301 W Osborn: an office tower conversion that locked the permit path first

What it is

301 W Osborn, marketed as Lief Midtown, is a four-story cast-in-place concrete office tower from 1971 on a corner parcel in Midtown Phoenix, with a large subterranean garage. A broker reached out about it, Fowler walked it, and LÏEF Development put it under contract for $3.85M in December 2024 and closed in September 2025. The plan is 22 for-sale luxury condominiums with twelve-foot ceilings over a 51-stall garage.

It is LÏEF's own project, with Fowler as Principal running acquisition, entitlement and pre-development directly. Three things made the default path of a full-service architecture firm and the standard queue wrong for this building: the parcel's C-1 H-R zoning put a question mark over the whole program, the outside quotes for the same scope came in far enough apart that the number had stopped describing the work, and on a conversion the city's plan-review queue is a larger risk than any single code question.

What Common Ground did

• Settled zoning first. The city's zoning confirmation in April 2025 and a written plan-check recap in May 2025 confirmed multifamily by right, with no rezone, variance or hearing, before any design work started.
• Locked the permit classification before the unit count: an existing-building Level 3 alteration under the IEBC with a change of occupancy from Group B office to Group R-2 residential, the exact case Phoenix's self-certification program is built for. There a registered architect of record certifies the set and the permit issues in one to five business days instead of going through the standard queue. Only then was the program locked: six residences on each of the two lower floors and five on each of the two upper, from 871 to 2,101 SF each.
• Filed the fire-access appeal in December 2025, months ahead of the certification packet, after the city's October 2025 site-plan comments raised it, so it could not stall the one step the path depends on. The 83-page packet was assembled with fill, page and assembly scripts rather than by hand, in days instead of weeks.
• Kept the architect of record for the stamp and the certification, and built the Revit model in house: fourteen specialist skills driving a 138-tool connection into Revit, and a model that reached 12,684 elements. The agentic tools carried roughly 40 percent of the architectural work. Against outside quotes of $300,000 to $400,000 for the same scope, the in-house direct spend was about $12,000, a differential of roughly $150,000 before the team's own hours.
• Rebuilt the quality check an outside firm would have provided instead of skipping it: the model's geometry is exported and checked by agents against code parameters and the project's design criteria, and a person clears every flagged item. The check flagged two errors, a wrong building setback among them, before a person reviewing alone would have had to. An earlier version of the model that carried geometry from an unrelated building's set was ruled out before it shipped.
• Commissioned an independent owner-side code study the day after a July 2026 project meeting found no complete code study had ever been finished: 89 pages, every finding cited to a code section and a sheet, the critical findings handed to the architect pre-cleared. Among them, the plan set's title block carried another parcel's address, the exit-stair separation looked short of the code distance, the construction type was stated three inconsistent ways, and an elevator cab fell short of the ambulance-stretcher minimum.
• Handed the architect of record a 182-file, nine-section packet in June 2026 and turned it into a reusable ten-item template for the next handoff.
• Sold the building's rooftop telecom lease after turning down the buyer's opening ask for an 85-year easement across the entire roof. The grant was cut to the carrier's equipment footprint and closed in April 2026, with the proceeds paid at closing and the rest of the roof kept for the conversion's equipment, amenity space, a future carrier or solar.
• Caught, through outside counsel, a perpetual 2.5 percent match payment on investor distributions buried in an architect's profit-sharing note. That contract was never signed.
• Built the project's data room in June 2026 with every link checked by hand, ran a completeness audit in July that staged what the room was missing and corrected three claims that had drifted from the record, and re-audits it each time the project moves.

Results

• Multifamily confirmed by right, with no rezone, variance or hearing.
• A self-certification packet assembled for the architect of record to certify, on a path that issues a permit in one to five business days.
• An in-house model and review pipeline in place of the outside pre-development scope, roughly $150,000 under the outside quotes, with the stamp kept and nothing that carries liability cut.
• A rooftop grant scoped to the equipment footprint, paid at closing, with the rest of the roof retained.
• The residential floors run at 89.5 percent efficiency, and the projected sellout is $30M+. The entitlement and design work is complete, temporary construction is done, and capital is still being raised.

External links

• Official website: Lief Midtown
• Public data room: 301 W Osborn data room

Public record

• LÏEF Development
• Lief Midtown Look Book

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