Capture a Room-by-Room Heat-Load Scan with the Reonic App

The Heat Load Scan in the Reonic Mobile App is the field-capture side of room-wise heating design. You point your iPad at each room, the device's LiDAR sensor builds a 3D model, and Reonic turns that model into a structured room record: dimensions, walls, openings, ceiling and floor boundaries, plus the heating system for each room. The structured record is what the heat-load calculation uses. The 3D model is what backs the customer-facing visualisation in the offer. When LiDAR isn't an option (an Android device, an older iPad, a site that can't be scanned), you build the same room records by hand. The calculated result is identical either way. Only the 3D view changes.

This guide covers the capture side: what to do on the iPad, what to fix on-site, what to expect when you build rooms by hand. The downstream review-and-calculate step happens in the Portal. See Run the room-wise heat-load calculation for that side of the workflow.

Before You Start

• The project must already exist in Reonic: an energy-house request or residential offer with the customer's address and basic data filled in. Start the scan from an existing project.
• The Heatload tab must be available on the project. It attaches to heat-pump / heat-load projects when your workspace has heat-load enabled. If the tab is missing, contact your Reonic account manager.
• Bring an iPad Pro or iPhone Pro with a LiDAR sensor. See Devices That Support LiDAR Scanning below.
• Charge the device. LiDAR scanning is battery-intensive: expect 40 to 60 % drain over a full house.
• Get the customer's go-ahead to walk every room. The scan captures the property layout, including bedrooms and basements.
• Confirm the country mode on the project. Germany uses DIN-EN-12831. The UK uses a parallel UK calculator. Country is set on the request and drives which material lists you see.

Note: If a capture or save step does nothing on a tablet (a tap that produces no result), room-wise capture may not be switched on for your workspace. Ask your Reonic account manager to confirm it's enabled before a site visit, or do the data entry in the Portal instead.

Devices That Support LiDAR Scanning

LiDAR scanning runs on Apple devices that ship with a LiDAR sensor. The Reonic app detects this at start-up. On a device without LiDAR, the Scan tile is replaced with a banner: "Scanning is only supported on Apple devices equipped with a LiDAR scanner."

Supported devices:

• iPad Pro (2020 and later, 11" or 12.9", any storage).
• iPhone Pro and Pro Max (iPhone 12 Pro and later).

For every other device (iPad Air, standard iPad, iPad mini, non-Pro iPhones, and all Android phones and tablets), use the manual flow. Go to Capture Rooms by Hand Without LiDAR below. That path produces the same room records, just without the 3D model.

Prepare the Building for a Clean Scan

A LiDAR scan is only as good as the room you point it at. A few minutes of prep buys you better geometry and fewer corrections later.

• Turn on every light. The LiDAR sensor doesn't need light to range, but the camera feed does. Dark rooms produce poor texture for re-orienting between rooms.
• Open interior doors between rooms you intend to scan together. The sensor needs an unobstructed path to move from one room into the next.
• Move loose objects out of the corners. Boxes, plants, pet beds: the scanner tries to model them as geometry. Empty corners give cleaner wall edges.
• Pull back curtains and blinds so windows are visible. The scanner identifies window openings from the recess, not by reading glass.
• Note the heating fixture in each room before you start: radiator or underfloor heating (the two options Reonic records). You record this per room.
• Check ceiling height. If you have a tape measure, sample one room. The LiDAR is usually accurate to a few centimetres. For an unusual ceiling (vaulted, stepped, partial) you can edit it later.
• Have the build year and material types for major elements (walls, windows, roof) ready. You can fill these in later, but doing it on-site while the customer is there is faster.

Open the Project and Fill the Basic Data

1. Open the Reonic app on the iPad.
2. Sign in with your installer account.
3. Open Projects and tap the customer's project.
4. Tap Heatload to open the heat-load overview.
5. The overview shows four setup tiles: Existing heating, Building properties, Basic materials, and Scan. Fill them top-to-bottom, in order.
6. Tap Building properties and enter built year, number of inhabitants, airtightness, soil depth, shielding factor, heat-bridge factor and temperature preference. Each field validates as you type, and out-of-range values are rejected with an inline message.
7. Tap Basic materials and pick the default material per element (exterior walls, roof, ceiling, floor). These become the per-room defaults, which you can override per room after the scan.
8. Return to the overview. The Scan tile is now active.

Pro tip: Fill Building properties and Basic materials before scanning. Each newly detected room then comes pre-populated with sensible material defaults, so you don't fill the same material on every room by hand.

