Upgrade your home with Internal Wall Insulation Manchester, designed to reduce heat loss by insulating solid walls without changing the exterior appearance. This makes it an ideal solution for properties where external alterations are not suitable.Improve indoor comfort, lower heating bills, and enhance your property’s energy performance while maintaining the original character of your home.
Solid walls lose up to twice as much heat as cavity walls. Internal Wall Insulation (IWI) helps retain heat by adding insulation to internal walls, reducing energy loss and improving overall home efficiency — without altering your property’s external appearance.
Reduce heat loss through solid walls by up to 40–50%, helping you save approximately £300–£600 per year on heating costs.
No changes are made to the exterior of your home, making it ideal for conservation areas and listed buildings where external alterations are restricted. Perfect for Manchester’s Victorian and Edwardian terraced housing.
Eligible homeowners may qualify for fully funded Internal Wall Insulation under the ECO4 scheme, reducing or eliminating installation costs.
Creates warmer internal wall surfaces, reducing cold spots, draughts, and internal condensation for a more comfortable living environment.
Internal Wall Insulation (IWI) is ideal for solid wall properties where external changes are restricted, such as conservation areas or homes with preserved facades. It helps improve thermal efficiency without altering the building’s exterior appearance.
Alternative — External Wall Insulation (EWI)
If you can change external appearance and have space around your property, EWI is an option. EWI requires planning permission in conservation areas.
Timber or metal frame (50mm-100mm deep) filled with insulation (mineral wool or PIR), finished with plasterboard. Minimises cold bridging. Best for rooms where you want service cavities (electrics, plumbing).
PIR insulation (40mm-80mm) bonded to plasterboard. Directly fixed to wall using adhesive (dot and dab). Fastest installation, minimal thickness. Best for rooms where space is limited.
Stud at service areas (around sockets, switches, pipes), insulated plasterboard elsewhere. Best of both — service access where needed, thinner build-up elsewhere.
| Thickness | U-Value | Space Loss | Best For | Performance Level |
|---|---|---|---|---|
| 40mm Insulated Plasterboard | 0.45 | 40–50mm | Small rooms / minimal disruption | Basic upgrade |
| 60mm Insulated Plasterboard | 0.30 | 60–70mm | Most residential rooms | Standard recommended level |
| 80mm Stud + PIR Insulation | 0.18 | 100–120mm | Cold external walls | High efficiency |
| 100mm Stud + PIR Insulation | 0.15 | 120–140mm | Deep retrofit projects | Maximum efficiency |
Building Regulations recommend U-Value of 0.30 or better for wall insulation.
Insulation must continue to floor level. Thermal bridge at floor edge if insulation stops short. We insulate floor edges with PIR or expanded polystyrene.
Insulation must continue to ceiling. Thermal bridge at ceiling edge if insulation stops short. We insulate ceiling edges.
Skirting boards must be removed and refitted after insulation. New skirting may be required if original is damaged.
Insulation must continue into reveals (sides of windows/doors). Thermal bridge at reveals if not insulated. We insulate reveals with insulated plasterboard or PIR.
Electrics, plumbing, and switches must be repositioned or extended. We coordinate with electricians and plumbers.
We assess wall construction, room size, services locations, and thermal bridge points.
We specify insulation thickness, method (stud or insulated board), and detail all thermal bridges.
We provide certification and advise on future decoration.
Small bedroom: £1,500-£2,500 — ECO4 grant upto 100% — Your cost £0 if eligible
Living room (typical 4m x 5m): £2,000-£3,500 — ECO4 grant upto100% — Your cost £0 if eligible
Whole house (2-3 bed terrace): £6,000-£12,000 — ECO4 grant upto 100% — Your cost £0 if eligible
Whole house (3-4 bed semi): £8,000-£15,000 — ECO4 grant upto 100% — Your cost £0 if eligible
| Property / Room Type | Typical Size / Example | Estimated Cost | ECO4 Grant Support | Final Cost (If Eligible) |
|---|---|---|---|---|
| Small Bedroom | Single external wall room | £1,500 – £2,500 | Up to 100% funded | £0 |
| Living Room | Approx. 4m x 5m | £2,000 – £3,500 | Up to 100% funded | £0 |
| Whole House (2–3 Bed Terrace) | Full internal lining | £6,000 – £12,000 | Up to 100% funded | £0 |
| Whole House (3–4 Bed Semi-Detached) | Larger multi-room property | £8,000 – £15,000 | Up to 100% funded | £0 |
Note: Final pricing depends on wall condition, insulation thickness, ventilation requirements, and survey results. ECO4 eligibility is confirmed through a professional assessment.
Choosing the right installer is just as important as choosing the right insulation system. At Compliant Retrofits, we focus on delivering high-performance, regulation-compliant Internal Wall Insulation solutions designed for long-term energy efficiency, comfort, and moisture safety.
We carefully design and detail all junctions—such as floors, ceilings, windows, and external walls—to minimise thermal bridging and prevent unwanted heat loss. This ensures your insulation performs effectively across the entire property, not just on flat wall surfaces.
We assess your eligibility for ECO4 funding and manage the full application process on your behalf. This helps eligible homeowners access fully or partially funded insulation upgrades with minimal hassle.
Proper moisture management is essential in solid wall homes. We incorporate vapour control layers and correct installation techniques to reduce the risk of condensation, damp, and mould formation after insulation.
Choose from silicone, acrylic, or mineral render systems, allowing you to match performance requirements with your preferred aesthetic style and breathability needs.
We use high-performance PIR insulation boards and certified materials from trusted UK manufacturers, ensuring durability, thermal efficiency, and compliance with current building standards.
We provide a no-obligation consultation to assess your property, discuss insulation options, and determine your funding eligibility before any work begins.
A: 80-150mm per insulated wall, depending on insulation thickness. A 4m x 4m room becomes 3.7m x 3.7m (approx 10-15% floor space loss).
A: No, if installed correctly with vapour control layers. We design for your property’s specific needs. IWI can actually reduce condensation by warming internal walls.
A: Yes. IWI preserves external appearance, making it suitable for listed buildings and conservation areas (subject to consent). We advise on consent requirements.
A: Yes. Sockets, switches, and pipework will need to be extended or relocated. We coordinate with electricians and plumbers as part of the installation.
