Permitted Development Rights review - phase 3: consultation analysis

3. Non-Domestic Renewables

3.1 Non-Domestic Solar Panels

Class 6J of the GPDO allows the installation, alteration or replacement of solar panels (or solar thermal equipment) on any non-domestic building. Panels installed under these PDR must be mounted on the building itself and there are specific restrictions regarding the placement of the panels depending on whether they are mounted on a pitched or a flat roof or on external walls.

The PDR do not apply if installed on buildings in certain designated areas, namely: sites of archaeological interest; National Scenic Areas; historic gardens and designed landscapes; conservation areas, National Parks and within the curtilage of a listed building. Class 6J is also restricted within 3km of an aerodrome or technical site associated with civilian and military air traffic services.

There is also a restriction on total energy output of equipment installed on a building, which is limited to 50 kW in relation to electricity generation, or 45 kW thermal if used to produce heat.

It is proposed that class 6J PDR should be amended by:

(i) Removing the output restrictions of 50Kw and 45Kw respectively.

(ii) Removing the requirement for wall mounted panels to be not less than 200mm from the edge of the wall, allowing installations to extend to the edge and to ‘wrap around’ corners.

(iii) Retaining the 200mm limit on protrusion from wall or pitched roof and allowing 500mm protrusion from surface of flat roof.

(iv) Enabling solar panels to be attached to non-domestic buildings which are located in conservation areas – subject to conditions that they are not permitted on a principal elevation or side elevation fronting a road or within the curtilage of a listed building.

(v) Stipulating that solar panels must be removed as soon as is practical should they become inoperative, or are no longer in use.

Views are also sought on:

(vi) Removing or reducing the current 3km exclusion zone around airports and aviation or defence installations to 2km.

(vii) Retaining the 3km distance but allowing limited installation of solar panels within that area in certain circumstances.

Additionally, a new PDR is proposed for free-standing solar panels within the curtilage of non-domestic buildings, subject to conditions and limitations that:

(viii) The surface area of the panels may not exceed 12 square metres.

(ix) The installation must be wholly within the curtilage of the non-domestic building the solar panels provide power or heat to.

(x) No more than one installation within any particular curtilage.

(xi) The PDR does not apply in national scenic areas, National Parks or within the curtilage of a listed building.

(xii) If the building is located in a conservation area, the PDR only permits installations in the rear curtilage.

(xiii) Equipment is to be removed if inoperable or no longer in use.

Question 10: Do you agree with the proposed amendments to class 6J PDR for solar panels attached to non-domestic buildings?

Responses to Question 10 by respondent type are set out in Table 9 below.

Table 9

	Yes	No	Don't know	Total
Organisations:
Planning authority	13	3	1	17
Public body or corporation	1			1
Professional or representative body	8	3	2	13
Private sector - energy/renewables	5	1		6
Private sector - thermal efficiency/heating		1		1
Private sector - other	2		1	3
Third sector - built environment/conservation	4	1		5
Third sector - shooting			2	2
Third sector - community councils/representative groups	1	1		2
Third sector - other	1		1	2
Total organisations	35	10	7	52
% of organisations	67%	19%	13%
Individuals	33	18	30	81
% of individuals	41%	22%	37%
All respondents	68	28	37	133
% of all respondents	51%	21%	28%
% excluding “don’t know” responses	71%	29%

Percentages may not sum to 100% due to rounding

A very small majority – 51% of those who answered the question – agreed with the proposed amendments while 21% disagreed and 28% did not know. Excluding those who answered “don’t know”, 71% agreed and 29% disagreed. Among organisations 67% agreed.

Please add any comment in support of your answer

Around 65 respondents provided a comment at Question 10

Reasons the PDR should be amended

Some respondents expressed support or support in principle for the proposed amendment to class 6J PDR, including because it will allow generation of more solar energy and will support businesses to decarbonise and reduce their energy costs. It was also suggested that the proposed changes are reasonable and that remaining limitations will be sufficient to minimise landscape impacts. Other benefits identified included aligning PDR for domestic and non-domestic buildings and aligning Scotland with other parts of the UK.

Although broadly supporting the principle underlying the amendments, some respondents argued that the Scottish Government should go further than proposed while others added caveats, clarifications or additional limitations they would like to see, most frequently in respect of conservation areas.

Reasons the PDR should not be amended

Among respondents who did not agree with the proposed amendments, several also highlighted issues in relation to conservation areas. Other reasons for disagreeing with the proposed changes included a view that regulations and planning permission should always be required or, at the opposite end of the spectrum, that there should be no restrictions on businesses that want to install solar power.

Concerns were also expressed regarding the waste stream arising from solar panels at the end of their lifespan.

Comments on proposed limitations

The analysis below considers each of the five limitations proposed in the consultation paper in turn, followed by various additional conditions or additional permissions that were suggested.

Removing the output restrictions of 50Kw and 45Kw respectively

This was supported by those respondents who commented specifically, including because current restrictions may not reflect the energy requirements of the business occupying a particular building.

