Question 1

1. Do I need to pay VAT on insulation materials?

Accepted Answer

There’s currently 0% VAT on the installation of insulation and other qualifying energy-saving materials in UK residential properties. This zero rate applies from 1 April 2022 until 31 March 2027, and includes installation in roofs, walls, ceilings, pipes, water tanks, and more. After that date, the VAT rate is set to revert to the reduced rate of 5%. This zero-rate covers both the supply and fitting of the materials when carried out by a contractor.

Materials bought separately without professional installation remain subject to the standard 20% VAT rate. The relief applies to residential and qualifying charity buildings, and includes related work carried out as part of the insulation installation.

You can find more details in this article on GreenMatch.

Question 2

2. What building regs apply to insulation material?

Accepted Answer

Different parts of the UK have different regulations for building insulation. If your project is in England, you’ll need ‘Approved Document L: Conservation of Fuel and Power’. Wales has its own separate set of standards which are described in Document L1A & B (Wales). Scotland’s standards are set out in their Section 6 (Energy) document. You can find more details in this handy guide to building regulations and insulation from YBS.

Question 3

3. What material is best for insulation

Accepted Answer

The best insulation material for your project will depend on the job at hand, as well as own your personal preference. Mineral wool is common for walls; PIR boards suit flat roofs and floors; spray foam is used for hard-to-reach areas. Materials traditionally used for insulation in the UK include Fiberglass, Polyurethane (PUR), Polystyrene and PIR Board (Polyisocyanurate).

Question 4

4. What’s the best insulation to use for a metal building?

Accepted Answer

Rigid foam panels or spray foam are commonly used for metal building insulation. They offer high thermal resistance and help control condensation.

Question 5

5. What are R values in building insulation?

Accepted Answer

R values measure a material’s resistance to heat flow. Higher R values mean better insulation performance. Product data sheets include R values for easy comparison.

Question 6

6. Do insulating materials need to be breathable?

Accepted Answer

Some do. Breathability helps prevent trapped moisture. Use breathable insulation in solid walls or roof constructions without ventilation gaps.

Insulation materials

Celotex 120mm XR4120 2.4m x 1.2m

Unilin XT Thermal Liner DD Insulation PIR Board 2400 x 1200 x 37.5mm

Unilin XT Thermal Liner DD Insulation PIR Board 2400 x 1200 x 50.5mm

Eurowall Plus Cavity Full Fill, 1200 x 460 x 90 mm

Knauf Frametherm Slab - All Sizes

Xtratherm Cavity Wall Board XT/CW 1200 X 450 X 50mm

100mm Rockwool Thermal Insulation Cavity Batt 1200mm X 455mm Pallet Of 20 (65.52m²)

1500mm X 10m Superfoil SF40 Multi Foil Insulation

VELUX Insulation Collar With Underfelt Collar 114 X 118cm

Actis Hcontrol Hybrid Multi-foil 6.25 X 1.6m X 45mm

75mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm X 1200mm (8' X 4')

Regupol 3912 Acoustic Isolating Strips 15m X 100mm X 6mm

Cellecta Deckfon 30T Acoustic Overlay Floorboard 2400mm X 600mm X 30mm T&G (1.44m2)

Ikoustic Isolation Strip 2000mm X 46mm X 4/8mm

Ikoustic Mutemat OSF 750-05 10m X 1.3m X 5mm (13m2)

75mm Ecotherm Eco-cavity Wall Insulation Board 1200mm X 450mm (3.24m2/pack)

100mm Knauf Earthwool Loft Roll 44 Insulation Combi-Cut - Pallet of 24 Rolls (333.24m2/Pallet)

100mm Rockwool RW5 Acoustic Sound Insulation Slab (1.44m2/Pack)

QA Underlay Sonic Excel Acoustic Vapour Gold 5mm x 1x15mtr 15m²

50mm Rockwool RW5 Acoustic Sound Insulation Slab (69.12m2/Pallet)

VCL 250 Air and Vapour Control Layer - 2m x 50m (100m2)

Unilin CavityTherm Full Fill Insulation PIR Board 1200 x 450 x 90mm

Knauf Insulation Building Slab RS45 75mm

GTEC Fire Board S/E 1800x900x12.5mm

Xtratherm Foilboard XT/PR 2400 X 1200 X 100mm

Superquilt Multi Foil 1.5 X 10M 15M2

120mm Ecotherm Eco-versal Insulation 2400mm X 1200mm (8' X 4')

Drylining Metal Ceiling 14 Acoustic Hanger With Anchor 70mm

Isover CWS 32 Cavity Wall System Batt Heavy Duty 100mm 3.28m²

1500mm X 10m Superfoil SF40BB Multi Foil Insulation

20mm Jablite External Wall Insulation 1200mm X 600mm Pack Of 30

British Gypsum Gypframe Acoustic Hanger 70mm GAH2 Box Of 100

GTEC Phonissimo Acoustic Hanger PHONIMO Box Of 50

Ikoustic Mutemat OSF 750-10 5m X 1.3m X 10mm (6.5m2)

Ikoustic Muteboard 4 1200mm X 1200mm X 29mm (1.44m2)

125mm Ecotherm Eco-versal PIR Insulation Board 2400mm X 1200mm

ARC Fire Stop Slab 140mm Cavity 145mm X 100mm X 1200mm (18/pack)

ARC Cavity Stop Sock 250mm Cavity 260mm X 200mm X 1200mm (4/pack)

Airguard® Reflective Vapour Control Layer 1.5m X 50m

Knauf Insulation Timber Frame Party Wall Slab 60mm 11.52m2