# Stop Throwing Money Out the Roof: The 2026 Guide to Loft Insulation & Instant Savings **By Customer Service (Next Day Insulation)** · 2026-02-27 If your home feels like a fridge in the winter and a sauna in the summer, you don’t necessarily need a new boiler or expensive triple-glazing. You might just need to look up. In an uninsulated home, **a staggering 25% of heat escapes through the roof.** That is literally like throwing a quarter of your heating budget out into the street every single month. At **Next Day Insulations**, we believe the smartest renovation is the one that pays for itself. Here is why upgrading your loft insulation is the ultimate "quick win" for your wallet and your comfort. ## Why Your Current Loft Insulation Might Be Failing You Many UK homes _think_ they are insulated, but they are actually under-performing. If your loft was insulated more than 10 years ago, you’re likely falling short of modern standards. 1. **The "Compression" Problem:** If you’ve been using your loft for storage and squashing your glasswool rolls under heavy boxes, the insulation loses its R-value. Compressed insulation is just expensive carpet. 2. **The 270mm Rule:** Current building regulations recommend a depth of at least **270mm** for mineral wool. Most older installs are only 100mm or 150mm thick. 3. **Gaps and Draughts:** Over time, old batts can shift or shrink, leaving "thermal bridges" where heat escapes freely. ## The Best Solutions for Every Loft Type To get the best results without wasting money, you need the right material for the job. Here are our top recommendations: ### 1\. The All-Rounder: Glass Mineral Wool (Loft Roll) This is the classic "blanket" insulation. It’s budget-friendly, easy to install, and offers excellent fire resistance. - **Best for:** Standard joisted lofts with easy access. - **NDI Pick:** [**Knauf Loft Roll 44**](https://nextdayinsulations.com/products/knauf-earthwool-loft-roll-44-combi?_pos=1&_sid=962ffb30c&_ss=r "Knauf Earthwool Loft Roll 44 (Combi Cut) - All Sizes") or [**Isover Spacesaver**](https://nextdayinsulations.com/products/isover-spacesaver-roll-all-sizes?_pos=1&_psq=Isover+Spacesaver&_ss=e&_v=1.0 "Isover Spacesaver Loft Roll - All Sizes"). They are lightweight, perforated for easy fitting, and won't break the bank. ### 2\. The Space-Saver: PIR Rigid Foam Boards If you want to board out your loft for storage or a hobby room but don't want a massive floor-to-ceiling buildup, PIR boards are the answer. - **Best for:** High thermal performance in tight spaces. - **NDI Pick:** [**Celotex GA4000**](https://nextdayinsulations.com/products/celotex-ga4000-pir-insulation?_pos=1&_sid=5b6263d01&_ss=r "Celotex GA4000 PIR Insulation Board") or [**Kingspan TP10**](https://nextdayinsulations.com/products/kingspan-thermapitch-tp10-pir-insulation?_pos=1&_psq=Kingspan+TP10&_ss=e&_v=1.0 "Kingspan Thermapitch TP10 PIR Insulation 1200mm x 2400mm - All Sizes"). These boards offer roughly double the insulation power of wool at half the thickness. ### 3\. The DIY Specialist: Multi-Foil Insulation If you’re insulating the _rafters_ (the underside of the roof) rather than the floor, multi-foils are a game-changer. They reflect radiant heat back into the house and are incredibly thin. - **Best for:** Converting a loft into a usable "warm" room. - **NDI Pick:** [**Superglass Multi-Roll 44**](https://nextdayinsulations.com/products/superglass-multi-roll-44-loft-insulation?_pos=2&_psq=super&_ss=e&_v=1.0 "Superglass Multi-Roll 44 Loft Insulation"). It’s easy to staple up and acts as a vapour barrier at the same time. ## How Much Can You Actually Save? According to the Energy Saving Trust, topping up your loft insulation from 0mm to 270mm can save the average detached home **up to £445 per year** on energy bills. Even a "top-up" (adding a layer to existing insulation) can save over £100 annually. The best part? Loft insulation is one of the few home improvements that **pays for itself in less than two years.** ## Get It Done Tomorrow The biggest barrier to home improvement is waiting for materials. At **Next Day Insulations**, we don't do "weeks." Whether you need a few rolls of Knauf or a pallet of Celotex, we specialise in getting it to your site or doorstep the very next day. **Ready to stop the heat leak?** **[Browse our Loft Insulation Range Here](https://nextdayinsulations.com/ "Browse our full loft insulation range")** or call our expert team at [**0330 133 4833**](tel:0330%20133%204833 "Call Next Day Insulations London") for a bulk-buy quote today. **Tags:** advice, Celotex, guide, insulation, Isover, Kingspan, money-saving, roof, Superglass --- > Source: [Next Day Insulation](https://nextdayinsulations.com/blogs/smart-advice/stop-throwing-money-out-the-roof-the-2026-guide-to-loft-insulation-instant-savings)