is where the aged permit approach pays off.
What "aged" means in practice
An aged permit, in the context of commercial HVAC intelligence, is a permit that:
- Was applied for between 60 and 120 days ago (the "warm" window)
- Is in a work class that historically carries HVAC scope — tenant improvements, commercial renovation, change of occupancy, new commercial build
- Does not yet have a corresponding mechanical sub-permit filed (indicating the HVAC scope may still be unawarded)
- Has an estimated project cost above a threshold relevant to your minimum job size
In Calgary's open-data feed, cross-referencing the building permit dataset against the mechanical sub-permit dataset allows you to identify exactly this class of record: projects that declared intent, are now in execution, but have not yet filed mechanical work. That is a list of decision-makers who are likely in active conversations about HVAC scope right now.
The timing math
Consider a commercial tenant improvement permit applied for on March 1 with an estimated project cost of $380,000. The building permit issues around March 22 (18-business-day average in Calgary). Demolition starts around March 28. Rough framing is done by mid-April. HVAC rough-in typically needs to start in week 7–9 of a project at this scale, which puts the mechanical sub-trade award decision somewhere in the window of April 14–28.
If you are monitoring new permits weekly and you saw this permit in your March 3 feed, that is useful — but you have 6 weeks before a decision is made, and the project is at a stage where the GC is still assembling the team. If you are monitoring aged permits in early April, this same record surfaces again — now flagged as a project where mechanical work is likely imminent and no sub-permit has been filed. Your outreach in early April is better-timed than your outreach in early March.
Permit types with the highest HVAC conversion rate
Based on historical analysis of Calgary's permit feed, the permit categories where the aged-permit HVAC approach has the highest signal-to-noise ratio:
- Change of occupancy (commercial): Any change of occupancy almost always triggers an HVAC upgrade or reconfiguration. These are high-confidence HVAC leads regardless of project cost.
- Medical and dental fitouts: Healthcare tenants have very specific HVAC requirements (negative pressure rooms, exam-room exhaust, air-quality compliance). These permits almost always carry a substantial mechanical scope and often require a specialized mechanical contractor.
- Restaurant and food-service fitouts: Kitchen exhaust systems, makeup air units, and fire-suppression-adjacent HVAC work make every food-service fitout permit an HVAC lead.
- Industrial-to-commercial conversions: Upgrading an industrial bay to commercial use requires reclassifying the HVAC system, which is always a significant scope.
What aged permit data is not
It is worth being clear: aged permit data does not tell you that the HVAC scope is definitely available. It tells you that conditions are favorable for a conversation. The permit has been filed, the project is live, no mechanical sub-permit has appeared yet, and the timing suggests the decision has not been made. That is a warm lead, not a guaranteed contract. Your estimating team still needs to make the call, price competitively, and deliver the follow-through. The data just gets you in the room earlier than competitors who are not reading it.
The scale of the opportunity
In Calgary alone, the 60–120 day aged permit window contains approximately 150–200 qualifying commercial permits at any given snapshot — permits with HVAC-relevant work classes and no corresponding mechanical sub-permit filed. That is a manageable list for a well-run HVAC estimating team to work through each month. At a typical commercial HVAC project close rate of 15–20%, working that list systematically could represent a meaningful increment to your pipeline.
Analysis based on City of Calgary Open Data permit feed (datasets c2es-76ed and related mechanical sub-permit feeds). No individual business names are identified in this analysis. Timing estimates are derived from observed lag distributions in the public dataset.