Monthly lease rates by unit size, what City of Dallas Development Services Department requires, the 139 mph Vult (Risk Category II) engineering that applies here, and the point where buying beats renting. Real numbers for budgeting, not a "call for pricing" page.
Adjusted for this metro. Rate only; delivery, set and site work are separate and listed below.
| 8' x 20' · 160 sf2-3 people · Single office, one desk plus a small table. Fits a tight urban lot. | $225$200/mo on 12 mo · $175/mo on 36 mo |
| 10' x 40' · 400 sf4-6 people · Two-room split with a lavatory option. The most-leased jobsite size. | $395$355/mo on 12 mo · $310/mo on 36 mo |
| 12' x 44' · 528 sf6-8 people · Open bullpen plus a private office. Standard superintendent trailer. | $525$470/mo on 12 mo · $410/mo on 36 mo |
| 24' x 44' double · 1056 sf12-16 people · Doublewide, two entries, restrooms. Project field office for a large GC. | $985$885/mo on 12 mo · $770/mo on 36 mo |
| 24' x 60' double · 1440 sf18-24 people · Conference room, private offices, ADA restroom. Program office. | $1,385$1,245/mo on 12 mo · $1,080/mo on 36 mo |
| 36' x 60' triple · 2160 sf28-36 people · Triple-wide complex. Owner, GC and inspector share one building. | $2,050$1,845/mo on 12 mo · $1,600/mo on 36 mo |
Budgeting estimates based on researched market rates, not binding quotes.
This is where lease budgets break. Every one of these is a real line item.
| Delivery and set (single unit, level site)Truck, pilot car when required, block and level, tie-down. Rises with distance and crane need. | $1,400 - $3,200 |
| Delivery and set (doublewide / triple)Multiple trailers, marriage line seal, crane or forklift set, interior trim-out of the seam. | $3,600 - $9,500 |
| Teardown and return freightMirrors the set cost. Budget it at lease signing, not at the end of the job. | $1,400 - $9,500 |
| Steps, landings and ADA rampWood steps are cheap. A compliant ADA ramp with handrails and a 5 ft landing is not. | $650 - $6,800 |
| Skirting and anchoring packageRequired in most wind zones and by most municipal temporary-use permits. | $900 - $4,200 |
| Utility connection (electrical, water, sewer)The single most variable line. Depends entirely on how far the nearest service point sits. | $1,800 - $14,000 |
| Damage waiver / physical damage coverageStandard on lease paper. You can often substitute your own certificate of insurance. | 8% - 14% of monthly |
DFW's growth is the driver. Industrial and distribution construction across the Alliance and airport corridors, data center development, the Plano and Frisco corporate campus buildout, and one of the fastest-growing school-district populations in the country, which puts portable classroom and district field-office demand on a recurring cycle rather than a one-time spike.
Dallas is the market where the lease-versus-buy math flips fastest, because the metro's construction cycle is long-duration. When a distribution or data center program runs three to five years, the cumulative lease cost passes the purchase price well before the job ends and ownership plus resale becomes the cheaper path.
Conventional office space in Dallas asks $33.73 per square foot per year (Partners Real Estate Q4 2024 vacancy; Newmark Q4 2024 average full-service asking rent). A 24' x 44' double modular office of 1056 square feet on a 12-month term runs about $885 per month, or $10,620 per year, which works out to roughly $10 per square foot per year including the building itself. Put differently, the annual cost of that modular building buys you about 315 square feet of conventional Dallas office space at current asking rents. If you need more than that much space for more than three years, conventional space is probably cheaper. If you need less, or you need it at a specific site, or you need it before a landlord can build out a suite, the modular building wins.
Dallas-Fort Worth shows the paradox of a soft market with rising rents: vacancy at 25.2% while average full-service asking rents climbed 8.2% year over year to $33.73. Class A space in the Far North Dallas corridors asks roughly $40 to more than $60 per square foot. High vacancy does not mean cheap space in the submarkets where the work actually is.
That comparison is the honest one, and it does not always favor the modular building. What it does favor is control. A conventional lease puts you where the space exists, on the landlord's build-out schedule, with a multi-year term. A modular building puts a working office exactly where the work is, usually inside weeks rather than months, and it leaves when the job leaves.
