What a flex site plan has to solve
A flex park is a cluster of shallow-bay buildings, typically under 100,000 SF each, with a higher office finish than a warehouse, a mix of grade-level doors and a few dock-high doors, shared drive aisles of 24 to 26 ft and smaller bay spacing. It serves local-service, light manufacturing and small-business tenants in infill locations, and it costs more sitework per square foot and a more complex parking field than a bulk building. The demand case is in the vacancy numbers: small-bay space under 100,000 SF ran about 4.1 percent vacancy against over 10 percent for big-box, and small-bay rents carry roughly a 31 percent premium, at $12 to $15 per SF [1]. The blog's flex space as a mispriced asset class covers the investment side.
A preliminary site plan for flex is drawn tenant by tenant. The site data table items that decide whether a flex scheme works:
- Building count, bay count and the range of unit sizes.
- The office share of each bay, which drives parking.
- Door mix: grade-level and dock-high, by building.
- Car parking required against provided, and the ratio the code applies.
- Drive aisle widths, truck court depth on the loading side, and fire access.
- Outdoor storage: excluded, or carried under a permit.
- Site lighting, landscape and screening that design review will check.
The shallow-bay program
| Element | Shallow-bay and flex benchmark | Basis |
|---|---|---|
| Building size | Typically under 100,000 SF each | Flex park convention |
| Clear height | 24 to 28 ft | Benchmark for new shallow-bay |
| Truck court depth | 120 to 130 ft | Benchmark; 130 ft is the minimum functional depth for 53-ft trailers [5] |
| Dock doors | 1 per 10,000 to 15,000 SF, mixed with grade-level doors | Benchmark |
| Drive aisles | 24 to 26 ft, shared between buildings | Flex park convention |
| Car parking | 2 to 3 per 1,000 SF | Rule of thumb |
| Occupancy | B (business) or F-1 (moderate-hazard factory) | [6] |
| Sprinklers | ESFR or a wet system, under NFPA 13 | Benchmark |
| Electrical service, light industrial | 200 to 400 amp, three-phase | Rule of thumb [7] |
The bulk-building equivalents (deeper courts, higher clear heights, denser door ratios) are on the warehouse site plan page, and the zoning, coverage and stormwater context for all industrial product is on the industrial site plan page.
Bay module, office front and loading side
The flex building is drawn as a row of bays, each a tenant unit with its office at the front and its loading door at the back or side. Bay width and bay depth are set to the tenant sizes the market supports, and every bay added brings office area and the cars that come with it, so the plan tests the bay module against the parking ratio before the building outline is fixed. The front-office, rear-loading arrangement keeps visitors and cars on the street side and trucks on the service side, and it turns the office frontage toward the road.
Grade-level doors serve tenants with vans and box trucks. The few dock-high doors serve tenants that take trailers, and for those the court needs the full 130 ft that a 53-ft trailer requires [5]; a court at the shallow end of the flex range does not give it. Where two buildings face each other across a shared loading court, both loading sides draw on the same depth. Fire apparatus access still has to reach every part of each building's exterior, and the next section sets out how the shared drive aisle carries it. The blog's flexible industrial parks piece covers how office and warehouse functions are balanced inside the bay.
Fire access, sprinklers and building area
In a flex park the shared drive aisle usually doubles as the fire apparatus access road, so the fire code sets its width as much as the tenants do. IFC 503.1.1 requires an access road within 150 ft of all portions of the building exterior, measured by an approved route, and a road with a hydrant must be 26 ft wide [8]. IFC 503.2.1 sets 20 ft of unobstructed width and 13 ft 6 in of vertical clearance [9]. Under IFC Appendix D, a building over 62,000 SF gross needs two separate approved fire apparatus access roads [10], which a flex building near the top of the shallow-bay size range can reach. A 24 to 26 ft shared aisle clears the 20 ft minimum, and the 26 ft end of the range is the one that serves a hydrant road.
Dead-end drives are where flex parks most often run short, because the park road ends at the last building:
| Dead-end length (IFC Appendix D, Table D103.4) | Minimum width and turnaround |
|---|---|
| 0 to 150 ft | 20 ft, no turnaround required [11] |
| 151 to 500 ft | 20 ft, with a 120 ft hammerhead, a 60 ft Y or a 96 ft cul-de-sac [11] |
| 501 to 750 ft | 26 ft [11] |
Appendix D binds only where the adopting ordinance references it, so the city's adopted fire code is read before the park road is laid out [12].
