Buying an unconventional passive house

mbugsy18

ComicGeek - or anyone else. Would replacing the electric heating with a wood burner improve the rating?

Alan2020

mbugsy18 said:

ComicGeek - or anyone else. Would replacing the electric heating with a wood burner improve the rating?

Wood burning is very very bad for your and your neighbours health - It is simply not banned due to the greed of people.  Whilst it is OK in remote places, wood burning is worse than smoking.  People will tell you its OK, but nearly all scientists and engineers will tell you is the most polluting way and the highway to getting cancers.
https://woodsmokepollution.org/index.html

FreeBear

mbugsy18 said: Would replacing the electric heating with a wood burner improve the rating?

You don't really have the space to store much firewood, and local suppliers are going to be expensive. In an urban environment, wood stoves are not really appropriate.

mbugsy18

FreeBear said:

mbugsy18 said: Would replacing the electric heating with a wood burner improve the rating?

You don't really have the space to store much firewood, and local suppliers are going to be expensive. In an urban environment, wood stoves are not really appropriate.

I think the wood burner would only be used to boost the living area for warmth when temperatures are really cold. A few days per winter I am assuming.

FreeBear

mbugsy18 said: I think the wood burner would only be used to boost the living area for warmth when temperatures are really cold. A few days per winter I am assuming.

So £3-5K to improve the EPC rating and for a bit of extra heating a few days a year plus the hassle of sourcing & storing fuel somewhere dry.

mbugsy18

Point made. I’ll live with the EPC as it is for now.

ProDave

ComicGeek said:

It is a full on construction EPC as the average fabric U-values are quoted - they aren't for RdSAP EPCs for existing dwellings.

The EPC rating is purely based on running costs, so the electric heating is really pulling down the result - even if there is a much smaller heat loss with the Passivhaus standard, it still costs more to heat than with a gas boiler.

It's very, very difficult to get an A rating without PV panels. 

Yes you are right.  EPC and SAP is all about carbon footprint, and to get up to 100 (some may argue the holy grail) your house will have to have some form of renewable energy that generates as much energy as the house uses.

Doozergirl

mbugsy18 said:

ComicGeek - or anyone else. Would replacing the electric heating with a wood burner improve the rating?

Woah there! 

I appreciate that ProDave has a wood burner, but we also have built our house on the principles of Passive House and despite me wanting one, I was told point blank that we should/could not have a wood burner. 

a) because you're punching a hole in an airtight house (I believe there might be fires that minimise air leakage) 
b) you won't get much draw on the fire because it is airtight and you're purposely
limiting air changes via mechanical means. 
c) the entire house would get hot very quickly so as to be uncomfortable and you'd have to open all of the windows.  

I've not gone all numbers on this, but my SAP assessor told me that the current EPC does not work with the principles of passive house.  They put too much emphasis on renewables, so a normal house that uses more energy to heat can get a better rating than a passive house that absolutely minimises it.  

Our house is one point off an A rating.  We do need some heating because the plot isn't orientated correctly and the LA insisted on a style that meets the vernacular, rather than the box principal of a passive house.  It takes about three days to drop from 21 to 18 degrees though, with no heating on in the middle of winter!  

I did not choose to have renewables because we've spent a fortune on the fabric of the house already and, at present, renewables will not pay us back within 20 years.  I've done my bit. When the government decide to make renewables affordable, we're ready.  

Anyhow, a wood burner does not affect the EPC.  

I'll tell you something.  Ignore the EPC.  As ProDave mentioned, living in a temperate house with no cold spots, no temperature falls overnight and a sense of clean air all the time is amazing.  I don't think that I will ever be able to go back to living in a 'normal' house.   

Doozergirl

mbugsy18 said:

FreeBear said:

mbugsy18 said: Would replacing the electric heating with a wood burner improve the rating?

You don't really have the space to store much firewood, and local suppliers are going to be expensive. In an urban environment, wood stoves are not really appropriate.

I think the wood burner would only be used to boost the living area for warmth when temperatures are really cold. A few days per winter I am assuming.

It's a Passive House.  That doesn't happen! 

People think this house is boiling hot.  It isn't, it's heated evenly with no obvious heat source.  It doesn't have freezing cold and hot spots like a normal house.  

ProDave

Doozergirl said:

mbugsy18 said:

ComicGeek - or anyone else. Would replacing the electric heating with a wood burner improve the rating?

Woah there! 

I appreciate that ProDave has a wood burner, but we also have built our house on the principles of Passive House and despite me wanting one, I was told point blank that we should/could not have a wood burner. 

a) because you're punching a hole in an airtight house (I believe there might be fires that minimise air leakage) 
b) you won't get much draw on the fire because it is airtight and you're purposely
limiting air changes via mechanical means. 
c) the entire house would get hot very quickly so as to be uncomfortable and you'd have to open all of the windows.  

I've not gone all numbers on this, but my SAP assessor told me that the current EPC does not work with the principles of passive house.  They put too much emphasis on renewables, so a normal house that uses more energy to heat can get a better rating than a passive house that absolutely minimises it.  

Our house is one point off an A rating.  We do need some heating because the plot isn't orientated correctly and the LA insisted on a style that meets the vernacular, rather than the box principal of a passive house.  It takes about three days to drop from 21 to 18 degrees though, with no heating on in the middle of winter!  

I did not choose to have renewables because we've spent a fortune on the fabric of the house already and, at present, renewables will not pay us back within 20 years.  I've done my bit. When the government decide to make renewables affordable, we're ready.  

Anyhow, a wood burner does not affect the EPC.  

I'll tell you something.  Ignore the EPC.  As ProDave mentioned, living in a temperate house with no cold spots, no temperature falls overnight and a sense of clean air all the time is amazing.  I don't think that I will ever be able to go back to living in a 'normal' house.   

Lots of miss understanding about wood burning stoves.

Ours is a small (4.5kW) stove, but crucially is is "room sealed"  The combustion air (both primary and secondary) is ducted in straight from outside. And obviously the exhaust goes up the flue.  So it does not draw air from the house, and it does not imbalance the mvhr.  when not in use no doubt it will leak some heat out of the house but not a lot.

The next myth is they will overheat the house in 5 minutes.  Not true if properly designed.  Our house has an open layout with both main rooms opening with double doors to the centrally placed stair well.  As long as you make sure the doors are open when the stove is on, then that little stove will heat the whole house including upstairs without overheating a single room.

We use the stove as indulgance. The house is normally heated to a constant 20 degrees, but sometimes on a cold grey wet winters day it is nice to stoke up the stove and get the whole house up to 25 degrees.

And finally the fuel for the stove is entirely from our own trees or scavenged fallen wood. I would not have a wood burner if I had to pay for the fuel.

Oh and one last last comment, I DO NOT for one moment think a WBS is either "green" or environmentally friendly, and i shudder at things like DRAX burning wood on an industrial scale and claimed to be "green"