Guy Martin’s House Without Bills

[sgt_woulds]

3 hours ago, Nickfromwales said:

If moisture was routinely buffered any further into the fabric of a domestic residence, that’s just too far and has not been addressed or controlled properly.

 

Seasonally, perhaps this is an acceptable swing, but day to day it should be the immediate room interior surfaces at most.

 

I dislike this approach, and am not afraid to say it!

 

Grab the heat and moisture, use it to better facilitate heat recovery, and get the MVHR in and running.

 

Tin hat time. 

 

 

Restricting moisture sorbing and release to the surface materials (Gypsum plaster boards) limits the positive benefits of stable indoor moisture levels that natural insulations can provide.  Not an issue with MVHR of course (unless there is a sustained power cut in winter with high occupancy) as this is artificially removed.

 

Personally, I'd rather not rely on a mechanical system to stay healthy indoors.  Horses for courses.  And I prefer my straw hat to tin foil 🙂 

[JohnMo]

11 minutes ago, sgt_woulds said:

Personally, I'd rather not rely on a mechanical system to stay healthy indoors.

I've done both, woodcrete ICF is a good hydrophilic material I believe, but good airtightness and MVHR to capture any ventilation heat losses.

[Nickfromwales]

1 hour ago, sgt_woulds said:

I'd rather not rely on a mechanical system to stay healthy indoors

So no mechanical fans in kitchen / utility / bathrooms etc?

[sgt_woulds]

With iPSV you don't need a fan in the bathroom or kitchen, to maintain overall conditions.  You might want a small fan to assist with kitchen odours though.

 

We do have an extract fan in our kitchen, as an easy route for passive stack was not available. 

 

Building from scratch, these problems could all be mitgated at the design stage. 

[SimonD]

On 20/02/2026 at 15:57, Nickfromwales said:

So no mechanical fans in kitchen / utility / bathrooms etc?

 

If it's all properly designed, there's no need for them, but BCO might ask for them to be installed. I have an old inline fan in a cupboard in the kitchen but not connected, another in the guest bathroom not connected and a small one in the ensuite that I've just put in at minimum fan speed because my wife was worried.....