thermly

Thermal compliance, clearly documented.

H1 thermal calculations for New Zealand building consent.

Build wall, roof, floor, glazing and slab inputs; derive areas from marked-up plans; check H1/AS1 Calculation Method results; and generate source-backed thermal evidence for consent documentation.

Free during pre-launch. Create an account and start using the full product catalogue, saved projects and reporting workflow immediately.

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From architectural plan to a passing H1/AS1 compliance report: plan take-off, AI plan reading, live heat-loss checks and report-ready evidence, in one project.

Built around NZS 4214:2006 construction R-values, H1/AS1 6th edition Calculation Method, calibrated plan take-off, and recorded product source evidence.

H1 compliance guideFind an H1 climate zone

The workflow

The full H1 workflow, in one place.

From construction R-values to plan areas, live H1 checks and report-ready evidence.

Thermly Assembly Builder showing a 140mm timber-framed wall build-up with a bridged insulation layer and the construction R-value breakdown totalling R2.15
A 140 mm timber-frame wall in the Assembly Builder: bridged insulation layer, framing fraction, and the per-layer R-value breakdown.
Step 1.

Build up your catalogue of roof, wall and floor assemblies.

Layer up each construction from catalogue products or custom R-values, and save it to reuse across projects. Bridged layers apply the NZS 4214:2006 parallel-path method with the H1/AS1 38% framing default, or use the built-in framing layout calculator to justify a lower fraction from member spacing and noggings. Every layer's contribution is itemised so the result can be reviewed line by line.

Thermly product catalogue showing 2,875 sourced products, filtered to the skylight catalogue with per-unit R-values, sizes, applications and source links per product
2,700+ NZ products and reference materials, each with a source trail. Continuously updated.
Step 2.

Pick products from a sourced NZ catalogue.

Every layer in an assembly selects from 2,700+ manufacturer products and reference materials, with R-values, thicknesses and applications, including a dedicated skylight catalogue of complete manufactured units with published whole-unit R-values, sizes and glazing options. Each record links back to a manufacturer datasheet, BRANZ/NZS reference, or published table so assumptions can be checked before submission.

Thermly is built as an end-to-end V6 H1 compliance workflow: sourced product data, R-value assemblies, calibrated plan take-off, H1/AS1 heat-loss checks and report-ready evidence stay connected in one project record. Thermly is independent and is not affiliated with, endorsed by, or sponsored by the product manufacturers listed.

Window openings dropped onto the calibrated wall: Thermly reads each opening's dimensions and its schedule number straight from the plan.
Step 3.

Trace areas from the plan.

Use the plan PDF directly: let Thermly scale it automatically, or calibrate each axis manually from a known dimension. Trace elements as polygons with snapping and precise length entry, or measure walls as lines or polygons. Drop window and door openings onto a wall and Thermly reads each opening's dimensions and its schedule number straight from the plan text, with no re-typing. Areas are calculated from the markup and synced directly to the relevant H1 row.

Thermly H1 compliance page showing building envelope rows for a sample residential project, with the live heat-loss check passing at 13% headroom and report export buttons
The built-in sample residential project, climate zone 3.
Step 4.

Check heat loss as you build the envelope.

The H1/AS1 Calculation Method check updates live as the envelope is entered (proposed vs reference heat loss, headroom, and per-element minimums), with one-click H1 report, insulation take-off and CSV exports when it passes.

First page of a generated Thermly H1 compliance report showing proposed and reference building heat-loss tables and a PASS result
Step 5.

Generate the report. Evidence, not just a number.

The H1 report sets out the proposed and reference building heat-loss tables with the equations behind every figure, per-element minimum R checks, assembly build-ups, marked-up plan extracts, and a references page citing the standards and manufacturer datasheets behind each value, so a processing officer can trace every assumption.

Apply your own logo and accent colour and they replace Thermly's on every page. Set it once, and every report your organisation generates goes out under your practice's brand.

Thermly dashboard showing project cards with compliance status, folders, a section shared with an organisation, and search and filter controls
Projects with live compliance status, folders, and an organisation-shared workspace.

Every project, one dashboard.

Organised, shared, and searchable.

File projects and assemblies into folders, and share them with your organisation: teammates get role-based access and co-edit safely with one editor at a time, so nothing is ever overwritten. Each card shows the live H1 status, envelope area and whether a plan is attached.

Search and filters cover every project and assembly, or press Ctrl K anywhere in the app to jump straight to any project, assembly or page.

Capabilities

Built for the full H1 compliance workflow.

Thermly brings the H1 thermal workflow into one place: construction R-value assemblies, sourced product data, postcode-based climate zones, calibrated plan take-off, AI-assisted plan reading, H1/AS1 Calculation Method checks, and PDF-ready supporting records.

  • 01

    Build construction R-value assemblies

    Layer up walls, roofs and floors with simple and bridged layers, including framing fractions, surface resistances and NZS 4214:2006 calculations.

  • 02

    Use sourced product data

    Select insulation, lining, cladding, slab and reference materials from a catalogue with source documents, retrieval dates and manufacturer data trails.

  • 03

    Check H1/AS1 Calculation Method results

    Enter envelope areas, glazing, doors, slabs and floors to compare proposed heat loss against the H1/AS1 reference building.

  • 04

    Mark up plans and derive areas

    Attach plan PDFs, calibrate scale, draw element polygons, and sync measured take-off areas back into H1 rows.

  • 05

    Read plans with AI assistance

    Pull project information, window and door schedules, and insulation specifications straight from uploaded plan PDFs to pre-fill your H1 inputs, ready to review and adjust.

  • 06

    Look up climate zones, windows and slabs

    Use postcode climate-zone lookup plus table-based helpers for glazing and slab-on-ground R-values.

  • 07

    Save assemblies and project evidence

    Reuse common assemblies, keep versions as designs change, and maintain a record of the assumptions behind each result.

  • 08

    Generate report-ready evidence

    Produce thermal resistance certificates, H1 reports and calculation summaries with marked-up plan extracts, professional details and source-backed assumptions.

  • 09

    Work as a team

    Share projects and assemblies across your organisation, invite colleagues with roles, and co-edit safely with one editor at a time so work is never overwritten.

Also built in

  • Save and reuse common assemblies across projects.
  • Keep project calculations versioned as designs change.
  • Derive H1 areas from calibrated plan mark-ups.
  • Include marked-up plan extracts in generated reports.
  • Personalise certificates with your professional details.
  • Export by PDF or email.
  • Use Thermly on desktop, tablet or phone.