Scan a Building Story by Story

The scanner organises rooms by story (cellar, ground floor, upper floors, attic). Each story is its own scanning session. Inside a story, you scan rooms one after another and the app stitches them into a single coordinate frame.

1. From the overview, tap Scan to open the building's story-and-room list.
2. Tap Add story and pick a story type: Cellar, Ground floor, Intermediary floor, or Attic (the top story). You get one Attic and one Cellar per building, and the picker enforces that. You can add any number of Intermediary floor stories; each one you add is auto-named Upper floor 1, Upper floor 2, Upper floor 3, and so on. Pick "Intermediary floor" to add an upper floor.
3. With the story selected, tap Start scan. The first time on a story, a sheet asks whether to start an independent scan or continue from an adjacent already-scanned room. For the first room, tap Start new scan.
4. The Scanning view opens with a live camera feed. A subtle 3D overlay shows what the sensor has captured.
5. Walk slowly around the room. Sweep the iPad across walls, corners, ceiling and floor. Move at the pace of a slow walking tour, so the sensor has time to range each surface.
6. Watch for tracking warnings in the on-screen banner:
   • Excessive motion: slow down, you're moving the device too fast.
   • Insufficient features: point at a more textured surface. A corner with a picture frame works better than a blank white wall.
   • Relocalizing: hold still, the sensor is re-orienting.
   • Device too hot: pause and let the iPad cool. LiDAR, camera and screen together heat the device.
   • Scene size limit exceeded: you're capturing too large a continuous area. Split it into multiple rooms.
7. Tap Take photo at any point to attach reference photos to the room (radiators, control panels, anything you might want to inspect later).
8. When the room is captured cleanly, tap Stop. The app saves the room's geometry.
9. To capture the next room, tap Start scan again. This time, choose Continue from adjacent room and pick the room you just finished. The scanner re-orients against the previous room so the new room snaps into the same coordinate frame.
10. Repeat for every room on the story.
11. When the story is complete, tap Finalize. The story scan uploads to Reonic and appears in the Portal as a ready-to-review room set.

Pro tip: "Continue from adjacent" is what stitches your story into a coherent 3D model. Always picking "Start new scan" leaves you with isolated rooms that don't share a coordinate frame, and the customer-facing 3D view in the offer looks disconnected. Use "Continue from adjacent" between rooms on the same story, and keep tracking steady through doorways. If tracking is lost mid-story, re-scan the affected rooms or adjust the geometry in the Portal.

Scan the Transition Between Two Rooms

The doorway between two rooms is the hand-off point. A clean transition is what lets the scanner re-orient into the next room.

1. While in the Scanning view, sweep the doorway slowly with the iPad camera pointing through it. Capture both the frame and a glimpse of the adjacent room beyond.
2. Wait for steady tracking before you step through the doorway. The Relocalizing warning, if it appears, clears once tracking is back.
3. Once the transition is captured, stop the scan, return to the story view, and start the next room with Continue from adjacent.
4. The scanner uses the previous room plus the doorway capture to align the new room into the existing frame.

Finalise a Story and Review Captured Rooms

1. After every room on the story is scanned, tap Finalize on the story view.
2. The finalize screen opens with a list of detected rooms.
3. Tap each room to open the per-room editor, organised into segmented tabs:
   • Walls: each detected wall with its length, height, what it faces (Outside air, Heated room, Unheated room, Other building, Outside ground), the material, and the U-value. Set internal adjacency to another heated room by linking the wall to that room, shown as Adjacent.
   • Floors: floor area, what the floor sits over (Heated, Unheated, Outside air, Ground), the material, U-value.
   • Roof: top story only. Sloped vs flat geometry, area, dormers, roof windows.
   • Heating: which heating system this room has (radiator or underfloor heating, the two options). For a radiator, pick the radiator type and its dimensions; for underfloor heating, enter the surface area (plus optional expert settings). You also pick the valve. Flow and return temperatures are set on the Portal side (they drive the radiator-replacement results table and the UK calculation), not in the app.
   • Room: name, room type (Normal, Bath, Kitchen, Hallway and so on), target temperature, air-exchange rate.
4. Walk through every room and fix anything the scan got wrong: a window the scanner merged into the wall, a ceiling height that looks off, a wall material that's wrong. (To add a wall the scanner missed entirely, do that in the Portal — see Record Windows and Doors on a Wall below.)
5. Tap Save to upload the story.
6. Repeat the scan-and-finalise cycle for every story in the building.

Set What Each Wall Faces

The single most important piece of metadata on a wall is what it faces. Reonic calls this Towards, and heat loss is calculated off this value.

