Most deck cost articles give you a national average per square foot. That number is close to useless here, because the two things that move a Downers Grove deck price the most, access and what is already attached to your house, do not show up in a per foot rate.
So here is how we actually price work in Downers Grove, what the ranges look like in 2026, and where the money goes on a lot in 60515 or 60516.
One note up front. The ranges below are the ones we quote across the western suburbs, including Downers Grove. They assume composite decking with railings, ground level to mid height. They are planning numbers, not a quote. Nobody can price your deck without standing in your backyard, and any contractor who gives you a firm number over the phone is guessing.
Planning ranges for 2026
| Deck size | Approximate installed cost |
|---|---|
| 200 sq ft (10×20) | $15,000 to $22,000 |
| 300 sq ft (12×25) | $20,000 to $30,000 |
| 400 sq ft (16×25) | $26,000 to $40,000 |
| 500+ sq ft (multi level) | $36,000 and up |
Elevated decks, long stair runs, lighting and built ins push above these. Simple layouts close to grade come in under.
The spread inside each row is wide on purpose. Two homeowners about nine miles apart asked us for the same 16×25 composite deck last spring, same board, same railing. One came in a little over $28,000 and the other closer to $37,000. Neither was overcharged. Almost everything that separated them had nothing to do with the deck.
Roughly a third of your money is spent before a board goes down
This is the part that surprises people. Getting equipment into the yard, digging footings deep enough for the soil you actually have, and dealing with whatever the last builder left behind typically accounts for about a third of the total.
In Downers Grove that third is unusually expensive, for three reasons specific to this village.
The housing stock is old. Downers Grove has a large inventory of 1950s and 1960s ranches and split levels, plus the older streets around downtown. If we are tearing off a deck built in the 1980s, we frequently find a ledger board nailed straight to the sheathing with no flashing behind it. That means opening up siding and repairing whatever rotted underneath. It is the most expensive surprise a homeowner here can hit, and we wrote about how that damage spreads in how an old deck can rot your house.
The lots near downtown are tight. On the older streets close to the Main Street and Fairview Metra stations, side yards are narrow, the parkway trees are enormous, and there is often a fence, a gate and an air conditioner condenser lined up in the only gap. When we cannot get a skid steer into the backyard, footings get dug by hand and every yard of concrete gets wheelbarrowed in. That is usually one to two extra days of labor, and it is a real line on the estimate. It also means protecting the parkway tree on the way through, which we covered in our post on Downers Grove tree rules and deck footings.
The soil is heavy clay. DuPage County clay holds water and moves with the freeze thaw cycle. Standard footing depth around here is 42 inches, and on some lots that is the floor rather than the answer. Where a large tree is pulling moisture out of clay soil, or where the grade drops toward a low spot, we sometimes go deeper or switch to helical piles. We compared what we find on different soil conditions in DuPage River versus Ogden Avenue deck footings.
Height costs more than width
If you take one thing from this, take this one. A ground level deck and an elevated deck of identical square footage can land twenty percent apart.
Elevation adds larger posts, deeper footings, more stairs, and guardrail on every exposed side. A deck that starts eight or ten feet off the ground is a different structure, not a taller version of the same one.
This matters in Downers Grove because of where the walkouts are. Lots backing onto the ravines and the wooded areas, and the properties along the Ogden Avenue corridor with walkout or lookout basements, put the back door well above the yard. If that describes your house, price the 400 sq ft row expecting the top of it rather than the middle. Our writeup on second story decks, helical piles and post sizing covers what changes structurally once you get up there.
What the Village adds to the timeline and the budget
Downers Grove runs everything through an online permit portal. There is no walk in counter for this.
First review takes approximately 10 business days. If staff come back with comments, you are expected to respond within five business days, and then it goes around again. Build that into your schedule, because a spring project that starts its permit in April is not breaking ground in April.
Two things catch people out on cost.
