Room-in-Roof Insulation

RIR

What Is Room-in-Roof Insulation (RIR)?

Room in Roof Insulation (RIR) is designed to insulate converted loft spaces where sloped ceilings, stud walls, and dormer structures form part of the living area. It improves energy efficiency by reducing heat loss through the roof and surrounding elements — making loft rooms warmer, more comfortable, and cheaper to heat.

Under the PAS 2035 framework, RIR is treated as a high-impact measure within a coordinated, whole-house retrofit plan overseen by a Retrofit Coordinator. Installers must be PAS 2035 certified and TrustMark registered to ensure quality, safety, and compliance.

INSTALL

What’s Included in a Room-in-Roof Insulation?

A standard PAS 2035-compliant RIR installation includes:

Sloping ceilings – Insulated plasterboards (e.g. PIR boards) fitted over existing boards for maximum thermal performance.
Stud walls – Insulated internally, typically with PIR boards or insulated plasterboard from within the loft space.
Dormer cheeks – Internally insulated using slimline, high-performance insulation (typically 10–12mm).
Flat ceilings (if present) – Topped up with loft roll insulation to meet current U-value targets.
Party walls – Insulated to prevent heat transfer into neighbouring, unheated lofts.
Eaves voids – Insulated and ventilated to avoid cold bridging and condensation risk.

All installations are fully finished with plastering, decoration, and restoration of any fixtures or finishes— returning the room to a liveable standard.

COMPLIANCE

PAS 2035 Compliance

To meet compliance standards under the PAS 2035 retrofit framework, RIR must:

Be assessed as part of a whole-house retrofit plan by a qualified Retrofit Assessor and Coordinator.
Be installed only by PAS 2035:2023-certified and TrustMark registered contractors.
Use materials that meet strict thermal, fire safety, and moisture management standards.
Include detailed design to prevent thermal bridging, condensation, and poor indoor air quality.
Integrate with ventilation strategies and complementary measures (e.g. loft insulation, heating upgrades).

This ensures the system is safe, effective, and long-lasting — not just a cosmetic upgrade.

PROS

Benefits of Room-in-Roof Insulation

Energy Efficiency

Reduces heat loss in converted loft rooms— often cutting bills by up to 25%.

Improves Aesthetic Appeal

Converts previously cold or draughty spaces into warm, comfortable living areas.

Grant-Fundable

Fully or partially funded under ECO4, GBIS, and LAD schemes.

EPC Improvement

Boosts your property’s Energy Performance Certificate (EPC)— helpful for homeowners and landlords.

Quick Installation

Most RIR installs are completed in 3 to 5 days, including finishings.

Planning-Friendly

As an internal upgrade, RIR rarely requires planning permission.

CONS

Considerations & Potential Drawbacks

Slight Loss of Room Space

The insulation build-up may reduce internal dimensions— especially in tight lofts.

Temporary Disruption

Rooms may be unusable during installation, requiring short-term relocation.

Not Suitable for All Lofts

Only applies to converted lofts with a fixed staircase and usable floor area. Unconverted lofts fall under Room-in-Roof conversion or loft conversion, not RIR.

ALIGN

Is Your Home Suitable for RIR?

Room-in-Roof Insulation may be recommended if:

Your loft has already been converted into a bedroom or living space.
Your home has a low EPC rating (E, F, or G) and is eligible for funded upgrades.
There is limited insulation in the roof or walls of the loft room.
You’ve had or will have complementary upgrades (e.g. ventilation, heating).

A PAS 2035 Retrofit Assessment is required to confirm suitability, calculate U-values, assess condensation risk, and design the correct insulation system.

SUMMARY

Conclusion

Room-in-Roof Insulation is a powerful way to upgrade converted loft spaces—improving warmth, reducing energy bills, and making full use of your home’s footprint.

Delivered under the PAS 2035 framework and installed to PAS 2030:2023 standards, RIR is a compliant, high-impact retrofit measure that unlocks access to government funding and boosts overall property value.

Whether you’re a homeowner or a landlord, investing in RIR is a smart move towards comfort, carbon savings, and future-proofing your home.