I also live in a conservation area in Derbyshire. I simply emailed the planning department to ask the question. The reply was unequivocal; I did NOT require planning permission. That, however, won't help you much as each council seem to have their own criteria.

Thank you for your feedback, Morgan, and indeed councils interpret planning requirements in different ways.

I see you have retrofitted your energy system. I looked at Alpha ESS G3 Inverter & Battery (5kW/10kWh), although not sure what the 'Smile' means. I was linked through Heatable for this product. Alpha seem to be big on mainland Europe and now breaking into the UK market.

Early stages for us, not having completed our purchase yet, but trawling the market and going to trade shows to see what's on offer currently. It's a bit of a minefield tbh; although finding RHH has been good, reading about real-world customer experience. I have ordered the Ultimate Guide too.

If you have the time, I'd be interested in your view  and experience with your Alpha kit and how well it integrates with your PV and ASHP.

@colinc 

Simple answer is that it all works fine. That said, whilst I can recommend the ESS kit I cannot do the same for my installer who has gone into liquidation and now trading under a different name.  That applies only to the solar installer who is separate from the ASHP installer.

@morgan  Thanks, and sorry to read about your PV installer;  hopefully all is  good with the panel installation though.

I am new here and guess that "name & shame" breaks RHH Rules.

I'll post again when the Council Planners reply.

@colinc 

Do your own due diligence re reviews etc but if you decide to go with Alpha ESS see link below re finding an installer.

If necessary I might be able to find the new name of mine.  He’s based in N Yorkshire so may not be a concern to you.

https://www.alpha-ess.co.uk/find-alphaessuk-installer

Update: ....  Council said, "Yes", to installing PV & ASHP,  with a few Conservation Area (CA) caveats: basically don't put PV on walls facing a highway; and ASHP max volume is 0.3 m3, basically sited out of view from within the CA.  ...  😎 

North Devon Council turned around my 'Pre-Application' very quickly; just over a week, with their due date by 10th Nov. 

<Extract from transcript - verbatim>

Solar PV

After conducting a history search on the property, I can see that Part 14 (renewable
energy), of Schedule 2 of the GDPO remains intact. In order for the proposed works to be
completed under permitted development, the solar panels must comply with the
restrictions stated in Class A (installation or alteration etc of solar equipment on domestic
premises).

Class A states that development is not permitted if-
i. the solar PV would protrude more than 0.2 metres beyond the roof slope when measured from the perpendicular with the external surface of the pitched roof slope.
ii. in the case of solar PV on a pitched roof, it would result in the highest part of the solar PV or solar thermal equipment being higher than the highest part of the roof
(excluding any chimney)
iii. in the case of land within a conservation area the solar PV would be installed on a
wall which fronts a highway.

Condition A.2 reiterates that development is permitted by Class A subject to-
i. solar PV is, so far as practicable, sited so as to minimise its effect on the external appearance of the building;
ii. solar PV is , so far as practicable, sited so as to minimise its effect on the amenity of the area.

To confirm, if your proposal conforms with the above rules/conditions, works can be
completed under permitted development and no formal planning permission will be
required for the installation of Solar PV.

ASHP

You are also proposing to install air source heating. In order for this to be completed under
permitted development, you must comply with Part 14, Class G (installation or alteration
etc of air source heat pumps on domestic premises).

Development would not be permitted by Class G -
i. Unless the air source heat pump complies with the MCS Planning Standards
ii. Development is not permitted by Class G if —
iii. (a) in the case of the installation of an air source heat pump, the development would
result in the presence of more than two air source heat pumps on, or within the
curtilage of, a detached dwellinghouse;
iv. the volume of the air source heat pump’s outdoor compressor unit (including any
housing) would exceed 0.6 cubic metres —
v. (i) in the case of the installation of an air source heat pump on, or within the
curtilage of, a dwellinghouse, exceed 1.5 cubic metres;
vi. in the case of land within a conservation area the air source heat pump —
(i) would be installed on a wall or a roof which fronts a highway; or
(ii) would be installed so that it is nearer to any highway which bounds the curtilage
than the part of the dwellinghouse which is nearest to that highway
If your proposal for the installation of an air source heat pump conforms with the above
rules/conditions, works can be completed under permitted development, and no formal
planning permission will be required.

So, PV and Battery install planning can commence.

ASHP planning can also start with Heat Loss Calcs, and assessing the viability of continuing with the existing CH plumbing with Microbore Rads. Meantime we will continue with the Oil boiler; likely through this winter into next Spring, because I deem it foolhardy to make a major CH changes into the upcoming Winter.

POVs welcome.

Posted by: @colinc

↑

Meantime we will continue with the Oil boiler; likely through this winter into next Spring, because I deem it foolhardy to make a major CH changes into the upcoming Winter.

POVs welcome 

If there is any way you can determine daily oil consumption (with date) through the season I suggest you do so.  Ideally run your oil boiler for the season as close to the way you would an ashp as possible ie low flow temp on 24*7 or at least most of the time.

This will enable you to fairly robustly sense check heat loss, which may be absolutely crucial given you have microbore, by plotting against average daily temp.  I am guessing your house isn't standard estate build so it's probably the type of house where surveys can be way out (eg a factor of 2).

A crude sense check can be done from annual consumption which is better than nothing (and you can presumably do now to allow you to interrogate surveys) but if you can do daily it's much better.  It doesn't matter if a few days are missing so long as you have the dates.

@jamespa Thanks for the input James, recording Oil usage is something I will try to do. I'm unsure whether there's any metering or a way of measuring, other than a visual on the tube outside the tank; which will likely make daily measuring a challenge.

Posted by: @colinc

↑

@jamespa Thanks for the input James, recording Oil usage is something I will try to do. I'm unsure whether there's any metering or a way of measuring, other than a visual on the tube outside the tank; which will likely make daily measuring a challenge.

Oh I see, I thought that there might be some sort of gauge, I have never had oil heating!  In that case you are pretty much reliant on annual consumption, which is still much better than nothing as a means to perform a sense check, which I strongly recommend you do given what you have said about the house.

@jamespa No worries, haven't seen an oil fired system in decades. I'll get there.

Posted by: @jamespa

↑

Oh I see, I thought that there might be some sort of gauge, I have never had oil heating!

When we had our oil boiler, we had one of those wireless gauges that relied on some kind of echo system. Never worked, so we relied on a dipstick. And, me being the dipstick in question, I’d have to find a spare stick from time to time. Not accurate.