Planning and paperwork: common questions
Short answers on what needs permission, what needs notifying, and which documents will still matter in ten years.
10 questions · last reviewed
Do I need planning permission for a heat pump?
Usually not. Most installations fall under permitted development, which means no application.
The condition people most often fall foul of is noise: it must not exceed 37 decibels at a neighbour's window. Listed buildings and conservation areas have their own rules.
Do solar panels need planning permission?
Most roof arrays do not. The usual conditions are that panels sit close to the roof plane and not above the ridge.
Listed buildings, conservation areas and flats all have their own rules, which your council can confirm.
What is the 37 decibel rule?
A limit on how loud a heat pump may be at a neighbour's window or door — not at the boundary, and not at your own house.
It is worked out by calculation, not measured, and your installer has to do it before relying on permitted development.
My heat pump fails the noise check. Is that the end of it?
No. It means the current position does not work, not that the house cannot have one.
Moving it further away is worth about six decibels per doubling of distance. Bringing it out of a corner is worth three per wall, and a solid barrier in the line of sight can be worth ten.
Does building control need to know?
Yes, but your installer handles it. Both heat pumps and the electrical side of solar are notifiable.
You should receive a compliance certificate. If an installer suggests you make the application yourself, ask why.
What is a DNO notification?
Telling the company that owns the wires in your street that you have connected something that generates electricity.
Small systems are connected first and notified within 28 days. Larger ones need approval before connection, and that approval is not guaranteed.
What is export limitation?
Where the local network cannot take your full output, you may be allowed to install anyway on condition that a device caps how much you send back.
The annual cost is usually small, a couple of per cent, but it should be disclosed in the quotation.
Which documents matter afterwards?
The certificate above all — it is what grant schemes, export payments and your buyer's solicitor will want.
Then the design calculations, the commissioning records, and the insurance-backed guarantee policy.
My certificate has not arrived. What do I do?
Ask the installer, in writing. Registering the installation is their job and there is a time limit on it.
If that does not work, their certification body is the next step. Missing paperwork is a straightforward complaint for them to act on.
Does any of this affect my EPC?
Yes. Both solar and a heat pump feed into the calculation, though how much depends on the assessment method in force at the time.
The assessor will want to see the certificate as evidence, so keep it somewhere findable.
References
- MIS 3002 — Solar photovoltaic systems
- MIS 3005-D — Heat pump systems: design
- MCS 020 — Sound and vibration for air source heat pumps
MCS publishes its standards in full at mcscertified.com. Where this page describes a requirement, the standard is the authority and this is a reading of it.
Work it out
These run the arithmetic described above.
Heat pump noise assessment
Works out the sound pressure level at a neighbour's window and whether it clears the permitted development limit.
Read next
Installers and certification: common questions
Short answers on what certification means, who checks the checkers, what happens if an installer goes under, and who to complain to.
Heat pumps: common questions
Short answers on whether a heat pump suits your house, what it costs to run, how loud it is and what has to change before one goes in.
Batteries: common questions
Short answers on what a battery does for a house with solar, how big is big enough, whether it keeps the lights on, and whether the sums work.
Heat pumps: common questions
Short answers on whether a heat pump suits your house, what it costs to run, how loud it is and what has to change before one goes in.
Installers and certification: common questions
Short answers on what certification means, who checks the checkers, what happens if an installer goes under, and who to complain to.
Solar panels: common questions
Short answers on what a roof will generate, whether direction and shading matter, what happens to the electricity you do not use, and what the panels need.