Home Assistant Best Practices
Core principle: Use native Home Assistant constructs wherever possible. Templates bypass validation, fail silently at runtime, and make debugging opaque.
Decision Workflow
Follow this sequence when creating any automation:
0. Gate: modifying existing config?
If your change affects entity IDs or cross-component references — renaming entities, replacing template sensors with helpers, converting device triggers, or restructuring automations — read references/safe-refactoring.md first. That reference covers impact analysis, device-sibling discovery, and post-change verification. Complete its workflow before proceeding.
Steps 1-5 below apply to new config or pattern evaluation.
1. Check for native condition/trigger
Before writing any template, check references/automation-patterns.md for native alternatives.
Common substitutions:
{{ states('x') | float > 25 }}→numeric_statecondition withabove: 25{{ is_state('x', 'on') and is_state('y', 'on') }}→condition: andwith state conditions{{ now().hour >= 9 }}→condition: timewithafter: "09:00:00"wait_template: "{{ is_state(...) }}"→wait_for_triggerwith state trigger (caveat: different behavior when state is already true — seereferences/safe-refactoring.md#trigger-restructuring)
2. Check for built-in helper or Template Helper
Before creating a template sensor, check references/helper-selection.md.
Common substitutions:
- Sum/average multiple sensors →
min_maxintegration - Binary any-on/all-on logic →
grouphelper - Rate of change →
derivativeintegration - Cross threshold detection →
thresholdintegration - Consumption tracking →
utility_meterhelper
If no built-in helper fits, use a Template Helper — not YAML.
Create it via the HA config flow (MCP tool or API) or via the UI:
Settings → Devices & Services → Helpers → Create Helper → Template.
Only write template: YAML if explicitly requested or if neither path is available.
3. Select correct automation mode
Default single mode is often wrong. See references/automation-patterns.md#automation-modes.
| Scenario | Mode |
|---|---|
| Motion light with timeout | restart |
| Sequential processing (door locks) | queued |
| Independent per-entity actions | parallel |
| One-shot notifications | single |
4. Use entity_id over device_id
device_id breaks when devices are re-added. See references/device-control.md.
Exception: Zigbee2MQTT autodiscovered device triggers are acceptable.
5. For Zigbee buttons/remotes
- ZHA: Use
eventtrigger withdevice_ieee(persistent) - Z2M: Use
devicetrigger (autodiscovered) ormqtttrigger
See references/device-control.md#zigbee-buttonremote-patterns.
Critical Anti-Patterns
| Anti-pattern | Use instead | Why | Reference |
|---|---|---|---|
condition: template with float > 25 | condition: numeric_state | Validated at load, not runtime | references/automation-patterns.md#native-conditions |
wait_template: "{{ is_state(...) }}" | wait_for_trigger with state trigger | Event-driven, not polling; waits for change (see references/safe-refactoring.md#trigger-restructuring for semantic differences) | references/automation-patterns.md#wait-actions |
device_id in triggers | entity_id (or device_ieee for ZHA) | device_id breaks on re-add | references/device-control.md#entity-id-vs-device-id |
mode: single for motion lights | mode: restart | Re-triggers must reset the timer | references/automation-patterns.md#automation-modes |
| Template sensor for sum/mean | min_max helper | Declarative, handles unavailable states | references/helper-selection.md#numeric-aggregation |
| Template binary sensor with threshold | threshold helper | Built-in hysteresis support | references/helper-selection.md#threshold |
| Renaming entity IDs without impact analysis | Follow references/safe-refactoring.md workflow | Renames break dashboards, scripts, and scenes silently | references/safe-refactoring.md#entity-renames |
template: sensor/binary sensor in YAML | Template Helper (UI or config flow API) | Requires file edit and config reload; harder to manage | references/template-guidelines.md |
Reference Files
Read these when you need detailed information:
| File | When to read | Key sections |
|---|---|---|
references/safe-refactoring.md | Renaming entities, replacing helpers, restructuring automations, or any modification to existing config | #universal-workflow, #entity-renames, #helper-replacements, #trigger-restructuring |
references/automation-patterns.md | Writing triggers, conditions, waits, or choosing automation modes | #native-conditions, #trigger-types, #wait-actions, #automation-modes, #ifthen-vs-choose, #trigger-ids |
references/helper-selection.md | Deciding whether to use a built-in helper vs template sensor | #numeric-aggregation, #rate-and-change, #time-based-tracking, #counting-and-timing, #scheduling, #entity-grouping, #decision-matrix |
references/template-guidelines.md | Confirming templates ARE appropriate for a use case | #when-templates-are-appropriate, #when-to-avoid-templates, #template-sensor-best-practices, #common-patterns, #error-handling |
references/device-control.md | Writing service calls, Zigbee button automations, or using target: | #entity-id-vs-device-id, #service-calls-best-practices, #zigbee-buttonremote-patterns, #domain-specific-patterns |
references/examples.yaml | Need compound examples combining multiple best practices | — |