casa in legnoHere begins a long discussion on the various aspects to consider when choosing to make or let me build a wooden house.

1) it is said that the wooden houses are less durable than traditional masonry.
I have to refute this belief for various reasons. First of all if the structure of the house is not only truly made of bricks, but rather in reinforced concrete, it is shown that the concrete has a duration of 100 years, after which it crumble and tends to return to dust after centuries.
Second, a wooden house is very flexible to use, and if tomorrow I want to add or move a room etc.. structure allows me to do so.
I could’nt make changes on a reinforced concrete structure, because this is calculated for “that” original structure and it is difficult to contemplate changes. From a regulatory standpoint also the seismic changes constantly, so a project about today is no longer ava well tomorrow and all the reinforced concrete structure must be done again.

2) the wooden house is not suited to the Italian Mediterranean climate.
It ‘s true, partially. It ‘s true to the principle that a trullo is the best structure to spend the hot Italian summers. It ‘also true that much can be done to improve the homes’ new’, without resorting to thick walls that are costing us in temini volumes of material and construction.
A little known thing to look at is the ‘”ammetenza thermal intena” surfaces.

3) What is it and why in a wooden house is the fundamental thermal ammittanza?
the thermal ammittanza, also known admittance or thermal diffusivity, is one of the two components which determine for example, our sensation of heat or cold when we put a body part in contact with a surface (the other component is the temperature of the material ). It is the determination of conductive contact which depends on the material (determined by the product of conductivity, specific heat and mass).
Depending dell’ammettenza thermal, that surface is more or less able to “exchange” heat quickly with the surrounding atmosphere.
Now: it happens in certain summer days, the air temperature to rise well above 25 ° C. Well: simplifying we believe we are well up to 25 ° and if the temperature rises above this value begin to sweat and feel excessive heat (=’re coming from a range of comfort).
But we also have to ventilate: if we do, and from 0.3 to 0.5 vol / h of air exchange, as the law requires us, this means that in 2, maximum 3 hours abbiuamo changed all the air inside the outside!
We said that in summer the outside air can also be at 25 ° and more. At this temperature, add the warmth created by the sun beating through the windows, add the warmth created by people (approx 100W heat.), From household appliances and DC.
We see that the tenmperatura can rise considerably.

What can save us? The wall insulation?
No! inside because we said it may be warmer than outside.
The only thing that saves us is the internal thermal admittance of the housing, the ability of the casing on the inside to absorb heat from the air.

Examples?
We all know the effect cellar. The air is warm as outside, but the MRI are cold and we feel the benefit.

CONTINUES … …

By Giovanni Sasso

Si occupa di tutti gli aspetti legati alla bioarchitettura nella progettazione urbanistica ed edile, ingegnerizzazione di strutture in legno-paglia, consulenza energetica. Presidente INBAR, Esperto in Bioarchitettura INBAR, Progettista Junior Casaclima, Corso Progettista PassivHaus, Progettista di Piani Urbanistici, Net Zero Energy Buildings, Passivhaus, ideatore di un unico sistema costruttivo in paglia. Formatore in master, corsi e convegni su bioarchitettura, certificazione e diagnosi energetica, materiali. is an expert in Bioarchitecture by INBAR Italian Institute of Bioarchitecture sassobrighi.com