Open a wall in the editor and set Towards to one of:

• Outside air: exterior wall facing the open air.
• Heated room: interior wall to another heated room. To model heat flow correctly, link the wall to the specific adjacent room. That link is surfaced as Adjacent.
• Unheated room: wall facing an unheated space (attached garage, cold staircase).
• Other building: wall shared with a separate building (a semi-detached neighbour, for example).
• Outside ground: wall in contact with soil (a typical basement wall). For partial earth contact, set the percentage to ground on the wall.

The same idea applies to ceilings and floors. Set Ceiling towards and Floor towards to the right boundary type so the calculation knows what's above and below the room.

Record Windows and Doors on a Wall

The LiDAR scanner captures the room's walls. In the app, windows and doors are recorded as properties of the wall they sit on, not as separate items you add. There is no "Add window" or "Add door" button.

1. Open the room in the editor and select the Walls tab.
2. Tap the wall you want to edit. (Windows and doors only apply to walls that face the outside — an Outside air wall, or an Outside ground wall with partial earth contact.)
3. Turn the Windows switch on if the wall has windows, then fill in:
   • The total window area on that wall (m²).
   • The window material (pick the closest match from the drop-down; material lists branch by country — see Adjust the Country-Specific Materials List below).
4. Turn the Doors switch on if the wall has doors, then fill in the total door area (m²) and the door material the same way.
5. Save. The windows and doors now contribute to that wall's heat-loss.

Note: The app records windows and doors as a per-wall area plus material. To model openings as individual items, or to add a wall, do the editing in the Portal.

Capture Roofs, Dormers and Drempel Walls

On the top story, the room editor exposes roof-specific fields.

1. Open the top-story room and select the Roof tab.
2. Toggle Has roof on.
3. Pick Sloped or Flat.
4. For a flat roof, enter the roof area and material.
5. For a sloped roof, enter:
   • Roof area (m²).
   • Slope length: eaves-to-ridge length of the slope.
   • Jamb wall height (Drempel): the short vertical wall between the floor and where the slope starts. Common in attic conversions. Set this to model the attic correctly.
6. Add dormers: tap Add dormer and enter width and slope length. Each dormer becomes its own roof element.
7. Add roof windows (skylights): tap Add roof window and enter the area, material and U-value.

Note: Keep each dormer narrower than the roof it sits on. The combined width of the dormers on a sloped roof must not exceed the roof's slope length, or the heat-load calculation rejects the building with a dormer wider than roof error. Check the dormer widths against the slope length before you run the calculation.

The roof slope drives the orientation surface for PV planning in the same project, so setting it correctly here benefits the PV side too.

Capture Rooms by Hand Without LiDAR

When LiDAR isn't available (an Android tablet, an older iPad, a basement too cramped to walk with the scanner), build the same room records by hand. This works on every device that runs the Reonic app, including Android.

1. Open the project's Heatload tab. On Android, the banner about Apple-only scanning appears. The rest of the Heatload screen is fully available, so continue past it.
2. Fill Building properties and Basic materials as in the LiDAR flow.
3. Open the building's story list and add stories as usual.
4. Inside a story, tap Add room (or the + button on the rooms list).
5. The empty room editor opens. Fill in:
   • Identity: room name, type, target temperature.
   • Geometry: tick Rectangular if it applies, then enter length and width (the area auto-computes) and ceiling height. For a non-rectangular room, untick Rectangular and enter the area directly.
   • Walls: open each wall the room has and set its length, height, Towards, and material. The app edits the walls on the room; to add a wall, use the Portal.
   • Windows and doors: recorded on each wall as a per-wall area plus material (see Record Windows and Doors on a Wall above), not as separate items.
   • Ceiling and floor: pick what each one faces (heated, unheated, outside air, ground), enter the area and material.
   • Roof: top story only. Same fields as the scanned flow.
   • Heating system: pick radiator or underfloor heating (the two options), then the radiator type and dimensions (or floor-heating surface area) and the valve. Flow and return temperatures are set on the Portal side, not in the app.
6. Save.
7. Repeat for every room and every story.

Note: Manual entry produces the same room records as a LiDAR scan, so the heat-load calculation runs identically. The 3D model is the only difference: the customer-facing 3D visualisation falls back to a non-3D rendering for this project. The calculated result is unaffected.

Trace Rooms over a Floor Plan (Portal)

If you have a 2D floor plan from the customer or an architect's drawing, you can pin it under the room editor as a background image and trace rooms against it. This is done in the Portal, not the app — the floor-plan tracing tool lives in the Portal's Roomwise Building editor.

