AIR-SOURCE HEAT PUMPS · SITING · ACOUSTIC DESIGN
Heat-pump noise assessments.
Plan your heat-pump installation around the people who will hear it. ACP assesses relevant sound data, location and operating conditions to support a practical acoustic design.
From a domestic installation check to a commercial plant assessment, we define the right method and the evidence your project needs.
Read the illustration description
An outdoor heat-pump unit next to a dwelling, a neighbouring window and a reflective wall. Numbered features identify equipment sound data, separation, reflections and screening with airflow maintained.
DEFINE THE BRIEF
Get the acoustic detail right
before installation.
An installation that fits physically still needs an acoustic review. We examine how the proposed unit, its position and the surrounding buildings affect the relevant receivers.
Domestic heat-pump checks
Review acoustic evidence for the proposed installation and the relevant MCS calculation route. Confirm the assessment position and the equipment data used.
Explore the domestic check →Planning noise assessments
Where a planning report is required, establish the local assessment brief, operating conditions and source-specific method.
Explore planning support →Commercial & larger systems
Assess plant arrays, relevant operating combinations and nearby sensitive uses. Develop a mitigation brief that fits the mechanical design.
Explore commercial plant →TAILOR YOUR PROJECT BRIEF
Direct link to this version →Start with the unit and the site.
Share the model, proposed location, site postcode and any planning correspondence. We will identify the relevant assessment scope.
Include a sketch or plan showing the unit and nearby windows when available.
SURVEY · ASSESS · COORDINATE
Model the proposal.
Refine the location.
We compare the source data and site geometry with the required assessment approach. Where a concern is identified, we investigate practical options before the equipment location is fixed.
Identify the consent and assessment route
Confirm the proposal, site and authority request. Distinguish the acoustic part of an MCS check from other permitted-development conditions and planning assessment requirements.
Review usable sound data
Obtain the exact model, sound power data, operating modes and relevant technical information. The domestic MCS calculation does not permit the low-noise-mode sound power value. Detailed planning assessments need their own explicit operating basis.
Assess the relevant receivers
Use the appropriate calculation positions and account for the site arrangement. For a detailed planning assessment, establish whether background measurements and sound-character analysis are needed.
Develop and explain the response
Compare feasible siting, equipment and acoustic-control options. Record the assumptions, proposed measures and any further design or verification work.
Manufacturer data may describe different quantities and operating conditions. We check the information used rather than treat every quoted dB figure as interchangeable.
THE DETAILS THAT SHAPE THE ANSWER
The details behind
a meaningful dB result.
The assessment should describe the actual unit, intended operation and relevant neighbouring locations. Small changes in position or data assumptions can change the calculation.
| Consideration | What the assessment needs to address |
|---|---|
| Equipment and operating mode | Identify the exact model, the specified sound power level and relevant modes. For the domestic MCS calculation, do not substitute a low-noise-mode value. Other assessment routes need clearly defined operating scenarios. |
| Assessment position | Use the position required by the applicable standard or planning brief. A property boundary, neighbouring window and an arbitrary point one metre away are not interchangeable. |
| Distance and geometry | Measure the relevant separation and document walls, corners and other reflecting surfaces. The acoustic path depends on the actual arrangement. |
| Screening and enclosures | Check the sound path and proposed dimensions. Preserve safe airflow, servicing access and manufacturer clearances; an improvised enclosure can undermine system performance. |
| Sound character and background | For relevant planning assessments, review tonal or other distinctive characteristics and the local background context. An MCS calculation and a BS 4142 assessment serve different purposes. |
| Multiple sources and structure-borne sound | Consider relevant simultaneous units and other plant where required. Mounting and vibration transmission into buildings may need separate advice. |
Technical reference: MCS 020 a), Issue 1.1 — domestic permitted-development sound calculation.
EVIDENCE INTO ACTION
Better siting.
A more considered installation.
Acoustic design starts with the equipment and layout. We consider practical controls in context with the installer and building-services team.
Choose suitable equipment
Review reliable sound data and the required heating duty. A lower-noise mode must still meet the project’s operating needs and any commitments made in the assessment.
Use the site intelligently
Explore separation, orientation and existing building screening. Avoid assuming that hiding a unit visually also screens sound at the relevant window.
Coordinate acoustic measures
Consider suitable screens, isolation and other controls where justified. Document the required performance and coordinate airflow, access and installation details.
Two identical units can produce different assessment results in different layouts. We review your arrangement and the relevant route rather than rely on a generic setback or a quiet-product label.
THE RIGHT METHOD FOR THE RIGHT QUESTION
Guidance, scope
and the local requirement.
We identify which guidance and requirements apply to your project. The assessment method, the planning decision and any other statutory process each have their own role.
MCS 020 and domestic installations
MCS 020 a), Issue 1.1 sets the current domestic permitted-development sound calculation. We provide acoustic advice alongside the installer’s responsibilities; we do not offer MCS certification.
England permitted development
Air-source heat-pump rights have conditions and limits. Planning status depends on the property, location and complete proposal; the installer or planning adviser should confirm the applicable route.
BS 4142 planning assessments
Where applicable, a detailed industrial or commercial sound assessment considers the source, background, sound character and context. It is not replaced by a domestic MCS calculation.
Local requirements and other duties
Confirm the authority’s assessment brief for planning applications. Planning status and acoustic calculations do not remove other applicable responsibilities, including statutory nuisance considerations.
DEFINED DELIVERABLES
A clear acoustic basis
for the installation.
