Passive House Beginner Guide: Principles and Materials (Not Certification)
Passive House (Passivhaus) is a rigorous fabric-first building standard. This beginner guide explains the principles in plain UK English and which material types Insulation Warehouse Direct sells that often appear on low-energy projects — without claiming we certify Passive House buildings.
Quick answer
Passive House aims for very low heat demand through continuous insulation, airtightness, thermal-bridge control, high-performance windows and whole-house ventilation (usually MVHR). Insulation Warehouse Direct sells insulation boards, mineral wool, membranes, tapes and drylining materials that designers may specify on such projects. We are not a Passive House certifier, designer or installer. For the standard itself, see the Passivhaus Trust.
Principles (materials angle)
| Principle | What it means for materials |
|---|---|
| Continuous insulation | Fewer gaps; careful detailing at junctions; thickness from the PHPP / designer’s calculation — use manufacturer data and our PIR U-value calculator |
| Airtightness | Membranes, tapes and sealed board joints — VCLs / tapes |
| Thermal bridge control | Details matter as much as board λ values |
| Moisture management | Right membrane in the right place — moisture control |
Product families we stock that often appear
- PIR and phenolic (Kooltherm) for high performance per thickness.
- Stone wool and glass wool where the detail wants a fibrous fill.
- External wall insulation components where an EWI approach is specified.
- Drylining and plasterboard for internal finishes.
U-value and Part L context for England: what U-value you need. Passive House targets are often tighter than backstop regs — your certifier’s numbers win.
Frequently asked questions
Can you certify my build as Passive House?
No.
Do you stock certified Passive House components by name?
We stock mainstream insulation brands; check each product’s certificates on its datasheet against your specification.
Do you install insulation, do surveys or help with grants?
No. Insulation Warehouse Direct sells insulation materials online. We do not install insulation, carry out surveys or handle grant applications. If you want it fitted, use a qualified installer, and for grants check the official GOV.UK energy schemes. We are happy to supply the materials your installer specifies.
| Where | What we deliver | Delivery charge |
|---|---|---|
| England | All ranges | Free on insulation, plasterboard and drylining from £400 ex VAT. Celotex: £400 ex VAT minimum, free delivery. Access panels: £15 + VAT under £300 ex VAT, free from £300 |
| Mainland Wales and mainland Scotland | British Gypsum (including Gypframe), Celotex, Knauf and access panels | £400 ex VAT minimum plus £40 + VAT (access panels: £15 + VAT under £300 ex VAT, free from £300) |
| Scottish islands | Not delivered | – |
| Northern Ireland | Not delivered | – |
Company: Bay Drywall and Insulation Supplies Ltd (company no. 14473556), Unit 3 Babbage Court, Totnes Industrial Estate, Totnes, Devon TQ9 5JE.
Sources: Passivhaus Trust; Approved Document L (GOV.UK). Figures are indicative and correct at the time of writing; they are not a substitute for a calculation by your designer or the manufacturer's technical team, and Building Control has the final say.