One suggestion was that, other than on listed buildings, PDR should enable all rooftop solar installations up to 3MW.

Removing the requirement for wall mounted panels to be not less than 200mm from the edge of the wall, allowing installations to extend to the edge and to ‘wrap around’ corners

Retaining the 200mm limit on protrusion from wall or pitched roof and allowing 500mm protrusion from surface of flat roof

Few respondents commented on the second and third provisions, although there was a view that panels should no longer need to be hidden. There was also a query regarding depth, and why a ‘1m bubble’ should not be adopted.^[2] Other suggestions included that:

• The limit on protrusion from a pitched roof should be increased to 500mm as this would both afford additional opportunities without significant impact, and give consistency between pitched roofs and flat roofs.
• Panels should not be allowed to overhang the public road or a public footpath/cycle path.

It was also argued that permitting panels to wrap around corners could have implications in conservation areas.

Enabling solar panels to be attached to non-domestic buildings which are located in conservation areas – subject to conditions that they are not permitted on a principal elevation or side elevation fronting a road or within the curtilage of a listed building

This was the amendment that attracted the greatest number of comments, often reflecting concerns raised at Questions 1 and 2 with respect to the visibility of solar panels from other places in a conservation area, and that a blanket approach to the elevations that are of significance could have unintended consequences that damage the character of the area. An alternative view was that extending PDR to non-domestic buildings in conservation areas should not adversely impact their character.

Specific suggestions included that to protect the character of conservation areas the PDR should not apply:

• At all in a conservation area.
• To rear elevations fronting a road.
• To sloping roofs fronting a road.
• To side or rear elevations fronting public or green space.
• To side elevations, whether or not fronting a road, particularly for wall mounted panels.
• To any elevation visible from the street or a public place or in any location visible from the public realm.

Other comments included that:

• Guidance should state a presumption against development unless conservation issues are addressed and a good reason for any changes is demonstrated.
• Article 4 Directions might be required with respect to higher elevations that are not considered to be the front elevation but may nevertheless be prominent.

Stipulating that solar panels must be removed as soon as is practical should they become inoperative, or are no longer in use.

Limited comments on the final condition included that this is either not practical or cannot be enforced. It was also noted that there are currently no safeguards with respect to restoring roofs after panels are removed, and a suggestion that this raises a possibility that the PDR could effectively allow a change of roof covering in a conservation area.

Suggestions for clarification, additional restrictions or wider PDR

Proposals for clarifications or additional restrictions included:

• Clarifying that the PDR does not cover attaching panels to a listed building.
• Specifying that the PDR does not apply to World Heritage Sites and restricting wall mounting in National Parks and National Scenic Areas.
• Defining ‘site of archaeological interest’ more precisely as the lack of a statutory definition could cause legal uncertainty.
• Addressing fire safety concerns associated with the mass roll-out of solar PV.
• Restricting deployment close to the operational railway line where glint and glare could distract or dazzle train drivers, creating concerns for safety.
• Retaining the 3km exclusion zone round airports or consulting with the Civil Aviation Authority (CAA) and the MOD.
• Requiring ancillary equipment to adhere to noise limits as for ASHPs and free-standing turbines.
• Providing guidance for bird proofing or bird proof design to avoid causing nuisance to neighbouring properties.
• Requiring installations to be above 2.5m.

Suggestions for extension of the proposed PDR included:

• Extending the PDR to all rooftop solar on non-domestic buildings other than on listed buildings.
• Including unlisted non-domestic buildings in the curtilage of a listed building.
• Relaxing roof mounting criteria in National Parks and National Scenic Areas to reflect those for domestic properties.

Two other issues identified as having potential to act as barriers to deployment of solar panels were grid capacity and the status of businesses renting premises. With respect to the former, one Professional or representative body respondent provided examples of businesses that have delayed investment in solar panels or involvement in projects due to lack of grid capacity or delays in upgrading grid connections. They also highlighted the situation of businesses that do not own their buildings and hence lack control over the installation of renewable energy infrastructure on roofs. In this case it was suggested that landlords should be encouraged and incentivised to facilitate solar panel installation.

Question 11: Do you have any comments on the potential to amend the current restrictions that apply to solar panels on non-domestic properties (class 6J) and solar canopies in parking areas (class 9M) within 3km of airports and technical sites associated with civilian and military air traffic services?

Around 45 respondents provided a comment at Question 11 although some to note that they would defer to industry experts or airport operators.

Reasons PDR should be amended

The reason given most frequently in support of amending the 3km exclusion zone around airports and aviation or defence installations was that some airports (including Glasgow and Edinburgh) either have, or are planning, installation of their own solar panels. Other arguments included that:

• Solar panels are designed to absorb irradiation and have a lower reflectance than either architectural glass or water which are often found around airports.
• The UK Government’s National Policy Statement for Renewable Energy Infrastructure^[3] reports that ‘there is no evidence that glint and glare from solar farms results in significant impairment on aircraft safety’.
• The NPF 4 removed language around ‘glint and glare,’ in light of evidence that solar panels do not interfere with communications equipment or infringe on airspace.
• Scotland is the only part of the UK that has constraints on non-domestic solar due to aviation interests.

