Passive house Shepards hut ?

[Waterworks]

Would it be possible to design a Shepards hut on a passive house principle ?

 

This would be a pretty big maybe 3 x 6 metres internally , and clad in galvanised corrugated sheets.  The design would take into account up to 300mm of PIR insulation, maybe vacuum panels in the front door and there would certainly a small wood stove. 

 

What would the design need to consider ?

[JohnMo]

5 minutes ago, Waterworks said:

300mm of PIR insulation

Why that much?

7 minutes ago, Waterworks said:

vacuum panels in the front door

Over thinking things.

 

You can use passivhaus principles for any build.

 

Main things are thermal bridges, continuous insulation, form factor, airtightness.

 

So you need to consider ventilation.

 

[ProDave]

With that level of insulation and such a small space, don't fit a WBS, you will melt the first time you light it.

[saveasteading]

2 hours ago, Waterworks said:

Shepards hut on a passive house principle ?

Of course. But any time you open the door most heat will shoot out so I can't see the point.

And the surface area compared to volume also provides a poor figure.

 

Spending a fortune on sustainability for a building that is far from sustainable through the material/carbon content doesn't make sense.

 

A shepherd would not do that.

[Crofter]

PassivHaus is all about energy/m², rather than total energy. Which I think is wrong and drives up house sizes.

We don't measure cars in mpg per ton of vehicle. 

 

Also, it's very difficult to meet PH standard in a small build because the volume: surface area ratio favours larger buildings. Another thing counting against a PH Shepherd's Hut is the exposed floor. You've got a very large surface area and a small volume inside it. 

 

I came up against all of this on my own build, which is a 5*10m house on legs.

[Iceverge]

20 minutes ago, Crofter said:

PassivHaus is all about energy/m², rather than total energy. Which I think is wrong and drives up house sizes.

We don't measure cars in mpg per ton of vehicle. 

 

Also, it's very difficult to meet PH standard in a small build because the volume: surface area ratio favours larger buildings. Another thing counting against a PH Shepherd's Hut is the exposed floor. You've got a very large surface area and a small volume inside it. 

 

I came up against all of this on my own build, which is a 5*10m house on legs.

 

Exactly this. 

 

https://passivehouseplus.ie/magazine/insight/the-small-passive-house-problem-a-solution

[Waterworks]

OK, passive house is not practical this small , so what would be the level of insulation required for the minimal heating fuel requirement in tne winter in the UK ? 

 

Im asking based on the houseboat I currently live on which has 40 mm PIR insulation and is costing a fortune to heat , I want my Shepherds hut to use the minimum fuel possible and my design is built around insulation, however much is required.  

[Crofter]

I would start by looking at all the background heat you expect to be generating in there- two humans, a fridge, some cooking. 

Then do a basic heat loss calculation based on notional insulation values and the surface area of the hut. This will be dependent on outside temperature- do you want to use this all year round, or summer only? 

 

Just to give you a data point, my little place needs no heating for about nine months of the year. The fridge, hot water tank, and a bit of solar gain seem to be enough. I've got u values of between 0.1 and 0.15, with the windows at about 1.0.

[Nickfromwales]

On 09/02/2026 at 12:48, ProDave said:

With that level of insulation and such a small space, don't fit a WBS, you will melt the first time you light it.

Yup. 
 

Just fit A2A (air con) for heating but also for cooling. You’ll need more cool than heat.

 

300mm of PIR is 150% passive!! Take a chill pill and we’ll guide you back on track   

[SteamyTea]

On 09/02/2026 at 17:08, Crofter said:

We don't measure cars in mpg per ton of vehicle. 

We could tax them on it.

Mine does 35 mpg/tonne (ish), my last car 37 mpg/tonne, but it was not so good. 60 MPG for a 1.6 tonne car as opposed to 62 MPG for a 1.8 tonne now.

 

Many years ago, when I was studying automotive engineering, I read an article about this, seem to remember at the time (1982) that mass divided by 540 gave the gallons per mile.  My passengers on Tuesday were most impressed that my car does 4 lt/100 km (they are used to that metric).

[Adrian Walker]

On 09/02/2026 at 12:28, Waterworks said:

Would it be possible to design a Shepards hut on a passive house principle ?

 

This would be a pretty big maybe 3 x 6 metres internally , and clad in galvanised corrugated sheets.  The design would take into account up to 300mm of PIR insulation, maybe vacuum panels in the front door and there would certainly a small wood stove. 

 

What would the design need to consider ?

