There are still many people nowadays, who believe that a certain brand or make is essential to achieve good values for the air tightness in buildings.
We don´t think so - it´s the attention to details, which ensures a good overall performance. Ideally you should create an air tight strategy for your building before you start major installation work.
Keep things as simple as possible, e.g. try to shift your sockets and switches to interior walls instead of using exterior walls, where you have the risk of punching the cavity. Take care of a good air tightness for the floor-to-wall junction, especially on the ground floor. Check that the window tapes are installed in the right way with a good adhesion to the block. Do not leave blocks of the exterior walls uncovered (without plaster or air tight paint). Take attention to the appropriate sealing of every penetration through the air tight layer. Explain the importance of a complete and intact air tight layer to every tradesman at your site.
By considering all of such details, you should be in the position to bring the overall performance of your building to a value of 1.5 ACH @ 50Pa or even less. That will save you plenty of running costs for your heating and heat recovery ventilation system on the long term.