Written by Josh Jackman Published on 14 June 2023 ✔ Fans are 25 times more efficient than portable air conditioners✔ Painting your roof white can reduce the temperature inside by 2-5°C ✔ Get some plants to instantly cool down the inside of your homeWhen it’s too hot, no-one can function properly – and climate change means you’re increasingly enduring high temperatures.But life goes on, and you can’t always lie in a cold bath all day.Here are all the best ways to keep your house cool in summer without spending too much or adding a lot to your carbon footprint. The best ways to keep your house cool at a glance1. Install insulation2. Buy fans or a portable air conditioning unit3. Paint your roof white4. Keep your windows closed in the day and open at night5. Shut doors when you can6. Hang shades or curtains7. Put some plants in your home8. Try to avoid using your oven9. Change your light bulbs10. Plant some trees11. Buy an air-to-air heat pump1. Install insulationThe best first step to cooling your home is insulation.It allows you to maintain a consistent temperature, without letting in all the heat that makes life so difficult in the summer.You’ll also be able to achieve a cool home with less energy, which will allow you to save some money – and if you choose to insulate your loft, you can usually do it yourself.If you’re looking to be as green as possible, use wood fibre, sheep’s wool, recycled plastics, cellulose, or cotton. Other common insulation materials like fibreglass and mineral wool will also do the job nicely, and achieve the same eco-friendly rise in energy efficiency.Make sure you also insulate your doors and windows by filling in gaps with tape, seals, and draught excluders.2. Buy fans or a portable air conditioning unitThese are both good, affordable options to swiftly cool your home down, instead of installing a costly, time-consuming air conditioning system into your whole house.Portable air conditioning units are more effective than fans, as they pump hot air out the window and push cold air into the room, while fans just move air around more quickly.However, fans are much cheaper and more energy-efficient – they use around 25 times less energy – plus they’re much lighter than their bulky air conditioning cousins.Whether you choose to buy a fan or an air conditioning unit, try to get a cross breeze going for maximum results – and if it’s really hot, place a bowl of ice in front of the machine for a refreshingly cold blast.If you get a ceiling fan, make sure you put it on high and set it to rotate anti-clockwise in summer to send air straight down, cooling down the room.In winter, it should rotate clockwise at a slower speed, to warm your space. 3. Paint your roof whiteThis low-cost solution reduces the heat absorbed through your roof by enabling it to act as a heat shield – a tactic already used by millions of people around the world.Painting your roof white, with a special reflective coating on top, usually costs around £200 – and it typically lowers the temperature inside by 2-5°C, according to an Indian study reported by BBC News.This means at current prices, the average three-bedroom house can save £164-£410 with just a bit of paint.4. Keep your windows closed during the day and open at nightThis step instantly makes sense when you think about it.During the day, when the air is hot, keep it out by shutting your windows – then at night, when the air reverts to a humane temperature, open your windows for a cool breeze.It’s free, environmentally neutral, and an easy way to make life more bearable in summer.Just make sure you close your windows each morning, before the temperature soars.5. Shut doors when you canIf you’re not going in and out of certain rooms in your home on a given day, shut their doors.That way, you can cool the rest of your home more easily, because there’s less space to cover – and keep that area cooler for longer.There’s no reason to cool the bathroom or your bedroom if you’re barely going to spend any time in them in the next few hours.6. Hang shades or curtains to keep the heat outThis is another way of quickly insulating your home from heat, in a relatively affordable manner.High-quality thermal curtains usually cost around £100, but any curtains or blinds will block some heat from entering your home and therefore save you money on cooling your home.If you can’t wait, or you’re on an especially tight budget, covering your windows in bubble wrap is a legitimate option, or if it’s easier, you can use pieces of cardboard wrapped in aluminium foil. 7. Put some plants in your homeFor the price of a few plants, you can make the inside of your home look and smell nicer – and also make it significantly cooler.Plants cool down their surroundings through a process called transpiration that’s basically equivalent to human sweating – but without the gross smell.When the temperature rises, plants release excess water from their leaves, which drifts into the air and cools it down.For the best results, choose a few different plants. Here are some good options: ficus, Boston Fern, Aloe Vera plant, Snake Plant, Bamboo Palm, and Spider Plant.8. Try to avoid using your ovenCooking with your oven will heat up your home incredibly quickly, and if you’ve insulated well, that heat will stick around for an interminable amount of time.When possible, take advantage of the good weather and cook outside. Everyone loves a good barbecue.If you can’t avoid cooking with your oven, you could wait to use it until the sun goes down and air cools down, then put it in the fridge for the next day.If you absolutely have to use your oven while it’s hot outside, see if you can close all the doors in the rest of the house and move your fans or air conditioning unit into the kitchen.9. Change your light bulbsIncandescent bulbs are common in the UK, but thankfully not for much longer.Their energy efficiency is poor, plus they give off far too much heat – which is especially horrible during summer.Homes are increasingly switching to LED bulbs, which can cool your house down and cut your electricity bills, all at the same time.A typical three-bedroom household will pay £145 to replace all its light bulbs with LEDs, and make an annual energy saving of £40 – which puts the break-even point at 3.6 years.If you want to get the best LED bulbs around, check out our guide to the best smart light bulbs.10. Plant some treesGreenery is incredibly versatile. Not only can it help cool down your home from the inside, but it can also block sunlight from getting through your windows in the first place.Plant some trees, vines, and other plants that provide you with coverage, and you’ll make your home an oasis from the heat in summer.If you can, get deciduous trees. These little miracles protect you from heat in the summer, then shed all their leaves in the autumn, meaning you can enjoy all the winter sunshine the UK can provide.We'd also recommend avoiding artificial grass and plants, as these won't have the same cooling effect – not to mention it's bad for the environment.11. Buy an air-to-air heat pumpBuying an air-to-air heat pump will cost you around £2,000.But as long as you’ve insulated your home effectively, it’ll cool down your property in summer, and heat it up in winter.An air-to-air heat pump can do the work of a portable air conditioner – taking hot air from the inside of your home and pumping it outside – but also provide heating in the colder months.You can even use it to set different temperatures for individual rooms, meaning everyone in your home can have exactly what they need to get to sleep.It also means you don’t need to waste money cooling down rooms that no-one’s using.Bonus tip: cool yourself downIt’s important to keep your house cool, but it’s also crucial to keep your own temperature low.Taking cold showers and wearing damp cloths can keep you cool, and we also recommend wearing light, loose clothing made of cotton.If possible, you should also sleep on cotton bedsheets, as they’re breathable and won’t doom you to waking up feeling clammy. Written by: Josh Jackman Lead Writer Josh has written about eco-friendly home improvements and climate change for the past four years. His work has been displayed on the front page of the Financial Times, he's been interviewed by BBC One's Rip-Off Britain, and he regularly features in The Telegraph and on BBC Radio.