Compare site layouts, unit mix and parking before detailed design

Establish the study boundary before testing a program

Begin with a validated parcel identity and available boundary. PARCIC’s site concept workflow can use the parcel geometry or a custom study area within the original parcel. A drawn study area defines where the concept is tested; it does not change ownership, create a legal lot or establish a right to develop.

Confirm the intended use and the applicable rules separately. Height, setbacks, FAR, coverage and other dimensional inputs need a documented basis. The editable concept assumptions do not overwrite official source evidence. Where essential rules are missing, an assumed concept can help explain a question, but it cannot establish permitted capacity. Keep that distinction in any saved comparison or conversation with a seller.

Select the building type and record what the quantity means

The concept tools distinguish low-detail massing, multifamily, industrial, retail, single-family, data center and hotel studies. The resulting quantity depends on the selected type: a conceptual home count, guest-room count or building area is not interchangeable. A data center mass does not establish electrical capacity; a hotel mass does not establish an approved room layout.

For supported residential and hotel programs, review the unit or room size and mix rather than accepting a headline count. Gross area includes more than rentable or saleable space. Efficiency is an entered planning assumption; corridors, cores, service rooms and a detailed floor plan still require design review.

A worked unit-mix trade-off

This fictional worksheet starts with 12,000 gross sq ft and an assumed 80% net efficiency: 9,600 net sq ft. It compares two exact area allocations. These are teaching quantities, not layouts generated or approved for a real site; they omit interior planning and do not establish density permission.

Assume, only for this exercise, one target parking space per home and an independent preliminary sketch with capacity for 15 spaces. Option A needs 16, leaving one target space unresolved. Option B needs 14, within that sketch capacity. PARCIC selects no more stalls than the target. The comparison makes B worth investigating; it does not prove parking compliance or make the larger homes financially preferable.

Check parking and circulation as geometry

PARCIC draws concept parking and circulation from the entered program and dimensional inputs. Compare target spaces with actually placed spaces. A requested count and a drawn count answer different questions: demand can exceed what the current geometry accommodates. Do not replace the unresolved target with the smaller placed count to make the option appear complete.

Inspect stall sizes, drive aisles, access and the relationship to buildings and roads. A modeled road width or centerline turning radius is an assumption, not an approved fire-access design or a vehicle swept-path analysis. Loading, pedestrian routes, visibility and agency access requirements need their own review.

The U.S. Access Board’s parking guide explains why accessible parking includes more than a space count: access aisles, accessible routes, location, surfaces and vertical clearances can matter. Applicability varies with the facility. A concept drawing does not certify those requirements or replace the governing local review.

Use 2D and 3D to inspect the same option

Switching view should change the presentation, not the program. Compare the footprint and parking in 2D with the building mass and story assumptions in 3D. Check the selected scheme before reading quantities or exporting a saved study. A perspective image can communicate an option, but it cannot establish neighboring conditions or a planning approval.

Where retrieved USGS point elevations are available, treat them as terrain context. USGS explains that the point service interpolates elevations from its source data and does not return precisely measured ground-survey values. Sparse samples are not a surveyed terrain surface. PARCIC does not turn them into measured cut-and-fill volumes or a drainage design.

Compare bounded options, then brief the design team

The saved study can test up to three distinct bounded programs. These are alternatives within the entered assumptions, not proof of a global optimum or highest-and-best use. When the inputs produce fewer distinct options, fewer useful schemes are preferable to duplicated drawings.

Use Notes & markups to record the decision each option tests: “smaller footprint,” “larger homes” or “access retained.” Record why it differs and keep its costs linked to that geometry. If you change the boundary, building type or layout, review the recalculated outputs and financial assumptions before comparing again.

Give your architect or civil team the chosen version, evidence references, inputs and remaining questions. Ask them to verify the site-specific constraints and turn the concept into an appropriate design. The early study is valuable when it makes that next review more focused, even if the answer is that a different program is needed.

Official references

• U.S. Access Board: Guide to the ADA Standards, parking spaces

  Explains accessible parking scoping and design considerations. A PARCIC concept is not an accessibility determination.

  Reference retrieved 2026-10-18. This date does not establish a rule’s effective date or a property’s eligibility.
• USGS: Accuracy of Elevation Point Query Service elevations

  Explains interpolated elevations and the distinction from ground-survey measurements. It does not establish terrain accuracy at a particular study site.

  Reference retrieved 2026-10-18. This date does not establish a rule’s effective date or a property’s eligibility.