Program Versus Envelope on an Infill Site
A 0.9-acre (39,200 sf) infill parcel is under contract for a medical office building. Zoning allows FAR 0.85, a 45 ft height limit, and requires 1 parking space per 400 sf of gross floor area. Setbacks leave 33,000 sf of the site usable for building and parking. The client's program: 19,000 sf net of clinical space, 4,300 sf net of administration, and 2,000 sf of building support (mechanical, electrical, storage) that counts directly in gross area. Your planning benchmarks give 62% efficiency for clinical space because of exam room and corridor ratios, and 85% for administration. Three stories at 14 ft floor-to-floor fit under the height limit. Surface parking, including drive aisles, consumes about 350 sf per stall. The client wants a schematic layout in three weeks.
1. Calculate the gross building area and parking demand. Does the program fit?
Read the worked answer
Apply each block's own efficiency, and do not pass building support through an efficiency factor.
- Clinical: 19,000 / 0.62 = 30,645 gross
- Administration: 4,300 / 0.85 = 5,059 gross
- Support: 2,000 gross
- Total: 37,704 gross
FAR test: 39,200 x 0.85 = 33,320 allowed, so the program is 4,384 sf over (13%).
Parking: 37,704 / 400 = 95 stalls required. Footprint at three stories = 37,704 / 3 = 12,568 sf; parking area = 33,000 - 12,568 = 20,432 sf / 350 = 58 stalls. Shortfall: 37.
Even at the code maximum, 33,320 gross requires 84 stalls with an 11,107 sf footprint, leaving 21,893 sf of parking for 62 stalls - still short 22.
The conclusion is not simply that the program is too big. It is that area reductions alone will not solve the parking, because the parking ratio is tied to the same gross area you are cutting.
2. Recommend a strategy. Show the arithmetic for at least two options and state what you would reject.
Read the worked answer
A combined strategy closes both deficits; a single move does not.
- Challenge the 0.62 efficiency first. A two-sided, same-handed exam module with shared sub-waiting typically reaches 0.66-0.68. This is a design claim that must be proven with a test fit, not assumed.
- Cut 1,700 sf net of clinical space from the lowest-volume service line, not from the exam rooms that generate visits.
- Result: 17,300 / 0.66 = 26,212 + 5,059 + 2,000 = 33,271 gross, 49 sf under the 33,320 cap.
- Parking: 84 required; 33,271 / 3 = 11,090 footprint; 21,910 sf / 350 = 62 stalls. Lease or share 22 stalls.
Reject: (1) seeking a variance as the primary strategy - it costs a year you do not have; (2) a fourth story - the 45 ft limit allows three at 14 ft; (3) a shared-parking agreement with the adjacent medical office without a demand study - its peak is the same weekday morning peak, and overlap, not total count, decides whether sharing works; (4) fixing FAR by squeezing circulation, which is where the 0.62 came from in the first place.
Price the alternative honestly: 22 stalls at roughly $30,000 each in a podium is about $660,000, against the revenue from the exam rooms you would otherwise cut.
3. What do you need from the client, and what would you verify, before committing the fee to this strategy?
Read the worked answer
The strategy depends on two claims that are currently assumptions.
Verify internally:
- Draw the 0.66 exam module as a test fit before promising it. If it fails, the FAR problem returns and the program cut grows from 1,700 to roughly 4,400 net sf.
- Test the three-story massing on the site plan with the actual setback envelope, not the 33,000 sf area number.
Get from the client:
- Whether 19,000 net is driven by provider count or room count - 1,700 sf is roughly 10 exam rooms at about 165 sf each including corridor share. What visit volume does that support?
- Peak parking demand by hour, staff versus patient, and counts from the adjacent garage - a shared-parking study, not a handshake.
- Capital tolerance for structured parking, and whether the adjacent parcel or garage can be leased or bought.
- Whether the practice can tolerate a phased second floor later if volumes grow.
Frame the decision for the client as three priced options: fewer exam rooms, roughly $660,000 of structured parking, or a documented parking reduction with leased stalls. Do not spend the three schematic weeks until the client picks one.