The Complete Guide to Room in Roof Insulation

Is your loft conversion freezing in winter and boiling hot in summer? You're probably missing the one thing that turns an uncomfortable attic into a cosy living space: good room in roof insulation.

This often-overlooked home improvement could slash your energy bills while making your upstairs rooms comfortable all year round.

You might be asking what room in roof insulation actually is? It's just a special kind of insulation made for lofts that have been turned into rooms people live in. 

Regular loft insulation just lies flat above your ceiling in an unused attic. 

But room in roof insulation is different - it fits between and under the roof beams, wrapping your loft room in a warm layer that keeps heat from leaking out through your roof.

In this guide, we'll cover everything you need to know about room in roof insulation. You'll learn about the benefits, understand the costs, discover different insulation materials, and follow a clear installation process.

Whether you're planning to do it yourself or hire professionals, this article will help you make smart choices about insulating your roof space.

What is Room in Roof Insulation?

This one is made specially for lofts that you've turned into bedrooms, offices, or other living areas.

It's different from normal loft insulation, which just lies flat on the floor of an empty attic.

Instead, room in roof insulation covers the slanted ceilings, walls, and any flat ceiling areas in your converted loft.

The main purpose of this insulation is to wrap your loft room in what's basically a warm blanket.

This usually involves placing insulation boards between the roof beams (rafters), behind the plasterboard.

These boards are often made from materials like polystyrene or polyurethane because they're really good at blocking heat from moving through them.

This insulation creates a barrier that controls where heat goes. 

During cold winter months, it keeps the warmth inside your loft room rather than letting it escape through the roof.

In hot summer weather, it stops outside heat from getting in. This means your loft stays comfortable no matter what the season.

Benefits of Room in Roof Insulation

At Energex Eco Limited, we've seen how proper room in roof insulation transforms uncomfortable lofts into cosy living spaces while dramatically cutting energy bills.

Beyond just comfort, this simple upgrade delivers remarkable benefits that impact your wallet, wellbeing, and the environment.

Lower Energy Bills

One of the best reasons to install room in roof insulation is the money you'll save.

Most homes lose a lot of heat through the roof, and good insulation can dramatically cut this loss.

Homeowners can save up to £395 each year on energy bills with proper room in roof insulation.

More Comfortable Living Space

Without good insulation, loft rooms are known for wild temperature swings – freezing cold in winter and unbearably hot in summer.

Room in roof insulation creates a stable environment by keeping heat in during winter and out during summer. 

This makes your loft space usable and comfortable all year.

Higher Property Value

Adding room in roof insulation doesn't just make your home cosier, it can add real value to your property.

Today's home buyers are keen on energy efficiency and often willing to pay more for a well-insulated loft space.

When it's time to sell, good insulation becomes a strong selling point that can help your home stand out and fetch a better price.

Better for the Environment

Room in roof insulation is good for the planet too. 

When your loft stays warm in winter and cool in summer without cranking up the heating or air conditioning, you use much less energy.

This means your home puts less carbon into the atmosphere. 

It's a simple home improvement that helps you live more gently on the earth without changing your daily habits.

The benefits of room in roof insulation extend far beyond just keeping your loft space warm.

From substantial energy savings and improved year-round comfort to increased property value, it's an investment that continues to pay dividends, which is why Energex Eco Limited is committed to helping homeowners create more efficient, comfortable living spaces.

Types of Room in Roof Insulation Materials

Several materials work well for room in roof insulation, each with different features and prices:

Mineral Wool

• Cost: £13-£17.5 per m²
• Features: Good heat and sound insulation, won't burn
• Best for: Fitting between rafters

Sheep Wool

• Cost: £17.5-£22 per m²
• Features: Natural, sustainable, excellent at keeping heat in
• Best for: Eco-friendly homes

Fibreglass

• Cost: £10 per m²
• Features: Affordable, widely available
• Best for: Budget-conscious projects

PIR/PUR Boards

• Cost: £5-£15 per m²
• Features: Very efficient at stopping heat loss, rigid structure
• Best for: Spaces with limited depth due to their high performance

Corkboard

• Cost: £17-£22 per m²
• Features: Natural, sustainable, good insulation properties
• Best for: Environmentally friendly projects

Wood Fibre Board

• Cost: £12-£24 per m²
• Features: Natural, good at storing heat
• Best for: Green building projects

Installation Process

You can install room in roof insulation yourself or hire professionals. Here's a simple guide to the process:

Step 1: Get Ready

Set up good lighting so you can see clearly. If needed, place boards to walk on safely. 

