Does it cost more money or less money to build a passive house

dellas1979

Stemmed discussion from another thread. It does deserve to be discussed more. So that people are informed.

Does it cost more or less money to build a passive house (not a house with some passive elements, an actual passive house), compared to a usual oil/boiler heated, usual electrics, in a house, and get it certified?





Everyone wants to make a point, and all discussion is welcome. No derogatory remarks. No need for that. We are in 2018. All have ideas and options and we are adults. Unhelpful comments and behaviour should be moderated.

B-D-P--

Thoughts being that if you build passive, you dont need an expensive A2W system and that will even it out?

General question, not a sarcastic remark.

sydthebeat

it cost more to buy an electric car currently, but they has much less running and administration costs so over its lifetime it should save you money.


Its the very same principle with Passive houses.
They may, and usually do, cost more initially to build.... but their running costs throughout their (much longer) lifetime means that you actually save money in the long term.

The salient point here is that, as the building regulations get more and more onerous, the gap between building passive or not is lessening all the time. Our building regs changed in 2008, 2011 and will change again in 2018.

Dudda

It completely depends on the passive house and the house your comparing it to. You can't compare a passive house in an urban area where you can't orientate windows where you want and may not be able to use solar panels as opposed to the countryside where you’ve potentially more freedom. Similarly the size of the house matters a lot.

Usually a major factor is if you can completely remove the wet heating system. In a passive house where the energy use is so low you can have a small heating coil in the MVHR system rather than a full heating system. Therefore you don’t need UFH, radiators, heat pumps, boilers, pumps, all the pipes and controls, etc. This idea was employed in a housing estate in Wexford and various reports, presentations and other documents published on it showing how in certain cases a passive house can be cheaper to build than a traditional build IN CERTAIN CIRCUMSTANCES only. They’ve published a cost analysis and breakdown of the materials and elements showing how it was cheaper. This project is living, documented proof that you can build a passive house cheaper than a traditional but it’s not typical.

EDIT: I remember going to a Passive House CPD and reading they had it showing the house was cheaper but after googling and finding some cost analysis data on the project it now looks like it was a tiny bit more expensive. Maybe it was Phase 2 of the scheme or something. Anyway cost analysis case study from the Passive House Academy below:

http://www.passivehouseacademy.com/downloads/Cost_Analysis_of_Bennett_Wexford_Passive_House.pdf

BryanF

For example excluding something like a stove (which often isn’t needed in a passive house) could render the prices similar.

gooner99

Dudda wrote: »

It completely depends on the passive house and the house your comparing it to. You can't compare a passive house in an urban area where you can't orientate windows where you want and may not be able to use solar panels as opposed to the countryside where you’ve potentially more freedom. Similarly the size of the house matters a lot.

Usually a major factor is if you can completely remove the wet heating system. In a passive house where the energy use is so low you can have a small heating coil in the MVHR system rather than a full heating system. Therefore you don’t need UFH, radiators, heat pumps, boilers, pumps, all the pipes and controls, etc. This idea was employed in a housing estate in Wexford and various reports, presentations and other documents published on it showing how in certain cases a passive house can be cheaper to build than a traditional build IN CERTAIN CIRCUMSTANCES only. They’ve published a cost analysis and breakdown of the materials and elements showing how it was cheaper. This project is living, documented proof that you can build a passive house cheaper than a traditional but it’s not typical.

EDIT: I remember going to a Passive House CPD and reading they had it showing the house was cheaper but after googling and finding some cost analysis data on the project it now looks like it was a tiny bit more expensive. Maybe it was Phase 2 of the scheme or something. Anyway cost analysis case study from the Passive House Academy below:

http://www.passivehouseacademy.com/downloads/Cost_Analysis_of_Bennett_Wexford_Passive_House.pdf

I think I read about that estate before. I think the system is a hybrid mvhr with air to air heat distribution from Nilan. Seems to be getting more popular with developers as it does away with wet systems and stoves and ticks the boxes along with PV. Anyone know how this system works in real life. Should be some real world experiences now, giving it's out a few years and we've just gone through a harsh winter.?

sydthebeat

gooner99 wrote: »

I think I read about that estate before. I think the system is a hybrid mvhr with air to air heat distribution from Nilan. Seems to be getting more popular with developers as it does away with wet systems and stoves and ticks the boxes along with PV. Anyone know how this system works in real life. Should be some real world experiences now, giving it's out a few years and we've just gone through a harsh winter.?

