Frame materials and glass packages for a Chicago winter

Chicago sets a floor before taste comes into it. For a residential building up to four stories above grade, the ordinance adopting the 2022 Chicago Energy Transformation Code caps a replacement window at a U-factor of 0.30 and a solar heat gain coefficient of 0.40, and that number is written against the whole assembly, frame and glass together, not the glass alone. It applies even when your job needs no building permit. So the glass package is largely set for you, and the frame material is the decision you actually still own. Only one Chicago price carries a named author and a date: standard vinyl at $650 to $1,200 per window installed and energy-efficient vinyl at $700 to $1,250 (Modernize Illinois, Isabella Andersen, reviewed by Catie Bonner, March 18, 2026, read 2026-08-11). Choose the frame on your opening, your exposure and your maintenance appetite, then make every quote state its rated U-factor and SHGC in writing.

This is the hub for everything this site publishes about what a window is made of, and the four pages under it are linked below. The standard every figure here is held to is set out on our methodology page. The code itself, quoted at length, is on the energy code page, and the full attributed price tables are on cost by frame material.

The number every material has to hit

Most material comparisons start with opinion. Chicago lets you start with a requirement instead, which is a better place to start because it is checkable. These three values govern a residential building up to four stories above grade.

Component	Chicago maximum	Where it is written
Window (fenestration) U-factor	0.30	Table R402.1.2, repeated in Table R402.1.3
Glazed fenestration SHGC	0.40	Same two tables. Footnote b: "The SHGC column applies to all glazed fenestration"
Skylight U-factor	0.55	Same two tables. The same footnote excludes skylights from the window column

Read in SO2022-2008.pdf, the ordinance adopting the 2022 Chicago Energy Transformation Code, hosted on chicago.gov, 2026-08-11. Chicago is climate zone 5A (Section C301.1). The scope sentence reads: "The residential provisions of the Chicago Energy Transformation Code apply to Group R-2, R-3, R-4, and R-5 occupancies with no more than four stories above grade plane."

Three consequences fall out of those three rows, and each one changes how you shop.

• The frame counts toward the number. Table R402.1.2 is titled "MAXIMUM ASSEMBLY U-FACTORS AND FENESTRATION REQUIREMENTS". An assembly is the frame and the glass together. That is why the frame material is an energy decision and not only an appearance decision, and it is why a glass specification on its own tells you nothing about compliance.
• No material is banned and none is exempt. The code names a performance target, not a product. Any material that reaches 0.30 as a finished unit complies, and any material that does not, does not. That is the argument for asking about the rated unit rather than arguing about the material in the abstract.
• The solar cap applies everywhere on the house. The SHGC column covers all glazed fenestration, north elevations included. Our reading, said as ours: that closes off the passive-solar strategy some national guides recommend, which is to buy higher solar gain on south-facing glass in a heating climate. Chicago's prescriptive table does not offer that option.

It applies even when nobody comes to check

Chicago publishes that a building permit is not required for "Repairing or replacing (in-kind) an exterior window or skylight in the existing opening" in a residential building up to four stories above grade. On the same page it publishes the sentence that settles what that does not mean: work performed without a permit "must still comply with all applicable requirements of the Chicago Construction Codes", and the section allowing it "does not waive any applicable requirements of the Chicago Construction Codes or of the Municipal Code other than the requirement to obtain a building permit".

Where a permit does apply, the city says the same thing a second way. The Express Permit Program terms for exterior window and door replacement read: "Replacement windows and doors installed under this permit must meet the U-value and solar heat gain requirements of the Chicago Energy Transformation Code."

Our reading, labelled as ours. On an exempt job no inspector arrives, no plan review happens, and nobody from the city ever looks at what was installed. The requirement is real and the enforcement is absent, which means the contract and the rated numbers on the units you buy are the only place compliance actually gets settled. Put both numbers in writing before anything is ordered.

City of Chicago, work not requiring a building permit, exterior, and Express Permit Program terms and conditions for exterior window and door replacement. Both read 2026-08-11.

The four materials, and how they behave in a freeze-thaw climate

Read this table as material property, not as measurement. Nothing we read publishes U-factor, air leakage or service life by material, so none of those appears here. What is below is the general behaviour of each material, which is enough to narrow the field before you start asking for rated numbers on specific units.

