Lightweight or CLT? What you need to know before building your own wooden house

If you have decided to build a wooden house, great! You have already taken a step towards sustainable and environmentally friendly construction. As we have previously detailed in our blog, wood is to date the most sustainable building material that exists because it is renewable, recyclable and reusable.

Now, there are several timber construction systems and you will probably have many queries about which is the best option for your home. So read on and learn more about the two main construction systems: light framing and CLT.

‍

What is light framing?

Light framing is a construction system that consists of creating the main structure with very slender and thin pieces of wood, spaced a short distance apart and fixed to closed frames.

It originated in North America in the 19th century and was born as a consequence of two factors: 1) the high availability of sawn timber and nails and 2) the need for a fast building system due to the colonisation of the Western United States.

Although it is most commonly used for the construction of one- or two-storey single-family houses, it can also be used for the construction of buildings.

This system has been refined over time, but its main features remain the same:

• Fast construction: The construction time is less than that of a traditional construction. The structure of a house can be erected in less than a month.
• Dry construction: Most of the work is executed dry (factory), which makes it a cleaner and faster process, and is not dependent on the weather season.
• Insulation: Wood is a natural insulator in itself, but in addition to this, light-framed construction results in cavity walls, which can be filled with insulating material to increase the insulation of the house.
• Savings: As it is a lightweight structure, this means a saving in the foundations of the land. Also, as it is built in less time, there is a saving in labour costs.
• Flexibility: It is very flexible in terms of the initial design and also in terms of changes that can be made on site.
• Finishes: This type of construction can be finished with any type of exterior finish.

‍

What is CLT?

CLT has been called "the concrete of the future" because it provides the same (or even greater) structural strength than reinforced concrete. CLT stands for Cross Laminated Timber. It is the result of joining timber boards or lamellas in perpendicular layers to achieve enormous dimensions; between 2.40 m and 4 m in height and up to 12 m in length, or even more if necessary.

It is a relatively new construction system. It was born in the 1990s in Germany and has expanded mainly in Europe. In its beginnings it was used for the construction of low-rise single-family houses, but due to its great rigidity and resistance it has become a growing option for the construction of high-rise buildings.

The main characteristics of the CLT are as follows:

• Fast construction: The construction time is incredibly short, in a matter of days the entire structure of a house can be assembled. The time investment is mainly in the design.
• Prefabrication: All parts are pre-manufactured and then moved and assembled on site. This is done using specialised software and machinery that allows each part to be planned to the millimetre, so that no adjustments can be made on site.
• Insulation: CLT sheets can have a thickness of 51 and 297 mm, which provides exceptional insulation. However, if necessary, it can be covered with a layer of insulating material to reinforce it.
• Savings: Rapid construction and minimisation of waste and errors can result in significant savings over traditional construction.
• Finishes: If non-visual CLT, which is intended to be clad, is used, any preferred finish can be added. There are also visual CLT panels that are designed to be exposed.

Take a look at this video of the assembly of one of our wooden houses with CLT structure.

Is light framing or CLT better?

So, the million-dollar question is: Which of these two timber construction systems is better? And the answer is not so simple, because there is no one right answer, but rather it will depend on the requirements of each project.

Both are excellent options for building a wooden house, so consider the following when making your decision:

• In general, light framing is usually a bit cheaper than CLT because less wood is used: Light framing is a hollow wall and CLT is a solid wood wall. That said, if you plan the design properly to avoid mistakes and waste, and also play around with leaving some timber exposed, CLT can come in at a price.
• CLT allows for much quicker construction but once the design is fixed it is not possible to make changes on site, while light framing takes a little longer but is flexible in terms of changes you may want to make on site.
• If you want to incorporate exposed wood into the design of your home, CLT is a better option, as there are specially manufactured panels for this purpose.
• CLT makes it possible to build taller buildings in record time. For example, the first building in London to be constructed with CLT was a 9-storey building and the assembly of the structure was done by 4 people in 27 working days.

‍

In conclusion, to choose the best building system for your new wooden house you should think about your personality (Can you stick to an idea until the end or do you prefer to have the freedom to make changes during the process?), your budget and the design you want for your house.

If you are contemplating the idea of building a passive wooden house, schedule a video call with us and let's start shaping your project.