Crazy idea. And the stove is a no-no

[Mr Punter]

17 hours ago, Adrian Walker said:

Crazy idea. And the stove is a no-no

 

+1.  May as well heat it with the car exhaust!

[Nickfromwales]

1 hour ago, Mr Punter said:

 

+1.  May as well heat it with the car exhaust!

Apart for all the deaths, that’s a great idea  

 

A handful of solar PV panels, small UVC for hot water, and split AC for heating and cooling. 
 

Job done. ✔️. 

[saveasteading]

6 minutes ago, Nickfromwales said:

Job done.

And a very comfortable shepherd. 

Isn't the point of a shepherd's hut that it's a bit basic?

 

[Nickfromwales]

10 minutes ago, saveasteading said:

And a very comfortable shepherd. 

Isn't the point of a shepherd's hut that it's a bit basic?

 

No minibar then??? 🫣

[saveasteading]

A spare room for a poorly or favourite sheep?

[Nickfromwales]

1 hour ago, saveasteading said:

A spare room for a poorly or favourite sheep?

You’re being racist to me now eh?  

[SteamyTea]

I was helping on my friend's farm.  Had to get some sheep into a pen.

One just refused to go in and just kept stepping backwards towards me.

My farming friend said 'a good sheep will do that for you'.

[Waterworks]

On 13/02/2026 at 12:06, Nickfromwales said:

Apart for all the deaths, that’s a great idea  

 

A handful of solar PV panels, small UVC for hot water, and split AC for heating and cooling. 
 

Job done. ✔️. 

There will be no connection to mains electricity.  

 

The reason for the wood stove. 

[Waterworks]

On 12/02/2026 at 14:28, Crofter said:

I would start by looking at all the background heat you expect to be generating in there- two humans, a fridge, some cooking. 

Then do a basic heat loss calculation based on notional insulation values and the surface area of the hut. This will be dependent on outside temperature- do you want to use this all year round, or summer only? 

 

Just to give you a data point, my little place needs no heating for about nine months of the year. The fridge, hot water tank, and a bit of solar gain seem to be enough. I've got u values of between 0.1 and 0.15, with the windows at about 1.0.

What kind and thickness of insulation have you got ?

[Waterworks]

To go an alternative route to this question , if you were designing an off grid metal clad sheperds hut for one person for all year round use that will use the minimum of heating fuel how would you insulate it ? 

 

 

 

 

[Nickfromwales]

14 minutes ago, Waterworks said:

There will be no connection to mains electricity.  

 

The reason for the wood stove. 

Who are the intended occupants, and what are they going to do in it?

 

Bathroom in a room, rest of the space open plan?

 

[Crofter]

7 hours ago, Waterworks said:

What kind and thickness of insulation have you got ?

Floor: 300mm mineral wool

Walls: 150mm wool+ 50mm PIR

Warm pitched roof: 150mm wool+ 100mm PIR

 

Plus airtight membrane battened and taped.

 

Windows are 3G with u values of 1.0 or less.

[Iceverge]

9 hours ago, Waterworks said:

one person for all year round use that will use the minimum of heating

 

A hut probably has a surface area of 30m².

 

Assume it has 50mm of PIR it will end up with an average U value of 1 W/m²K including bridging and windows. At -5 it will need 750w. 

 

The smallest timber stove is about 4kW so you'll quickly overheat. 

 

A campervan type diesel heater would be more comfortable. 

 

 

[JohnMo]

1 hour ago, Iceverge said:

 

A hut probably has a surface area of 30m².

 

Assume it has 50mm of PIR it will end up with an average U value of 1 W/m²K including bridging and windows. At -5 it will need 750w. 

 

The smallest timber stove is about 4kW so you'll quickly overheat. 

 

A campervan type diesel heater would be more comfortable. 

 

 

Our summer house, is insulated, floor, roof and walls, double glazed wall with plenty of air leakage (rubbish design) and a dMEV fan. Insulation a country mile away from passivhaus, airtightness even further away.

 

Heating is by fan coil as an extension to the house UFH system (all run as single zone), ASHP flow temp set at 28.5 degs. Heating consumption for summer house is the best part of nothing much, as it piggy backed on to house and summer house is sitting at 19.5 degs most of the time. If we need additional heat we flick on an electric heater and it bumps it up to 21 in 30 to 40 mins.

 

Going passivhaus on a small building isn't worth the effort as with some insulation heat costs are tiny. Not even sure a diesel heater is worth the effort, small storage heater, electric panel heater or a room through wall heat pump heater, sized at about 1+kW.