Spray foam insulation in Northwest Indiana: get up to 3 quotes from vetted local installers
Request free quotes from up to three vetted spray foam installers serving Lake, Porter and LaPorte counties in Northwest Indiana. Below: what your climate zone means for foam choice, how much insulation to ask for, Indiana's code, and the NIPSCO rebate.
- Climate zone: 5A (2021 IECC)
- Attic target: R-60 (ENERGY STAR, uninsulated attic)
- State code: 2018 IECC (via 2018 IRC Chapter 11) with Indiana amendments
- Utility rebates we verified: NIPSCO Home Energy Assessment
- Federal 25C credit: ended for 2026 installs
Facts last checked October 16, 2026. Sources are linked in each section.
Where we match quotes from this page
Requests from ZIP codes in Lake County, Porter County, LaPorte County go to our Northwest Indiana partner installers (51 ZIP codes): 46301, 46302, 46303, 46304, 46307, 46311, 46312, 46319, 46320, 46321, 46322, 46323, 46324, 46327, 46340, 46341, 46342, 46345, 46346, 46347, 46348, 46350, 46356, 46360, 46365, 46368, 46371, 46373, 46375, 46376, 46377, 46382, 46383, 46385, 46390, 46391, 46393, 46394, 46402, 46403, 46404, 46405, 46406, 46407, 46408, 46409, 46410, 46532, 46552, 46554, 46574. Outside these? Send the form anyway and we'll tell you if we can't match you.
Climate zone 5A: what it means for spray foam
Northwest Indiana spans several counties. Their 2021 IECC climate zones:
| County | 2021 IECC zone | 2015/2018 IECC zone |
|---|---|---|
| Lake County | 5A | 5A |
| Porter County | 5A | 5A |
| LaPorte County | 5A | 5A |
All three counties are zone 5A (cold) on both the 2015/2018 and 2021 maps.
Source: PNNL-33270, Guide to Determining Climate Zone by County (IECC 2021).
Open cell vs closed cell in Northwest Indiana
Attic roofline: in zone 5A, IRC Section R806.5 requires that air-impermeable insulation under an unvented roof deck either be a Class II vapor retarder itself or be covered with a vapor-retarder coating. Closed-cell foam meets that on its own at typical thicknesses; open-cell foam needs vapor-retarder paint. In a hybrid assembly the foam layer at the deck must be at least R-20.
Rim joists and basement walls are where spray foam pays off fastest in cold climates: closed cell air-seals the leaky band joist and blocks moisture in one pass, which is hard to do with batts.
How much insulation to ask for
| Where | ENERGY STAR recommendation for zone 5A |
|---|---|
| Attic, uninsulated | R-60 |
| Attic with 3–4" of existing insulation | add R-49 |
| Floor over unconditioned crawlspace/basement | R-30 |
| Basement or crawlspace walls | R-15 continuous or R-19 cavity |
| Exterior walls (when re-siding) | add R-5 to R-10 insulative wall sheathing beneath new siding |
To reach R-60 with foam alone you'd need roughly 16.2–17.1" of open cell (about R-3.5 to R-3.7 per inch) or 8.6–12.0" of closed cell (about R-5 to R-7 per inch). Many roofline spray foam jobs are installed thinner than that and justified through the code's performance path or the unvented-attic rules, so ask every installer to write the foam type, thickness and resulting R-value on the quote and explain how it meets your local code.
Source: ENERGY STAR, Recommended Home Insulation R-Values (based on 2021 IECC). ENERGY STAR's figures are recommendations for existing homes; your local code sets the legal minimum for new work.
Indiana energy code
2018 IECC (via 2018 IRC Chapter 11) with Indiana amendments, effective December 26, 2019. Indiana amendments set ceiling insulation at R-38 (instead of R-49) and wood-frame walls at R-15 in climate zone 4.
Source: NAHB, "Residential Provisions of the IECC: State Adoption Status" (current as of May 2026); official state status at DOE Building Energy Codes Program.
Homes in Northwest Indiana
| County | Housing units | Median year built | Built before 1980 | Single-family detached | Gas heat | Owner-occupied |
|---|---|---|---|---|---|---|
| Lake County | 217,436 | 1968 | 66% | 71% | 86% | 72% |
| Porter County | 72,662 | 1982 | 48% | 75% | 87% | 78% |
| LaPorte County | 50,038 | 1969 | 65% | 78% | 83% | 75% |
ACS 2020–2024 5-year estimates.
