Do I need planning permission for air conditioning in Carmarthenshire?
For most houses in Carmarthenshire a reversible air-to-air unit is permitted development if it's under 1.5 m³, meets 37 dB at the neighbour's window and isn't on a wall facing the road in a conservation area; flats are limited to one unit per building up to 1 m³ (Class G (Wales), checked 25 Sep 2026). Carmarthenshire has 25 conservation-area records on file (status on-record, snapshot 25 Sep 2026).
permitted if the conditions hold
Check your address
- WAL-01. Is the building a house, or a building that is wholly flats?
- WAL-02. What is the noise result at 1 m outside the neighbour's nearest habitable-room window?
- WAL-03. How many outdoor units will the building have once this one is installed?
- WAL-03. Is the house detached?
11 more unchecked conditions are listed below.
| Measure | Nights | Source |
|---|---|---|
| 2026 nights ≥ 18°C | 5.9 | ERA5, June–August |
| 2025 nights ≥ 18°C | 1.2 | ERA5, June–August |
| 1991–2020 average ≥ 18°C | 0.6 | ERA5, June–August |
| 2026 nights ≥ 20°C | 2.0 | ERA5, June–August |
| 2025 nights ≥ 20°C | 0.0 | ERA5, June–August |
| 1991–2020 average ≥ 20°C | 0.1 | ERA5, June–August |
https://datamap.gov.wales/layers/geonode:conservation_areas_wales · 2026-09-25 · n=6541 · ERA5 hn-era5arco-1 for nights; Class G or Class 6H for the planning sentence; census shares where a housing table is shown · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class PLN-C08
WAL-01 · Class G, permitted development · checked 2026-09-25. The installation, alteration or replacement of an air source heat pump—(a) on a dwellinghouse; or (b) within the curtilage of a dwellinghouse, including on a building within that curtilage. Source
Full engine wording and the measurement caveat
This cannot be fully checked from the data available — one or more conditions have no record. This means 'not checked', not 'permission not needed'; verify directly with your local planning authority.
What noise limit applies here?
In Wales the noise method on this card is MCS 020 a) — Air Source Heat Pump Sound Calculation (For Permitted Development Installations), Issue 1.1. Threshold 37.0 dB(A). §3.2 Step 8, checked 2026-09-25: "If the calculated sound pressure level at all assessment positions is equal to or lower than 37.0 dB(A) then the heat pump will comply with the Permitted Development noise limit"
computed
| Method | Threshold dB(A) | Checked |
|---|---|---|
| mcs020a_1_1 | 37.0 | 2026-09-25 |
https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.1-Final.pdf · 2026-09-25 · n=6541 · threshold copied from decision-contract.yaml; no local measurement · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class unmatched
mcs020a_1_1 · §3.2 Step 8 · checked 2026-09-25. If the calculated sound pressure level at all assessment positions is equal to or lower than 37.0 dB(A) then the heat pump will comply with the Permitted Development noise limit Source
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
Is the £2,500 air-to-air grant available here?
£2,500 is the air-to-air amount in England and Wales when the household predicates are met. £2,500 for air-to-air heat pumps (AAHP) (in residential properties only) (p.6 summary table, checked 2026-09-25). The heating system and the property type are still to enter for this address.
not supplied
| Field | Value |
|---|---|
| Nation | Wales |
| Eligible | not supplied |
| Amount or rule | £2,500 for air-to-air heat pumps (AAHP) (in residential properties only) |
https://www.ofgem.gov.uk/sites/default/files/2026-07/boiler_upgrade_scheme_guidance_for_installers_v5.1_20260630135616-20260701135531.pdf · 2026-09-25 · n=6541 · evaluate_grant; property type not entered; technology air_to_air · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class unmatched
BUS-amount · p.6 summary table · checked 2026-09-25. £2,500 for air-to-air heat pumps (AAHP) (in residential properties only) Source
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
Which registered offices are within 25 km of Carmarthenshire?
461 registered offices in this Companies House catalogue sit within 25 km (centroid is the postcode-weighted mean of linked districts, haversine to the registered office). An MCS air-to-air certificate is not on file for 150573 of 150573 companies (last attempt 2026-09-25). An F-Gas number is not on file for 150573 companies.
computed
| Company | Company number | Office district | Distance |
|---|---|---|---|
| TRYDAN ELECTRICAL SERVICES LIMITED | 07117254 | SA32 | ≈2.2 km |
| 360 ELECTRICAL SOLUTIONS (WALES) LTD | 17134507 | SA32 | ≈2.8 km |
| H2O HEATING AND GAS SERVICES LIMITED | 05632085 | SA14 | ≈3.7 km |
| HEAT PUMPS SOUTH WALES LTD | 16482772 | SA14 | ≈3.7 km |
| MODULAR INTEGRATED SYSTEMS LTD | 11968934 | SA14 | ≈4.1 km |
Companies House snapshot in installers.csv · 2026-09-25 · n=6541 · haversine ≤ 25 km from centroid to registered office; a missing MCS row is not a count of zero certificates · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class unmatched
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
How hot does it get around Carmarthenshire?
