7 reasons to build airtight & weatherproof

“What are the advantages of airtight buildings?” – a question that not only we at SIGA, but also you as a builder or architect have often been asked. We list the main reasons.

Stefanie Schaller
in airtightness , windtightness
20. May 2020 4 minutes reading time

Buildings need energy

How much energy do you think buildings use worldwide?



No, it’s even more.

In the European Union, buildings still consume over 40 % of the energy produced, of which more than 80 % comes from non-renewable sources such as oil, coal and gas. Climate change is unfortunately unstoppable. But it is possible to slow it down. There are many ways to do this. Every step counts, no matter how small. One possibility is to build houses which are tight and more energy efficient.

Why build an airtight house

Many building owners are not aware that airtight construction not only saves a lot of money in the long term, but also increases living comfort. Plus: An airtight building lasts longer.

We see the main reasons for airtight building in the following points:

  • Save energy and heating costs, means less CO2 emissions
  • No structural damage due to hidden mould
  • No draught in the living space
  • Better indoor air quality (dust, pollen, odours), less pollutants from outside
  • Ventilation systems work more efficiently
  • Better sound insulation
  • Gas and smoke barrier in case of fire

Airtight vs. weatherproof– what is the difference?

All you want is a tight building envelope, right? When we speak of a tight building envelope, we usually distinguish between airtightness and wind-tightness.

The airtight building envelope prevents heat loss through convection and ensures that no condensation occurs in the construction. Airtightness prevents air currents from flowing through the building envelope from the inside to the outside. If the airtightness is not given, heated or cooled air can escape from the inside of the building. This leads to energy loss.

And heat loss is something you don’t want to have.

This is annoying because it reduces the efficiency of the building envelope and leads to higher energy loss and consumption, which in turn affects heating or cooling costs.

Do not confuse air tightness with diffusion tightness! Even if no air flows through the building envelope, water vapour can still diffuse through the building membranes.

Wind-tightness, on the other hand, protects the building from air currents that enter the insulation from outside and exit elsewhere. As a result, the insulation becomes less efficient, resulting in higher energy consumption and higher costs.

Closed building envelope

The more energy-efficient a building needs to be, the more important it is to build airtight. There is a wide range of suitable products for making the airtight layer, such as air and vapour control layers and adhesive tapes (we list the main types of vapour control and airtightness control in this article). All materials, plastics and adhesive products used in a building must be extremely resistant to ageing, as a building should function perfectly for decades.

It’s not only about the products. It’s more about “how to use the products”

The installing is just as important as the use of high-quality materials. Only if you install the products correctly, you can prevent leaks and thus the penetration of moisture into the building envelope. This again can lead to mould growth and resulting in structural damage.

Learn how to install products correctly

Make use of the SIGA training offers

Airtightness brings living comfort

You’re still not convinced why airtightness is important? Protection against mould damage is not the only reason for an airtight building envelope.

Airtight buildings provide a pleasant living climate, protect the environment and reduce energy costs. They therefore protect the building, the health of the occupants and their wallets at the same time.

To ensure that nothing stands in the way of a comfortable climate in the building, make sure to choose products that are free of residential toxins when creating the airtight building envelope.

Stefanie Schaller

Inbound Marketer at SIGA in Switzerland who loves books, yoga and travelling the world.

Similar articles

Cornelia Wollnow in culture

Apprentices at SIGA

Bertie Dixon in airtightness

Airtightness in Irish Building Regulations

Stefanie Schaller in airtightness

Vapour barrier vs. vapour control layer

Bertie Dixon in airtightness , windtightness

Airtightness regulations in the UK

Stefanie Schaller in culture

Approved for production

Stefanie Schaller in culture , sustainability

SIGA invests 30 million in the Schachen site

Alejandro Jimenez in culture

SIGA receives Airtightness Gold Supplier Award

Kate de Selincourt in airtightness , windtightness

Beware thermal bypass – it’s air behaving badly!

Kate de Selincourt in airtightness , sustainability

Can airtight buildings protect your health

Lenny Antonelli in airtightness , windtightness

[Checklist] Get ready for your blower door test