1. In the Portal, open the project's Roomwise Building editor and the story you're working on.
2. Set a floor-plan background and upload the image, or pick one from the project's files.
3. Scale and position the image so a known dimension (a door width, a wall length you measured) matches the on-screen scale. The room grid fits the scaled image, so traced rooms come out at actual scale.
4. Add rooms by tracing rectangles over the background. Each rectangle becomes a room with geometry filled in from the scale.

The floor-plan upload accepts PNG and JPG images only — not PDF. If your plan is a PDF, export or screenshot a page to PNG or JPG first. If a site is impractical to walk-scan (a large estate, a complex roof), ask your Reonic account manager about capturing the building from drone photos instead.

Adjust the Country-Specific Materials List

The material dropdowns in the room editor branch by country.

• Germany (DE): the default. Built-year-banded U-values are looked up automatically, and you can override per element.
• UK: a parallel UK material set and a separate UK calculator. The dropdowns change shape accordingly.
• Italy (IT): its own Italian material set for Conto Termico filings.
• France (FR) and Spain (ES): use the generic shared materials. If you need country-specific labels, flag it with your Reonic account manager.

Your workspace can also carry custom materials. Define your own material entries with built-year-banded U-values under Settings → Simulation → Heating load Materials, which is useful for installer-specific wall constructions or known products.

Re-scan a Room or Fix a Botched Scan

If a room came out wrong (wrong geometry, a missed wall, a misaligned floor), you have two options.

Option A: fix it in the editor. Open the room and edit walls, openings and dimensions by hand. This is the right move for small fixes such as a missing window, a wrong wall material, or an off ceiling height.

Option B: re-scan the room. From the rooms list inside a story, delete the broken room, then tap Start scan again and re-capture. Choose Continue from adjacent if the surrounding rooms scanned cleanly, so the new room snaps back into the existing coordinate frame. If rooms have shifted relative to each other after the scan, re-scan the affected story with Continue from adjacent to re-orient them into the correct coordinate frame.

Note: A re-scanned room starts fresh: the heating system, materials and window/door records from the old room don't carry over. Re-enter the heating system and verify materials on the new room.

Pro tip: For a room that's almost right, fix it in the editor rather than re-scanning. Editing is fast. Re-scanning costs you the per-room heating-system setup again.

Hand Over to the Portal for the Calculation

The Reonic app captures rooms. The Reonic Portal calculates the heat-load. Once every story is scanned (or entered manually) and finalised:

1. From the Heatload overview, tap Data review & results.
2. The Portal opens in a new tab, jumping straight to the room-wise heat-load view for this project. Sign in to the Portal with the same account.
3. Continue with the room-wise heat-load calculation for the review, edit, calculation and sign-off side of the workflow.

The per-room editing experience is richer on the Portal: wider screens, cross-room operations, the warnings list, and the calculation button itself. The app is for capture, the Portal is for review.

File the KfW Heat-Pump Subsidy Through Reonic's Förderservice (Germany)

Residential only. The KfW Förderservice runs on residential heat-pump projects in Germany.

On residential heat-pump projects in Germany, the room-wise heat-load you just captured is what KfW needs to confirm a Heizungsförderung subsidy. Reonic offers a paid Förderservice that files the two KfW forms on your behalf, from inside the same project: the BzA (Bestätigung zum Antrag, the pre-application confirmation) and the BnD (Bestätigung nach Durchführung, the post-installation confirmation). The Förderservice is the final stage of the Heatload workflow after Scan, Building, Materials and Review.

When to use it:

• Country mode is Germany. The subsidy is a German federal program, so the Subsidy step shows on Germany projects.
• Your workspace has the subsidy capability enabled, and your user has the subsidy right turned on. If the Subsidy step doesn't appear, ask your Reonic account manager to confirm both.
• The heat-load calculation is reviewed and plausible. KfW expects per-room load and radiator/UFH sizing as inputs, so run the Portal review described above first.
• Customer data is complete in the project. Reonic files on the homeowner's behalf, so the customer block must be filled in.

What the service costs. €210 + VAT per project, invoiced when you submit the BzA. The fee covers Reonic preparing and filing both the BzA and the BnD. The KfW grant itself flows to the homeowner, not to Reonic. Phone support on +49 821 80830802 is included, with no per-document or per-call surcharges.

Note: The €210 fee is charged at BzA submission, before KfW responds, and cancellation after submit does not refund it. Double-check the form before pressing Submit, and use Save draft if you need to step away.