Sprinklers follow the tenant mix. Under IFC and IBC 903.2.9, a building containing a Group S-1 occupancy is sprinklered throughout where an S-1 fire area exceeds 12,000 SF, is located more than three stories above grade plane, or the combined S-1 fire areas on all floors including mezzanines exceed 24,000 SF [13]. Small flex buildings sit close to that line: Grove City's recent approvals include a 12,000 SF building and two 6,000 SF buildings [14, 15], and IND-1 there permits public warehousing and storage beside contractors and wholesale [2], so the storage share of each building is settled before the sprinkler assumption goes on the plan.
For a larger building, IBC Section 507 allows unlimited-area one-story and two-story Group B, F, M and S buildings, other than Type V construction, when fully NFPA 13 sprinklered and surrounded and adjoined by public ways or yards not less than 60 ft wide; the yard can drop to not less than 40 ft for up to 75 percent of the perimeter where that wall carries a three-hour rating with three-hour opening protectives [16, 17]. Flex buildings are typically B or F-1 occupancies [6], so the same yard applies to a flex box that outgrows the allowable area tables.
Parking and coverage
Car parking for flex runs 2 to 3 spaces per 1,000 SF as a rule of thumb, and building coverage 35 to 45 percent, also a rule of thumb that varies by market and parking demand. The office share is the variable to watch: the more of each bay that is finished as office, the more the parking field governs the site. For office-heavy programs, the office site plan page covers the office side, and for showroom frontages, compare retail center site plans. The blog's parking ratio benchmark database sets the ratios side by side by asset type.
Codes set the ratio, not the rule of thumb. In Grove City a parking plan is required in final development plan review, and all off-street parking and loading areas, including spaces and driveways, have to be paved and adequately drained in conformance with Grove City Engineering standards, with lighting directed away from adjoining properties [18]. The parking ratios sit in GCC 1137.06 and the loading space schedule for commercial and industrial buildings in GCC 1137.07 [18, 19]; read both against the tenant mix before the building is sized.
Model project: small-bay industrial in Grove City, Ohio
The Grove City model project is 50,000 to 120,000 SF of small-bay industrial or flex on 5 to 10 acres. It is a model project: it tests a flex program against Grove City's published rules, the Codified Ordinances in the 2026 S-15 edition, to show how they shape the plan [2]. Recent Grove City flex approvals ranged from 2.24 acres (12,000 SF) to 27.41 acres (270,000 SF) [15, 20].
Zoning. IND-1 Light Industry permits SIC 15XX to 17XX contractors, 4215 courier, 422X public warehousing and storage, 47XX transportation services, 50XX wholesale and listed light manufacturing; IND-2 adds heavier manufacturing; unlisted uses go to the Planning Commission, which recommends to Council [2]. PUD-I, the planned unit development industrial district, is the alternative, with preliminary and final development plans [21]. Outdoor sales, storage and display, and mini or self storage, need a Special Use Permit in C-1, C-2, IND-1, IND-2, IND-3, CBD, PUD-C or PUD-I [2]; a storage-led program belongs on the self storage or RV and boat storage pages.
Approval path.
| Step | Body | Rule | Timing, fee and format |
|---|---|---|---|
| Pre-application | Development Department staff | Not stated | Not stated |
| Rezoning to PUD-I, if needed | Planning Commission recommendation, Council ordinance | GCC 1135.14 [21] | Not stated |
| Development Plan | Planning Commission recommends; Council approves [14, 15] | GCC Ch. 1141; 1135.09 | Monthly Planning Commission cycle, staff report issued the Friday before the hearing; one full-scale 24 x 36 set of all plan sheets [22] |
| Special Use Permit, outdoor storage | Planning Commission findings, Council ordinance | GCC 1135.09(b)(12) [2] | $100; the Commission acts within 60 days; void if not commenced within 6 months |
| Lot split, if needed | Planning Commission final action, then Franklin County | GCC 1135.08 [23] | Not stated |
| Construction stormwater | Ohio EPA | OHC000006 [4] | Notice of intent; coverage is not effective until the director's approval letter is received [4] |
| Engineering and stormwater design | City Engineering | Grove City Engineering standards | Not stated |
| Building plan approval, then certificate of occupancy | Certified building department; building official | Ohio Building Code | Not stated |
Ohio EPA's construction NOI fee is $200 for 1 to 5.99 acres, plus $20 for each whole acre above that, with a $500 maximum fee at 20 acres and up [24]. Coverage under OHC000006 applies to disturbance of 1 acre or more, or less as part of a larger common plan, and is not effective until the director's approval letter is received [4].
