Last updated: September 11, 2026
When the Furnace or AC Fails
HVAC is the decision people make under pressure, usually in the week the system dies. The replacement ranges are wide because "HVAC" covers four different products:
| What you're replacing | Typical installed cost |
|---|---|
| Central air conditioner | $3,800–$7,500 |
| Furnace | $2,800–$6,500 |
| Heat pump | $4,500–$8,000 |
| Complete system (AC + furnace) | $6,500–$12,000 |
| Ductwork, if it needs replacing | $2,000–$5,000 extra |
Three rules decide repair versus replace, and they're worth knowing before a technician is standing in your hallway. If the system is under 10 years old, repair — it has a decade of life left. If it is 10-15 years old and the repair costs more than half of replacement, replace. And if it uses R-22 refrigerant, replace regardless: R-22 was phased out in 2020 and now costs $500-$1,000+ per pound to recharge, so you would be paying premium prices to keep obsolete equipment alive.
One money-saving detail: if the furnace is over 15 years old when the AC fails, replace both at once. The labour is already paid for, and a matched system runs more efficiently than mismatched components. Region moves the total substantially — West Coast pricing runs about 1.3× the national average, the Northeast about 1.2×, and the South about 0.9× — which the HVAC Replacement Cost Calculator applies along with your home size and efficiency tier. Federal tax credits are also available through 2032 (up to $2,000 for an Energy Star heat pump).
The Roof Is Not a Cosmetic Decision
A roof is the one item on this page you cannot defer — it protects everything else, it is one of the first things a buyer's inspector flags, and a failing roof can knock $10,000-$20,000 off offers. Costs vary more by material than by anything else:
| Material | Installed cost (1,700 sq ft) | Expected lifespan |
|---|---|---|
| Asphalt shingles (architectural) | $7,500–$12,000 | 25–30 years |
| Corrugated metal | $8,500–$15,000 | 40–50 years |
| Standing seam metal | $13,500–$24,000 | 50–70 years |
| Clay / concrete tile | $17,000–$30,000 | 50–100 years |
| Slate | $25,000–$50,000+ | 75–150 years |
The lifespan column is why the cheapest quote is not always the cheapest roof. A metal roof at roughly double the asphalt price can be the better 50-year decision — the Roof Replacement Cost Calculator shows both the installed cost and the lifetime cost for exactly this comparison. Asphalt replacement recoups about 60-65% at resale.
Does Solar Actually Pay Back?
Most solar payback calculators you will find online are run by companies that install solar, which is worth knowing while reading their numbers. The honest version: payback is typically 6-10 years, and the single biggest driver is your electricity rate, not how sunny you are.
| Where | Electricity rate | Typical payback |
|---|---|---|
| California | ~32¢/kWh | ~5 years |
| Massachusetts | ~27¢/kWh | ~6 years |
| US average | ~16¢/kWh | ~7 years |
| Texas | ~14¢/kWh | ~8 years |
| Washington | ~11¢/kWh | ~10 years |
Over 25 years, typical savings run $20,000-$60,000, and the 30% federal tax credit cuts net system cost by nearly a third — on a $20,000 system, $6,000. The credit is in effect through 2032 and steps down after that. Owned systems also tend to add value at resale: NREL and Zillow studies put the uplift at around 3-4% of home value, though leased systems add much less because the buyer has to assume the lease.
Now the part that matters most, and the part quotes tend to leave out:
- Net metering rules are changing. Many states have reduced the credit you get for power you export to the grid. That directly stretches your payback, and policy can shift after you sign.
- Your roof age is part of the calculation. Panels are warrantied for decades; if the roof underneath needs replacing in eight years, you pay to remove and reinstall the array. Replace the roof first if it's near end of life.
- Inverters get replaced once. They typically last 10-15 years in a 25-year system life, and that replacement is a real cost usually absent from the headline payback figure.
- Payback assumes you stay. If you move in five years, you don't reach break-even — the remaining benefit passes to the buyer, partly reflected in resale value but not necessarily at full value.
A battery is a separate question that rarely pays back on arbitrage alone: it adds $7,000-$15,000 and mainly buys outage backup and time-of-use shifting. It makes most sense where outages are frequent, rates are time-of-use, or net metering has been cut back. The Solar ROI Calculator runs your state, rate and system size against these assumptions so you can see how sensitive the answer is.
