Home services: HVAC / Intermediate

The HVAC that is old enough to ask about

Test a permit-age clue before calling it a lead.

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WHAT YOU WILL MAKE

A three-property evidence table with unknowns and a draft validation plan.

A builder working with an HVAC business that knows its service area.

Estimated effort: 45–60 min sample exercise
Cost / access: Free sample / data costs vary
First move: Separate old, missing, and recent records in the three fictional property rows.

Prerequisites, inputs & cost details

Before you begin

An HVAC domain reviewer
Check local source coverage and permitted use before real research

Inputs you need

Permit dates and record coverage
Service-area and sale-date context

Use the fictional rows for free. Public-record access, licensed data, and any later mail pilot have separate costs.

YOUR PLAY WORKSPACE

Make it your next small win.

My saved work

Write a brief, practice the workflow, and keep your notes. This workspace saves your planning; it does not run tools or send anything.

See the fictional sample

Invented properties and dates; no property condition is asserted.

property_id,last_hvac_permit,sale_date,record_coverage
HOME-A,2010-06-12,2026-08-01,Digital records since 2005
HOME-B,none_found,2026-09-15,Digital records since 2020
HOME-C,2024-03-20,2026-10-02,Digital records since 2005

Compare three fictional HVAC permit histories. Identify which record is old, which is recent, and which cannot support an age claim. Produce an evidence table and questions for an HVAC reviewer. Any marketing stays a draft and must describe records rather than equipment condition.

Check coverageWrite what each source history can and cannot show. Treat HOME-B as unknown.
Classify the cluesGroup the rows as old record, recent record, or insufficient evidence.
Plan human validationName the HVAC reviewer, source spot-check, and local-use questions.
Draft a bounded pilotOutline a small authorized validation test and an unsent plain-language letter if appropriate.

Review before a real build.

An old permit is not a diagnosis. Stop if record coverage or permitted use is unclear.
Use fictional or authorized data. Do not enrich homeowner contact details; approve any real mail and budget separately.

Measures to consider

Count rows with enough historical coverage, out of all rows reviewed.
If an authorized pilot is later run, count reviewed records and booked estimates separately; do not predict them.

Editorial scenario · Source review 2026-11-01. A learning hypothesis, not an independently validated result or proof of customer demand. The sample is fictional; linked tools require their own access and cost checks.

Understand the approach.

A house changed hands and the last HVAC permit is older than the loan. That is a reason to write.

The outcome

You are not selling a mailer. You are giving an HVAC company a way to find homeowners with an old system before the system fails.
Front end: signal, then a letter to the address, then a booked estimate. Back end: the job is scheduled, finished, invoiced and followed until paid, on the software the company already uses.
Sell the HVAC company the whole path from 'old unit' to 'paid invoice'.

Who this is for

Independent HVAC companies with a small office and a real service area.
Owners who say 'we get work from referrals and the phone, and nothing in between.'
A team that already runs a field-service tool and an accounting tool.

Signals to investigate

The last HVAC or mechanical permit on a home is old, or there is none on record.
A recent sale: new owners often plan work in the first year.
Homes built in a period when systems were common to need replacement now.
A heat wave or a cold snap in the forecast for the area.
A competitor's yard sign on the street is not a signal. Public records are.
Equipment past its typical life: ENERGY STAR suggests considering replacement of an air conditioner or heat pump past ten years and a furnace past fifteen. Typical, not a promise.

Conversation starters

To the HVAC owner: 'Do you know which homes in your service area have a system that is past its usual life?' Most do not.
Then: 'Which software do you use for jobs and for invoices?' and 'What still falls through?'
Show a map of one neighborhood: how many homes have no permit on record for a long time. One ask: a short call.
To the homeowner, by mail to the address: a plain letter that says what the record shows and offers a free look. No names are needed.

Validate before building

Pull one neighborhood's permits and sales. Count homes with an old or missing system record. Check against what the HVAC owner tells you from experience.
Check the local rules for using property records in marketing. Ask someone who knows your state.
Send one small mail drop to one set of addresses. Count booked estimates, not letters sent.
Look at their software for the leak: does a finished job turn into an invoice with no one touching it?

Build the smallest useful version

Download the city or county permit data and the sales data for your pilot area.
For each address, find the latest HVAC or mechanical permit and the last sale date.
Rank homes by how long since the last record. Check a sample by hand.
Mail a short letter to the chosen addresses using addressed marketing mail through a print shop or mail service, with a page or number that tracks responses. Every Door Direct Mail covers whole carrier routes, so it only fits when the signal is neighborhood-wide.
When a job is won, make sure it is scheduled, finished, invoiced and followed until paid, using their tools.

Deliver and operate

AI cleans the data, ranks the addresses and drafts letters. A person reads every letter before it prints.
After a job is won, the delivery layer keeps it moving: confirmations, reminders, an invoice when the work is done, and follow-ups until it is paid.
Show the owner one weekly page: letters sent, estimates booked, jobs done, invoices paid.

Limits and things to check

An old record is not a broken system. Say what the record shows and nothing more. No safety scare tactics.
Permit records miss unpermitted work, so the signal is a reason to look, not a fact.
Some states limit using certain property or owner data for marketing. Check yours and ask a lawyer.
Mail goes to the address. Do not look up homeowners' phone numbers or emails.
Respect each data source's terms. Do not scrape sites that forbid it.

Tools and supporting resources

Pythondownloads the public data and cleans it Supabasestores homes, permits and mail results n8nestimates, reminders and invoice follow-up PostHogsee which page or QR code the letter sent people to

Source recommendations; check current access, costs, API availability, and setup in the linked documentation. No integration is installed by opening this guide.

Plan your version.

Read the planning prompt

I have permit and sales records for [city/county] as CSV files: [list columns]. 1. Match each address to its most recent heating, cooling or mechanical permit and its last sale date. 2. Flag addresses with no such permit on record, or one older than [X] years. 3. Tell me how reliable that signal is: what permit records usually miss (work done without a permit, records that were not digitized). 4. Draft a short letter to 'Current Resident' that says what a public record shows and offers a free look. No scare language. No claims about safety. 5. List what I must check about local rules before I mail anything. Use only the data I give you. If a column is unclear, ask. Treat this scenario as a hypothesis, not a proven business result. Check source coverage, permissions, costs, and integration support for my location and accounts. Work with sample or authorized data. Keep outreach and external changes in draft until I approve. Report unverified assumptions.

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