Check for any damp patches or structural problems that need fixing before you start.

Step 2: Measure Up

Measure your loft space carefully to work out how much insulation you'll need.

Measure from the top of the roof down to where the joists start, and multiply by the width.

Also measure between the rafters to know what width of insulation to buy.

Step 3: Choose Your Approach

You can insulate either under or between the rafters:

• Under the rafters: This is often easier as you don't need to worry about ventilation gaps. Attach insulation boards directly to the rafters using a nail gun, then cover with plasterboard. For foil insulation, just staple it to the rafters.
• Between the rafters: For this method, cut insulation to fit snugly between rafters (usually 400mm to 600mm apart). The insulation should fit well without being squashed, which would make it less effective.

Step 4: Add a Moisture Barrier

A moisture barrier is essential to prevent dampness. Install this on the warm side of the insulation (the room side). Be careful to seal around any holes for wires or pipes.

Step 5: Add Extra Layers If Needed

To reach the recommended thickness of 270mm (as required by UK building regulations), you might need to add more layers. 

Place these at right angles to the first layer to cover any gaps and improve efficiency.

Step 6: Finish Up

Complete the job by sealing any gaps around the edges of the insulation with good quality sealant.

This prevents drafts and ensures the insulation works properly. Finally, cover everything with plasterboard or your chosen finish.

Costs of Room in Roof Insulation

The price of room in roof insulation depends on several factors, including your loft size, the insulation material you choose, and whether you do it yourself or hire professionals.

• Material Costs

As mentioned earlier, prices range from about £5 per m² for basic PIR boards to £37 per m² for spray foam insulation.

• Labour Costs

Professional installation typically costs around £250 per day. The total time depends on the size and complexity of your loft space.

• Total Project Cost

For a typical UK home, roof insulation averages around £1,100 for a detached property.

Room in roof insulation will cost more depending on your specific needs.

• Potential Savings

While the upfront cost might seem high, room in roof insulation can save up to £395 yearly on energy bills, meaning it often pays for itself within a few years.

Government Schemes and Funding

Room in roof insulation is available through two major government schemes that can help cover the costs:

Energy Company Obligation (ECO4) Scheme

The ECO4 scheme can pay for your room in roof insulation if you qualify. You might be eligible if you:

• Get certain benefits like Universal Credit, Housing Benefit, Pension Credit, or Income Support
• Have a household income under £31,000 per year
• Own your home or rent privately
• Live in a home with an Energy Performance Certificate (EPC) rating of D to G

If you qualify, ECO4 can cover the full cost of insulating your loft room.

Great British Insulation Scheme (GBIS)

The GBIS is another way to get funding for room in roof insulation. You can qualify if:

• Your home has an EPC rating of D or below
• Your property is in council tax bands A-D in England or A-E in Scotland and Wales

The GBIS sometimes offers free insulation, especially for households with lower incomes.

Getting room in roof insulation through this scheme could save you around £395 a year on energy bills by keeping heat from escaping through your roof.

Is room in roof insulation worth it?

Yes, room in roof insulation is definitely worth the money. 

It can save you up to £395 per year on energy bills, make your loft space comfortable year-round, increase your property value, and reduce your environmental impact.

Most homeowners find that the insulation pays for itself through energy savings within a few years.

Conclusion

Room in roof insulation is one of the smartest investments you can make for your home.

It transforms uncomfortable loft spaces into cosy, energy-efficient rooms that are pleasant to use all year round.

While the initial cost might seem significant, the long-term savings on energy bills, increased comfort, and added property value make it worthwhile.

Whether you choose to tackle the project yourself or hire professionals like Energex, properly insulating your room in the roof will pay dividends for years to come.

Don't let your heat (and money) escape through the roof – invest in quality insulation and enjoy the benefits of a truly comfortable home.

Posted on May 07, 2025.

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