Ever noticed that the most ambitious, poverty solving, health improving, carbon saving schemes always seem to get watered down. It happens when the bean counters discover what it costs to do the job properly. In our case, instead of quality MVHR ventilation that should provide twenty years of service (if looked after), it’s cheap noisy bangers that barely last five. Units that drag in air pollution instead of filtering it out, and units that don’t tell you they’ve been off for months when you’re investigating ‘damp problems’.

People switch noisy systems off at the isolator or consumer unit because they sound expensive to run, they keep you awake, or they disturb the TV. When that happens your sealed property has no air movement, so the six pints of water everyone puts into the air every day has nowhere to go. Within no time you’ve got damp, mould, kids developing asthma, and bills for redecoration if not claims for damages.

To reach net zero or anything close, at the same time creating comfortable, economical homes where young families or old folks with respiratory conditions can live without inhalers, you really need thing big with the budget. You need to recognise the cost benefit of healthy, affordable living, and think long-term ROI, because while quality costs more up front, it costs less to own as soon as you’re on to your second banger.

The Sterling Prize for Goldsmith Street really got the ball rolling, and now more and more social housing providers understand the benefits of Passivhaus. Green champions like Norwich, Glasgow, and Manchester to name a few. Since we began ventilating social homes in 2012, we’ve noticed more and more asset managers opting for higher capex in return for lower RMI cost. Pilot projects are finally becoming proper projects. It’s brilliant to see social housing at the forefront of sustainability.

If you’re a champion, more power to you. We’d love to help.

In the olden days the RSL appointed the architect, the property was designed, the QS set the spec based on cost rather than performance, contractors tendered for the build, then ‘ventilation’ became their responsibility. It meant the MVHR had to be designed way beyond RIBA stage 4, meaning the designer had to work backwards, effectively retrofitting MVHR into finished construction drawings. They were retrofit projects even before the build started.

When the plant cupboard size, location, joist type and direction are all set in stone, the designer has to work around obstacles that don’t need to be obstacles. It adds unnecessary material cost, system pressure, noise, and energy consumption. In terms of physical size, the MVHR machine itself is only around 10% of the whole system. It could fit just about anywhere. But it’s the other 90% that’s critical for Passivhaus and Part-F compliance in terms of acoustics and energy performance. It’s the exterior terminals, mass-flow ducting, access for servicing, and the insulation line that dictate where the machine can go.

The correct and most efficient way to design MVHR is for the specialist designer to work alongside the architect from the outset, to assist with the construction drawings before it’s even gone to tender. Because MVHR needs more space than all the other plant combined, to some extent the house needs designing around the ventilation rather than the other way around. See our design process for details.