While some respondents specifically noted their approval for reduction of the exclusion zone to 2km or 1km, Private sector - energy/renewables respondents in particular proposed that the exclusion zone should be eliminated altogether. Arguments in favour of removing the exclusion zone included the potential for generation of renewable energy by solar canopies over airport carparks. It was also suggested that:

• PDR regulations are sufficient to determine the suitability of solar installations.
• If a local risk to aviation was demonstrated, Councils could seek to restrict PDR by way of an Article 4 Direction.

Reasons PDR should not be amended

Some respondents simply stated a view that the PDR should not be amended while others cited visual impact or safety, including the impact of glint and glare impact on flight crew and air traffic controllers as reasons that the 3km exclusion zone should be retained.

Private sector - other respondents who opposed the potential changes noted their own obligations under International Civil Aviation Organisation (ICAO) and CAA regulations to ensure the safety of aircraft manoeuvring on the ground, taking off, landing or flying in the vicinity of the airport. They highlighted safeguarding advice in relation to solar developments set out in guidance on renewable energy developments created by the Combined Aerodrome Safeguarding Team^[4]. This guidance operates in the context of applications for planning permission for development in the vicinity of airports and other safeguarded sites. They also referred to their own obligation to consider all the potential hazards posed by solar photovoltaic developments on or in the vicinity of an aerodrome. Early consultation by developers was seen as essential to ensure safe operation of airports.

It was reported that the guidance sets out requirements for developers to provide airport operators with safety survey information relating to potential for creation of:

• Glint and glare impacting flight crew or control tower staff.
• Wildlife safety hazards (such as nesting birds attracted to solar panels).
• Interference with airport communication, navigation and surveillance systems.

The guidance also suggests developers should consider and provide information to operators on other issues including, thermal plume, turbulence and access routes for fire and rescue vehicles.

Caveats and concerns

Some respondents who expressed support in principle for amending PDR added caveats that this was provided that:

• Aircraft safety is considered.
• No specific objection is raised by a local airport operator or defence facility.
• The CAA and MOD do not object to the changes.
• National Scenic Areas and National Parks remain excluded.

Concerns were also raised that local authorities may lack expertise on solar glare in the context of aviation safety, and that it would be preferable to proceed in consultation with airports, the CAA and MOD.

In terms of other criteria that might be set out in the PDR, suggestions included:

• A requirement for bird proof design around a canopy to ensure no nuisance (noise, bird droppings, insects) is caused to neighbouring properties.
• A requirement for ancillary infrastructure, such as inverters and transformers to adhere to noise limits as for ASHPs and free-standing turbines.
• Specification of a timescale for removing panels that are no longer in use.

Question 12: Do you agree with the proposed new PDR for solar panels within the curtilage of non-domestic buildings?

Responses to Question 12 by respondent type are set out in Table 10 below.

Table 10

	Yes	No	Don't know	Total
Organisations:
Planning authority	14	3	1	18
Public body or corporation	1			1
Professional or representative body	9	2	1	12
Private sector - energy/renewables	5			5
Private sector - thermal efficiency/heating			1	1
Private sector - other	2		1	3
Third sector - built environment/conservation	3		1	4
Third sector - shooting			2	2
Third sector - community councils/representative groups	2			2
Third sector - other	2		1	3
Total organisations	38	5	8	51
% of organisations	75%	10%	16%
Individuals	33	16	31	80
% of individuals	41%	20%	39%
All respondents	71	21	39	131
% of all respondents	54%	16%	30%
% excluding “don’t know” responses	77%	23%

Percentages may not sum to 100% due to rounding

A small majority – 54% of those who answered the question – agreed with the proposed new PDR, while 16% disagreed and 30% did not know. Excluding those who answered “don’t know”, 77% agreed and 23% disagreed. Among organisations, 75% agreed.

Please add any comment in support of your answer

Around 50 respondents provided a comment at Question 12.

Some respondents welcomed the proposed new PDR which was described as pragmatic, or as a reasonable compromise that will bring Scotland in line with planning regulations other parts of the UK. The importance of generating more solar power was also highlighted. Among respondents who disagreed, only a small number opposed the new PDR in principle.

However, most of those who agreed and those who disagreed argued for changes to the proposed clauses as set out in the consultation paper, broadly taking one of two positions:

• That one or more of the proposed limitations should be broadened or tightened, and/or that additional conditions should be added.
• That proposed limitations should be made less restrictive or removed altogether and/or that the development permissible under the PDR should be extended.

Approximately equal numbers of respondents took each position: slightly more respondents proposed an additional limitation, although some of those seeking loosening of restrictions argued for multiple amendments.

Comments on proposed limitations

The surface area of the panels may not exceed 12 square metres

All of the respondents who commented specifically on the proposed 12m² limit on the area of solar panels argued that is too low, too restrictive or an arbitrary figure.