Material	What it is	Behaviour that matters in a Chicago winter	Repairable in place?
Vinyl	Extruded PVC with hollow chambers, corners welded, colour through the material rather than painted	Moves more with temperature swing than wood or fiberglass. Dark exterior colours absorb more heat, which is a specification question on a west or south elevation	No. A failed frame is replaced, not repaired
Wood, and clad wood	Solid wood, or wood with an aluminum, vinyl or fiberglass exterior skin	Insulating by nature. Bare exterior wood needs a maintained finish; where the finish fails, freeze-thaw and standing water do the rest. Cladding moves that exposure off the wood	Yes. Sash, sills and glazing are repairable, which is why vintage stock keeps surviving
Fiberglass	Pultruded glass fibre in resin, typically painted	Dimensionally stable, and it expands at a rate close to the glass it holds, so the frame and glass move together through a freeze-thaw cycle	Partly. Finish is renewable; the frame is a manufactured unit
Aluminum	Extruded aluminum, sometimes with a thermal break separating inside from outside	Conducts heat far better than the others, so a frame with no thermal break is the weak point of the assembly in a long heating season. Strongest per section, thinnest sightlines	Partly. Hardware and glazing yes, the extrusion no

General material properties, not Chicago measurements and not figures from any source read this session. Where a number would be needed to make one of these arguments, this site does not have one and does not publish one.

Composite frames, which blend wood fibre with polymer, sit across those rows rather than in one of them, and the national price sources treat composite as its own category. Its bands are in the price table below.

What the materials cost, and which figures are actually local

One line of this table is a Chicago figure. Every other line is national and is not relabelled as anything else. That distinction is the whole point of the table, because the material decision is usually argued in national numbers that were gathered somewhere with a shorter winter and a different labour market.

Material	Today's Homeowner, Sep 3, 2025	This Old House average, Jun 23, 2026	Modernize, Mar 17, 2026
Vinyl	$450 to $800	$527	$400 to $850
Wood	$600 to $1,500	$567	$800 to $1,500 or more
Fiberglass	$500 to $1,000	$491	$900 to $1,400
Aluminum	$400 to $850	$448	$650 to $1,100
Composite	$500 to $1,200	$529	$1,000 to $1,800
Clad wood	Not broken out	Not broken out	$950 to $1,800, all cladding types together

Today's Homeowner: Elisabeth Beauchamp, reviewed by Amy DeYoung, updated September 3, 2025. This Old House: Stephanie Minasian-Koncewicz, updated June 23, 2026, from a November 2025 survey of 1,000 homeowners. Modernize: Catie Bonner, reviewed by Isabella Andersen, updated March 17, 2026. Clad wood: Modernize, "Clad Wood Windows", Rob Sabo, reviewed by Catie Bonner, August 29, 2025. All read 2026-08-11. Two further sources are labelled rather than blended in: Bob Vila (Katie Flannery and Evelyn Auer, updated June 10, 2024) is the only pre-2025 source on this site, and Pella (updated May 14, 2026) is a manufacturer writing about its own product category. Their bands are on cost by frame material.

The Chicago and Illinois figures	Value
Chicago, standard vinyl double-hung, per window installed	$650 to $1,200
Chicago, energy-efficient vinyl, per window	$700 to $1,250
Illinois, basic specification tier	$575 to $1,000 per window
Illinois, mid tier	$825 to $1,300 per window
Illinois, high-end tier	$1,250 to $2,700 per window
Illinois, triple-pane upgrade	Add $150 to $350 per window
Illinois, split between materials and labour	Materials about two-thirds, labour about one-third

Modernize, "Window Replacement Cost and Pricing in Illinois (2026)", Isabella Andersen, reviewed by Catie Bonner, updated March 18, 2026. Read 2026-08-11.

Two things are worth pulling out of those two tables together. First, the Illinois tier bands overlap the material bands almost completely, which means how well a window is specified moves the price as much as what it is made of. A high-end vinyl unit and a basic clad wood unit can land in the same place. Second, materials are about two-thirds of an Illinois job. That is the argument for spending your attention on the product rather than negotiating the installation line, and it is also why a quote that is cheap because its labour line is thin is usually telling you something about the crew rather than about the price.

