TestFit for Architects: AI-Powered Feasibility Studies and Building Configuration

Feasibility studies in real estate development have always been tedious. An architect receives a site, a zoning envelope, and a developer’s wish list, then spends days or weeks manually testing configurations. How many units fit? Does the parking work? What happens if the unit mix shifts from one-bedrooms to two-bedrooms? Each question means redrawing plans, recalculating areas, and updating spreadsheets. TestFit replaces that cycle with a real-time building configurator that generates optimized site plans in seconds, letting architects and developers explore hundreds of scenarios before committing to a single design direction.

This guide walks through what TestFit actually does, how its algorithm works under the hood, and how architects can integrate it into feasibility workflows for multifamily, mixed-use, and other development types.

What TestFit Is and Why It Matters

TestFit is a cloud-based building configurator designed for real estate feasibility analysis. You define a site boundary, set zoning constraints, choose building typologies, and the software generates optimized building configurations in real time. Unlike traditional CAD-based feasibility studies where every option requires manual drafting, TestFit uses algorithmic generation to produce layouts that satisfy your constraints simultaneously - unit count, parking ratios, setbacks, FAR limits, and financial targets.

The platform sits at the intersection of architecture and real estate development. It does not replace detailed design tools like Revit or ArchiCAD. Instead, it occupies the critical pre-design phase where the question is not “what does the building look like?” but “does this project even work?” For architects who regularly do feasibility work for developer clients, TestFit compresses what used to take a week of study into an afternoon of exploration.

TestFit was founded in Dallas, Texas, and has grown steadily since its launch. The platform now serves architecture firms, developers, and general contractors across North America, with expanding use in Europe and Asia-Pacific markets.

How the Algorithm Works

TestFit’s core engine is a constraint-satisfaction solver combined with generative algorithms. Understanding how it works helps you get better results and interpret its output correctly.

When you input a site boundary and constraints, the algorithm works through several layers simultaneously:

Site-level optimization. The solver considers the parcel shape, setback requirements, easements, and access points. It determines where buildings can physically sit on the site and how vehicular and pedestrian circulation routes connect to adjacent roads.

Building footprint generation. Based on the typology you select (podium, wrap, slab, courtyard, L-shape), the algorithm generates footprint options that maximize buildable area while respecting your constraints. It tests multiple orientations and configurations, scoring each one against your target metrics.

Unit packing. This is where TestFit’s algorithm is most distinctive. Once a building footprint is established, the solver packs individual units into the floor plate. It handles corridor routing, core placement (stairs, elevators), and unit orientation. The algorithm respects minimum unit dimensions, window requirements for habitable rooms, and adjacency rules.

Parking integration. The solver simultaneously calculates structured or surface parking. For podium buildings, it determines how many levels of parking are needed below the residential floors. For surface lots, it lays out stalls with drive aisles and calculates the land consumed by parking versus building.

The key insight is that all of these layers run together. When you change one variable - say, increasing the parking ratio from 1.0 to 1.5 stalls per unit - the algorithm instantly regenerates the entire configuration, adjusting building footprint, unit count, and floor plate layout to accommodate the change.

Setting Up a Project and Defining Site Constraints

Starting a new feasibility study in TestFit follows a structured workflow. Here is how a typical project setup looks in practice.

Importing the Site

You begin by defining your site boundary. TestFit offers several options:

1. Address search - Type the property address, and TestFit pulls the parcel boundary from public GIS data
2. Drawing tools - Manually draw the site boundary on the integrated map
3. DXF/DWG import - Upload a survey or site plan from your CAD software
4. Shapefile import - For larger land parcels with complex boundaries

For most urban infill sites, the address search works well. The platform pulls parcel geometry and overlays it on satellite imagery, giving you immediate spatial context including neighboring buildings and street access points.

Defining Zoning and Setbacks

Once the site boundary is established, you input zoning parameters:

• Setbacks - Front, side, and rear setbacks in feet or meters
• Height limits - Maximum building height (stories or absolute height)
• FAR (Floor Area Ratio) - Maximum allowable floor area relative to lot size
• Lot coverage - Maximum percentage of the site that buildings can cover
• Easements - Utility or access easements that restrict buildable area

TestFit visualizes these constraints as overlays on the site plan. The buildable envelope shrinks in real time as you add restrictions, giving you an immediate sense of what the zoning allows before any configuration runs.

