Major construction projects are traditionally implemented on-site, regardless of the conditions and amount of natural light. Consequently, the possibilities of efficient, high-quality construction decrease with more difficult weather conditions and reduced light. Lehto Group has addressed this development need.

Lehto Group is a Finnish company specialising in economically driven construction. It aims to replace prototype construction – that is, the individual construction of each building on-site – with industrial production, which is more cost-effective and ensures higher quality. Homes will increasingly be built in factories, where it is easier to control the quality and costs of production.

Using wood in off-site construction

Metsä Wood also supports the transition to industrial prefabrication, or off-site construction. “Urbanisation and climate change are global megatrends that necessitate the development of more sustainable solutions in response to the continuously increasing demand for homes,” says Virva Juhola SVP sales and marketing at Metsä Wood.

“In this transition, industrial prefabrication and scalable concepts lead the way for new ways of doing things better in the construction industry, which is lagging significantly behind other sectors in productivity development.”

The use of wood as a building material, alongside concrete and steel, supports Lehto Group’s strategy of efficient construction methods. As a light material, wood is easy to transport and handle, which enables the industrial production of wood-based elements. Lehto Group uses Metsä Wood’s Kerto® LVL as a building material. Manufactured by gluing softwood veneers together, Kerto LVL beam and panel products are ideal for the industrial prefabrication of construction elements. Their material efficiency also makes them suitable for this cost-optimising construction philosophy.

Metsä Wood finds it important to support various operators in the production of wooden elements. “We have created an industrial ecosystem – a network of partners – around Kerto LVL, as well as a technical customer service concept, to increase the efficiency of our customers’ element production,” Juhola explains.

Traditional construction is inefficient

Lehto Group wanted to find a way to improve construction processes. In traditional on-site construction, builders may spend up to 60 per cent of their working time on operations not related to the actual construction work. This may involve making corrections to work that has already been completed, overcoming challenging working conditions or dealing with other interruptions in the project, for example. According to Hannu Lehto, CEO of Lehto Group, these all lead to inefficiency: “We want to make processes more efficient and reduce interruptions, so we can offer a little more to the customer for the same money.”

Lower construction costs

Everything begins from planning. Lehto Group designs the buildings in-house, making use of concepts. This enables the company to make use of solutions that have already been proven to work well. On-site conditions are stabilised by carrying out complicated production work in factories. This reduces errors, improves quality and cuts costs.

Industrial production is an effective way to overcome the challenges of on-site construction: changing weather conditions and teams, as well as different design methods. “On-site construction is error-intensive, as well as being slow and expensive. This is where we want a complete turnaround,” says Lehto. “More and more complicated components are transferred off-site, and digitalisation controls the value chain.”

Increasing digitalisation is one way to enhance the efficiency of construction. At Lehto Group a digital model is created of the building project as early as the planning phase, and the model is maintained alongside the building, even after the building has been taken into use. It serves as a platform that makes maintenance easier, cheaper and quicker. “Generally, people don’t quite know what products and components their buildings consist of. This is something we want to improve, and the construction culture will change dramatically in the process. Instead of using components provided by various parties as the project progresses, we create a comprehensive and consistent plan, and the information included in the plan will be available through the digital model,” Lehto explains.

Modular construction meets customers’ needs

At Lehto Group, industrial production for construction is based on the principles of modularity. The company has a range of pre-designed, compatible roof, wall and window elements that can be combined and modified to produce the desired result. “It’s a little like playing with Legos,” says Lehto.

The customer’s needs and the modules can usually be combined. “If the customer has preliminary drawings, we ask if we can modify them slightly. As there is no one right way to build, the design can usually be adjusted a little to make it compatible with our standard elements.” Lehto Group is not seeking customers who are aiming for completely unique buildings. “Such buildings are extremely expensive.”

Creativity and modularity are combined by using top architects in the design of the elements. The material of the facade can be changed, which is why Lehto Group’s buildings are never identical. They are in harmony with their surrounding environment and the local town plan. With some major customers, such as hotel developers, the concept model has been further developed in cooperation with the customer to meet their individual needs.

Efficient building material

Combining wood with concrete and steel supports Lehto Group’s philosophy of efficient construction methods. Wood has many strengths as a building material, including lightness. Metsä Wood’s Kerto LVL products are also designed to be durable and strong.

Lehto Group uses Kerto LVL in load-bearing structures, intermediate floor structures, roof structures and even walls in wooden apartment buildings. “Like its value promise says, Kerto LVL is fast, light and green. It’s a strong but light material, and its use supports our economically driven construction method. It has good dimensional stability and consistently high quality, meaning that it doesn’t warp or twist. In addition, Kerto products enable long spans in roof elements, for example,” says Lehto. Lehto Group also uses Kerto LVL in concrete apartment buildings, in the wooden frames of washrooms and kitchens.

Metsä Wood delivers cut-to-size Kerto LVL products to Lehto Group. This increases efficiency in terms of time management, material optimisation and the reduction of waste.

Wood construction is ecological

Climate change calls for increasingly ecological decisions, and cities have started to allocate larger and larger areas for wooden apartment buildings in their town plans. “Timber construction is a growing and increasingly significant trend. We have to listen intently to what our customers value and want,” says Lehto. In Lehto Group’s approach, ecological thinking and efficient industrial production support one another. “Timber construction combines these benefits,” Lehto points out.

“Construction using wood is fast, light and ecological – in other words, ideal for industrial production,” Virva Juhola, from Metsä Wood’s sales adds. The key competitive advantages of Kerto LVL are its material efficiency and its strength-to-weight ratio. In Kerto LVL, northern spruce enables longer spans and lighter structures than the same amount of other materials in other products. For this reason, Kerto LVL makes it possible to shorten production lead times by reducing the waste of material and the need for labour during prefabrication.