Agree whether the deliverable is an acoustic calculation review, a planning noise report, option appraisal or a defined verification survey.
Assessment route
The purpose, applicable method and limits of the acoustic scope.
Source information
Unit identification, technical data and operating assumptions.
Site and receivers
Relevant geometry, assessment locations, reflecting surfaces and screening.
Calculated findings
Results and their basis, with sound-character or contextual assessment where applicable.
Design recommendations
Siting, equipment or mitigation options and the responsibilities for detailed design.
Next steps
Inputs, installation commitments and any verification requirements still to be addressed.
ACP · TECHNICAL EXPERTISE
Acoustic knowledge.
Clear project advice.
ACP brings acoustics together with wider environmental expertise. We help project teams turn technical findings into practical decisions and a defined next step.
Our team includes Institute of Acoustics members. Qualifications across the team include the IOA Diploma in Acoustics and Noise Control, an MSc in Applied Acoustics and a PhD in Air Quality and Environmental Noise.
Understanding changing sound.
Ayan Chakravartty’s co-authored 2025 research examines motorway speed management and environmental noise using high-resolution monitoring.
That research sits alongside our project-specific assessment work. Your advice will address the actual source, site and decision.
Explore the published research →FEES & PROGRAMME
Understand the scope
before you commit.
A single domestic calculation review and a multi-unit planning assessment involve different work. Send the model, site layout and council request so we can quote for the right scope.
Send the information you have. A consultant can request the supporting plans, technical details and authority correspondence needed to confirm the deliverables and programme.
What shapes your quotation?
Installation scale
Number of units, relevant receivers and alternative locations to compare.
Evidence required
Availability of suitable product data, drawings and any background measurements.
Design and reporting
Calculation review, planning report, mitigation advice or verification scope.
ENGLAND · LOCAL PROJECT CONTEXT
Where is your project?
We discuss projects across England and confirm practical survey arrangements in the quotation. Select your region and tell us the site postcode.
SITE-SPECIFIC SCOPING
England — national guidance
Share the site postcode, council request and project stage. We establish the relevant authority and assessment requirements for the actual site.
Include the planning reference or council request where available. We review the requirements for the actual authority and project.
We confirm the relevant council requirements, survey access and project scope before quoting.
Direct link to this selection →BEFORE YOU BOOK
Clear answers.
A better project brief.
Share the authority’s request if you are unsure what is required. We can help distinguish the assessment, design advice, monitoring or verification that your project needs.
Do I need a heat-pump noise assessment?
The answer depends on the proposal and its planning route. A domestic permitted-development installation has acoustic and other requirements. A planning application or larger system may need a more detailed report. Send the site and unit details so we can identify the acoustic scope.
Is the MCS check the same as a planning noise report?
No. The MCS procedure has a defined purpose and calculation method. A planning assessment may require site measurements, BS 4142 analysis and additional contextual information. We establish which evidence the project needs.
Is the old 42 dB rule still the right reference?
MCS 020 a), Issue 1.1 uses 37 dB LAeq,5mins at its prescribed neighbouring assessment positions, excluding façade reflection. This differs from the older 42 dB calculation. Meeting the acoustic test alone does not establish all permitted-development requirements.
Can the manufacturer’s noise label tell me if it will pass?
Not by itself. The figure needs to be interpreted correctly, including whether it is sound power or sound pressure and which operating mode it represents. Site geometry and the required assessment position also matter.
Can we use quiet mode in the assessment?
The domestic MCS 020 a) calculation must not use the low-noise-mode sound power value. For a separate planning assessment, any operational restriction needs a justified basis and agreement where required; it cannot be assumed to satisfy MCS.
Will moving the unit further away solve the issue?
It may help, but distance is only one factor. Reflecting surfaces, receiver position and screening can also change the result. We can compare feasible locations using a consistent calculation basis.
Can you specify an acoustic enclosure?
We can advise on the acoustic performance required within the agreed scope. The enclosure supplier and installer must also address airflow, clearances, access and equipment requirements. We do not assume a box around the unit is an adequate solution.
Can you assess several heat pumps or a commercial system?
Yes. We scope the relevant operating combinations, receivers and assessment route. Detailed product data and the mechanical design help establish the appropriate scenarios.
What about noise or vibration inside our building?
Structure-borne transmission, mounting details and internal plant noise may need separate consideration. Tell us about the construction, mounting proposal and affected spaces so we can include the relevant work.
What should I send for a quotation?
Start with the site postcode, unit model, approximate position and any council request. We can then request the site plan, manufacturer data and supporting information needed to define the scope.
LET’S SCOPE YOUR PROJECT
Let’s review your heat-pump proposal.
A short brief is enough to start.
Send the essentials
Your site postcode, proposal, timing and any council request.
Discuss the technical scope
A consultant can request drawings, existing reports and the project-specific information needed.
Receive a defined quotation
Understand the deliverables, fee, programme and any separately scoped work.
HEAT-PUMP ACOUSTIC ADVICE
Tell us what you need.
Your enquiry goes to ACP Consultants. See our privacy policy.
Technical references
- MCS 020 a), Issue 1.1 — domestic permitted-development sound calculation
- General Permitted Development Order: Part 14
- Planning Practice Guidance: noise
- BSI: BS 4142
- Chakravartty, Dissanayake and Bell (2025) — published acoustic research
Technical references reviewed 26 October 2026. Illustrations explain assessment concepts; they are not measured or predicted project results.