Passive house requirements for new build

[The Moose]

barryrs said:

The Moose said:

Very interesting view. What do you consider the most efficient (or cheapest!) primary heating/hot water source is?

Number one is fabric first and air tightness as mentioned above so that you minimise your energy consumption from the start rather than offset it with renewables. That approach with a natural gas heating & hot water system with renewable/low carbon add-ons is my preferred approach.

And if gas isn't available in the area?

[Smiler.]

Rosscow said:

RC1807 said:

Rosscow said:

RC1807 said:

Our "passive" house isn't as cheap to run as you're led to believe. "A" rated, my sharmy arse!
Blower test and calcs all prove that it's "A", but it's more expensive to run than the "G" rated house we lived in before.

Really? How is that even possible?!

What do you put it down to - heating system? What do you have?

We've an air source heat pump/recirulating system, solar panels, wet UFH. Actually, looking back at my updated electricity consumption, we're now paying ~€160/month by DD.

After 1 year in the house, paying an estimated bill every 2 months, I had a massive debt to repay then over the following year, which was scary. (My build thread's noted in the Wiki - I used to be "5PotTurbo")

We're now in the habit of only using UFH when it's really cold, and not using the air circulation (in/out) in the Summer, but only for air extraction due to steam from shower rooms. Windows are open in the summer for circulation.

Interesting. We are looking at putting wet UFH (from a conventional condensing boiler) in a large extension next year.

Would you say it's the air source heat pump that is the problem?

Usually, yes. In a lot of instances, the flow & return temps of the heating pipework is not given the required design consideration, couple that with greater actual fabric heat loss than by calculation & the system will be running constantly. Big electric motor plus an immersion to counter the lack of heat pump capacity vs demand.

Every system is slightly different but the general principle applies.

I wouldn't consider it without seeing the calculations proving performance & compliance.

[barryrs]

Equus said:

barryrs said:

Not according to the 2015 adopted local plan unfortunately.

Adopted Plan be damned... there is overarching legislation that allows it to be challenged.

Been there, done that...

We challenge any code requirements as their is no basis in planning legislation now and hence why I cancelled my license however my understanding is that this condition is allowable due to government policy contained within the climate change act.

The LA were recently forced to up the number of new dwellings in the core strategy from 14,000 to 22,000 after the nationls took it to a judicial review yet this policy has remained unchallenged.

[barryrs]

The Moose said:

And if gas isn't available in the area?

Oil is pretty competitive at the moment but of course we don't know how long that will last.

There are some electric combi boilers on the market but I have no personal experience of the likely running costs. I thend to find that immersion backups on electric only systems have to be used much more than is claimed and this is the reason for high running costs. To address this their are some solar PV systems designed to run the immersion during the day so that you have "free" hot water in the evening which might be worth a look.

[Equus]

barryrs said:

...my understanding is that this condition is allowable due to government policy contained within the climate change act.

It is challenging under overarching legislation and the published guidance on the application and use of Planning conditions.

Get yourself a decent Planning Consultant.