Passiv house costs.

[Dan F]

37 minutes ago, MPx said:

Interesting - the £7k one is a Moralt door.  Didn't get any joy from Moralt directly (told they don't deal with the public only wholesale).  But was put onto Principaldoorsets in Barnstable who provided the quote for a Moralt door of the appropriate spec.

We used lathams. Model was "Moralt 68mm Ferro Firesafe EI30 door kit"

[MPx]

Well a change there then @Dan F.  Latham's (Timber) wouldn't do it on the basis that I needed an FD30 cert and that has to come from a licensed processor - and they told me that PrincipalDoorsets was that for the UK.  The quoted door is a Moralt 98mm Ferro Passiv Firesafe EI30 door kit.  So it looks like the extra 30mm thickness is £5k!!

 

Latham steel doors couldn't supply a door to spec.

 

 

[Oz07]

On 24/08/2026 at 09:49, -rick- said:

 

Beat me to it!

 

For as long as petrol cars are common it seems like a sensible rule. Fuel leaking into the ground floor is both a huge issue to clean up and in the event of fire likely blocks the exit and causes rapid spread. Having said that, this is one of the reasons my preference would be for a garage that is not part of the house if there is space (can always put a covered/weather protected walkway in between them).

 

Hopefully will get removed once EVs take over.

I'm digressing a bit but...

New place already has existing flat roof garage approx 900mm away from side of proposed house. My idea is once the house wall is built to knock 1 side of garage wall down and extend the garage to make 900mm wider. There won't be a door through internally, just attached. Would an attached garage in this sense worry you? Brick and block cavity so I'm pretty relaxed about it. 

[Oz07]

1 hour ago, MPx said:

Well a change there then @Dan F.  Latham's (Timber) wouldn't do it on the basis that I needed an FD30 cert and that has to come from a licensed processor - and they told me that PrincipalDoorsets was that for the UK.  The quoted door is a Moralt 98mm Ferro Passiv Firesafe EI30 door kit.  So it looks like the extra 30mm thickness is £5k!!

 

Latham steel doors couldn't supply a door to spec.

 

 

I'd be less worried about a garage door needing super u value. I know nothing about passiv but does the raised temp in garage compared to outside mean you can cheat a bit on that door?

[-rick-]

19 minutes ago, Oz07 said:

I'm digressing a bit but...

well it is Buildhub

 

19 minutes ago, Oz07 said:

New place already has existing flat roof garage approx 900mm away from side of proposed house. My idea is once the house wall is built to knock 1 side of garage wall down and extend the garage to make 900mm wider. There won't be a door through internally, just attached. Would an attached garage in this sense worry you? Brick and block cavity so I'm pretty relaxed about it. 

 

It wouldn't bother passivehaus standards or likely building control (as long as the wall was built to the right standard) but for me a concern would be whether insurance then considered the garage part of the house. I want a garage partly so I can do hobbies in the garage that I wouldn't want to do in the house (and I'm pretty sure insurers wouldn't want that either). So for me, keeping a completely separate building has advantages there, far enough away from the garage that if I screwed up in some way and there was a fire in the garage that it would not affect the house in any way (and thus the insurers would not have to worry about that).

 

Edit: If you just want to park a car in the garage I don't really see an issue assuming planning are happy.

Edited 4 hours ago by -rick-

[JohnMo]

@MPx is this Passivhaus or "a passivhaus" as certified or sort of a Passivhaus?

 

2 hours ago, MPx said:

Including Groundworks/GSHP/Underfloor Heating/Specialist Rads/wiring - cost us £60k and I did most of the labour

ASHP is now about £2k for a 4kW Hiaer. UFH shouldn't cost more than £1k. Do a direct UVC for domestic hot water, about £600. £60k is a lifetime of direct electric heating on a decent tariff.

[Dan F]

2 hours ago, MPx said:

Well a change there then @Dan F.  Latham's (Timber) wouldn't do it on the basis that I needed an FD30 cert and that has to come from a licensed processor - and they told me that PrincipalDoorsets was that for the UK.  The quoted door is a Moralt 98mm Ferro Passiv Firesafe EI30 door kit.  So it looks like the extra 30mm thickness is £5k!!

 

That's probably the passive one i was quoted just over £2k for.  That's £5k for a bit of paper.  quite a racket!

 

Lathams got the fire safety certificate for me, that shows the "smoke tightness classification" from Moralt in Germnay.  It was all in Germnay but building inspector accepted it.

Edited 3 hours ago by Dan F

[MPx]

Very much sort of passive @JohnMo.  But we are trying our best to fully buy in to the concept when mentally we're still old school bricks and mortar, heating systems, opening windows - so we're doing loads of stuff that's way outside our comfort zone.  Eg We wont have a heating system - which seems bonkers - but we're trying to buy in to the numbers that say it wont be required.

 

As you read, my point about our old house was that as "pioneers" in GSHP we took some costs on the chin but installed something that looked like a good thing to have and would work well for us.  Obvs in the intervening decade and a half things move on.  Most of that stuff is old hat now and much more "normal" costings.

