Passive House

[Idilka]

Hi

I didn't know what passive foundation was so I did some research and learnt a little about passive house and Passivehaus standard.

Do I really need to meet the Passivehaus standard or would passive foundation, ground source heating and solar panels be sufficient to keep the house warm (without any gas/electricity bills)?

Are there any (government) incentives in meeting the Passivehaus standard?

Thanks

 

[endecotp]

You might like to ask on the "Green Building Forum" (google it).

 

[John D v2.0]

Passive standard is significantly better than the standard needed to meet building regs which is all you have to meet. If you're on a budget you don't want to aim for passive haus.
What makes you ask?

 

[^woody^]

You are either building to the standard or you are not. Compensation elsewhere in the build is possbile, you will need to work out the detail, but that will go against the principle of buiding a passive house in the first place.

 

[endecotp]

building regs which is all you have to meet.

It's not all you have to meet if you want "to keep the house warm (without any gas/electricity bills)".

 

[John D v2.0]

Oh sorry didn't spot that bit on my phone

 

[Doggit]

Stories are starting emerge where the Pasivhaus standard is so good for the winter, that the house overheats in the summer.

 

[John D v2.0]

Stories are starting emerge where the Pasivhaus standard is so good for the winter, that the house overheats in the summer.

In that case it's not a proper passive haus as the energy usage includes cooling, it should have the correct canopies and thermal mass to avoid it.

 

[Doggit]

Essentially you're right Johnm but I think the Germans know how to do it, but we don't yet. You install a cannopy, but it still gets hot inside, you have a thermal mass to keep it cool in the summer, and that makes it more difficult to heat in the winter. I saw a great design in building magazine, where they ran tubes under the ground, and with the aid of just a fan, that provided cooling in the summer, and heating in the winter. I think we have a way to go before we get things right, but I have to admit that I'm not convinced on it yet.

 

[John D v2.0]

Thermal mass doesn't make things hard to heat, it keeps the temperature stable over longer period.
You need at least enough to keep it stable overnight.
The insulation keeps the heat out as well as in, and the solar gain you only need in cooler seasons, so you have to calculate the amount of glazing and size and position of the shading (canopy) not to let the hottest summer sun in.
Shading is absolute bog standard on office buildings nowadays, you can see it everywhere because it is economical. Houses are more traditional so need regulation or fanatical passive house people to make it happen

 

[Doggit]

I think part of the problem we have in England, is that the temperature can fluctuate so much even over the course of a day (and during the night) whilst in Germany, being more inland, things are more stable. I have to agree with everything you are saying John, but I'm still not convinced it works for us.

 

[John D v2.0]

Think about it another way, you dig a tunnel 10 feet under ground and it'll be the same temperature all year round day and night. Doesn't matter if you're in Egypt or Scotland. It's just physics.

 

[bernardgreen]

whilst in Germany, being more inland, things are more stable.

My recollection from school geography lessons is that the thermal mass of sea water surrounding the UK tends to stabilise the air temperature. And when living in Germany I did experience some days when temperatures went from below freezing in the morning to very hot and back to freezing when the sun went down.

 

[Idilka]

Thanks for the replies. It's a very interesting read.

Does anyone have a rough estimate of how much it's likely to cost in comparison to a standard build?
My detached house floor area is ~176sqm.
Also, would I need to go through the planning application process again (extra cost) for passive house?

Regards

 

[chappers]

My recollection from school geography lessons is that the thermal mass of sea water surrounding the UK tends to stabilise the air temperature. And when living in Germany I did experience some days when temperatures went from below freezing in the morning to very hot and back to freezing when the sun went down.

yeah less seasonal fluctuation, but more unpredictable weather, I would imagine both places have 4 seasons in a day at certain times of year.