Setting Access and Circulation

You mark vehicular entry points along the site perimeter. This tells the algorithm where drive aisles and parking access must connect. You can also mark pedestrian access points, which influences building entry placement and walkway routing. For corner lots or sites with multiple street frontages, getting the access points right is critical because they fundamentally shape how the algorithm organizes the site.

Unit Mix and Floor Plate Optimization

The unit mix is where TestFit becomes genuinely powerful for architectural feasibility work. Instead of manually testing “what if we add more studios?” by redrawing floor plates, you adjust sliders and watch the configuration update instantly.

Defining Unit Types

TestFit comes with a library of standard unit types (studio, 1-bed, 2-bed, 3-bed) with default dimensions. You can customize these or create entirely new unit types with specific dimensions, square footage targets, and bathroom counts. Each unit type has configurable parameters:

• Net square footage range (minimum and maximum)
• Width and depth constraints
• Number of bedrooms and bathrooms
• Whether the unit requires an exterior wall (for windows/balconies)
• Balcony or patio dimensions

Adjusting the Mix

The unit mix panel lets you set target percentages for each unit type. A typical multifamily project might start with something like 20% studios, 40% one-bedrooms, 30% two-bedrooms, and 10% three-bedrooms. As you move these sliders, the algorithm repacks every floor plate in the building, adjusting corridor lengths, core positions, and unit orientations to fit the new mix.

This is where the time savings become dramatic. In a manual feasibility process, changing the unit mix means redrawing floor plans, recounting units, recalculating areas, and updating the pro forma spreadsheet. In TestFit, the entire chain updates in seconds.

Corridor and Core Efficiency

TestFit tracks the ratio of net leasable area to gross floor area. As the algorithm packs units, it reports the efficiency percentage. A well-configured floor plate typically achieves 80 to 88 percent efficiency. If the algorithm produces a layout with low efficiency, it usually means the building shape or core placement needs adjustment. You can manually reposition cores or switch to a different building typology to improve the ratio.

Parking Configuration and Ratios

Parking is often the constraint that kills a project. TestFit handles both structured and surface parking with enough detail for feasibility-level analysis.

Structured Parking (Podium and Below-Grade)

For podium buildings, you specify the number of parking levels and whether they are above or below grade. The algorithm calculates stall counts per level based on the building footprint, accounting for ramps, drive aisle widths, and structural column grids. Below-grade parking is significantly more expensive to build, so TestFit tracks the parking construction cost separately from the residential floors.

You set the parking ratio (stalls per unit), and the algorithm determines whether your configuration meets the requirement. If it does not, you will see a deficit flag, prompting you to either add parking levels, reduce unit count, or adjust the building footprint.

Surface Parking

For suburban sites or garden-style apartments, TestFit lays out surface parking lots with standard stall dimensions and drive aisle widths. The algorithm balances parking area against building footprint, showing you exactly how much site area each component consumes. This trade-off is critical in suburban development where land cost is lower but parking requirements are higher.

Tandem and Mechanical Parking

TestFit supports tandem stalls and can model mechanical parking systems for dense urban sites where conventional structured parking does not fit the footprint. These options carry different cost assumptions that flow into the financial model.

Financial Metrics and Pro Forma Integration

TestFit is not just a geometry tool. It connects building configuration directly to financial performance, which is what makes it genuinely useful for developer-architect conversations.

Built-in Financial Metrics

The platform calculates and displays key development metrics in real time:

• Total unit count and breakdown by type
• Net rentable square footage (total and per unit type)
• Gross building area and efficiency ratio
• Construction cost estimate (using configurable cost per square foot)
• Land cost per unit (based on input land price)
• Parking cost (separate line item for structured vs. surface)
• Revenue projections (based on rent per square foot by unit type)
• Yield on cost - the ratio of stabilized net operating income to total development cost

Customizing Cost Assumptions

You input cost assumptions that reflect your local market. Hard construction costs, soft costs, land price, parking construction cost per stall, and expected rents are all configurable. TestFit applies these to the generated configuration, so when you change the unit mix or add a parking level, the financial impact is immediately visible.