Points raised in favour of a more generous figure included that 12m²:

• Only equates to around 2.5kW of generation capacity and does not reflect the likely higher energy demand of non-domestic properties.
• May represent a significant barrier to development or mean development costs are not justified for the energy generation return from such a small area.
• Is a very small areas for crofters and farmers, particularly in view of the separate PDR for installation of agricultural buildings of up to 1000m².

Suggested amendments included:

• Rather than a fixed area, a sliding scale according to location (for example whether close to houses) or a percentage of the area within a building’s curtilage.
• Defining industrial areas that would be considered permitted development.
• Raising the figure to 1000m² on farms and crofts.

The installation must be wholly within the curtilage of the non-domestic building the solar panels provide power or heat to

One respondent disagreed with the requirement for the installation to be located within the curtilage of a non-domestic building rather than within the property boundary. It was argued that PDR should provide flexibility to install solar panels in the most efficient or logical location.

No more than one installation within any particular curtilage

Again, those who commented saw this condition as too restrictive. In particular, it was suggested that it is not clear why PDR should be restricted to a single, larger array if there are other benefits in splitting the same area into two smaller arrays.

The PDR does not apply in National Scenic Areas, National Parks or within the curtilage of a listed building

This was the clause that attracted the highest number of comments, albeit from respondents arguing two very different viewpoints.

For some the exclusion of National Scenic Areas and National Parks was welcome with one respondent reasoning that defined curtilages are not always present in rural areas, leading to a risk of the proliferation of installations in sensitive locations. Others argued that the exclusion should also be extended to conservation areas or to:

• World Heritage Sites.
• Scheduled Monuments.
• Battlefields.
• The Inventory of Gardens and Designed Landscapes.
• Sites of Special Scientific Interest (SSSI).
• National Nature Reserves.

With respect to heritage assets, it was argued that it is important to distinguish between curtilage and setting, and that restrictions on development within the curtilage of a heritage asset can only partially mitigate against potential effects on its wider setting.

A different perspective was that National Scenic Areas, National Parks and the curtilage of listed buildings should not be excluded from the PDR, as some installations could be appropriate in these areas. Arguments in favour of this position included that:

• Solar installations do not have a permanent impact and can be managed in the design stage to have a minimum impact on historical sites or archaeological remains.
• Small scale installations within the curtilage of a listed building would have no more adverse impact on the character of the building than a car park or a café.
• It is inconsistent that (subject to complying with the size and location specifications and obtaining Listed Building Consent) solar panels can be attached to non-domestic listed buildings but there is no PDR for the installation of solar panels within the curtilage of non-domestic listed buildings.

A specific suggestion was that the PDR should be extended to the curtilage of Category C listed buildings.

If the building is located in a conservation area, the PDR only permits installations in the rear curtilage

Some respondents referred back to points made at Questions 1 and 2 with respect to concerns regarding the potential for solar panels to be visible from public spaces within conservation areas, with suggestions that that the PDR should apply to the rear curtilage in a conservation area ‘unless the rear elevation faces a public or green space’ or that any location visible from the public realm in a conservation area should be excluded.

There were also views that:

• Installations in the rear curtilage of non-domestic buildings in conservation areas would be acceptable as the impact on character and appearance of conservation areas would be minor.
• Many rural and agricultural buildings do not have ‘front’ and ‘rear’ curtilages that reflect public visibility of solar installations.
• Allowing PDR for innovative designs and layouts that are compatible with conservation areas would create a market for innovative solar designers.

Equipment is to be removed if inoperable or no longer in use

Respondents commenting on this clause highlighted issues regarding enforceability for inoperative panels including that, in practice, it will be impossible to police.

It was also argued that:

• Visual impact does not depend on whether solar panels are operative or otherwise.
• Even if electrical generation capacity is impaired, it may still have a useful function as a canopy.
• In contrast, farmers are not required to remove derelict farm buildings.

Suggestions for additional restrictions or wider PDR

Respondents also proposed both additional restrictions they would like to see put in place and additional aspects to which they would like PDR to be extended:

In terms of further conditions on where the PDR should apply suggestions included restrictions:

• In all cases, for non-public elevations facing a road, given the potential for glare from the panels.
• Within 3km of an aerodrome to ensure safeguarding processes are followed.
• In close proximity to the operational railway line where glint and glare could distract or dazzle train drivers, creating concerns for safety.
• In areas used for parking or vehicle servicing, to ensure these facilities are retained.

Additional requirements were also suggested with respect to:

• Application of the same tests as applied to buildings which neighbour domestic households as for domestic installations.
• Noise limits for ancillary infrastructure.
• A specification that all installations should be above 2.5m.
• Load management rules for days when renewable generation could overwhelm national grid.
• A prior notification and approval process to improve mitigation of potential impacts on the historic environment.

In terms of possible extension of the PDR there were suggestions that:

• PDR should be granted in the case of certain, non-intrusive ground fixings such as ballasted systems, as these would propose less risk of disturbing buried archaeological artifacts or areas of interest.
• Agrivoltaics should be included or otherwise afforded the same planning consenting as for glasshouses and polytunnels.

