Love life in your loft? See if you could save and stay warm

In an uninsulated home, around 25% of heat is lost through the roof. If you’ve got loft space, you can keep your home warmer and save up to £240 a year [1] on energy bills - by ensuring the whole area is efficiently insulated. Room In Roof Insulation (RIRI) is ideal if you use your loft space as a room, enabling you to insulate the sloping surfaces of your roof using sheet insulation, rather than insulating the floor. If you already know what you’re looking for, you can jump straight to that section using the links below:

What is Room In Roof Insulation?

Room In Roof Insulation is where insulation boarding is installed in between the rafters underneath the existing plasterboard walls to help keep the heat inside. The rigid foam insulation boards are generally made from polystyrene or polyurethane.

Installation of insulation boarding

How does Room In Roof Insulation work?

The insulation boards are placed in the space between the rafters in the loft and act as a protective layer against the cold outside whilst keeping the warm air inside.

The rigid insulation structure provides a complete waterproof barrier and means that the rising warm air can’t escape.

If you‘ve already converted your loft into a liveable space, the insulation boards are cut to the right size and inserted underneath the walls. This could mean removing the ceiling or removing and re-roofing the tiles to reach underneath. Or, a second option is to add another layer to the ceiling which could fit the insulation. This might be easier and cheaper, but is more likely to restrict headroom. If you haven’t converted your loft space but you’re thinking of doing so in the future, the insulation boards can be installed and plasterboard placed on top.
Close up of a workman installing roof insulation

What are the benefits of Room In Roof Insulation?

  • Excellent for insulating loft conversions
  • Prevents heat escaping through your roof
  • Reduces your energy bills
  • Can be covered with plasterboard for an attractive finish
  • Makes your home feel cosy and warm
Empty loft conversion

How much does Room In Roof Insulation cost?

Any additions you make to your home are likely to cost money, but by insulating effectively, you will benefit from savings on your energy bills, particularly through the winter months.

Room In Roof Insulation Detached house Semi-detached house Semi-detached house Mid/end terrace house Detached bungalow
Fuel bill savings (£/year) £225 £135 £120 £195
Typical installation cost [2] £1500 - £2700 £1500 - £2700 £1500 - £2700 £1500 - £2700
Carbon dioxide savings (kgCO₂/year) 990kg 590kg 530kg 850kg

Are there any restrictions?

Yes, there are some restrictions on what actually counts as a ‘room in a roof’ [3]. We'd recommend having a pre-installation survey done, to ensure you’re picking the correct insulation for your home. Some key requirements to take note of are:

The room must have stairs leading up to it which are accessible enough to be able to walk down facing forward - so that means no attic ladders.

You’ll need to determine that your room isn’t actually just another storey, which wouldn’t count as a room in a roof. This means that the height of at least 50% of any vertical walls shouldn’t be over 1.8 metres.

The room, particularly the rafters, needs to be adequately ventilated, to avoid condensation building up.

The roof shouldn't be damaged or weakened - meaning no damp, mould, rot, flaking timbers or unreliable electrical connections.

What’s the difference between Room In Roof Insulation and regular loft insulation?

Loft insulation in the traditional sense involves insulation being laid on the loft floor between the joists with an additional layer laid on top at right angles. This type is most common and is usually made from mineral wool, in the form of soft rolls. The ideal height of insulation, as recommended by the Energy Savings Trust, is 270mm, making it difficult for the loft to be used for extra storage and leaving the insulation exposed.

If your loft space is unused and hasn’t been insulated in the last 20 years you should consider installing this regular type of loft insulation.

However, if you do use your loft as a living space or for excess storage it's likely Room In Roof Insulation would be a better fit for your needs.

Room In Roof Insulation won’t be visible, as it’s inserted between the rafters behind walls or plasterboard.

Both methods of insulation are designed to prevent heat from escaping through your roof, which can help making savings on your energy bills too.

Can I install it myself?

Installing insulation can be a tricky job so it is recommended that you use a professional installer to do the job.

However, if you’re experienced at DIY, you may be able to do this yourself. Just make sure you're confident that your loft does not have any damp problems and your Room In Roof has the necessary requirements.

If you find that a more complex insulation system is needed, you may wish to contact certified installers.
Workman installing roof insulation

What if Room In Roof Insulation isn’t for me?

If your loft space is too small or inaccessible, there are still plenty of other options available.

If it’s tough to access, for example, if your loft hatch is too small or the space is too cramped to around move inside, blown insulation is the next alternative. This must be installed by an approved professional using specialised equipment.

Alternatively, it may be worth looking into other insulation measures such as cavity wall insulation.

Find out if you’re eligible for free cavity wall or loft insulation.
Insulating foam being applied in a loft coversion