Airtightness Test Planner is a free, single-file tool for preparing whole-building airtightness test plans. Open a construction drawing PDF (or drag one in), and use the app to mark up the test boundary, fan locations (any TEC or RetroTec model), interior and exterior envelope reference tubes, temporary seal locations, area measurements for surfaces or zones of interest, network-communication paths, notes, and more. Manometers can be placed and connected to fan and reference lines with simple drag-to-snap behavior — channel assignments stay live and labeled.
Use the Calibrate Scale tool to set a per-page drawing scale by drawing a two-point ruler over a known dimension. Once calibrated, the app computes lengths, perimeters, and enclosed areas for every drawn feature, surfaces them on hover and in the Component Summary, and includes them as latent fields in the exported config.
When the plan is ready, export it as a high-resolution PNG, a multi-page PDF (with an auto-generated Component Summary appended), or a slim .atp-config.json file: a manufacturer-agnostic test-setup handoff that test software like TECLog or FanTestic can import to seed a session — no more re-typing channel assignments on site.
Click Open PDF (or drop a file anywhere on the workspace). Multi-page PDFs load every page — use the ◀ ▶ arrows or PageUp/PageDown to move between them. Each page keeps its own annotations and undo history.
| Select & Move | Click to select; drag to reposition; double-click to edit text on manometers and callouts. Drag empty space to pan. |
| Test Boundary | Click to add a boundary around the tested area. Return the line to the first point (or double-click) to close the polygon. |
| Area Measurement | Like Test Boundary, but for marking arbitrary regions you want to measure (heated area, conditioned area, surface area of interest, etc.). Closed polygon; pick a line color from the palette in the labeling popup. |
| Calibrate Scale | Draw a two-point ruler over a feature of known length on the drawing (a dimensioned wall, a stair tread, etc.), then enter the real-world length and unit (ft / in / m / mm). Once calibrated, every other annotation shows length / perimeter / area on hover and in the Component Summary. One calibration per page; drawing a new ruler replaces the old one. The ruler stays visible as a dashed reference, but is not included in PNG / PDF exports. |
| Fan | Multi-point red line for any air-moving device — a blower-door fan, duct blaster, or other. Drag the endpoint near a manometer port to snap to a channel. The labeling popup includes a Fan Model dropdown (TEC and RetroTec models) that drives the channel type in the exported config. |
| Exterior Reference | Green line indicating an exterior envelope reference tube. |
| Interior Reference | Blue line with arrowhead indicating an interior envelope reference tube. |
| Network Communication | Yellow multi-point line designating a network communication channel between computers, manometers, and/or devices. Small yellow squares appear at each end — double-click the line (or either end square) to fill in start and end labels (e.g. 'WiFi from computer', 'Cat5 to manometer 467'). |
| Temp Seal Area | Click & drag to draw a dashed ellipse marking a temporary seal (door, vent, damper, etc.). |
| Manometer | Places a dual-channel unit with four ports (A-Input, A-Ref, B-Input, B-Ref). Enter its serial number. Connected lines follow the manometer when moved. Drag a corner to resize. |
| Text Callout | Adds a yellow note with a leader line. Drag the dot to relocate the leader endpoint. Drag a corner to resize. |
| Computer | Drops a computer icon — use to mark the PC or laptop running the testing software. No label. Drag a corner to resize. |
| Device | Drops a small black-box device — use for an ethernet switch, Wi-Fi repeater, or similar. Double-click to label. Drag a corner to resize. |
| Place Key / Legend | Drops a KEY legend box onto the plan, auto-populated with the symbols you've used. Drag a corner to resize it. |
| Place Component Summary | Drops a spreadsheet-style summary table listing every labeled component on this page: manometers with their 4-channel port assignments (blank channels show as “Ambient”), fans, reference lines, network communications, and test boundary — each with its label and location. Drag a corner to resize. |
| Compass Rose | Drops a compass rose with cardinal N/E/S/W labels and a blower-door icon at the center. Drag the orange tether handle to rotate N to match the plan's actual north (hold Shift for 15° snaps). Drag the corner to resize. |
| Shift (hold) | Lock your in-progress drawing line to 0° / 90° from last point. While rotating a compass rose, snaps rotation to 15° increments. |
| Space (hold) | Pan the view while dragging. |
| Scroll wheel | Zoom in / out, centered on the cursor. |
| Esc | Cancel an in-progress line or boundary. |
| Delete / Backspace | While drawing: remove the last point placed. Otherwise: delete the selected item. |
| Ctrl+Z / Ctrl+Y | Undo / Redo (per page). |
| PageUp / PageDown | Previous / next page. |
| 1–0, A, C, D, E, R, S | Quick-switch tools: 1 select, 2 boundary, 3 fan, 4 ext ref, 5 int ref, 6 seal, 7 manometer, 8 callout, 9 computer, A area measurement, R calibrate scale (ruler), D device, E network communication, 0 key, S summary, C compass. |
Save Project writes a single self-contained .atp.json file containing the loaded page bitmaps and every annotation in their current state. To pick up where you left off, just open that .atp.json file the same way you would a PDF — drag-and-drop, or click Open PDF and pick the project file. Every icon comes back live and editable, with its labels and connections intact. Undo history is reset on reopen.
Export PNG saves the current page as a high-resolution image, plus a separate -component-summary.png tabulating every labeled component (if any labels have been added). Export PDF writes only the marked-up pages from the loaded PDF into a single export (blank passthrough pages are skipped) and automatically appends a Component Summary page at the end. Ready to share with the client, GC, or field crew.
Export Config writes a slim, manufacturer-agnostic JSON file (.atp-config.json) describing the test setup — manometers and their port assignments, fans, reference lines, and any test boundaries / area measurements. It's designed so the test-software vendors (TECLog, FanTestic, etc.) can each write their own importer against a single stable, versioned schema. No bitmaps, no UI ornaments, just the plan. The schema is versioned (version: 1 at this build) and breaking changes will bump the version number.
Airtightness Test Planner was developed by Green Mountain Enclosure Consulting LLC. The app is designed for building enclosure consultants, BECx service providers, and anyone else who wants to execute well-planned, well-documented building airtightness tests.
Build V1.3
This tool is free. We've put a fair amount of time and thought into its development — if it has saved you an hour or few, a donation would be welcome: ☕ Buy me a coffee.
Feedback & feature requests are always welcome.
This tool is free and ad-free, built and maintained on nights and weekends. If it's saved you time on a test plan, a small tip helps keep it that way — no subscriptions, just a one-time thank-you.
☕ Buy me a coffee