Insulation in a positive house

How to insulate a positive house?

How to know the thickness of insulation in my positive house?

Insulation is the 2nd must-have of a positive house.
May you skipped the first, please check our post: ‘6 musts for a positive house’

What does insulation mean?

To insulate means to protect your house from the climate by placing a surrounding material to prevent the loss of heat and cooling (it also helps prevent the intrusion of sound).
Definitions a part, it means to put a blanket wrapping your house.
It’s like you do in winter when you watch a movie: you use a blanket to keep your heat from going away.

And you’ll be thinking, how does this work in summer? I would never use a blanket in summer?
Well, you’re a human and you produce heat naturally, while your house is a thing and does not produce heat naturally.
Well, technically your house will produce heat if you give a pizza party. In that way the oven will be producing heat and your family and friends will also produce heat (so if it’s summer, you’ll be more cozy doing a salad party outside by the pool!). 

Jokes apart, your house can produce heat or cooling by using the climatization systems.
This means that if you want to have a nap after lunch on a burning-hot summer day (35ºC); you’ll be most probably choose to have it inside with the AC. Then in a positive house, you’ll be using the cooling system for 10 minutes to cool your room for the rest of the afternoon. (Mind to use the alarm for that nice nap!) 

So, basically the insulation keeps the heat and the cooling inside for longer than we’re used to. Meaning, less consumption in energy.

So, there are 3 things to consider about insulation:

1) Calculate Insulation 

First, insulation must be calculated by using the passive house simulator.
The simulator gives you the specific insulation thickness for your house’s roof, façade and slab. And it does take into account all the parameters of your house (for more details on the parameters that the positive house simulator uses, please check ’10 keys to a positive house’.
You need to know that most architects don’t have the knowledge to do this. So they will hire another person to do this. That could mean more expensive services, but even worse, losing information with the multiple agents with little specific knowledge. I do recommend you to consider an architect that is also a passive house designer.

2) Draw Insulation as calculated

Secondly, the architect must draw a detailed side cut view.
Here you’ll be able to check the thickness of every piece of insulation on your roof, façade and slab.
This drawing must be in scale and the thicknesses must match the values from the passive simulation to be able to certify your positive house.

3)  Continuous insulation

Finally, the insulation must be continuous and surround all the house.
This means that the insulation on the slab must connect with the facade’s insulation with nothing breaking into it.
The same happens with the connection façade-roof: insulation must be continuous. No breaks.
May there be breaks, then they need to be calculated as what we call: thermal bridges. Then inserted into the passive simulator to check the effects of this leak of  comfort in your house.

Our professional recommendation:
Ask your architect to deliver a section cut with the insulation thicknesses with dimensions and in scale before construction starts.
May he not be able to deliver this, he hasn’t though all the encounters and this for sure will cause some thermal bridges and your house will not be 100% efficient.

You may also be interested in:
The 3rd of the 6 must-haves of the positive house: ‘No thermal bridges’

Hope this post ‘Insulation in a positive house’ is helpful!

Best of luck on this adventure.
See you on the next post,

P.S. Wanna get FREE tips for your project weekly? Yas! or follow us on Instagram, Pinterest, Twitter y Facebook