Glass packages, and what is actually decided for you

Frame material is a real choice. The glass package is much less of one in Chicago, because the assembly has to reach 0.30 and 0.40 and the glass is where most of the area is. The table below separates what each option does from what we can attribute a figure to, which for glass is very little.

Option	What it does	What we can attribute
Double glazing, sealed unit	The baseline for a replacement unit in this market	Priced inside the per-window bands above, not separately
Triple glazing	A third pane and a second sealed cavity. Adds weight, which the frame and hardware have to carry	Add $150 to $350 per window in Illinois (Modernize Illinois, March 18, 2026)
Low-emissivity coating	A microscopic metallic coating. It moves U-factor and SHGC together, which is why it is the lever that gets a unit under both Chicago numbers	No figure read. Named as the mechanism, not priced
Argon or krypton gas fill	Replaces air in the sealed cavity with a denser gas	No figure read
Warm-edge spacer	The strip separating the panes at the perimeter, where the edge of the glass is coldest and where condensation shows first	No figure read
Grilles, muntins and divided lights	Appearance. On vintage Chicago elevations this is often the detail that decides whether a replacement reads correctly from the street	No figure read. Landmark relevance is on the permits pillar

The triple-pane figure: Modernize, "Window Replacement Cost and Pricing in Illinois (2026)", Isabella Andersen, reviewed by Catie Bonner, updated March 18, 2026, read 2026-08-11. Every other row carries no figure because no attributable one was read. Descriptions of what each option does are general product description, not measurements.

The number of panes is not what the code asks about. Chicago's requirement is a U-factor of 0.30 on the assembly. It names no pane count, no gas fill and no coating. A salesperson describing triple glazing as needed for code is describing a product, not the ordinance. Triple glazing may still be worth buying for comfort near a cold surface or for noise on a busy street, and no source we read prices either of those benefits, so this site does not.

How you verify any of it is the same in every case: ask for the rated U-factor and the rated SHGC of the exact unit being quoted, in writing, on the quote. Those two numbers are usually published on the rating label a manufacturer attaches to a new window, commonly a National Fenestration Rating Council label. We have not read that council's own rules at source, so treat the label as the general practice it is, and treat the written quote as the thing you can actually hold someone to.

One more thing to not count on. The federal Energy Efficient Home Improvement Credit is no longer available for windows placed in service now, per the IRS page updated April 28, 2026 and read 2026-08-11. We publish no amounts, caps or eligibility rules for it, because those belong to the agency and they change. If any part of your glass decision rests on it, read it at the source: the IRS page for this programme.

Material, and the paperwork question nobody answers

Here is a genuine gap in the published rules, and it lands squarely on this pillar. Chicago exempts in-kind replacement from a building permit and defines in-kind as new elements "of the same type, size, and shape". Change the window type and you have plainly left that wording. Change only what the frame is made of, wood for vinyl say, and the published text does not say whether you have.

We are not going to resolve that by guessing, because the cost of a wrong guess falls on you and not on us. Ask the Department of Buildings before you order, and get the answer in writing. If the property is a designated or proposed Chicago Landmark or sits inside a landmark district, that question comes first anyway: the city states that its permit exceptions "may not apply" there. We do not restate the landmark rules on this page. They are quoted from the city on the landmark page, and they are worth reading before you choose a material rather than after.

City of Chicago, work not requiring a building permit, exterior, read 2026-08-11.

You may not need new windows at all

This site is paid a referral fee when a homeowner asks to be matched with a window contractor, which is set out in full on how we make money. So the cases where the answer is to spend nothing are worth stating plainly rather than burying.