The Development Plan is where the preliminary plan does its work: the Commission and Council decide on the layout, the elevations, the landscape and the lighting, and the engineering drawings follow at City Engineering and building plan review. Grove City staff reports review building elevations and materials directly [14, 15], so expect the Development Plan submittal to carry:
- Full elevations of all sides, with a materials callout.
- A landscape plan.
- A photometric plan showing the 0.5 fc minimum and cutoff fixtures.
- One full-scale 24 x 36 plan set.
Design standards. Site lighting uses cutoff fixtures directing light downward, all of the same type and style, with building illumination from concealed sources and no colored or flashing exterior lights; parking lighting must hold 0.5 footcandles minimum maintained, measured at grade (GCC 1135.12; 1137.06(n)) [3]. Where a flex program includes outdoor storage, Council may condition the Special Use Permit on screening (landscaping, walls, fencing), setbacks, access, paving, hours and dust or glare controls [2], so outdoor storage adds a separate, conditioned approval to the Development Plan.
Grove City's lighting rule sits inside a wider pattern that the photometric plan has to answer. The joint IDA-IES Model Lighting Ordinance of 2011 uses lighting zones LZ0 to LZ4 and the Backlight-Uplight-Glare (BUG) rating system (IES TM-15) to limit light trespass, with a prescriptive path based on BUG ratings and a calculated performance path [25]. Municipal ordinances commonly cap average maintained foot-candles at the property line, require full-cutoff or flat-lens fixtures, and set measurement at 3.5 ft above grade on a 10 ft grid; Countryside, Illinois is one example [26].
Recent approvals.
| Project | Program | Planning Commission | Outcome |
|---|---|---|---|
| Grove City Innovation Center | Two multi-tenant flex buildings, 270,000 SF on 27.41 acres | Dec. 5, 2023 | Recommended approval to Council [20] |
| Frazier Business Center | One 12,000 SF flex building on 2.24 acres, IND-1, Haughn Road | March 5, 2024 | Recommended approval to Council with stipulations [15] |
| Grove City development plan | Two 6,000 SF buildings, IND-1, the second shown as a future phase | Jan. 2, 2024 | Staff recommended approval with stipulations [14] |
Staff found that the Frazier building will provide the city with additional flex space that can cater to smaller-scale users [15]. The Wright plan shows that phasing works on one development plan: the future building was drawn on the approved plan, to be built later [14].
Outdoor storage beside flex
Flex and outdoor storage can share a parcel. In Grove City the yard needs the Special Use Permit above. Records elsewhere show the same pairing reaching review on a dimensioned plan:
- Howell Township, Michigan reviewed the Juett Outdoor Storage preliminary site plan, dated March 25, 2025, on April 15, 2025 in its Industrial Flex zone [27].
- New Prague, Minnesota took conditional use permit C1-2025 (Bevcomm) for an 80 ft by 120 ft exterior storage area in I-1, with site plans dated Feb. 14, 2025 [28].
- Casa Grande, Arizona placed DSA-22-00148, a warehouse and storage yard for dust control materials on a 6.2-acre site, on the June 8, 2023 Planning and Zoning Commission agenda as a Major Site Plan [29]. Its narrative brings trucks in through a gated drive and over a scale, coats the yard behind the site fencing in an all-weather material, and paves the vehicle parking and entry drive with asphalt [29].
- Union County, Oregon's industrial site plan review (File 2025-0040, Subsection 20.10) requires a scaled site development plan prior to construction [30].
