Willowbrook, IL Office Space for Lease: 2026 Costs, Buildings and Rents

Data as of October 2026 | Last updated October 17, 2026

Net absorption was a modest +3,000 SF over the past year. Tenant Advisors, Inc. represents only tenants in Willowbrook and the East-West Corridor office market, at no cost to tenants. Call (847) 778-0296.

Key Takeaways

• Vacancy is 15.5% across 8 tracked multi-tenant buildings.
• Net absorption over the past 12 months: +3,000 SF.
• Class B asks about $19–$22/SF gross; limited Class A-quality space about $24–$27/SF.
• The largest available block is about 7,000 SF at 625 Plainfield Rd.

Willowbrook Office Market Facts and Figures

Tenant Advisors tracks multi-tenant office buildings in Willowbrook, the competitive set where most tenants of 3,000 to 50,000 SF lease space. Owner-occupied buildings are excluded.

Metric	Willowbrook
Tracked buildings	8
Vacancy rate	15.5%
Net absorption, trailing 12 months	+3,000 SF
Class A asking rent	$24–$27/SF gross (limited Class A supply)
Class B asking rent	$19–$22/SF gross
Free rent	1–1.5 months per lease year
Tenant improvement allowance	$6–$8/SF per lease year (Class A)
Sublease space available	Little to none in tracked buildings
New construction	None
Most available space in one building	~7,000 SF (625 Plainfield Rd.)

Figures reflect Tenant Advisors’ market tracking of multi-tenant office buildings in Willowbrook. Rents and concessions are Tenant Advisors’ tracked-transaction ranges, quoted full-service gross. Data is updated quarterly.

What Does Office Space Cost Per Month in Willowbrook?

A 5,000 SF office in Willowbrook costs about $10,000 to $11,250 a month in a Class A building and about $7,900 to $9,150 a month in Class B, before free rent. Those figures use Tenant Advisors’ tracked gross rents of $24 to $27/SF in Class A and $19 to $22/SF in Class B.

Office size	Class A, monthly ($24–$27/SF)	Class B, monthly ($19–$22/SF)
2,000 SF	$4,000–$4,500	$3,150–$3,650
5,000 SF	$10,000–$11,250	$7,900–$9,150
10,000 SF	$20,000–$22,500	$15,850–$18,350

Monthly rent before free rent and improvement allowances. Gross rent generally includes real estate taxes and building operating expenses.

Gross rent is not always the whole bill. Ask each landlord about:

• In-suite electricity, which some buildings bill separately.
• Operating expense and tax increases over the base year, which a cap can limit.
• After-hours heating and cooling charges.
• Build-out costs above the improvement allowance, plus cabling, furniture and moving.

Is Willowbrook Office Space Filling Up or Emptying Out?

Holding steady, with a small gain. Willowbrook absorbed +3,000 SF over the past year. With vacancy at 15.5%, the lowest in the corridor, larger blocks of space are scarce and the best options lease quickly.

What Are the Notable Office Buildings in Willowbrook?

Building	Address	Size (SF)	Built	Class	% Leased	Available (SF)
Willowbrook Business Center	600–650 Executive Dr.	50,719	1979	C	95%	2,613
535 Plainfield Rd.	535 Plainfield Rd.	33,832	2000	B	96%	1,432
Willowbrook Office Plaza	621 Plainfield Rd.	25,600	1982	C	92%	2,156
625 Plainfield Rd.	625 Plainfield Rd.	25,000	1982	B	71%	7,281

Available SF includes direct and sublease space, including space coming available. Tenant Advisors market tracking, October 2026.

Willowbrook Business Center, 600–650 Executive Dr.

51,000 SF, Class C, built 1979. About 95% leased with roughly 3,000 SF available.

535 Plainfield Rd.

34,000 SF, Class B, built 2000. About 96% leased with roughly 1,000 SF available.

Willowbrook Office Plaza, 621 Plainfield Rd.

26,000 SF, Class C, built 1982. About 92% leased with roughly 2,000 SF available.

Which Willowbrook Buildings Fit Small and Large Tenants?

Small tenants do best in buildings with suites already built out, while companies needing a full floor or more should start with the buildings carrying the largest vacant blocks. Use this as a starting list; actual suites change month to month.

Space needed	Where to start looking	Why
Under 3,000 SF	Willowbrook Business Center, Willowbrook Office Plaza, 535 Plainfield Rd.	Well-leased small buildings
3,000–7,500 SF	625 Plainfield Rd.	The largest available block in Willowbrook, about 7,300 SF
Larger requirements	Nearby Burr Ridge, Downers Grove and Oak Brook	Willowbrook has no large blocks; vacancy is about 15.5%

Is There Sublease Office Space in Willowbrook?