I can recall a couple of passive houses built in carlow about 10 years ago that have an air to air heating system.

No idea of how they are preforming today

Carrickbeg

Im in the middle of a build I would go along with the idea that to build to passive standards, which I didn't, is not that much more expensive. Take out your, gas/oil boiler and all associated costs, take out your radiators and all associated costs, take out your annual heating costs, and you have 10-20k towards your passive heating and insulation extras.
My grandmother always says
The cheap thing is the dear thing in the long run.

jimmy_t

My 2 friends and I are all in the middle of our builds. Im building passive via contractor, friend A is building A2 rated via contractor and friend B is self building the cheapest A rated house possible. All houses are the same size pretty much.

My house from what I can see is very very similar to friend A in construction detailing. He has all the same components, triple glazing, air to water w/ufh and mvhr. His insulation levels appear to be very similar. His windows are cheaper and his heat pump is more expensive. My preliminaries are more expensive and I have been told that this is due to having to guarantee 0.6ach and the extra time on site required to achieve this. My house design is more complex in size of opes and cast in place lintels and has some unique architectural detailing but has a simple form. He has solar panels, I have none. His house is 1.5 story and of very regular design. He has some thermal bridges. His house is contracted to be 10% cheaper than mine. I would suggest only a portion of this is passive related.

Friend B house is again a very regular 2 story design but has no mvhr, very little airtightness detailing, ufh throughout, a more expensive heat pump, solar panels, triple glazing, less wall/floor/roof insulation, very little attention to thermal bridges. Detailing is very basic. No preliminaries as it is self build. His house, he is hoping will be 30% cheaper than mine, I highly doubt this and I reckon he might get it for 20% cheaper. He is stressed to the gills and is working every hour on the house and is trying to manage his day job at the same time. Im certain his house will be cheaper but it will take longer, be a lot more stressful, be of lower quality and be more expensive to run.

Im sure all 3 of us will be very happy with our houses when we are finished and I doubt any of us will regret anything.

Carrickbeg

jimmy_t wrote: »

My 2 friends and I are all in the middle of our builds. Im building passive via contractor, friend A is building A2 rated via contractor and friend B is self building the cheapest A rated house possible. All houses are the same size pretty much.

My house from what I can see is very very similar to friend A in construction detailing. He has all the same components, triple glazing, air to water w/ufh and mvhr. His insulation levels appear to be very similar. His windows are cheaper and his heat pump is more expensive. My preliminaries are more expensive and I have been told that this is due to having to guarantee 0.6ach and the extra time on site required to achieve this. My house design is more complex in size of opes and cast in place lintels and has some unique architectural detailing but has a simple form. He has solar panels, I have none. His house is 1.5 story and of very regular design. He has some thermal bridges. His house is contracted to be 10% cheaper than mine. I would suggest only a portion of this is passive related.

Friend B house is again a very regular 2 story design but has no mvhr, very little airtightness detailing, ufh throughout, a more expensive heat pump, solar panels, triple glazing, less wall/floor/roof insulation, very little attention to thermal bridges. Detailing is very basic. No preliminaries as it is self build. His house, he is hoping will be 30% cheaper than mine, I highly doubt this and I reckon he might get it for 20% cheaper. He is stressed to the gills and is working every hour on the house and is trying to manage his day job at the same time. Im certain his house will be cheaper but it will take longer, be a lot more stressful, be of lower quality and be more expensive to run.

Im sure all 3 of us will be very happy with our houses when we are finished and I doubt any of us will regret anything.

I'm like friend B but theres nothing cheap about building a modern A rated home!

jimmy_t

Here is an example of someone who built a passivhaus in the most cost effective way possible:
http://mollyglass2012.tumblr.com/
You will note: self build by a QS, PHPP completed by himself, compact simple form, very simple heating system (stove & back boiler).