No they don't, and there is no such thing as "Passive House Status". A house can be a PHI certified Passiv Haus, or it can be an equivalent or lower energy use passive house that has not been certified by the PHI and may or may not use PHI certified components.
The PHI certify on the basis of a whole raft of things that show that the house meets their performance standard, including the use of approved components, but they do not do air leakage tests. UK building regs require air leakage testing (as do many other nations building regs) and all the PHI stipulate is that air leakage should not exceed 0.6 air changes per hour with the house at a pressure differential of 50 Pa relative to the outside air pressure. The PHI require that the house performance is designed and assessed using their method, the Passiv Haus Planning Package, and that includes a great many things other than air leakage. It's like a more complex version of the UK building regs Standard Assessment Procedure (see here: https://www.gov.uk/g...sment-procedure ) that has to be used for new builds.
Making a house smaller can make it harder to reduce the energy consumption to passive house levels. Larger houses can comply more easily, because heat loss for a large house tends to be dominated by ventilation heat loss, not fabric heat loss.
If you build a large house to UK building regs minimum fabric performance standards (the U values for the structure, doors, windows etc) then you could possibly still achieve a passive house performance level with good airtightness and an efficient heat recovery ventilation system.
Edited by jsharris, 09 April 2016 - 01:18 PM.