- With 66% of homes built before 1980, many attics here predate modern energy codes. Older attics often need old insulation removed or air-sealed first, and knob-and-tube wiring must be checked before any insulation covers it. Ask whether removal and prep are in the price.
- 86% of homes heat with utility gas. Spray foam makes a house much tighter, which changes how gas furnaces, water heaters and fireplaces draft, so ask whether the installer (or your HVAC contractor) will do combustion safety testing after the job. Some utility rebates require it.
Rebates and incentives for Northwest Indiana
Utility programs that may apply, depending on which utility serves your address:
NIPSCO Home Energy Assessment
Up to $700 off a licensed insulation contractor's invoice when existing attic insulation is R-11 or less and the upgrade reaches R-38 or higher; the assessment and work must happen in the 2026 program year.
Read on the program's own page October 16, 2026. Programs change; confirm before you sign.
Indiana state Home Energy Rebates
Open (some programs) Indiana Energy Saver Program
Electrification/appliance rebates (HEAR): "Applications for the Indiana Energy Saver Program are NOW OPEN!"
Whole-home efficiency rebates (HOMES/HER): "Applications for the Indiana Energy Saver Program are NOW OPEN!"
Official source: Indiana Office of Energy Development. Status text compiled via referencesource.org, last checked by them August 25, 2026. Full Indiana rebate page →
What spray foam costs (national published ranges)
We don't have enough local quotes for Northwest Indiana to publish local prices, and we won't make them up. These national ranges are a starting point; your installers' quotes are what count.
| Example job (typical thickness) | Estimated installed range |
|---|---|
| 1,000 sq ft attic roofline, open cell (6") | $3,600–$9,600 |
| 1,000 sq ft attic roofline, closed cell (3") | $3,900–$9,300 |
| 1,500 sq ft walls, open cell (3.5") | $3,150–$8,400 |
| 1,500 sq ft walls, closed cell (2") | $3,900–$9,300 |
| 200 sq ft rim joists, closed cell (2") | $520–$1,240 |
Board feet × Angi's 2026 installed price per board foot. Angi reports a national average spray foam project of $2,888 (typical $1,455–$4,337). Check a quote you already have →
Questions to ask each installer
- Foam type, brand, thickness and resulting R-value for each area, in writing.
- Which climate zone and code edition they're designing to.
- Whether removal of old insulation, air sealing, and any required ignition/thermal barrier coating are included.
- Whether they participate in NIPSCO Home Energy Assessment, and who files the paperwork.
- Whether they'll do (or coordinate) combustion safety testing if you have gas appliances.
FAQ
What climate zone is Northwest Indiana in?
Under the 2021 IECC county map, the counties in Northwest Indiana are Lake County 5A, Porter County 5A, LaPorte County 5A (PNNL-33270).
Should I use open-cell or closed-cell spray foam in Northwest Indiana?
In zone 5A, open cell under a roof deck needs a vapor-retarder coating (IRC R806.5); closed cell doesn't. Closed cell is also the standard choice for rim joists and basement walls.
How much attic insulation do homes in Northwest Indiana need?
ENERGY STAR recommends R-60 for an uninsulated attic in zone 5A (or adding R-49 on top of 3–4 inches of existing insulation). Indiana's code: 2018 IECC (via 2018 IRC Chapter 11) with Indiana amendments.
Are there spray foam or insulation rebates in Northwest Indiana in 2026?
The federal 25C tax credit does not apply to insulation installed after December 31, 2025. Utility programs that may apply, depending on which utility serves your address: NIPSCO Home Energy Assessment. Indiana's state Home Energy Rebate program status: Open (some programs).
How much does spray foam cost in Northwest Indiana?
We don't publish local prices until we have enough real local quotes. National published ranges are about $0.60–$1.60 per board foot for open cell and $1.30–$3.10 for closed cell, installed (Angi, 2026), and many companies have a $1,000–$2,000 minimum.
How does requesting quotes work?
Fill in the form once. We pass your request to up to three vetted partner installers who serve Northwest Indiana, and they contact you to schedule an estimate. It's free and there's no obligation.