I’m currently planning a loft conversion and I’ve been told that I should go for thicker insulation like 150mm to meet modern standards, but I’m not entirely sure if that’s necessary or just a recommendation. It seems like quite a lot compared to thinner options, so I’m wondering if it really makes that big of a difference in energy efficiency.
For lofts and roofs, thicker insulation is usually the better choice because heat loss is much higher in those areas, and while checking some options I came across view 150mm which explains that 150mm insulation is commonly used in roofs and attic spaces to achieve higher thermal performance and comply with building regulations, especially in colder climates or for long-term energy savings.
That makes sense if it helps reduce heat loss significantly, especially since heating costs are getting higher. If 150mm insulation can make a noticeable difference in keeping the house warm, it’s probably worth the extra investment upfront.