DIY vs. professional home insulation: costs, pitfalls and what’s actually worth paying for

Yes, in certain circumstances - namely when the radiator is fitted to an uninsulated external wall - it helps prevent heat being transferred outside the building (and therefore lost). This contrasts with heat absorbed through internal walls, which is redistributed elsewhere in the home.

Yes, the multiple layers in thermal curtains help slow heat loss through the windows they cover. They’re most effective when used with single-paned or poorly sealed windows to block draughts at night-time. Make sure you purchase a multi-layered thermal curtain to maximise its effect. Find out more in our guide to fitting thermal curtains and lined blinds.

To avoid breaching your tenancy agreement, focus on temporary fixes that can be easily removed without causing damage when you leave, such as:

• Stick-on window insulation film
• Draught excluders
• Radiator foil
• Chimney balloons
• Removable foam insulation for lagging pipes.

Ensure you affix them with easily removable materials that won’t damage paintwork or frames, such as double-sided sticky tape.

If you’re unable to insulate a room’s external walls, ceiling or floor, there are still ways you can make it feel warmer without spending a fortune. Low-cost hacks that work include:

• Fit window insulation film to single-paned windows
• Fit thermal curtains or blinds to block draughts
• Block draughts through doors and windows
• Fit reflector panels behind your radiators and make sure they’ve been bled
• Place rugs on bare floors.

Find out more about these effective hacks with our dedicated guide, which includes tips on fitting for maximum effect.

In specific circumstances, yes. If your loft isn’t being used for anything but storage, has regular joists that are easily accessible and is dry and free from damp, you can fit the insulation yourself.

You can purchase mineral wool rolls of loft insulation from any good DIY store. You’ll need to lay two layers with a combined depth of 270mm. The first layer is laid between the joists before a second layer is laid over the joists at right angles to the original layers.

Make sure you keep any eaves ventilation clear and, if you plan to board over the area after insulating it, ensure the boards aren’t fixed directly to the joists to help avoid condensation and mould. Also, avoid compressing the insulation rolls when fitting because this will reduce their effectiveness, leading to more heat loss through your roof.

It’s technically possible but not recommended. Kitchen foil will oxidise quickly, becoming dull and losing what slight effectiveness it has. Specialist radiator foil will do a much better job of reflecting heat from the wall back into the room. It also lasts much longer, but don’t forget to only place it behind radiators attached to uninsulated external walls for the best effect.

Thermal curtains are specifically designed to reduce heat loss and draughts. They come with one or more insulating linings made up of a thick fabric backed by an insulating layer (often metallic to help reflect more heat into the room). In contrast, blackout curtains are made from an opaque coating or tightly woven fabric with the sole aim of preventing light from entering a room. 

Yes, window insulation films are designed to be attached and removed easily. Choose a film kit from a reputable manufacturer, such as Duck, Stormguard or 3G, for best results. When measuring to fit, ensure the film is slightly larger than the pane it’s due to cover so it can be safely attached to the frame using double-sided tape. Find out more with our dedicated guide. 

Before embarking on fitting window insulation film, make sure you’re fully prepared:

• Check the weather forecast before you begin: insulation film shouldn’t be fitted on a damp or windy day
• Avoid cheap kits: instead, stick with a reputable manufacturer like Duck, 3G or Stormguard
• Measure twice, cut once: add on a couple of centimetres to the width and height of your film to ensure it’ll cover the entire glass . Ay gaps will reduce its effectiveness
• Fit carefully: apply your double-sided tape on the frame, not the glass. This ensures the window is completely sealed
• Shrink and smooth: use a heat gun or hair dryer on a low heat to ensure the film fits tightly
• Don’t clean: the film will look mottled and hazy at first, but this should disappear on its own after four weeks at most.

Weatherstripping is a special type of seal or gasket you fit along the edges of windows and doors to protect against weathering. They’re designed to cover gaps and cracks in existing seals, preventing cold air, water and dust from entering your home.

When fitted correctly, weatherstripping should last 5-10 years, but local conditions may mean your seals start to fail before then. As a result, carefully inspect them at regular intervals for signs of wear and tear, including gaps, tears and cracks. Also look for other tell-tale signs, such as draughts or excessive condensation near the edges of your windows and doors during cold and wet months.

Another key factor in how long seals last is the material they’re made from - for example, plastic-based brush seals and sponge tape are less robust than rubber.

To maximise the lifespan of your weatherstripping, follow these tips:

• Clean regularly, but without using harsh chemicals - instead, use a damp cloth with mild soap and water
• Ensure windows and doors are regularly lubricated to reduce wear and tear on weatherstripping. Choose a silicone-based lubricant over a petroleum one
• If you discover any damage, replace the weatherstripping promptly to prevent damage from spreading.