What Is the Florence 1570 Series?
The Florence 1570 Series is the primary USPS-approved cluster box unit (CBU) product line manufactured by Florence Manufacturing. It is the standard replacement and new-installation CBU for outdoor applications in all Arizona climate classifications. Florence Manufacturing holds the USPS approval for the 1570 Series under USPS Engineering Standards — which means this is not a product choice, it is the specification. A property seeking USPS-compliant centralized mail delivery with a CBU installation installs a Florence 1570 Series product.
The 1570 Series comes in six primary configurations — varying by the number of tenant compartment doors and parcel locker doors — plus decorative accessory options including caps and pedestals. All configurations use the same core enclosure dimensions and mounting footprint, which means foundation specifications and anchor bolt patterns are consistent across models. The selection decision is entirely driven by the property's unit count and the USPS STD-4C parcel locker ratio requirement.
Configuration Reference
The six standard 1570 Series configurations available for Arizona installation:
| Model | Tenant Doors | Parcel Lockers | Best For |
|---|---|---|---|
| 1570-4T5 | 4 | 2 | Small clusters, replacement of aging 4-door units, supplemental stations |
| 1570-8 | 8 | 2 | Small communities up to 40 units when multiple units are grouped |
| 1570-12 | 12 | 1 | Mid-size installations; note: single parcel locker may require supplemental parcel capacity for high-volume properties |
| 1570-13 | 13 | 1 | Configurations where 13 tenant doors align with a property's unit grouping |
| 1570-16 | 16 | 2 | Larger groupings; the most common configuration for 50–100+ unit HOA properties with multiple stations |
| 1570-8T6 | 8 | 4 | High e-commerce volume properties where parcel locker capacity is the primary constraint, not tenant door count |
Parcel locker ratio requirement: USPS STD-4C mandates a minimum of one parcel locker compartment for every five tenant compartment doors. A property using 1570-16 units (2 parcel lockers per 16 tenant doors) meets the 1:8 ratio, which exceeds the minimum. A property using 1570-12 units (1 parcel locker per 12 tenant doors) is below the 1:5 minimum and requires supplemental Florence 1590 Valiant standalone parcel lockers to close the ratio gap.
Parcel Capacity Planning
The parcel locker compartments included in each 1570 Series model are the baseline capacity. In Arizona markets where e-commerce delivery volume has increased sharply since 2020, properties frequently find that the USPS STD-4C minimum 1:5 ratio — which was established before modern parcel volume levels — produces chronic overflow conditions even when the ratio requirement is technically met.
A 48-unit HOA served by three 1570-16 units has 6 parcel lockers across the three stations. The 1:5 ratio requires a minimum of 9.6 — which rounds up to 10. The property is non-compliant at baseline. Adding a standalone Florence 1590 Valiant T1 (2-locker) unit brings the count to 8, which still falls short. Adding a T2 (4-locker) configuration brings total parcel lockers to 10, meeting the compliance threshold. The right calculation for your property requires knowing your unit count, your planned CBU configuration count, and your existing or projected parcel volume — which is part of the compliance assessment Ironpost Works performs at the initial site walk.
Finish Options
The Florence 1570 Series is available in six standard powder-coat finishes, all of which meet USPS appearance standards for installation in Arizona postal service areas. Finish selection is an aesthetic decision for the property — all finishes carry the same hardware specification and USPS approval:
- Sandstone (desert tan — most common in Arizona HOA communities, blends with stucco exteriors)
- Black
- Bronze
- Platinum (light silver-gray)
- Forest Green
- Hammered Silver
In Arizona's Sonoran Desert climate, darker finishes absorb significantly more solar radiation and achieve higher surface temperatures under direct sun exposure. The 1570 Series in black or bronze finish installed without passive thermal management reaches surface temperatures 30–40°F higher than sandstone or platinum under identical summer conditions. Ironpost Works recommends passive thermal management for all installations regardless of finish selection, and particularly for dark finishes in direct southern or western sun exposure.
Decorative Pedestal and Cap Options
The Florence 1570 Series pedestal mount option includes an aluminum alloy decorative pedestal base and matching cap that enclose the structural anchor post and provide a finished appearance. The decorative set is available in all six finish colors to match the CBU body. In Arizona HOA communities with architectural requirements or covenant-controlled appearance standards, the decorative pedestal/cap set is frequently specified to match the community's architectural palette.
The decorative pedestal does not change the structural foundation requirement. The concrete foundation, anchor bolt pattern, and embedment depth specifications are determined by the 1570 Series CBU load and the Arizona soil conditions at the installation site — not by whether a decorative pedestal is installed over the structural post. A common field error is underspecifying the foundation on decorative-pedestal installations on the assumption that the pedestal carries load. It does not. The concrete specification is determined by the CBU configuration, local soil bearing capacity, and Arizona seismic zone requirements.
Foundation and Installation Requirements in Arizona
All Florence 1570 Series CBU installations in Arizona require a structural concrete foundation. Gravel, pavers, asphalt, or compacted base material do not meet the anchor requirement for a USPS-compliant installation. The foundation specification — pad dimensions, thickness, rebar, anchor bolt pattern, and embedment depth — is an engineering calculation based on the CBU configuration, the number of units being installed, the installation site's soil classification, and local building code requirements.
Arizona's Sonoran Desert introduces specific foundation challenges. Caliche — the calcium carbonate hardpan layer endemic to the Phoenix metro and much of central and southern Arizona — varies in depth and hardness across sites. Breaking through caliche to achieve proper anchor depth requires specialized equipment and adds time to the foundation phase. Sites with shallow caliche may require deeper foundation footings to achieve below-caliche bearing capacity. Sites where caliche is at or near grade may allow shallower footings if bearing capacity is confirmed by geotechnical testing. Ironpost Works addresses all foundation specifications at the engineering gate — Gate 2 of our 5-gate installation process — before any excavation begins.
ADA compliance requires that the highest operable part of any tenant compartment door in the 1570 Series installation not exceed 48 inches above the finished floor surface (28 CFR §36.304). This height is a function of both the CBU model and the concrete pad height. Ironpost Works verifies ADA reach-range compliance as a named deliverable at the final installation inspection — not as an assumed condition.
Arrow Lock Coordination
All Florence 1570 Series CBUs use USPS-specification arrow locks in the carrier access panel. New installations require the postmaster to provision the arrow lock cylinder with the correct key type for the local delivery route. This coordination — which is part of the Ironpost Works project scope on every installation — must be completed before the postmaster conducts the final compliance inspection and formally accepts the installation for delivery service. A CBU that is physically installed and structurally complete but has not completed arrow lock coordination is not operational and will not pass the postmaster inspection.