In Pinal County the current districts are CI-B Industrial Buffer, CI-1 Light Industry and Warehouse, and CI-2 Industrial [31], and the Pinal County model project tests an outdoor storage yard or flex program against county and Casa Grande screening rules, which fix the wall height before the yard is laid out. The industrial outdoor storage site plan page and the IOS site plan guide cover the yard as a product of its own. Where the yard is the main product, the outdoor storage section of the industrial site plan page covers it as an asset of its own.
Cost and phasing
Third-party construction ranges put light industrial at $150 to $300 per SF [32]. For comparison, Cushman and Wakefield's 2025 Industrial Construction Cost Guide puts small warehouses, measured at 109,200 rentable SF, at an average of $139 per SF [33]. Because flex needs more site work for each square foot of building than a bulk box, the site budget deserves its own line from the first plan. Phasing spreads that cost: Grove City's approvals include a second building drawn on the first plan and built later [14].
Renderings for flex
Flex and industrial renderings answer two audiences: the county or planning board, and the tenants and brokers who lease the bays. By convention, the views that carry weight are an aerial showing truck circulation, screening and buffers; the frontage from the road with the office entries; and the loading side and clear height for tenant marketing. In a city that reviews elevations and materials at the Development Plan, the frontage view is a working document as well as a leasing one. See flex and industrial rendering.
What the engineer and architect of record add
The preliminary plan settles the bay count, the door mix, the parking field, the aisles, the loading court, the screening and the site data table for the Development Plan. The civil engineer of record designs drainage to Grove City Engineering standards, prepares the stormwater pollution prevention plan behind the Ohio EPA notice of intent, and designs utilities and paving. The architect of record carries the building through building plan approval under the Ohio Building Code. In Arizona, where the Pinal model project sits, a registrant must seal documents submitted to any regulatory or review body unless the document is marked "preliminary," "draft," or "not for construction" (A.A.C. R4-30-304(D)) [34], and A.R.S. 9-500.49 as amended by HB 2447 (Laws 2025, Ch. 31) requires cities to authorize staff approval of site plans and plats without a public hearing, effective from and after December 31, 2025 [35]. Where a sealed set is required, it is built on the preliminary plan; the guide to preliminary versus final site plans sets out the sequence, and the blog's industrial site plans in the US puts flex beside warehouse and storage.
Frequently asked questions
Is warehousing permitted in Grove City's IND-1 district?
Yes. IND-1 permits public warehousing and storage (SIC 422X), along with contractors and wholesale [2].
Who approves a development plan in Grove City?
Can flex tenants store goods outdoors in Grove City?
Only with a Special Use Permit, which Council may condition on screening, setbacks, access, paving, hours and dust or glare controls [2].
What does a Grove City Special Use Permit cost, and can it lapse?
$100. The Planning Commission acts within 60 days, and the permit lapses if the use is not commenced within 6 months or stops for 6 months [2].
What lighting standard applies to a Grove City parking lot?
Cutoff fixtures, and 0.5 footcandles minimum maintained, measured at grade [3].
Can a flex park be built in phases?
Yes. Grove City has approved a development plan with a future building shown for later construction [14].
When is the Ohio EPA construction stormwater permit needed?
For disturbance of 1 acre or more, or less as part of a larger common plan, under OHC000006; coverage is not effective until the director's approval letter is received [4].
Sources
- 1)The warehousing gap squeezing America's small businesses, WareCRE (citing Cushman and Wakefield and PW Development). Accessed 2026-07-30.
- 2)Grove City Codified Ordinances 1135.09, Permitted uses, City of Grove City, Ohio (via American Legal Publishing). Accessed 2026-10-09.
- 3)Grove City Codified Ordinances, lighting provisions GCC 1135.12 and 1137.06(n), as shown at 1135.10, City of Grove City, Ohio (via American Legal Publishing). Accessed 2026-10-09.
- 4)Ohio EPA Permit No. OHC000006, Construction Stormwater General Permit, Ohio Environmental Protection Agency. Accessed 2026-10-09.
- 5)Warehouse docking design, ENCOR Advisors. Accessed 2026-07-30.
- 6)International Building Code 2021, Chapter 3, Occupancy Classification and Use, International Code Council. Accessed 2026-07-30.
- 7)Loading docks, ceiling heights and power requirements: understanding industrial property specs, WareCRE. Accessed 2026-07-30.
