When should I engage a Passivhaus designer/consultant?

You’ve heard about Passivhaus and the superb comfort, excellent air quality, super-low energy costs and tiny COemissions all sound great. You’ve decided Passivhaus is what you want for your dream home, so when should you get a Passivhaus expert on board?


As early as possible! Ideally before the architect has started drawing anything.


Many clients come to me when they’ve already spent months developing a design with an architect. By this point in the design many of the most cost-effective opportunities for optimising the energy performance have passed. From here there are broadly three options – throw money at the design in order to improve its energy and comfort performance, keep the existing design and compromise on energy/comfort performance, or spend money on a major redesign to enable cost-effective energy efficiency at the build stage. Needless to say none of these options are very satisfactory.


What if you’re not sure that you want to go all the way to Passivhaus standard? Even then, maybe especially then, getting a Passivhaus specialist in early will help. The input they provide, even if the project doesn’t end up going for Passivhaus standard, will help the design be a lot more energy efficient than it would otherwise have been.


The reasons it works like this are multiple, but essentially most architects are used to the way energy is assessed for building regulations (using SAP for new builds), in order to produce energy performance certificates. SAP is notoriously bad at incentivising energy efficiency for reasons that are too long and boring to go into here, except to say check out this graph (from a Passivhaus Trust report on EPCs as efficiency targets) as an illustration of how poor a predictor of energy consumption EPC ratings are – energy use was remarkably similar across all EPC bands from B to E for the buildings studied.


EPCs and measured energy use


So get a Passivhaus expert on board at the same time as you get your architect on board (these can be the same person) and get them to talk to each other from day one. If you’ve already got an architect working on your designs then get a Passivhaus expert on board as soon as you can. The sooner you do the easier it will be to make your design super efficient and comfortable. You can search for Passivhaus qualified individuals near you using this searchable map.


For a free, no obligation chat about your project please get in touch.



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