Very little in the buildings Tenant Advisors tracks. Tenants who want sublease options nearby usually look at Burr Ridge, or ask us to check for space coming available. See our Chicago office sublease guide.

How Does Willowbrook Compare With Other East-West Corridor Cities?

City	Vacancy	12-mo net absorption (SF)	Asking rent, gross	Tracked buildings
Naperville	26%	-10,500	A $28–$32; B $23–$26	66
Oak Brook	27%	-69,000	A $34–$38; B $24–$28	52
Downers Grove	23.5%	-2,000	A $31–$35; B $24–$27	36
Lombard	29.5%	+15,400	A $28–$32; B $21–$24	31
Oakbrook Terrace	22.7%	+66,200	A $30–$34; B $23–$26	23
Lisle	31%	+10,900	A $27–$31; B $22–$25	23
Wheaton	17.5%	-6,800	A $24–$27; B $20–$23	17
Aurora	20.5%	-18,300	A $26–$29; B $21–$24	15
Burr Ridge	29%	-2,100	A $28–$32; B $23–$26	13
Warrenville	24%	-21,600	A $27–$30; B $21–$24	12
Woodridge	17%	+8,600	A $25–$28; B $20–$23	12
Willowbrook	15.5%	+3,000	A $24–$27; B $19–$22	8

Tenant Advisors market tracking, multi-tenant office buildings, October 2026. Rents are Tenant Advisors’ tracked-transaction figures per SF per year.

Should You Lease, Sublease or Use Coworking in Willowbrook?

Lease direct if you need space for three years or more, sublease if you want built-out space at a discount and the remaining term fits, and use coworking only for small teams that need flexibility for a year or less. Little to no sublease space is listed in the Willowbrook buildings Tenant Advisors tracks.

	Direct lease	Sublease	Coworking
Typical term	3 to 10 years	Whatever remains on the original lease	Month to month up to 1–2 years
Cost	Market rent, with free rent and an improvement allowance	Usually below direct rent	Priced per desk or office; usually the highest cost per SF
Build-out	Custom, funded largely by the landlord	As-is, often furnished	Ready to use
Watch out for	Committing to more space than you need	Landlord consent and the short remaining term	Rate increases at renewal and limited privacy

Where Is the Leverage in Willowbrook Right Now?

Selectively. At 15.5%, Willowbrook is the tightest city in the corridor, so leverage comes from pricing alternatives rather than from any one landlord’s vacancy. Willowbrook competes with Burr Ridge, Woodridge and Downers Grove for the same tenants, and pricing those options against each other is the most effective lever.

What Should Tenants Negotiate on a Willowbrook Office Lease in 2026?

• Rent: target effective rent after concessions, not the asking rate.
• Free rent: 1 to 1.5 months per year of lease term, or 5 to 7.5 months on a 5-year lease.
• Tenant improvement allowance: $6 to $8/SF per year of lease term in Class A ($30 to $40/SF on a 5-year lease) and about $3 to $6/SF per year in Class B. Get build-out pricing before you negotiate this number.
• Ownership protection: a non-disturbance agreement and build-out funding that survive a sale or foreclosure.
• Operating expense caps: 4% to 6% annually on controllable expenses.
• Flexibility: expansion, contraction and sublease rights, negotiated upfront.
• Parking: included in rent for the full term with no separate escalation.

How Does Tenant Advisors Find and Tour Space in Willowbrook?

We build a shortlist from every building in Willowbrook that fits your size, budget and timing, tour the best options in one block, and negotiate with several landlords at once. The landlord pays our fee, so there is no cost to tenants.

1. Requirements call: size, budget, move date and must-haves.
2. Building survey: every option that fits, including sublease space, with rents and availability.
3. Tours: your top choices scheduled back to back.
4. Competing proposals: requests to three or more landlords, compared side by side on net effective cost.
5. Negotiation and lease review alongside your attorney through signing and move-in.

Why Do Companies Lease Office Space in Willowbrook?

Willowbrook’s office market is a small group of Class B and C buildings along Route 83, Plainfield Road and Executive Drive, minutes from I-55 and I-294. It suits smaller professional services, healthcare and financial firms that want a southeast DuPage location at some of the lowest rents in the corridor. For the full market picture, see our East-West Corridor office market page.

Frequently Asked Questions

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About the authors: Tom Koelzer (Co-Founder & Managing Partner, LinkedIn) and Dave Ven Horst (Co-Founder & Managing Broker, LinkedIn) founded Tenant Advisors, Inc. in 2004. Both have worked in Chicago office leasing since 1986, and the firm has negotiated more than 2,000 office leases, representing tenants only. Benchmark your Willowbrook lease against the market: (847) 778-0296 | tkoelzer@tenantadvisors.com.

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