Scenario Comparison

One of TestFit’s most practical features for architects is the ability to save and compare multiple scenarios side by side. You might create three versions: a five-story podium with 1.0 parking ratio, a four-story wrap with 1.5 ratio, and a seven-story tower with below-grade parking. Each scenario shows its unit count, efficiency, construction cost, and projected yield. Presenting these comparisons to a developer client turns a subjective design discussion into a data-driven conversation.

Multifamily and Mixed-Use Workflows

TestFit’s strongest capabilities are in multifamily residential, but it handles several building types relevant to architectural practice.

Multifamily Residential

This is TestFit’s core use case. The platform handles garden-style (walk-up), podium, wrap (parking wrapped by units), and mid-rise slab configurations. For each typology, the algorithm understands the structural logic, circulation patterns, and unit packing rules specific to that building type.

A typical multifamily workflow in TestFit follows this sequence: import site, set zoning constraints, select building typology, define unit mix, set parking ratio, review financial metrics, adjust and iterate, export. The entire process for a straightforward site takes 30 to 60 minutes to produce several viable scenarios.

Mixed-Use Projects

For mixed-use configurations, TestFit allows you to designate ground-floor retail or commercial space. You set the depth and ceiling height for commercial floors, and the algorithm adjusts residential floors above. The solver accounts for the different structural grids and floor-to-floor heights that mixed-use buildings typically require.

Hotel and Student Housing

TestFit has expanded beyond standard multifamily to include hotel room packing and student housing configurations. The unit types and packing logic differ (hotel rooms are smaller and more uniform, student housing often uses suite-style layouts), but the fundamental workflow is the same.

How TestFit Compares to Manual Feasibility Studies

To understand TestFit’s value, consider the traditional feasibility workflow it replaces.

Manual process (typical timeline: 1 to 3 weeks):

1. Receive site information and zoning summary from developer
2. Draft a test-fit plan in CAD (1 to 3 days per option)
3. Calculate areas manually or with CAD measurement tools
4. Enter area data into a separate Excel pro forma
5. Developer requests changes to unit mix or parking
6. Repeat steps 2 through 4 for each revision
7. Compile options into a presentation

TestFit process (typical timeline: 1 to 4 hours):

1. Import site and set constraints (15 minutes)
2. Generate initial configurations (instant)
3. Adjust unit mix, parking, and typology interactively (30 to 60 minutes)
4. Review integrated financial metrics (no separate spreadsheet)
5. Save 3 to 5 scenarios and export comparison (15 minutes)

The time compression is significant, but the bigger advantage is exploration breadth. In the manual process, architects typically test 2 to 3 options because each one costs days of effort. With TestFit, testing 10 or 20 variations costs no additional time, which means you are far more likely to find the optimal configuration.

Revit Export and Integration with Design Tools

TestFit generates feasibility-level geometry, not construction documents. When a project moves from feasibility to schematic design, you need to bring the selected configuration into your primary design tool.

Exporting to Revit

TestFit offers DWG and Revit export options. The Revit export creates a basic model with floor plates, unit boundaries, and core locations. It is not a detailed Revit model with families and assemblies. Think of it as a starting framework that gives your design team the massing, floor plate geometry, and unit layout to begin refining in Revit.

The exported geometry typically includes building footprints as floor elements, unit boundaries as room separation lines or areas, core locations marked with placeholder elements, and site plan with parking layout.

Working with the Export

Architects who use TestFit regularly report that the Revit export saves about a day of setup work at the start of schematic design. Instead of building the floor plate from scratch, you import the TestFit layout and begin refining unit plans, adding wall assemblies, and developing the building envelope. The proportions, unit count, and parking already work because they were validated during the feasibility phase.

DWG and PDF Export

For presentations and initial client discussions, TestFit exports site plans and floor plates as DWG files or PDFs. These are clean enough for feasibility presentations but are not intended as construction-level drawings.

Pricing and Plans

TestFit uses a subscription pricing model. As of early 2026, the platform offers several tiers:

• Starter - Limited to basic multifamily configurations with a capped number of projects
• Professional - Full access to all building types, financial modeling, and export features
• Enterprise - Custom pricing for larger firms with multiple users, API access, and priority support

Pricing is not publicly listed on the website for all tiers. You need to request a demo to get current pricing for Professional and Enterprise plans. The platform offers a free trial period that gives you enough time to test it on a real project.

