Furnace Replacement in Highlands Ranch

The 1990s build wave is aging out together

Highlands Ranch has an unusual housing profile, and it matters for exactly this decision.

46% of every housing unit in Highlands Ranch was built during the 1990s — Census ACS 2024 five-year estimates, 18,244 of 39,551 units. Add the 2000s and you've accounted for roughly 72% of the community. The median home here was built in 1997.

Almost nowhere else in the metro is that concentrated. Aurora's biggest decade is 24% of its stock; Littleton's is 21%. Highlands Ranch put nearly half its homes up in ten years.

For furnaces, that means a synchronized replacement wave. A furnace installed in a 1995 build is around 30 years old now — well past the 15-to-20-year design life of a gas furnace. If yours is original and still running, it isn't unusual for the neighborhood and it isn't a sign you neglected anything. It's a cohort reaching the end of its life at the same time.

The practical consequence: when a hard cold snap hits, a lot of these houses call at once, and the metro's heating companies book out. If your furnace is original and you have the option, deciding in October beats deciding in January.

What a 1990s Highlands Ranch furnace usually is

Original equipment from that construction era is typically a mid-efficiency gas furnace — commonly in the 78% to 80% AFUE range — venting into a metal flue.

Two things follow from that. First, roughly 20% of the gas you buy goes up the flue rather than into the house; a 95% AFUE replacement cuts heating gas use by about 15%. Second, converting to high efficiency means new venting. A condensing furnace produces cool, acidic exhaust and cannot use the existing metal flue — it needs PVC pipe run to the exterior, which is $899 to $1,965 on top of the unit.

Homes here also tend to be larger than the metro average, which pushes many into the 80,000 to 100,000 BTU range: roughly $6,850 to $10,350 installed depending on efficiency.

One local factor worth naming. Highlands Ranch sits near 5,695 feet — over 400 feet above Denver proper — and gas furnaces lose roughly 4% of rated capacity per 1,000 feet. A contractor who derates for altitude sizes the unit correctly; one working off sea-level tables leaves you undersized on the coldest mornings. Ask how they calculated it.

HOA rules that affect the job

Highlands Ranch is a master-planned community, and the Highlands Ranch Community Association governs a great deal of what's visible from outside.

The furnace itself is indoors and not an HOA concern. What can be is anything the installation puts on your exterior: PVC vent terminations through a side wall on a high-efficiency conversion, or a condenser pad if you're weighing a heat pump. Some covenants address exterior penetrations, equipment screening, and placement.

Check before installation day rather than after. It rarely blocks anything, but discovering a placement rule while a technician is standing in your driveway is an avoidable problem.

Permits go through Douglas County, since Highlands Ranch is unincorporated rather than a municipality — a small difference from Denver or Littleton, but it means the county building department handles the mechanical permit and inspection.

Getting the sizing right the second time

A 30-year-old furnace was sized for the house as built. Since then many of these homes have added insulation, replaced windows, or finished a basement — all of which change the heating load.

Replacing like-for-like on capacity is the common mistake. A house that's been tightened up needs less furnace than it did in 1995, and an oversized unit short-cycles: it heats fast, shuts off, restarts a few minutes later, produces uneven rooms, and wears out the ignitor and blower ahead of schedule.

Ask for a load calculation rather than a match to the old nameplate. If a basement got finished, say so — that's conditioned square footage the original furnace never accounted for.

What the job looks like

Most replacements are one full day. The old unit comes out, the new one is set and connected to existing ductwork, gas, and electrical, and the venting is either reconnected or rebuilt for high efficiency. The county inspection follows within a few days.

It runs to two days when venting changes or ductwork needs rework. Furnaces in tight utility closets — common in this housing stock — add labor at both ends.

The full cost breakdown covers size and efficiency tables and what belongs in a quote. If you're not certain replacement is the answer yet, repair or replace works through it, and Xcel's rebates covers the $225 that a 95% unit earns.

Get an estimate for your house

Call (303) 226-1486 or send the form. One insured local heating professional will measure, check your 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 Littleton, Parker, Aurora, and the rest of the Denver metro.