Troubleshooting

My areas look wrong

Almost always a scale problem. Open the plan and check the scale chip: if it is amber ("Scale inherited from plan - re-calibrate for accurate areas"), the scale was carried over from another page. Re-calibrate against a known dimension on the page you are measuring. For a stretched or squashed PDF, use two-axis (H×V) calibration. See Uploading and calibrating your plan.

A roof area seems too small

Set the roof pitch. A flat default measures the plan footprint; a pitched roof's real (sloped) area is larger. The label shows both, for example "45.50 m² ∠30° (plan 39.40 m²)".

An element shows no R-value, or the result is incomplete

Every element needs a complete assembly. A layer missing its product or R-value leaves the element's R undefined and the total blank. Assign a sample assembly to get moving, then complete the layers. See Assemblies and products.

I get a warning that my wall is below 38% framing

H1/AS1 6th edition assumes at least 38% wall framing (timber or steel) unless a lower fraction is demonstrated for the building. Use the H1/AS1 min (38%) button, pick a Common layouts configuration (which includes the openings-and-junctions allowance), or fill in the framing-fraction calculator. Note that a bare single-bay calculator figure with no openings allowance still carries the caution: a single bay excludes the extra timber around openings, corners and junctions. If you hold real evidence - a supplier's timber-percentage report for the build, or a whole-wall take-off from the consent drawings - record the demonstration under the caution, naming the evidence; it prints verbatim on the report and clears the warning. See the 38% rule.

The report flags my skylight or supplied floor R as unverified

Those values have no automatic backstop, so Thermly asks you to confirm them. For a skylight, record the U-value basis (R = 1/U_w) or pick a catalogue skylight, whose manufacturer-published whole-unit R carries its own provenance. For a supplied floor, enter the manufacturer and source document, and tick the confirmation that the calculator determines the value in accordance with H1/VM1 Appendix E. The value is used as entered; the flag is a prompt to confirm it. See Supplied floors and rafts.

Snapping is not doing what I expect

Snapping is per-source, and only your own drawn points snap out of the box - closing a zone on its first corner, or starting a wall where the last one ended. The plan-derived sources (intersections, plan lines, the detected grid) are deliberately opt-in, because a point jumping to geometry you did not draw is how a trace lands in the wrong place on a dense consent plan. Turn on exactly the sources you want from the plan-view Snap menu, or set defaults under Settings → Plan markup.

My glazing fails the cap

The Calculation Method applies only while wall glazing is 40% or less of the gross wall area (§2.1.2.5). Above it, H1 requires the Modelling Method (H1/VM1). Reduce glazing to bring it under the cap, or switch to the modelling pathway.

I cannot save, or the project is read-only

An Approved project is final and locked - make a copy to revise it. On a shared project, an organisation admin can also lock a project, or a colleague may hold the editing lease ("Being edited by …"); wait for it to free up or ask an admin.

The plan will not open, or a download link fails

Plan links are time-limited for security and expire after about five minutes. Re-open the plan (or reload the project) to get a fresh link. If a plan still will not open, try Replace to re-attach it.

A product is missing, or its R-value looks wrong

Use Custom R-value on the layer and enter the figure from the manufacturer's current datasheet with its basis. Check Show source to see what the catalogue value rests on, and send product feedback from the app. See Product sourcing and provenance.

An assembly I updated still shows its old build-up on a project

A saved project keeps a snapshot of each assembly as it was when assigned, so an old report stays reproducible after you refine your library. To pick up the assembly's current definition on a project, re-select it from the element row's assembly picker.

Where are Export CSV and the insulation take-off?

On the H1 compliance page, next to Generate H1 compliance report — and a saved project's Dashboard card carries an Insulation button beside H1 Compliance. Both need the same inputs as the H1 report (climate zone, envelope areas, project name), so if they're disabled the tooltip lists what's still missing. See Generating your insulation take-off.

Still stuck?

Use the Feedback link in the header - it opens a form where you can pick Bug, Suggestion, Question or Other and attach a screenshot. Your account email, the page you came from, your browser and the app version are included automatically; add the project name and what you expected versus what you saw.