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

60mm Kingspan Kooltherm K5 External Wall Insulation Board 1200mm x 600mm (5.76m2/Pack)

70mm Kingspan Kooltherm K5 External Wall Insulation Board 1200mm x 600mm (4.32m2/Pack)

Rockwool Flexi Slab 1200mm x 600mm x 50mm - Pack of 12 | 8.64m2

SuperFOIL SF19BB Breathable Thermal Insulation 1.5m x 10m Roll - 15m2

Kingspan Thermaroof TR27 PIR Flat Roof Insulation Board 1200 X 1200 X 50mm - Pack of 6 Sheets

SuperFOIL Multi-Purpose Insulation and Foil Tape Set - 1m x 7m

ROCKWOOL RWA45 Acoustic Insulation Slab 1200mm x 600mm x 25mm

Ancon Staifix Universal Insulation Retaining Clip (bag Of 20)

TLX Silver Multi Foil Insulation 1.2 x 10m

B1F Building Paper 1.25m x 50m (62.5m2 Roll)

509B Reinforced Kraft Union Liner 1.8m x 50m (90m2 Roll)

SuperFOIL Heat Reflective Radiator Foil Insulation RadPack - 60cm x 5m

SuperFOIL SFTV Thermal Vapour Barrier 1.5m x 50m Roll - 75m2

Novia VC2 Air Leakage Barrier & Vapour Check Laminate - 50m x 1.5m

Knauf DriTherm 37 50mm Cavity Wall Insulation Slab - 6.55m2 Pack

Knauf DriTherm 37 125mm Cavity Wall Insulation Slab - 3.28m2 Pack

SuperFOIL SFTV Thermal Vapour Barrier 1.5m x 25m Roll - 37.5m2

Powerlon Air Barrier Membrane - 1.5m x 50m

Jablite Jabfloor 70G 2400 X 1200 X 100mm

Weather Defence Board 2400x1200x12.5mm

Thermal EPS Plasterboard Tapered Edge 2400x1200x50mm

Knauf Insulation Frametherm 32 140mm

Knauf Insulation Frametherm 35 140mm

Knauf Insulation Building Slab RS45 60mm

Knauf Insulation Omnifit Roll 150mm

Knauf Insulation Omnifit Roll 100mm

Superquilt Multi Foil 1.5 X 10M 15M2

British Gypsum Gyproc Firestrip 3600mm Box Of 5

Kingspan Kooltherm K5 External Wall Board 1200mm x 600mm x 50mm Pack Of 10 (7.2m2)

100mm X 20m Superfoil Met Poly Foil Tape

Ecotherm Eco-versal Insulation 2400mm x 1200mm x 25mm

British Gypsum Gyproc Soundcoat Plus 25kg

Isover APR Acoustic Partition Roll 75mm 14.64m2

Isover APR Acoustic Partition Roll 50mm 15.6m2

Isover CWS 32 Cavity Wall System Batt Heavy Duty 125mm 2.73m2

Knauf Insulation Rocksilk Flexible Slab 100mm

Rockwool Ablative Coating 5L

Ecotherm Eco-versal Insulation 2400mm x 1200mm x 150mm

40mm Kingspan Kooltherm K103 Floorboard 2400mm X 1200mm (8' X 4')

115mm Kingspan Kooltherm K106 Cavity Board 1200mm X 450mm (4' X 1.5') Pack Of 4 (2.16m²)