The first is bonds. Downers Grove may apply a bond to your permit on top of the fees, held to make sure the work gets finished and public infrastructure is protected. It is refundable, generally within three to four weeks after final inspections pass, but it is money out of your pocket during the build. Ask whether your project triggers one.
The second is inspection scheduling. Inspections are requested through the portal or by calling 630-434-5529, and the Village asks for 48 to 72 hours of notice. A contractor who does not plan around that will have crews standing idle, and idle crews eventually show up in somebody’s price.
If your permit requires a Site Management Sign or a Parkway Tree Protection Sign, you collect those at Village Hall and post them before work starts. Current fee amounts are published in the Village’s user fee schedule, and you can start the process on the Village of Downers Grove permits page.
Where resurfacing changes the math entirely
Not every project needs a new deck.
If the existing frame is sound, we can often pull the old boards and lay composite over the existing structure. That runs roughly a third of the cost of a full rebuild, which on a 300 square foot deck is the difference between a five figure project and something considerably smaller.
The question that decides it is joist spacing. A lot of the original cedar decks around Downers Grove were framed at 24 inches on center, and most composite boards will not span that. If yours is one of them, the frame has to come down and you are back to a rebuild. That single answer moves a project by ten thousand dollars or more, and you cannot determine it from a photo. Somebody has to get under the deck.
More on how we assess it on our deck resurfacing page.
The line items worth arguing about
When you have three quotes in front of you, the price gap almost never comes from one company being greedy. It comes from what is included and what is quietly missing.
Railing choice alone swings a project by several thousand dollars. Fasteners matter more than they sound like they should: on a 320 square foot deck you are installing around 1,400 of them, and the difference between a cheap coated carbon steel screw and a stainless structural screw works out to hundreds of dollars in material and years of difference in how the deck looks. Cheap fasteners rust and stain composite within three to five years.
Then there is footing depth. If a bid assumes a standard 42 inch footing on a lot that needs more, that is not a better deal, it is a change order waiting to happen. Ask each contractor what footing depth they specified, what post size, and whether the permit and bond are inside the number or outside it.
We put three real quotes side by side in why a $19,000 bid beat a $35,000 one, which shows what these differences actually look like on paper.
Frequently asked questions
How much does a deck cost in Downers Grove, IL in 2026? For composite decking with railings, ground level to mid height, plan on roughly $15,000 to $22,000 for 200 square feet, $20,000 to $30,000 for 300, and $26,000 to $40,000 for 400. Multi level and larger builds start around $36,000. Elevated decks and heavy stair runs sit at the top of those ranges or above.
Do I need a permit to build a deck in Downers Grove? Yes. Deck is a specific application type in the Village’s online permit portal. First review runs about 10 business days, and inspections need 48 to 72 hours notice.
Is there a bond on a Downers Grove deck permit? There can be. Bonds are applied in the portal when required and are generally refunded within three to four weeks after final inspections pass. Ask before you budget.
Why is my quote higher than my neighbor’s for the same size deck? Usually height and access. An elevated deck needs bigger posts, deeper footings, stairs and guardrail on every side. A backyard we cannot reach with a machine adds a day or two of hand digging. Both of those move the number more than square footage does.
Is resurfacing cheaper than rebuilding? Substantially, at roughly a third of a rebuild, but only if the existing framing is sound and the joists are spaced tightly enough for composite. Older decks framed at 24 inches on center usually cannot be resurfaced.
How deep do deck footings go in Downers Grove? 42 inches is the standard depth used across DuPage County. Some lots need more depending on soil and load. Confirm current requirements with Community Development at 630-434-5515.
Getting a real number
The only way to know what your deck costs is to have somebody stand in your backyard and look at the grade, the access, and whatever is already bolted to the house. We do that at no charge, and we will tell you if resurfacing makes more sense than rebuilding even though it is the smaller job for us.
Wolf Spirit Deck builds across Downers Grove, including 60515 and 60516, and the surrounding western suburbs. See what we do locally on our Downers Grove deck builders page, or request a free quote.
Wolf Spirit Deck, (312) 765-3998. Illinois Contractor License #TGC119852.