In Carmarthenshire last summer (2026) there were ≈5.9 nights that stayed above 18 °C — 10 times the 1991–2020 average of 0.6 (ERA5 reanalysis, grid ≈30 km, lower than street temperatures in cities). Figure is a household-weighted mean of 22 linked districts.
computed
| Measure | Nights | Source |
|---|---|---|
| 2026 nights ≥ 18°C | 5.9 | ERA5, June–August |
| 2025 nights ≥ 18°C | 1.2 | ERA5, June–August |
| 1991–2020 average ≥ 18°C | 0.6 | ERA5, June–August |
| 2026 nights ≥ 20°C | 2.0 | ERA5, June–August |
| 2025 nights ≥ 20°C | 0.0 | ERA5, June–August |
| 1991–2020 average ≥ 20°C | 0.1 | ERA5, June–August |
ERA5-ARCO district_heat.csv · 2026-09-25 · n=6541 · hn-era5arco-1 aggregated by household estimate · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class DST-C05
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
What planning records are on file for Carmarthenshire?
Carmarthenshire planning snapshot 2026-09-25. A count is records on file, and the address is still its own check.
computed
| Check | Status | Records or sample share | How to read it |
|---|---|---|---|
| Conservation area | on-record | 25 | records on file; the address is its own check |
| Article 4 | dataset-absent | pending_data | no record in this snapshot |
| Listed building | on-record | 3173 | a count of records cannot clear your building |
| Tree zone | dataset-absent | pending_data | no record in this snapshot |
https://datamap.gov.wales/layers/geonode:conservation_areas_wales · 2026-09-25 · n=6541 · snapshot counts; one address can differ · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class PLN-C08
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
Which postcode districts fall under Carmarthenshire?
22 postcode districts are linked below. Each has its own sample share and census row.
computed
| District | Page |
|---|---|
| SA14 | sa14 |
| SA15 | sa15 |
| SA16 | sa16 |
| SA17 | sa17 |
| SA18 | sa18 |
| SA19 | sa19 |
| SA20 | sa20 |
| SA31 | sa31 |
| SA32 | sa32 |
| SA33 | sa33 |
| SA34 | sa34 |
| SA35 | sa35 |
district_planning.csv · 2026-09-25 · n=6541 · link table, not a new statistic · updated 2026-09-25 · version 1.0.0 · CSV of the values on this page · class unmatched
Full engine wording and the measurement caveat
not a measured level, proof of permitted development, or a guarantee against nuisance
Every unchecked condition
- WAL-01. Is the building a house, or a building that is wholly flats?
- WAL-02. What is the noise result at 1 m outside the neighbour's nearest habitable-room window?
- WAL-03. How many outdoor units will the building have once this one is installed?
- WAL-03. Is the house detached?
- WAL-03-WIND. Is there a stand-alone wind turbine in the garden?
- WAL-04. What is the outdoor unit volume in cubic metres, including the housing?
- WAL-07. Is the building a scheduled monument?
- WAL-08. Is the building listed? A postcode search cannot clear this.
- WAL-09. Will the pump be used only for cooling, or for heating as well?
- WAL-10. Is this exact address inside a conservation area?
- WAL-10. Does the wall the unit would sit on face a highway?
- WAL-10. Does the roof face a highway?
- WAL-10. Would the unit sit nearer the highway than the building does?
- WAL-A4. Is there an Article 4 direction on this address?
- WAL-A4. Does that direction name this permitted-development class?
Postcode districts linked to this authority
Next steps for this council
- BUS grants in Carmarthenshire / Sir Gaerfyrddin
- Fitted cost in Wales
- Llanelli · 37 plumbing companies
- Carmarthen · 32 plumbing companies
- Ammanford · 13 plumbing companies
- Llandeilo · 12 plumbing companies
- Burry Port · 7 plumbing companies
- Carmarthenshire · 2 plumbing companies
- Cross Hands · 2 plumbing companies
- Kidwelly · 2 plumbing companies
- Llandovery · 2 plumbing companies
- Newcastle Emlyn · 2 plumbing companies
Better than a council page that only links to a form: the usual case is answered first, with the clause and the check date.