For firms that do regular feasibility work, the subscription cost typically pays for itself within one or two projects through time savings alone. A single feasibility study that previously took a week of billable time can be completed in a few hours.

Who Benefits Most from TestFit

TestFit is not for every architect. It delivers the most value in specific practice contexts.

Architects working directly with developers. If your firm regularly produces test-fit studies and feasibility analyses for developer clients, TestFit is a direct productivity multiplier. The ability to explore more options in less time makes your feasibility services more valuable and more profitable.

Design-build firms. Companies that handle both design and construction benefit from TestFit’s integrated cost estimation. The feasibility phase directly informs construction budgeting.

Large firms with dedicated pre-design teams. Firms that have staff focused on site analysis and feasibility can standardize their workflow around TestFit, creating consistent deliverables across multiple projects.

General contractors evaluating sites. GCs who need to quickly assess whether a site can support a viable project use TestFit to run initial numbers before engaging an architect.

Firms focused on single-family or custom residential work will find less value in TestFit. The platform is optimized for repetitive unit types and multi-unit configurations. Bespoke design projects do not benefit from algorithmic unit packing.

Limitations and What TestFit Does Not Do

TestFit is powerful within its scope, but understanding its boundaries prevents misuse and disappointment.

It is not a design tool. TestFit generates configurations, not architecture. The output tells you that 180 units fit on this site with 1.2 parking ratio. It does not tell you what the building should look like, what materials to use, or how the facade should be articulated. Design happens after feasibility, in Revit or your preferred tool.

Unit plans are schematic. The unit layouts TestFit generates show room proportions and approximate dimensions, but they are not detailed floor plans. Kitchens, bathrooms, and closets are represented as zones, not as fully designed rooms. You will refine these in schematic design.

Local code nuances may not be captured. TestFit handles standard zoning parameters (setbacks, FAR, height limits), but unusual local requirements - specific fire separation rules, accessibility mandates beyond standard codes, or overlay district restrictions - may need manual verification.

Cost estimates are rough. The financial metrics are useful for comparing scenarios and screening projects, but they are not construction estimates. They use cost-per-square-foot assumptions that vary significantly by market, building type, and time. Always validate TestFit’s numbers against local cost data.

Limited structural analysis. TestFit does not perform structural engineering. It assumes standard construction types (wood frame over concrete podium, for example) but does not analyze specific structural requirements.

Best Practices for Architects Using TestFit

After working with the platform across multiple project types, these practices consistently produce better results.

Start with accurate zoning data. TestFit’s output is only as good as the constraints you input. Spending 30 minutes verifying setbacks, height limits, and FAR before running the algorithm prevents false starts.

Use multiple typologies. Do not default to a single building type. Run the same site with a podium, a wrap, and a courtyard configuration. The results often surprise you - a typology you would not have considered manually sometimes produces the best yield.

Calibrate costs to your market. Update the default cost assumptions with data from recent local projects. Generic national averages can distort the financial comparison between scenarios.

Save scenarios systematically. Name your scenarios clearly (for example, “5-story podium 1.0 park” versus “4-story wrap 1.5 park”) so the comparison export is immediately readable by developer clients.

Present scenarios as a range. Rather than recommending a single option, present 3 to 5 scenarios that show the trade-offs between unit count, parking, construction cost, and yield. This positions you as a strategic advisor, not just a draftsperson.

Validate with a quick CAD check. Before presenting TestFit results to clients, spot-check one floor plate by overlaying it in CAD. Confirm that the unit dimensions are realistic and that corridor widths meet code. TestFit is accurate at the feasibility level, but a quick sanity check builds confidence.

Getting Started with TestFit

If you want to explore TestFit, the most practical approach is to request a demo through their website and then test it on a real project during the trial period. Feasibility tools are difficult to evaluate in the abstract. You need to see how the algorithm handles a site you already know - one where you have done the manual work and can compare results.

For architects building broader AI and technology skills for practice, our course catalog at Archgyan Academy covers computational design tools, BIM automation, and technology integration for AEC professionals.

TestFit represents a specific category of AI in architecture - not the flashy image generation tools that dominate social media, but the practical algorithmic tools that directly improve how firms deliver services. For architects involved in feasibility work, it is one of the highest-ROI technology investments available today.