• The code does not make you start. Chicago's revised R501.1.1 reads: "Except as specified in this chapter, this code shall not be used to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code. Unaltered portions of the existing building or building system shall not be required to comply with this code." A single-glazed sash from the 1920s that you leave alone is lawful. The code engages when you alter something.
• Storm windows and window film are named exceptions. The code's exception list covers "Storm windows installed over existing fenestration" and "Surface-applied window film installed on existing fenestration assemblies to reduce solar heat gain provided that the code does not require the glazing or fenestration assembly to be replaced", in both cases "provided that the energy use of the building is not increased". Chicago separately lists "Installing, maintaining, or removing a storm window" as work needing no building permit in any building, at any height. A storm window is the one improvement here that sits outside both the permit requirement and the new-construction performance numbers.
• One failed sealed unit is not a material decision. Repairing damage to an existing window and replacing the glass in an existing sash are both on the city's any-building no-permit list. A fogged pane is a glass problem, and pricing it against a whole-house material comparison is how a small repair turns into a five-figure quote. The economics are worked through on repair against replace.
• If you are outside the city, this page may not be your rulebook. Illinois preempts local residential energy standards and carves out only "a municipality with a population of 1,000,000 or more". We publish no statement about which Illinois municipalities meet that population test, because no attributable population figure was found: the Census API needs a key and QuickFacts returned 403. Check whether your own municipality meets the test. For contrast, the statewide provision at 20 ILCS 3125/20(c) exempts "glass-only replacements in an existing sash and frame" but not full window replacement. Read at ilga.gov, 2026-08-11. We publish no state values because we have not read them at source.

How to specify so two quotes can be compared

A reading aid, in order, ending in a recommendation. A page that lists considerations and reaches no conclusion has left the work to you.

• Settle landmark status first. It can decide the product before price is discussed, and it is the thing homeowners discover last.
• Write one scope before anyone visits. Number of openings, the type in each, whether every opening stays exactly as it is, the frame material you are pricing, and the two rated numbers you require. Send the same paragraph to three contractors.
• Require the rated U-factor and SHGC on the quote. Not "meets code", not "energy efficient". The two numbers, on the exact unit, in writing.
• Price one material change at a time. Ask for the same scope in vinyl and in your second choice. That is the only way to see what the material is actually costing you, rather than the material plus a different specification tier bundled together.
• Convert everything to a per-opening number. Divide each total by the number of openings, then hold it against the Chicago vinyl band of $650 to $1,200 (Modernize Illinois, March 18, 2026, read 2026-08-11). Above the band is not automatically wrong; clad wood, triple glazing, upper floors and a landmark specification all sit above it for reasons you can name.

The recommendation. For most Chicago houses up to four stories, in the existing openings, start by pricing vinyl and fiberglass against each other on one written scope, because that pair covers the affordable end and the dimensionally stable end and the code treats both identically. Move to clad wood when the elevation, the profile or a landmark review asks for it, and treat that as a specification requirement rather than an upgrade. Only choose aluminum where the building was built for it or where sightlines genuinely rule, and then insist on a thermally broken frame and the rated numbers to prove it. Whatever you pick, the finished window has to show a U-factor at or below 0.30 and an SHGC at or below 0.40, and that sentence belongs on your contract.

The three material pages under this hub

Each one is written for Chicago's stock and its winter, and each carries its own sources. Cost detail lives in the cost pillar; these pages cover the material itself. Aluminum has no page of its own. It is covered on this page instead, in the four-material comparison above, and clad aluminum is covered on wood and clad wood.

Vinyl windows

The Chicago default and the only material with an attributable local price: $650 to $1,200 per window installed for a standard unit and $700 to $1,250 for an energy-efficient one (Modernize Illinois, March 18, 2026, read 2026-08-11). That page covers welded versus mechanically fastened corners, what dark exterior colours ask of the extrusion, why a vinyl frame is replaced rather than repaired, sightlines against the openings on vintage stock, and how to read the specification tiers that move an Illinois vinyl quote from the basic band to the high-end one.

Wood and clad wood windows

The material most of Chicago's pre-war stock started with, and the one a landmark specification most often ends at. That page covers repair of existing sash as a live alternative, what a maintained finish actually requires on an exposed elevation, how aluminum, vinyl and fiberglass cladding differ in what they ask of you, and the honest limit on price: the only clad figure anywhere in our sources is national and groups all cladding types together at $950 to $1,800 per window (Modernize, "Clad Wood Windows", Rob Sabo, reviewed by Catie Bonner, August 29, 2025, read 2026-08-11). There is no Chicago clad price on this site.

Fiberglass windows

The material with the strongest freeze-thaw argument and the thinnest evidence base, and that page says both. It covers pultrusion and why a frame that expands at close to the rate of the glass it holds matters through a Chicago winter, painted finishes and colour changes later, sightlines against vinyl at the same strength, and where the national bands put it: $500 to $1,000 (Today's Homeowner, September 3, 2025) against $900 to $1,400 (Modernize, March 17, 2026), a disagreement large enough to be worth seeing rather than averaging.