Authority: City of Dallas Development Services Department.
Code enforced: 2021 International Building Code with City of Dallas amendments.
Dallas enforces the IBC with local amendments through Development Services, and a temporary construction field office is handled as a temporary use tied to the active building permit. Unlike Houston, Dallas does have a conventional zoning code, so the use classification of the parcel matters and a temporary-use authorization is the normal path for a unit that sits outside an active construction permit.
North Texas design wind speeds run near 139 mph Vult for Risk Category II structures. The bigger local engineering question is not sustained wind but hail and tornado-driven debris; roof rating and anchoring specification carry more weight here than in coastal markets, and hail history drives the physical-damage waiver conversation on lease paper.
Trinity River corridor floodplain regulation and the city's drainage requirements set finished-floor elevation on low-lying parcels, which changes pier height and step count.
| Permitting authority | City of Dallas Development Services Department |
| Building code edition | 2021 International Building Code with City of Dallas amendments |
| Design wind speed | 139 mph Vult (Risk Category II) |
| Oversize permit authority | Texas Department of Motor Vehicles (TxDMV) Oversize/Overweight Permits Office |
| Freight distance from South Florida | 1,310 miles · about 19 hours |
Run the arithmetic on the 12 x 44 reference unit for this market rather than accepting a rule of thumb.
| Monthly lease rate on a 12-month term | $470/mo |
| 12 months of lease payments | $5,640 |
| 24 months of lease payments | $11,280 |
| 36 months of lease payments | $16,920 |
| Purchase price, new, same unit | $87,100 |
| Purchase price, refurbished | $51,700 |
| Lease months to equal a NEW purchase | 185 months |
| Lease months to equal a REFURBISHED purchase | 110 months |
Lease payments on that unit reach the cost of a refurbished purchase at about 110 months and a new purchase at about 185 months. Under roughly eighteen months, leasing is the right answer for most projects: you carry no resale risk and no maintenance obligation. Past thirty months you are usually paying for the unit twice, and buying leaves you holding an asset that still has resale value when the job ends.
The case for leasing past that crossover is real but narrow. It applies when the project end date is genuinely uncertain, when the unit has to disappear from the balance sheet, or when a single project budget cannot absorb a capital purchase.
I-20 west then I-45 or I-35E north is the practical route from South Florida. Any section wider than 8 ft 6 in needs a TxDMV permit, and DFW's toll-road network has clearance and routing restrictions that make the approach plan matter more than the mileage.
Before delivery, three things decide whether the set goes smoothly: a level pad with truck access and adequate turning radius, a confirmed utility connection point, and a permit on file. The most common cause of a failed delivery is not the building. It is a site nobody walked first.
Lease agreements in this industry are drafted by the lessor and the default terms favor the lessor. Every item below is negotiable, and asking before you sign costs nothing.
| What is the minimum term, and what does early termination cost? | Most agreements carry a minimum. Ending early usually triggers the balance of the term rather than a flat fee. |
| Is return freight quoted now or at pickup? | Quoted at pickup means market rate on the day, which you cannot budget. Get the number fixed in writing at signing. |
| Can I substitute my own certificate of insurance for the damage waiver? | Usually yes, and it commonly costs less than the waiver percentage applied to the monthly rate. |
| Who services HVAC and appliances during the term? | Should be the lessor on a lease. Confirm the response-time commitment, not just who is responsible. |
| What condition standard applies at return, and what counts as normal wear? | The vaguest clause in most agreements and the most common source of a surprise final invoice. |
| Does the rate escalate on renewal or month-to-month rollover? | Rollover rates are frequently higher than the original term rate. Ask for that number now. |
| Who pulls and pays for the permit? | Varies by supplier. If it falls to you, budget both the fee and the review time. |
| Is the unit engineered for 139 mph Vult (Risk Category II)? | Ask for the anchoring and tie-down specification in writing rather than a verbal assurance. |
The two that cost the most money in practice are return freight and the return condition standard. Both are quiet at signing and loud at the end of the job.
Tell us the scope and the ZIP. You get a real delivered-and-installed number, not a "contact us for pricing" runaround.