3.2 Solar Canopies in Parking Areas

On 31 March 2023, PDR for solar canopies in qualifying parking areas were introduced in a new Class 9M of the GPDO. The purpose of such canopies was primarily to power EV chargers. The legislation does not rule out the use of any excess power generated for other purposes, but the primary purpose of the solar canopies must be to power EV chargers.

It is now proposed that:

(i) The restriction that solar canopies installed under Class 9M must primarily be for the powering of EV chargers should be removed.

(ii) No new maximum output capacity for electricity generation would be introduced to Class 9M.

Please note that PDR relating to solar panels on domestic and non-domestic buildings are covered at earlier questions and that answers to Question 11 (relating to potential amendment to current restrictions that apply to solar panels within 3km of airports) would also apply to solar canopies in parking areas.

Question 13: Do you agree with the proposal to extend the Class 9M PDR to allow these to apply to solar canopies generally, rather than only those for which the primary use is charging of electric vehicles?

Responses to Question 13 by respondent type are set out in Table 11 below.

Table 11

	Yes	No	Don't know	Total
Organisations:
Planning authority	15	1	1	17
Public body or corporation
Professional or representative body	5	1	3	9
Private sector - energy/renewables	6			6
Private sector - thermal efficiency/heating			1	1
Private sector - other	3		1	4
Third sector - built environment/conservation	1	1		2
Third sector - shooting			2	2
Third sector - community councils/representative groups	2			2
Third sector - other	1		1	2
Total organisations	33	3	9	45
% of organisations	73%	7%	20%
Individuals	31	15	30	76
% of individuals	41%	20%	39%
All respondents	64	18	39	121
% of all respondents	53%	15%	32%
% excluding “don’t know” responses	78%	22%

A small majority – 53% of those who answered the question – agreed with the proposal to extend class 9M PDR to allow these to apply to solar canopies generally, while 15% disagreed and 32% did not know. Excluding those who answered “don’t know”, 78% agreed and 22% disagreed. Among organisations, 73% agreed.

Please add any comment in support of your answer

Around 50 respondents provided a comment at Question 13.

Reasons to extend primary use

Some respondents saw the proposed changes as reasonable or logical, and it was suggested that other restrictions in class 9M PDR can protect amenity, minimise impacts in terms of landscape, or ensure that canopies are not overly dominant or inappropriately sited. It was also suggested that the current criteria are too restrictive or that all solar generation should be encouraged.

Private sector - energy/renewables respondents in particular pointed to potential to export power, either to the grid or to surrounding homes or businesses if opportunities for peer-peer trading allow generators to sell electricity to local consumers.

There were also suggestions that the Scottish Government should go further, for example to extend PDR to include associated infrastructure such as battery storage or to allow solar thermal to heat water.

It was noted that the proposed change could lead to much wider application of the PDR with some respondents seeing this as positive, resulting in more parking areas installing solar canopies ahead of requirements for EV charging in car parks or regardless of the presence of EV chargers.

Reasons not to extend primary use

Among Individual respondents who did not support the proposed amendments there were widely differing reasons – with a very small number arguing that there should be no restrictions at all, and a greater number that there is no need for change to the current arrangements. With respect to the latter position, it was suggested that there should be a requirement for planning permission and hence democratic oversight.

Specific objections to the proposed amendments included:

• That the revised PDR could effectively allow development of solar farms in inappropriate locations.
• A risk of cumulative damage to Scotland’s historic environment.

On the latter point it was argued that although a local authority can introduce Article 4 Directions, in practice these create additional resource pressures and are not likely to be used.

Caveats and concerns

Both respondents who agreed in principle and some who expressed more serious concerns highlighted conditions they would wish to see imposed if class 9M is amended, including with respect to:

• Limits on the size and dimensions of canopies.
• Limits on noise generated by ancillary infrastructure, with a suggestion that the noise limits for ASHP and free-standing turbines should be adhered to.
• Exclusion of statutory protected areas, World Heritage Sites, conservation areas, locations visible from the public realm in a conservation area and the curtilage of listed buildings.

Concerns were also raised with respect to potential for:

• Glint and glare.
• Loss of parking spaces or removal of shade such as existing trees in carparks to maximise energy generation.

Additionally, there were suggestions that planning guidance should:

• Specify that no part of the canopy or its supports should encroach onto pathways or footways on public land, resulting in pinch points or loss of pedestrian space.
• Include more information on fire performance.

Question 14: Do you agree that any extension of Class 9M PDR to be for the purposes of producing electric power generally, should not have a maximum power generation capacity?

Responses to Question 14 by respondent type are set out in Table 12 below.