Aluminum windows, covered on this page

Aluminum has a real weakness here and a real place in some buildings, and it gets no separate page. What we have on it is in the four-material comparison above: thermal conduction and what a thermal break is doing, the thin sightlines and strength per section some openings were built around, and the code answer, which is that the finished assembly has to reach 0.30 and the code names no material. Clad aluminum, meaning a wood window with an aluminum exterior skin, is on wood and clad wood. National bands run $400 to $850 (Today's Homeowner, September 3, 2025) to $650 to $1,100 (Modernize, March 17, 2026). No Chicago aluminum figure exists in anything we read.

What we could not source, and will not invent

Five things a homeowner comparing materials would reasonably want are missing here. Each is missing on purpose, and each is the kind of number a page like this usually makes up.

• Performance by material. No source we read publishes a U-factor, SHGC, air leakage rate or condensation rating for a material class. So this site never writes that vinyl or fiberglass "achieves" a number. The requirement is on the assembly, and the only honest answer is the rated number on the unit in front of you.
• Service life by material. Lifespan figures for windows circulate everywhere and none we found carried an author, a method or a date. No lifespan number appears here.
• A Chicago price for anything except vinyl. The only Chicago figures with a named author and a named reviewer cover standard and energy-efficient vinyl. Everything else on this page is national and labelled national.
• The numbers for a building over four stories. Above four stories the commercial provisions and Table C402.4 govern. That table did not come through text extraction from the ordinance PDF, so no value for it appears anywhere on this site. Ask the Department of Buildings, or read Table C402.4 in the ordinance yourself. A high-rise unit also has an association declaration sitting over the whole question, which the window types hub covers.
• Whether frame material is part of Chicago's definition of "type". The city does not publish an answer, so neither do we, and the question goes to the Department of Buildings in writing.

Related pages outside this pillar

• The Chicago energy code for replacement windows, which quotes the ordinance at length, including the alterations rule and the exception list that names storm windows and film.
• Window replacement cost by frame material, where every band names its publication, its author and its date, including the two sources labelled rather than blended into the table above.
• Choosing a window type in Chicago, which starts from the opening you already have. Type and material are separate decisions and only one of them is settled by your wall.

Sources

All read 2026-08-11: the ordinance adopting the 2022 Chicago Energy Transformation Code (Tables R402.1.2 and R402.1.3, the residential scope sentence, Section C301.1, 14N-R5-R501 and 14N-R5-R503); City of Chicago, Chicago Energy Conservation Code supporting information; Express Permit Program terms for exterior window and door replacement; work not requiring a building permit, exterior; 20 ILCS 3125, Illinois General Assembly; IRS, Energy Efficient Home Improvement Credit. Cost figures: Modernize, "Window Replacement Cost and Pricing in Illinois (2026)", Isabella Andersen, reviewed by Catie Bonner, updated March 18, 2026; Modernize national window replacement cost, Catie Bonner, reviewed by Isabella Andersen, updated March 17, 2026; Modernize, "Clad Wood Windows", Rob Sabo, reviewed by Catie Bonner, August 29, 2025; Today's Homeowner, Elisabeth Beauchamp, reviewed by Amy DeYoung, updated September 3, 2025; This Old House, Stephanie Minasian-Koncewicz, updated June 23, 2026, from a November 2025 survey of 1,000 homeowners; Bob Vila, Katie Flannery and Evelyn Auer, updated June 10, 2024; Pella, updated May 14, 2026. No competitor page, contractor marketing page, manufacturer brochure or search-engine summary informed any rule or figure above.

If you want real quotes to hold against these numbers, the form below passes your details to an independent licensed window contractor working in your part of the city. What that relationship is, and what it is not, is set out on the about page.

Straight answers

Questions Chicago homeowners ask

What does Chicago require a replacement window to hit?

For a residential building up to four stories above grade, a maximum window U-factor of 0.30 and a maximum solar heat gain coefficient of 0.40. Skylights are allowed a maximum U-factor of 0.55. Those three values are read from Table R402.1.2 in the ordinance that adopted the 2022 Chicago Energy Transformation Code, and the same three repeat in Table R402.1.3, which is a useful cross-check on the reading. The first table is titled "MAXIMUM ASSEMBLY U-FACTORS AND FENESTRATION REQUIREMENTS", so the number is written against the whole window, frame and glass together, rather than against the glass on its own. Read in SO2022-2008.pdf on chicago.gov, 2026-08-11. Above four stories different provisions apply and this site publishes no number for them.

