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

Rockwool RWA45 100mm x 1200mm x 600mm

Rockwool RWA45 75mm x 1200mm x 600mm

Knauf Insulation Loft Roll 44 Combi-Cut 100mm 13.89m2

Rockwool RWA45 50mm x 1200mm x 600mm

Knauf Dritherm Cavity Slab 32 (455mm x 1200mm) 100mm

Knauf 150mm DriTherm 32 Cavity Slab 2.18m2 Pack

75mm Kingspan Kooltherm K108 Cavity Board 1200mm X 450mm (4' X 1.5') Pack Of 6 (3.24m²)

25mm Isover APR 1200 2/600mm X 20m Acoustic Partition Roll (24m²)

1200mm X 10m Superfoil SF19+ Multi Foil Insulation

Rockwool Sound Insulation Slab - 50 x 600 x 1200mm 8.64m2

Knauf Earthwool Dritherm 37 Standard Light Duty Cavity Slab 50mm 6.55m2

GTEC Fire Board T/E 2400x1200x12.5mm

100mm Rockwool 32 Thermal Insulation Cavity Batt 1200mm X 455mm (3.28m²)

Soudal Genius Gun Gap Filling Expanding Foam 750ml

Ancon Staifix Universal Insulation Retaining Clip (bag Of 20)

Knauf DriTherm 37 75mm Cavity Wall Insulation Slab - 4.37m2 Pack

100mm Kingspan Kooltherm K108 Cavity Board 1200mm X 450mm (4' X 1.5') Pack Of 5 (2.7m²)

Jablite Jabfloor 70 Polystyrene Insulation 2400mm x 1200mm x 50mm

Superfoil Shed Insulation Kit (21m2)

Celotex CW4075 75mm x 1200mm x 450mm

Rockwool Thermal Insulation Loft Roll 2750X1200mm X 100mm (PK2) 6.6M2

120mm Celotex XR4120 PIR Insulation Board 2400mm x 1200mm

Celotex GA4050 PIR Insulation Board - 2400 x 1200 x 50mm

Celotex GA4060 General Purpose PIR Insulation Board - 2400 X 1200 X 60mm

75mm Isover CWS 36 Cavity Wall Slab 1200mm x 455mm (8.74m²)

Knauf Dritherm Cavity Slab 32 (455mm x 1200mm) 75mm

Knauf Dritherm Cavity Slab 32 (455mm x 1200mm) 125mm

Rockwool Sound Insulation 100mm Slab 1200x400

60mm Kingspan Kooltherm K108 Cavity Board 1200mm X 450mm (4' X 1.5') Pack Of 8 (4.32m²)

Kingspan Kooltherm Insulation Boards K108 Cavity Board 1200mm X 450mm X 50mm Pack Of 10 (5.4m2)

Celotex TB4030 PIR Insulation Board 2400mm x 1200mm x 30mm

Soudal B1 Fire & Acoustic Expanding Foam - Gun Grade 750ml

Powerbase MultiGas 300 Gas Barrier Membrane - 50m x 2m (100m2)

ISOVER Cavity Wall Slab 36 10.92m2 1200 x 455 x 50mm

Knauf Insulation DriTherm Cavity Slab 37 100mm 6.55m²

Knauf Dritherm Cavity Slab 37 1200mm x 455mm 150mm

Celotex GA4100 General Purpose PIR Insulation Board - 2400 X 1200 X 100mm

SuperFOIL SF60 Multifoil Insulation Roll 1.5m x 8m - 12m2

Rockwool Sound Insulation Slab 1200x600x70mm

Jabfloor 70 Floor Insulation 2400x1200x75mm