Table 12

	Yes	No	Don't know	Total
Organisations:
Planning authority	13	2	2	17
Public body or corporation
Professional or representative body	5	1	3	9
Private sector - energy/renewables	5			5
Private sector - thermal efficiency/heating			1	1
Private sector - other	2		1	3
Third sector - built environment/conservation
Third sector - shooting			2	2
Third sector - community councils/representative groups	2			2
Third sector - other	1		1	2
Total organisations	28	3	10	41
% of organisations	68%	7%	24%
Individuals	30	15	31	76
% of individuals	39%	20%	41%
All respondents	58	18	41	117
% of all respondents	50%	15%	35%
% excluding “don’t know” responses	76%	24%

Half of respondents – 50% of those answering the question – agreed that an extended class 9M PDR should not have a maximum power generating capacity, while 15% disagreed and 35% did not know. Excluding those who answered “don’t know”, 76% agreed and 24% disagreed. Among organisations, 68% agreed and only 7% disagreed, with Planning authorities and Representative bodies the only groups where any respondents disagreed.

Please add any comment in support of your answer

Around 35 respondents provided a comment at Question 14 although most were very brief.

Reasons there should be no maximum capacity

Some respondents simply noted their agreement with the proposed change or expressed a view that it is not necessary to restrict generating capacity. Others noted that, in practice, generating capacity will be determined by the size of parking structures.

Reasons that a maximum capacity should be retained

Reflecting objections raised at Question 13, some Individual respondents argued that a requirement to obtain planning permission should be retained. There was also concern that the amended PDR could be used to develop solar farms, and it was suggested that a limit should be based on the maximum requirement for onsite EV charging, plus requirements for onsite lighting and small shop or café.

Caveats and concerns

Also as at Question 13, respondents who agreed in principle and some who disagreed with the proposed amendment highlighted issues they would wish to see addressed with respect to:

• Maintaining limits on the size and dimensions of canopies.
• Excluding conservation areas and the curtilage of listed buildings.
• Addressing noise generated by ancillary infrastructure.

Other points raised more specifically with respect to removing the limit on power generation related to:

• Potential health and safety issues.
• Grid capacity and integrity.

On grid capacity it was argued that, although removing power generation constraints is welcome, grid constraints are already causing some businesses to delay installation of solar PV panels and that, without appropriate upgrading, potential benefits from exporting additional solar electricity to the grid will be lost.

3.3 Non-domestic air source heat pumps

There are currently no specific PDR for ASHPs associated with non-domestic buildings. However, the Heat in Buildings Strategy commits the Scottish Government to ‘develop and introduce strengthened regulation for non-domestic buildings, to ensure they reduce demand for heat where feasible and install a zero emissions heating supply’ and ASHPs are likely to play an important role in this.

It is proposed that a new class of PDR applying to all non-domestic buildings would allow the installation, alteration or replacement of an ASHP on the building or within its curtilage. The PDR would only apply:

(i) In the case of ASHPs attached to buildings – if it is attached to a rear or side elevation (or a rear elevation in a conservation area).

(ii) In the case of ASHPs within the curtilage of buildings – if it is within the rear curtilage and not within 5m of a curtilage boundary.

(iii) If it is not located within a World Heritage Site or within the curtilage of a listed building.

Although no size limits on ASHPs installed under this new PDR are proposed it is proposed that, if installed on a building which also contains residential accommodation, then the outdoor compressor unit must not exceed 1.5 cubic metres and the external parts of the ASHP (including any housing etc.) must not be within 1m of any window of a habitable room, or door of a flat in the same building. Additionally, the ASHP would need to be removed as soon as is reasonably practical where it is no longer needed or no longer capable of providing heating or hot water.

Question 15: Do you agree with the proposed PDR for air source heat pumps on non-domestic buildings?

Responses to Question 15 by respondent type are set out in Table 13 below.

Table 13

	Yes	No	Don't know	Total
Organisations:
Planning authority	12	6		18
Public body or corporation	1			1
Professional or representative body	9	2	2	13
Private sector - energy/renewables	1			1
Private sector - thermal efficiency/heating
Private sector - other	2		1	3
Third sector - built environment/conservation	2	1		3
Third sector - shooting			2	2
Third sector - community councils/representative groups	2			2
Third sector - other	2		1	3
Total organisations	31	9	6	46
% of organisations	67%	20%	13%
Individuals	25	16	33	74
% of individuals	34%	22%	45%
All respondents	56	25	39	120
% of all respondents	47%	21%	33%
% excluding “don’t know” responses	69%	31%

Percentages may not sum to 100% due to rounding

Nearly half of respondents agreed with the proposed PDR for air source heat pumps on non-domestic buildings; 47% of those answering the question indicated this, while 21% disagreed. The remaining 33% did not know. Excluding those who answered “don’t know”, 69% agreed and 31% disagreed. Among organisations 67% agreed.

Please add any comment in support of your answer

Around 50 respondents provided a comment at Question 15.

A number of these respondents referred to issues raised at Question 3 with reference to installation of ASHPs for domestic properties, for example highlighting concerns around visual and noise impacts, especially in conservation areas and designated areas.

