Window IQ · Spec intelligence for new builds

How much is your current window spec really costing?

For new-build projects. Compare typical North American double & triple-pane windows against LuxHaus European systems across the five metrics that matter: thermal performance, acoustic isolation, solar control, service life, and projected HVAC bill. Adjust for your project — the numbers update in real time.

Panoramic high-performance window system
Optional · Project InfoBrand this report

Fill in any of these — they'll appear on the PDF report. Leave blank to generate a generic Window IQ report. Nothing is saved or transmitted; this is for your branded output only.

Step 1 · Project ParametersDefine the Build
Project Region
Fine-tune window specs Override any parameter with your project's actual glazing package
Current window (North American spec)
Air leakage around sash and frame adds real heat transfer beyond the U-value. The NFRC AL rating measures airflow in cfm/ft² at design pressure. Lower is tighter. LuxHaus European systems are tested to EN 12207 Class 4 (the European equivalent of NFRC ≤ 0.1 cfm/ft²) — effectively airtight, the 1.00× baseline.
LuxHaus window (European spec)
2,800 sq ft home · ≈ 448 sq ft of windows (16%) m² home · ≈ 42 m² of windows (16%)
Steady-state methodology uses textbook U-value × HDD math. Real-world bills run much higher due to HVAC part-load inefficiency, duct losses, thermostat creep, non-linear infiltration in extreme temperatures, and sand/dust accumulation in GCC contexts. Multiplier auto-sets by climate on region change (cold = 2.0–2.5×, mixed = 1.5×, warm = 1.2×, GCC extreme-hot = 1.6×) based on NRCan, NREL, LBNL, KAUST, and Masdar Institute studies. Override anytime.
$0.245per kWh · marginal rate
Optional · Cost of Ownership Inputs Enter quoted prices and lifespans to model true 50-year cost of ownership. Leave blank to skip — the rest of the analysis still runs.
Current Window Spec
$—competitor quote today
—years to first replacement · industry typical: 15–20 yrs
LuxHaus Spec
$—LuxHaus quote today (quoted or estimate)
50years · LuxHaus 50+ year design life · industry: 15–20 yrs
LuxHaus systems are engineered for a 50+ year design life — most North American and GCC residential windows fail at 15–20 years. The "True Cost of Ownership over 50 Years" card below uses these inputs to show the full picture: purchase + replacements + HVAC over half a century. Replacement cost inflates 3%/year. All values stay private to this session.
Step 2 · The Performance GapWhere LuxHaus Moves the Needle
Set your parameters above, then tap Calculate the Gap to see the comparison.
Thermal performance · lower U-value is better
Current
U-0.28
LuxHaus
U-0.13
Acoustic isolation · higher STC is better
Current
STC 28
LuxHaus
STC 40
Side by SideFull Specification Delta
Metric Current Spec LuxHaus System Difference
Step 3 · The Long-Term Picture25-Year Outlook
Annual HVAC Bill Savings
—
Projected heating & cooling bill reduction for this new build. Compares the full HVAC operating cost at each window spec, holding the rest of the envelope equal.
25-Year HVAC Cost
—
vs. $— with current spec
Replacement Cost Avoided (inflated)
—
—
Total 25-Year Advantage
—
Combined energy savings + avoided replacement cost over 25 years. Excludes resale value, occupant comfort, and health benefits.

Opportunity costWhat if the savings were invested instead?

If both savings streams — annual energy savings and the avoided replacement cost — were invested in an S&P 500 index fund at the historical 10% average annual return. Annual savings compound across 25 years; the avoided replacement lump sum compounds from when it would have been spent through year 25.

S&P 500 · 25 yrs · 10%
—
Annual savings + avoided replacement, compounded · nominal, pre-tax

Ready to spec LuxHaus on your next project?

Submit your plans and we'll return a free estimate within 5–7 business days. Factory-direct from Germany, Italy & Poland. Passive House suitable. No showrooms, no middlemen.

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LuxHaus Windows & Doors
8 The Green · Dover, DE 19901 · Toll-Free 1-888-807-6516 · info@luxhauswindows.com · luxhauswindows.com

This calculator is indicative. Energy savings are modeled using simplified ASHRAE-style HDD/CDD heat transfer over the selected glazing area. Actual results depend on building envelope, orientation, HVAC efficiency, occupant behavior, and local utility rates. S&P 500 projection uses the historical nominal average of 10% annually (reinvested dividends, pre-tax, pre-fees) and is illustrative, not a forecast. Past performance does not guarantee future results. Specifications reflect typical published values; LuxHaus product datasheets control for any specific quotation.
About the tool

What Window IQ does

Window IQ is a free, instant comparison tool for new-build homes. It puts typical North American double- and triple-pane windows side by side with LuxHaus European systems, and updates the numbers live as you adjust your project. It compares across the five things that matter over the life of a home.

Thermal efficiency

How much heat your windows keep in — or out — and what that means for comfort and energy use.

Acoustic isolation

How effectively the system blocks outside noise from reaching your living space.

Solar control

How much unwanted solar heat and glare the glass manages across the day.

Service life

How long the system keeps performing before it needs replacing.

HVAC cost

The projected heating and cooling spend that follows from all of the above.

Set your region and climate zone, choose your current window and the LuxHaus system to compare (36 mm double-pane, or 48 mm / 56 mm triple-pane), and read the results instantly. Advanced users can fine-tune the exact glazing values — U-value, solar heat gain (SHGC), sound rating (STC) and air infiltration — to match a real spec, then add project, client and architect details to export a branded PDF.

Want to go deeper? Read the U.S. Department of Energy research on high-performance windows, see how Passive House performance targets work, and explore the LuxHaus window and door range.

Read it as directional. Window IQ is a planning tool built to help you weigh options early — not a replacement for engineering, code-compliance or energy-modelling deliverables. Our team will confirm the exact specification for your build.

Frequently asked questions

How much can better windows save on energy?

It depends on climate, glazing area and energy price. Window IQ models the heating and cooling difference for your project and shows the annual and 25-year figures.

How long do windows last?

Many standard residential windows are replaced after 15 to 20 years; well-built European systems are designed for a much longer service life. The calculator includes avoided replacements in the total cost of ownership.

Is the result an energy model?

No. It is a directional planning tool, not a replacement for energy modelling or code-compliance deliverables.

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LuxHaus Windows & Doors supplies high-performance European windows and doors factory-direct to North America, the Caribbean, Mexico and the GCC. Submit your plans or ask Emma, our 24/7 AI advisor.