Last month, the UK government announced that plug-in solar panels would become legal to buy from August 27. Now, new planning rules have passed into law that specify exactly where you can — and can't — install them. Before we get into the details, it's important to understand that these rules apply to "permitted development" – changes you can make to your home without needing to apply planning permission. If your solar panels don't meet the permitted development rules, you might still be able to install them, but you'll need to apply for planning permission first and pay the relevant fee. A planning officer will then do a survey and determine whether or not you can go ahead.If you install solar panels without the required permission, you could be fined and forced to take them down. Your local council's website will explain how to apply for permission, while the company supplying your plug-in panels should also be able to offer advice on the process."Plug-in solar has the potential to make renewable energy accessible to many more households, but it’s important that consumers have clear information about how and where these systems can be installed," explained a spokesperson for EcoFlow, which specialises in home power stations, solar generators, and panels. "As a manufacturer, EcoFlow recognises its responsibility to provide customers with the information they need to install and use its products in line with relevant UK requirements, and we will ensure our guidance reflects the regulations in place."With that in mind, here are three locations where plug-in solar panels aren't allowed without planning permission.1. On anything wooden(Image credit: Generated by Google Gemini)Before you start planning to install solar panels on your balcony, check what it's made from. If you live in a block of flats, plug-in solar systems don't qualify as "permitted development" if the panels or any other part of the system would be installed on a wooden balcony, wall, or any part of the building's exterior that's clad in timber.If you live in a house, you can't install plug-in solar panels if any part of the system would be mounted on a wooden gate, fence, wall, or other timber surface. This is to avoid the risk of fire. 2. Too high above your roofGenerated with Google Gemini AIGenerated with Google Gemini AIThere are also rules about where you can position solar panels on your roof, similar to those that apply to skylights. If you have a pitched roof (one that slopes downwards), the panels and equipment must not project more than 20cm beyond the roof slope, measured at right angles to it.If you have a flat roof, the highest part of your solar panels and equipment shouldn't sit any more than 60cm above the highest part of the roof — although this doesn't include your chimney.There are plenty of practical reasons for limiting how far out your panels project. They could alter the roofline, cast shadows over neighbours' houses, or catch more wind, which would put your roof under extra stress. 3. Sticking out too far from your wallGenerated with Google Gemini AIGenerated with Google Gemini AIIf you're mounting solar equipment on the wall of your house, it shouldn't project more than 40cm when measured perpendicular to the outside of the wall.The rules are stricter if your house is located right next to a highway. If your home is right beside a highway, your solar equipment must not protrude more than 20cm from the wall. In planning terms, the word "highway" means any route that people can use to pass through, whether on foot, by bike, on horseback or in a vehicle. This includes roads, footpaths, bridleways and cycle paths.If you live an a conservation area, or a World Heritage Site, you shouldn't have solar panels on walls next to highways at all without planning permission.Where to get adviceThere are also other factors to consider before installing a plug-in solar setup. For example, if you rent your home, you'll need permission from your landlord. And if you live in a flat, you might also need permission from the building's management company. "Planning requirements can also depend on the individual property and how and where panels are installed," says EcoFlow's spokesperson. "We would therefore encourage customers to follow the guidance provided with their system, check the latest government and local planning requirements, and contact their local planning authority where they are unsure whether planning permission is required."At EcoFlow, we believe accessibility and safety need to go hand in hand. Making solar available to more households is an important step forward, but it needs to be supported by clear guidance, appropriate regulation, and responsible installation so consumers can adopt the technology with confidence."