Reasons for supporting the proposals

Comments expressing support for proposals included a view that consistency of regulations across domestic and non-domestic buildings is a logical approach. This included reference to perceived inconsistencies across planning authorities in enforcement of current regulations for non-domestic ASHP, and delays caused by the additional administrative burden on authorities. There was also reference to the importance of decarbonising heat in non-domestic buildings for net zero policy aims, and a view that proposals can further support this process.

Responses also included support for specific aspects of the proposed PDR for non-domestic ASHPs. For example, respondents highlighted proposals to prevent installation of ASHPs on front elevations under PDR, restricting PDR in World Heritage Sites, and limiting installation to the curtilage of non-domestic buildings.

Concerns and opposition

Concerns raised by respondents were most commonly related to the potential noise impacts associated ASHP on non-domestic buildings, with some reiterating key concerns raised at Question 3 in relation to domestic properties. For example, respondents noted potential for cumulative noise impacts associated with multiple installations in close proximity (including on the same property), and issues with the current MCS 020 methodology for assessment of noise impacts. It was also suggested that proposed limits on the size and placement of external units will not be effective in mitigating noise impacts where buildings also include residential properties. Indeed, some suggested that noise impacts may be a particular concern for installation to non-domestic buildings, with reference to potential for multiple larger units to have a significant noise impact on neighbouring residential properties.

Respondents also reiterated concerns around potential visual impacts, including for conservation areas and other sensitive landscapes. This was highlighted as a particular concern if PDR does not specify any limit on the size or number of ASHP units for non-domestic buildings.

Other general issues and concerns in relation to PDR for non-domestic ASHPs included:

• A requirement for clarification around how proposed PDR for non-domestic ASHPs will relate to other regulations and planning requirements, for example around air conditioning compressor units, and whether these requirements could be challenged if PDR is granted only for ASHP installation.
• Concern around the potential impact of ASHPs installed to ground floor non-domestic buildings with residential properties above.
• A suggestion that requirement for use of acoustic enclosures for larger ASHP units may be appropriate.

Comments on proposed limitations

In the case of ASHPs attached to buildings – if it is attached to a rear or side elevation (or a rear elevation in a conservation area).

The proposed restriction of ASHPs to the rear and side elevation of buildings was seen as too restrictive, with some noting that installation to a rear or side elevation may not be feasible dependent on the building layout. It was also suggested that limiting installation to rear elevations in conservation areas is insufficient to mitigate against potential visual impacts, given the diversity of building design and layout in these areas. This included concerns around the potential impact of installations above ground floor level.

In the case of ASHPs within the curtilage of buildings – if it is within the rear curtilage and not within 5m of a curtilage boundary.

Respondents questioned the requirement that ASHPs must not be within 5m of a curtilage boundary, and suggested that this is too restrictive for businesses that may lack the external space to meet the requirement. There was also concern that the phrasing of this requirement could permit a wall-mounted ASHP within a short distance of a neighbouring property.

If it is not located within a World Heritage Site or within the curtilage of a listed building

The limit on PDR within the curtilage of a listed building was also questioned, and it was noted that these buildings are often used as event or business spaces where ASHPs would be desirable. It was suggested that PDR could be permitted in these locations, with appropriate conditions, without adversely impacting listed buildings.

Limits on size and positioning if installed on a building which also contains residential accommodation

There was concern that proposed limits on the size and positioning of external units may not be sufficient to limit noise impacts, especially for neighbouring residential properties. There was also concern around the potential for proliferation of heat pumps in highly visible locations, and it was noted that there is no limit proposed on the number of ASHPs installed to a single non-domestic building.

Size restrictions were also seen as potentially inhibiting innovation, for example if technological development results in larger ASHP units.

Suggestions for additional restrictions or wider PDR

Respondents suggested a wide range of additions and amendments to the proposed PDR for non-domestic ASHPs.

In relation to limiting installations to rear and side building elevation, respondents suggested that:

• Heat pumps should be limited to ground level.
• PDR should not apply in conservation areas, or should specify that installations in conservation areas should be in a location not visible from a public place.
• ASHPs should be permitted on a front elevation where installation to the side or rear elevation is not technically feasible.
• Reference to ‘attached’ should be expanded to permit ASHP outdoor units that are ground mounted but adjacent to the building.

In relation to limiting installations to the rear curtilage but not within 5m of boundary, it was suggested that this requirement should be removed or that there should be flexibility, for example relating to size, location and noise rating of the ASHP.

With respect to limiting PDR in World Heritage Site and within the curtilage of a listed building, respondents suggested:

• PDR should also be restricted in other designated areas such as Site of Special Scientific Interest, National Scenic Areas, National Parks, battlefields, the Inventory of Gardens and Designed Landscapes and National Nature Reserves.
• PDR should apply within the curtilage of a listed building, with appropriate conditions.

In relation to limits on the size and positioning of external units, respondents suggested:

• The location of units should also take account of noise impacts.
• Limits on distance from windows and doors on the same building should be extended to include distance from doors and windows on any neighbouring properties.
• The minimum permitted distance from any neighbouring residential properties should be increased where multiple ASHPs are installed to a non-domestic building.
• PDR should allow for rooftop ASHP installations for non-domestic buildings.