Open the Subsidy Step

1. In the Portal, open the customer's project.
2. Navigate to the Subsidy step, the final tab in the Heatload steps.
3. The screen renders a two-form layout: BzA (request) on the left, BnD (post-execution) on the right. The BnD form opens once the BzA comes back from KfW.
4. Above the forms, two options appear: Book a demo (a 15-minute call with the Reonic Förderservice) and Call us (+49 821 80830802). Use them if the customer's eligibility is unclear, or if you want a walk-through of the fee and scope before committing.

Submit the BzA (Bestätigung zum Antrag)

1. Tap Request BzA. The form opens with most fields pre-filled from what Reonic already knows about the project: the customer block, the heat-load result, the selected heat pump.
2. Fill in any remaining homeowner-identity, project and heat-pump-component fields.
3. Attach the required documents.
4. Review carefully, then submit. The €210 + VAT service fee is invoiced at this point.
5. KfW responds in about 3 working days. Status surfaces inline on the Subsidy step.

Wait for the BzA, Then Execute the Project

1. KfW returns the BzA. The homeowner is now eligible for the subsidy.
2. Install the heat pump, commission the system, and complete the on-site paperwork as normal.
3. The BnD form on the Subsidy step unlocks.

Submit the BnD (Bestätigung nach Durchführung)

1. Tap Request BnD. The form opens.
2. Fill in the post-execution fields: installation date, final component list, and any deviations from the BzA-stated plan.
3. Submit. KfW responds in about 5 working days.
4. On BnD confirmation, the homeowner can claim the grant from KfW.

Track Status

The Subsidy step shows the full arc per project: BzA request, wait for BzA, project execution, BnD request, wait for BnD, completion. Status is tracked per project on the Subsidy tab.

Things to Know

• The app captures rooms. The Portal renders results. When you tap Data review & results, the Portal opens in a new tab with the per-room kilowatt numbers, warning lists, and the calculation. The app's job ends at the room data.
• One project is one building. Each project ties to a single building. A multi-flat apartment building, a multi-house complex, or connected family homes need a separate project per building.
• Edits need a network connection. Scans cache on-device, so you can finish a story without signal. Form edits sync over the network. Scan in the basement, then edit at the kitchen table where the signal is better.
• Coordinate concurrent edits. If you and a colleague edit the same room from the app and the Portal at the same time, the most recent save is the one that's kept. Agree who owns a room before editing it in two places.
• Each project starts fresh. Rooms and stories are captured or entered per project. There's no copy of a room or a story between projects.
• Placeholder rooms are fine during data entry. A room with a name but no geometry is valid while you work. Fill it in before you run the calculation, or the calculation warns on it.
• A LiDAR scan backs the customer-facing 3D visualisation. Manually-entered rooms produce the same calculated result and fall back to a non-3D rendering for the customer view.
• DIN-EN-12831 is the default calculation standard. UK projects use a UK calculator. France, Italy and Spain run on the DIN-EN-12831 calculation with country-mode settings where applicable.
• Keep the device cool and stable on long scans. Close other apps before scanning. LiDAR, camera and screen together are memory- and thermal-intensive. Move at a walking pace, since fast camera motion stresses tracking. If a scan stops mid-room, reopen the app, restart the scan, and redo the affected room.
• The customer sees a heating-strategy view, not the raw data. The offer PDF (and the Customer Portal preview, if your workspace has it enabled) shows a 2D / 3D representation of the building's heating strategy before signing. The raw scan and per-room engineering data stay installer-side.
• A glass conservatory (Wintergarten) is best added by hand. Glass walls give the LiDAR sensor too few solid surfaces to range. Add the conservatory as a manual room: tap Add room, enter geometry by hand, set the walls' Towards to Outside air with the right glass material, and record the openings on the walls.
• Capture new building data after signature on a new variant. A signed offer variant locks so the customer always receives exactly what they signed. To bring a new scan into a signed project, fork to a new variant (duplicate the variant, then capture or edit the scan there) or open a follow-up project. Talk to your Reonic account manager if the lock is causing a practical problem.
• The KfW Förderservice is a paid Reonic service. €210 + VAT per project, invoiced when you submit the BzA (not when KfW approves it). Use the Subsidy step's draft-save before committing. The Subsidy step is available on Germany heat-pump projects.
• The homeowner doesn't have a Reonic login. Reonic talks to KfW on behalf of the installer, who talks to the homeowner. Subsidy status is visible to the installer inside the project.

Need help?

• Step-by-step questions about this flow → contact your Reonic account manager.
• Feature requests / something missing → drop a note to your account manager.
• Bug reports → include the URL where it happened in your support email.

Last updated on August 4, 2026