How airtightness testing differs between Building Regs and Passive House – and why it matters so much

Using a smoke pen to detect leaks during airtightness testing

Building Regulations Part F wants to know how much air (in m3hr) passes through each metre square area of the fabric (m2). This is the Air Permeability (AP or figure of the building. To get the AP figure, one… Continue Reading

How much does an MVHR or heat recovery ventilation cost to buy and install?


If you’re building or renovating to PassivHaus or low energy standards and you and your contractor are working hard to make sure the airtightness fabric is perfect, you will need mechanical ventilation in order to supply the fresh air you need… Continue Reading