The Passivhaus: a few reflections on reality

I started tweeting this week, albeit very cautiously; it's been quite odd to see who twitter recommends me following but maybe Ed Sheeran and Mrs Beckham are genuinely committed environmentalists with a lot to say on the subject, who knows? Anyway, I digress, we are periodically getting requests to see the house and it occurred to me that people might want to know more about it so I've set it up to tweet (who's the master now eh, house??). 

We're also coming to the end of Climate Week, just in case you haven't been deluged with green publicity, and I've had a couple of local school Eco Committees visiting which has involved me polishing my spiel and, in the process, reflecting on how the house works.

I first read about the Passivhaus concept in 2008 in the Guardian newspaper (where else?) but there's a world of difference between reading about innovative house design and living the reality of it. 

The first thing people say when they walk into the house (apart from the social niceties, of course, all our guests are well-schooled in etiquette) is "are you really enjoying the warmth?" and they are quite taken aback when we reply "not yet, we're not". On sunny days the house is very warm because the sun streams through the massive, triple-glazed, south-facing windows but, as I've said before, on grey days we're only as warm as the base temperature of the house and I was mildly entertained to note that when the last group of architectural visitors came round they put fleeces on after a while. The house is fantastically well insulated and we know from thermal imaging cameras and general observations in frosty weather that heat doesn't escape but we were warned by the builders and architect that we would need to put a lot of heat into the concrete structure in the first year and so we are. Overall the house is usually managing to maintain its temperature for several days before we need to boost the heating but if you want to sit comfortably in rooms on the ground floor you need to plug in an additional heater. Some of the architects who visit say we should have underfloor heating, or stoves on the ground floor to warm that floor up, or a timber structure not concrete and originally the glass porch was going to run the length of the south wall to add warmth. We should, perhaps, have the bedrooms on the ground floor and the living/working rooms on the top floor where it's warmer but that's not terribly practical so we're compromising by adding extra heat topically and hoping that the house temperature reaches an equilibrium soon.

What I've found interesting this week is that, for the first time, we've had several groups of visitors spaced out over a few days and that has actually impacted on the house's temperature. The Passivhaus design is intended to use not just the sunshine but the heat generated by lighting, white goods and people to heat the building but whilst I knew that in theory it was noticeable that all the visitors made the house warmer last week.  I find it a bit odd, if not sinister, that the house is taking people's heat energy and using it....isn't there something like that in Frank Herbert's Dune novels? Perhaps we ought to be regularly hosting large gatherings but having shared my space for a year with all the builders and subcontractors of Speller Metcalfe I feel I now need the occasional quiet day even if it does mean spending more on the electrics.

This house is very much an organic entity. Perhaps if you're an architect or builder or engineer you consider the form and workings of your house all the time but I've really only looked on ones we've lived in as four walls and a roof and not considered the building itself at all unless we've needed to do DIY on it. Now we're always taking the workings of the house into consideration and even though it's airtight and insulated we've also become acutely conscious of the external environment and whether or not the sun is shining or if it's raining because that has such an enormous effect on how the house functions. It's not so much a house, more like a quirky member of the family really but, although this has taken a bit of mental adjustment, at least we're not bored!