Why 270mm Loft Insulation Became the New UK Standard

If you’ve been researching loft insulation recently, you may have seen installers talking about and recommending 270mm–300mm insulation depth as the new UK standard. But why exactly is that the case? This guide explains what 270mm insulation means, why the standard increased, and what it actually does for your home without confusing technical jargon.

What Does That Actually Mean?

The 270mm refers to the thickness of the insulation layer laid across your loft floor. In most homes across Barking & Dagenham, this is done using mineral wool, fibreglass, or insulation rolls.

Years ago, many lofts were fitted with just 100mm–150mm of insulation. At the time, that was considered acceptable. But that was when energy costs were much lower, building materials were less advanced, and heat loss standards were not as strict.

Today, anything below 270mm is considered under-insulated and inefficient by modern standards.

Therefore, the UK Government and energy efficiency bodies increased the recommended depth due to a combination of these reasons:

Homes were losing too much heat through the roof
Energy bills were rising year after year
Older insulation depths were no longer providing enough protection
Heating systems were being overworked

It’s now widely accepted that up to 25% — sometimes even more — of a home’s heat can escape through the roof if the loft is poorly insulated. By upgrading to 270mm, heat loss can be reduced by up to 25%, meaning your boiler runs less often and for shorter periods.

Does 270mm Loft Insulation Work With All Insulation Types?

Yes — the 270mm standard applies across common insulation methods including:

Mineral wool (Rockwool)
Fibreglass insulation
Quilt & roll insulation

The key isn't about the material — it's about the loft insulation reaching full depth coverage without any gaps or compressed layers.

You can read more about the material options here: Different Loft Insulation Types

How Much Does It Cost to Upgrade to 270mm Loft Insulation?

The cost depends on a few factors such as:

Loft size
Ease of access
Whether old insulation needs removing
Whether boarding or ventilation upgrades are needed

Typical Barking & Dagenham pricing ranges are explained here: Loft Insulation Costs

Upgrading the insulation in an existing loft is often much cheaper than people expect, especially compared to long-term energy savings. As a rough guide, most homes fall between £650–£1,400, depending on size and condition.

What 270mm Insulation Does for Your Home

Upgrading to the correct depth isn’t only about rules — it’s about real-world benefits:

Keeps heat inside the home for longer
Reduces cold upstairs rooms and temperature drops
Cuts heating bills consistently year after year
Improves EPC rating
Reduces condensation and damp risk
Extends the life of roof timbers

Many homeowners in Barking & Dagenham who upgrade from old 100mm insulation to 270mm insulation save £300–£500 per year on average.

Is It Worth Upgrading If You Already Have Some Insulation?

Yes — topping up old insulation is one of the fastest return upgrades you can make. If your loft has:

Patchy insulation coverage
Compression from storage boards
Damp or damaged material
You still feel cold drafts in upstairs rooms
Your energy bills have gone up with no clear reason

Then even if "some insulation" is present, it's likely not doing its job properly.

The Bottom Line

Prevents up to 25% of heat loss
Cuts heating bills long-term
Reduces strain on your boiler
Makes your home more comfortable year-round

If your loft hasn’t been upgraded in years, there’s a strong chance you’re losing money every single month through the roof.

Ready to Check Your Insulation Depth?

If you’re unsure how deep your insulation is — or whether it meets the 270mm standard — speak with a local installer.

CALL NOW FOR A FREE LOFT INSULATION QUOTE BACK TO HOME