 

I realise there is a much more economical way - with stuff like @Oz07 and others suggest.  But that to me is national Housebuilder approach.  What is the minimum I can get away with and still apply a "label".  My approach is the opposite.  eg The concept demands airtightness.  So to me the ideal is airtight.  Because that's very hard and as always the few % cost a lot, you can get a certificate if you hit a certain number so why not just hit the number.  Well because its possible to do it better than that so why wouldn't you?  I'm not interested in certificates or labels I want to experience the concept working at its best.

 

This thread is about the current additional cost of going passiv.  Some are arguing its a minimal uplift.  I'm saying I'm seeing some huge numbers to make the jump.  You're arguing that I'm just being daft and doing it all wrong.  All of that likely to be true.

Edited 3 hours ago by MPx

[scottishjohn]

would it be easier to get a handle on it if someone can put number of kW a year for a passiv cert house and a good non passiv house of same size

then it would be easy to work out if extra costs are really worth it

 

you can then work out actual  costs using  a fixed price unit

 when I have tried to compare other peoples energy bill with mine in the past  it always falls down on they run there house colder or hotter than i do  or don,t heat all the rooms  or don,t have same appliances  or use them the same amount so a real comparison is  not possible

 you need fixed temp in the calc in all rooms for it to be meaningful

Edited 3 hours ago by scottishjohn

[JohnMo]

20 minutes ago, MPx said:

We wont have a heating system - which seems bonkers -

Yep, even in Somerset. UFH is so cheap to install, why wouldn't you, insurance even if not connected. Good for cooling as well.

 

Passivhaus still allows 10W/m² for heating demand so a 200m² house that's still 2kW heat demand on the coldest day (48kWh). I would rather that supplied via the floor than and electric panel heater being moved about.

 

22 minutes ago, MPx said:

opening windows

Sensible in ALL houses

 

 

[-rick-]

31 minutes ago, MPx said:

Some are arguing its a minimal uplift.

 

In some cases. Definitely easier for a developer, housing association, etc, where the design costs can be spread over multiple properties.

 

31 minutes ago, MPx said:

I'm saying I'm seeing some huge numbers to make the jump.

 

Not an uncommon situation. I'd guess the majority of self builders who want to design to passivhaus standards fit in this category (though sounds like your issue with the door is a bit exceptional, either bad advice or just bad timing - needing to meet a specific but also new spec - regs on fire doors have been changed recently and maybe the market hasn't caught up yet).

[scottishjohn]

12 minutes ago, JohnMo said:

Yep, even in Somerset. UFH is so cheap to install, why wouldn't you, insurance even if not connected. Good for cooling as well.

 

Passivhaus still allows 10W/m² for heating demand so a 200m² house that's still 2kW heat demand on the coldest day (48kWh). I would rather that supplied via the floor than and electric panel heater being moved about.

 

Sensible in ALL houses

 

 

fit UFH and if you are so sure that you will only need such a small amount of heat

then hit a stick electric boiler -they cost well under £1000 and can give up to 10kw  depending on size you pick 

 

I,ve got one here i got when we were doing a flat--7kw --but that did not happen so happy to sell you it cheap  BNIB

Edited 2 hours ago by scottishjohn

[Nickfromwales]

43 minutes ago, MPx said:

Eg We wont have a heating system - which seems bonkers - but we're trying to buy in to the numbers that say it wont be required.

Beware the great (PH) believers, aka salesman. I fear you may regret this decision......

[scottishjohn]

I may be wrong but walking about my house this summer in bare feet i think the sun is actually heating the water in the UFH by heating the slab

  so the whole floor feels same temp and my windows are not that big

[-rick-]

45 minutes ago, MPx said:

I realise there is a much more economical way - with stuff like @Oz07 and others suggest.  But that to me is national Housebuilder approach.  What is the minimum I can get away with and still apply a "label".  My approach is the opposite.  eg The concept demands airtightness.  So to me the ideal is airtight.  Because that's very hard and as always the few % cost a lot, you can get a certificate if you hit a certain number so why not just hit the number.  Well because its possible to do it better than that so why wouldn't you?  I'm not interested in certificates or labels I want to experience the concept working at its best.

 

PassivHaus is a means to an end. The goal being to tread lightly on our planet and minimise carbon emissions. In a way it's a little dated in the sense that to achieve that goal it can (depending on situation) be cheaper (financially and environmentally) to put more solar panels in than do some 'heroic' engineering to achieve a set energy use per/m2. (heroic in some buildings who's architectural concept didn't consider passive standards so now an energy inefficient form has to be forced to be energy efficient - not saying that's your case).

 

Being a sealed box is overengineering, building to a passive standard case study of balancing lots of variables and moving forward with the most efficient way to achieve the goals. Over doing it likely just ends up consuming more carbon in building materials and a lot more money in consulting fees. Once you have a target, there are often multiple ways of achieving it. For example, solutions like Aerobarrier can bring low air tightness scores for much less effort than traditional methods. It needs a good base, but the most difficult part of airtightness is the bit that Aerobarrier does in it's sleep.