Other additions and amendments suggested by respondents included that the Scottish Government should reconsider the approach to assessment and mitigation of noise impacts, consistent with suggested amendments to PDR for domestic ASHPs. This included suggestions that an alternative approach to noise assessment should take account of different levels of background noise and cumulative impacts, and set appropriate noise limits. It was also suggested that the Scottish Government should consider the findings of UK Government and other research on noise from ASHPs.

It was also argued that:

• PDR should specify limits on the number of ASHPs permitted on a single building.
• PDR should not apply within the curtilage of a building that also contains residential accommodation.
• Where an ASHP is to be installed within a statutory safeguarding zone, prior notification and approval should apply to ensure that MOD are consulted.
• PDR should be restricted where the ASHP unit would encroach onto a footpath or right of way.

3.4 Non-Domestic Ground Source and Water Source Heat Pumps

Class 6I PDR permit the installation, alteration or replacement of underground pipes within the curtilage of a non-domestic building required in connection with a ground source heat pump or a water source heat pump or both. There are a number of restrictions, including that the total heat output of all microgeneration installed within the curtilage of a non-domestic building would exceed 45 kilowatts thermal.

It is proposed that class 6I is amended to:

(i) Clarify that in addition to the underground pipes, the PDR also cover the ground/water source pump and any above-ground connections to the pump.

(ii) Remove the reference to maximum heat output.

Question 16: Do you agree with our proposed amendments to class 6I PDR for ground and water source heat pumps on non-domestic buildings?

Responses to Question 16 by respondent type are set out in Table 14 below.

Table 14

	Yes	No	Don't know	Total
Organisations:
Planning authority	14	3		17
Public body or corporation
Professional or representative body	8	2	2	12
Private sector - energy/renewables	2			2
Private sector - thermal efficiency/heating
Private sector - other	1		1	2
Third sector - built environment/conservation
Third sector - shooting			2	2
Third sector - community councils/representative groups	2			2
Third sector - other	1		1	2
Total organisations	28	5	6	39
% of organisations	72%	13%	15%
Individuals	28	14	32	74
% of individuals	38%	19%	43%
All respondents	56	19	38	113
% of all respondents	50%	17%	34%
% excluding “don’t know” responses	75%	25%

Percentages may not sum to 100% due to rounding

Half of respondents – 50% of those who answered the question – agreed with the proposed amendments to class 6I PDR for ground and water source heat pumps on non-domestic buildings, while 17% disagreed. Excluding those who answered “don’t know”, 75% agreed and 25% disagreed. The remaining 34% did not know. The balance of opinion was different amongst organisations, where 72% of those answering the question agreed with proposals.

Please add any comment in support of your answer

Around 40 respondents provided a comment at Question 16.

Reasons for supporting the proposals

A number of respondents expressed general support for the proposals as a reasonable approach to PDR for ground and water source heat pumps, including specific support for a consistent approach across domestic and non-domestic buildings. Proposals were also seen as important in contributing towards delivery of net zero targets.

Respondents indicated specific agreement with proposals to extend PDR to include the pump and above-ground connections, suggesting that this would provide much needed clarification. It was suggested that there is limited potential for adverse visual and other impacts if installations are within the curtilage of buildings.

There was also specific support for the proposed removal of the reference to maximum heat output. Respondents agreed that the requirement is no longer relevant with some also noting difficulties around accurate monitoring of maximum heat output to enable enforcement.

Concerns and opposition

There was specific concern that proposals do not include consideration of potential noise impacts associated with ground or water source heat pumps. Reference to potential noise impacts included specific issues for structurally connected flatted and other residential properties and neighbouring residential properties.

Some respondents sought clarification that current restrictions on PDR within designated areas would continue to apply, including a view that allowing ground and water-source heat pumps under PDR would not be appropriate in areas of archaeological interest. There was also concern around installation in areas of potentially contaminated land without sufficient risk assessment, and an associated view that there is currently a lack of understanding around contaminated land in relation to PDR. However, it was also suggested that ground and water-source heat pumps are suitable for use within the curtilage of World Heritage Sites, listed buildings and the Inventory of Gardens and Designed landscapes.

Some respondents wished to ensure that any restrictions and conditions on PDR are minimised to encourage installation of heat pumps across all suitable building types and locations, and to take account of potential future developments in technology.

Additions and amendment to proposals

Respondents suggested a small number of additions and amendments to proposals, including that PDR should:

• Be restricted in areas of archaeological interest, for example requiring archaeological oversight and reinstatement of surfaces.
• Include suitable noise controls.
• Specify a maximum time period for restoration of surfacing, and include a requirement that this incorporates appropriate controls on any contaminated soils.
• Require engagement with the local authority Contaminated Land Officer to identify any history of land contamination, and where risks are higher to agree the scope of risk assessment.
• Include conditions to protect the integrity of sites.

For installation of ground or water source heat pumps in areas impacted by mining or on brownfield sites or other locations with potential for contamination, it was argued that planning requirements outlined in PAN33 should apply.