Furnace Replacement in Aurora

A city that grew in two different decades

Aurora is the largest suburb in the metro and it doesn't have one housing story. It has two, and which one you live in changes the job.

Census ACS 2024 five-year data puts 23.9% of Aurora's 152,377 housing units in the 1980s and 23.3% in the 1970s. Nearly half the city went up before 1990, and the median Aurora home dates to 1985. Then a second wave: 14.5% in the 2000s and 11.6% in the 2010s, mostly on the southern and eastern edges as the city expanded outward.

So a furnace call in older north and central Aurora is a different conversation from one in a newer southeast subdivision. The first is usually a second or third replacement in a house with 1970s bones. The second is often an original furnace reaching the end of a first life.

Neither is harder. But a contractor who assumes one when you have the other will quote you wrong.

What that means for your furnace

If your home is from the 1970s or 80s — that's roughly half of Aurora — the original furnace is long gone and you're likely replacing a unit installed in the 1990s or 2000s. Worth knowing: the ductwork is probably still original. It was sized for the furnace that came out decades ago, and it may or may not suit what goes in now.

If your home is from the 2000s onward, you're likely facing a first replacement. Original equipment from that era is often a mid-efficiency unit around 80% AFUE, and the ducts were designed as one system with the furnace, so they usually still match.

Either way, the age arithmetic is the same. Gas furnaces have a 15-to-20-year design life. A 1985 house on its second furnace and a 2005 house on its first can both be due at the same time.

Sizing across very different houses

Aurora's size range is wide enough that the rule of thumb genuinely doesn't help. At 30 to 60 BTUs per square foot, a compact 1970s ranch might need 40,000 to 60,000 BTU while a larger newer two-story needs 100,000 to 120,000. That's the difference between a $5,650 to $8,600 installed range and $7,300 to $12,300.

Aurora's town center sits around 5,400 feet and the city rises toward its southern edge, and gas furnaces lose roughly 4% of rated capacity per 1,000 feet of elevation. A unit sized off sea-level tables shows up undersized. Ask the contractor how they derated for altitude — a local answer comes immediately.

The oversizing trap applies here as much as anywhere. A furnace that's too large satisfies the thermostat quickly, shuts off, and refires minutes later. That short-cycling produces uneven rooms and premature wear on the ignitor and blower. If your house has had insulation added or windows replaced since it was built, it may need less furnace than the nameplate on the old one suggests.

Permits and the three-county question

Aurora spans Arapahoe, Adams, and Douglas counties, which occasionally confuses people about where a permit comes from. It doesn't matter: the City of Aurora building division handles the mechanical permit regardless of which county your address falls in.

Your contractor pulls it, it should be a line on your quote at $80 to $150, and it triggers the inspection. That inspection is the only independent check that the gas connection and venting were done right. Anyone offering to skip it is offering to remove your safety net to save you a hundred dollars.

Colorado does not license HVAC contractors at the state level — the state licenses electricians, plumbers, and radon professionals. Ask about the contractor's local mechanical credentials and insurance specifically rather than accepting "licensed" as a general claim.

What the job looks like

A straightforward swap runs one full day: old unit disconnected and removed, new one set and connected to existing ductwork, gas, and electrical, venting handled, then the city inspection within a few days.

Two days is normal when converting to a high-efficiency unit that needs new PVC venting run outside, or when ductwork needs modification — which is more common in the older half of the city.

The full cost breakdown has the size and efficiency tables and what belongs in a quote. Not sure you need a replacement yet? Repair or replace works the decision honestly. The Xcel rebate page covers the $225 a 95% AFUE unit earns.

Get an estimate for your house

Call (303) 226-1486 or send the form. One insured local heating professional will measure the house, check the ductwork and venting, and put a written estimate in your hands. If your furnace has more life in it, that's what you'll hear.

We also serve Thornton, Parker, Highlands Ranch, and the rest of the Denver metro.