Which frame material should I choose for a Chicago winter?

We will not answer that with a performance claim, because nothing we read measures U-factor or SHGC by material, and a page that ranks materials on invented numbers is the thing this site exists to avoid. What we can say is sourced and still useful. The code is a performance requirement on the assembly, so it does not ban any material; it puts the same target on all of them. The only Chicago price with a named author is for vinyl, at $650 to $1,200 per window installed for a standard unit and $700 to $1,250 for an energy-efficient one (Modernize Illinois, Isabella Andersen, reviewed by Catie Bonner, March 18, 2026, read 2026-08-11). Everything else is national. So choose on the opening, the exposure, the maintenance you will actually do, and the rated numbers written into your contract.

Is triple glazing worth it in Chicago?

The honest answer is that we cannot price the benefit, only the upgrade. Modernize's Illinois page puts a triple-pane upgrade at an extra $150 to $350 per window (Isabella Andersen, reviewed by Catie Bonner, March 18, 2026, read 2026-08-11). No source we read publishes a Chicago payback period, a heating-bill saving or a comfort measurement, so this site publishes none. What the code settles is that you do not need triple glazing to comply: the requirement is a U-factor of 0.30 on the assembly, and it names no number of panes. Treat the third pane as a comfort and noise decision you are choosing to buy, and ask the contractor to state the rated U-factor with and without it rather than describing it as an upgrade.

If my job needs no permit, does the energy code still apply?

Yes, and this is the part people get wrong. Chicago publishes that a building permit is not required for "Repairing or replacing (in-kind) an exterior window or skylight in the existing opening" in a residential building up to four stories above grade. On the same page the city publishes that work performed without a permit "must still comply with all applicable requirements of the Chicago Construction Codes", and that the section allowing it "does not waive any applicable requirements of the Chicago Construction Codes or of the Municipal Code other than the requirement to obtain a building permit". The energy code is one of those codes. Read at chicago.gov 2026-08-11. Our reading, stated plainly: no city inspector arrives on an exempt job, so the contract and the rated numbers on the units are where compliance actually gets settled.

Does swapping wood frames for vinyl break the in-kind exemption?

We do not know, and we will not guess at your expense. Chicago defines in-kind replacement as using new elements "of the same type, size, and shape", read at chicago.gov 2026-08-11. Nothing the city publishes says whether frame material is part of "type". Changing the window type, a double-hung for a casement say, plainly leaves that wording; changing only what the frame is made of is genuinely unsettled in the published text. Ask the Department of Buildings before you order, and get the answer in writing. If the property is a designated or proposed Chicago Landmark or sits in a landmark district, settle that first instead, because the city states its exceptions "may not apply" there.

Is aluminum a bad choice in Chicago?

It is a material with a known weakness in a cold climate and a real place in some buildings, and we can only tell you the first part as general material property rather than as a Chicago measurement. Aluminum conducts heat far better than vinyl, wood or fiberglass, which is why a plain aluminum frame is a thermal weak point unless the frame is thermally broken. That is basic material physics, not something we read for Chicago. Set against it: aluminum gives the thinnest sightlines and the most strength per section, and in some buildings it is what the original openings were built for. The code does not ban it. It requires the finished assembly to meet 0.30, so ask for the rated number on the exact unit rather than arguing about the material.

Do these numbers apply in Oak Park, Evanston or Berwyn?

Do not assume so. Illinois preempts local residential energy standards at 20 ILCS 3125/45(b): no unit of local government, "including any home rule unit", may regulate them "in a manner that is either less or more stringent" than the state Act, with a short list of exceptions. The carve-out is written for "a municipality with a population of 1,000,000 or more". We publish no claim about which Illinois municipalities meet that population test, because no attributable population figure was found this pass: the Census API needs a key and QuickFacts returned 403. Confirm whether your own municipality meets it. If it does not, that suburb is generally on the state standard rather than Chicago's, and the state numbers do not appear on this site because we have not read them at source. Read the statute at ilga.gov, read 2026-08-11, then ask your own village or city building department which values it enforces.