- 8)Fire Compliance Guide, IBC 2018 (IFC 503.1.1 fire apparatus access roads), City of Tupelo, Mississippi. Accessed 2026-07-30.
- 9)Vancouver Municipal Code 16.04.150, Adoption of amended IFC Section 503, City of Vancouver, Washington. Accessed 2026-10-10.
- 10)International Fire Code 2018, Appendix D, Fire Apparatus Access Roads (International Code Council; Wyoming edition), International Code Council (via UpCodes). Accessed 2026-07-30.
- 11)IFC Appendix D, Table D103.4, dead-end fire apparatus access roads (International Code Council; California Fire Code summary), GoCodeBook. Accessed 2026-10-10.
- 12)International Fire Code 2021, Appendix D, Fire Apparatus Access Roads (Sioux Falls Fire Code 2021), City of Sioux Falls, South Dakota (via UpCodes). Accessed 2026-10-10.
- 13)2021 South Carolina Fire Code (2021 International Fire Code), Section 903.2.9, Group S-1, International Code Council. Accessed 2026-10-10.
- 14)Planning Commission staff report, development plan (Jan. 2, 2024), City of Grove City, Ohio. Accessed 2026-10-09.
- 15)Planning Commission staff report, Frazier Business Center final development plan (March 5, 2024), City of Grove City, Ohio. Accessed 2026-10-09.
- 16)International Building Code 2021, Chapter 5, General Building Heights and Areas, International Code Council. Accessed 2026-07-30.
- 17)Unlimited area buildings in the 2021 IBC, Dalkita. Accessed 2026-07-30.
- 18)Title Three, Additional Zoning Requirements, City of Grove City, Ohio. Accessed 2026-10-09.
- 19)Codified Ordinances, General Index, City of Grove City, Ohio (via American Legal Publishing). Accessed 2026-10-09.
- 20)News Flash Archive, Planning Commission Updates (Grove City Innovation Center), City of Grove City, Ohio. Accessed 2026-10-09.
- 21)Grove City Codified Ordinances 1135.14, Planned Unit Development District, City of Grove City, Ohio (via American Legal Publishing). Accessed 2026-10-09.
- 22)Supplemental materials letter, Park and Elm final development plan, City of Grove City, Ohio. Accessed 2026-10-09.
- 23)Planning Commission staff report, Midwest Industrial Grove City lot split (Aug. 6, 2024), City of Grove City, Ohio. Accessed 2026-10-09.
- 24)Stormwater Program, Ohio Environmental Protection Agency. Accessed 2026-10-09.
- 25)Model Lighting Ordinance (IDA-IES, June 2011), International Dark-Sky Association and Illuminating Engineering Society (hosted by USGBC). Accessed 2026-07-30.
- 26)Countryside Code, outdoor lighting regulations (example municipal ordinance), City of Countryside, Illinois (via American Legal Publishing). Accessed 2026-07-30.
- 27)Site Plan Review for Howell Township, Michigan, Planning Commission addendum (Juett Outdoor Storage preliminary site plan), Howell Township, Michigan. Accessed 2026-10-10.
- 28)Conditional use permit C1-2025, Bevcomm, exterior storage area, City of New Prague, Minnesota. Accessed 2026-10-10.
- 29)Planning and Zoning Commission agenda packet, June 8, 2023 (DSA-22-00148, Desert Mountain Corporation), City of Casa Grande, Arizona. Accessed 2026-10-10.
- 30)File No. 2025-0040 staff report, Bear Creek Bridge LLC industrial site plan review, Union County, Oregon. Accessed 2026-10-10.
- 31)Pinal County Development Services Code, Chapter 2.110, CI-2 Industrial Zone (current districts CI-B, CI-1, CI-2), Pinal County, Arizona (via Municode). Accessed 2026-10-09.
- 32)2025 update: commercial construction cost per square foot in the US, A design-build contractor (cost update). Accessed 2026-07-30.
- 33)Industrial Construction Cost Guide 2025, Cushman and Wakefield. Accessed 2026-07-30.
- 34)A.A.C. R4-30-304, Use of Seals, Arizona State Board of Technical Registration. Accessed 2026-10-10.
- 35)A.R.S. 9-500.49 as amended by HB 2447 (Laws 2025, Ch. 31), chaptered text (azleg.gov), Arizona State Legislature.