What Your Appliances Actually Cost to Run
This is the cheapest upgrade on the page because it starts with measurement, not purchase. The arithmetic is three steps: watts ÷ 1,000 × hours = kWh, then × your rate = cost. At the US average of about $0.16/kWh, the results separate cleanly into appliances that cost almost nothing and a handful that dominate the bill:
| Appliance | Watts | Typical yearly cost |
|---|---|---|
| LED bulb | 9 W | ~$4 |
| Laptop | 50 W | ~$23 |
| Television (55") | 80 W | ~$37 |
| Refrigerator (24h) | 150 W | ~$210 |
| Space heater | 1,500 W | ~$700 |
| Clothes dryer | 3,000 W | ~$1,400 |
| Central AC (3 ton) | 3,500 W | ~$1,636 |
| EV charger (Level 2) | 7,200 W | ~$3,365 |
The pattern is simple: anything whose job is making heat or moving it — heater, dryer, AC, oven — dwarfs everything else. A 1,500-watt space heater running eight hours a day costs about $1.92 a day (roughly $700 a year), which is why "just for a bit" adds up so quickly. The Appliance Electricity Cost Calculator takes your actual wattage, usage hours and utility rate — worth using, because rates range from about $0.10/kWh in Louisiana to over $0.38 in Hawaii.
And the free win most households miss: standby power, sometimes called vampire power. Devices draw 1-15 watts each while switched off but plugged in, and the US Department of Energy estimates a typical home with 20-40 such devices loses $100-$200 per year to it. Switchable power strips solve it for the price of the strip.
Which Upgrade First?
These systems interact, so the order matters more than the individual prices. A reasonable sequence:
- Fix whatever is failing or unsafe first. A leaking roof, dead HVAC or obsolete R-22 system changes the value of everything else — and some upgrades cannot even be installed on top of them.
- Roof before solar. This is the one ordering mistake that costs real money, because installing panels on a roof with a few years left means paying for removal and reinstallation.
- Tighten the house before upsizing the equipment. Insulation, air sealing and duct condition determine what size system you need. A larger unit on leaky ducts just wastes the extra capacity.
- Then solar, if your rate and roof both justify it. It pays back 6-10 years and adds resale value when owned; it makes less sense on a low electricity rate or a roof nearing replacement.
- Then the cheap wins. Standby power, appliance timing, and knowing which device is actually driving your bill cost nothing and often out-perform an expensive upgrade per dollar spent.
For payback comparison: HVAC replacement returns roughly 70% at resale and pays back in 3-7 years through lower bills; a roof recoups 60-65%; solar returns over 6-10 years rather than at sale. If you want each figure against the same yardstick, the Renovation ROI Calculator ranks projects side by side.
What These Estimates Can't Tell You
Every number on this page is a national range with regional adjustment. That leaves four real gaps:
- Quotes vary more than regions do. Two contractors in the same city can differ by 40% on identical scope. Three written quotes is not a formality — it is the single biggest lever on price.
- Your house has specifics no calculator can see. Roof pitch and layers, duct condition, panel capacity for solar, and whether a permit is needed all change the final figure.
- Incentives move. The federal solar credit steps down after 2032, state net metering rules keep changing, and tax credits only help if you have tax liability to offset.
- Payback is not the same as savings. Solar payback assumes you stay in the home and that rates keep rising roughly as they have. Check the sensitivity rather than trusting one number.
Start with whichever system is currently causing you a problem: the HVAC calculator if it is heating and cooling, the roof calculator if it is water, the solar calculator if you are planning rather than reacting, and the appliance calculator if you just want to know where the money is going.
Sources: NREL solar resource and PV cost data; US Energy Information Administration electricity rates (2026); 30% federal solar Investment Tax Credit (in effect through 2032); US Department of Energy estimates on standby power; Remodeling Magazine Cost vs. Value report for resale recoupment; published HVAC and roofing contractor pricing surveys for 2026; Zillow and NREL research on solar and home value. Figures are national averages with regional adjustment and are not quotes — always obtain at least three written estimates, verify licensing and insurance, and confirm local permit and code requirements before work begins.