Cross-laminated timber (CLT) technology is becoming increasingly popular in residential construction, including multi-family buildings. The reasons are clear: it offers fast project completion, precise prefabrication, excellent insulation properties, and a significantly reduced carbon footprint. Developers and investors considering the construction of apartment blocks, multi-family housing, or terraced buildings are increasingly asking: Is cross-laminated timber a viable alternative to concrete and steel on a larger scale? The answer is yes – provided that the design takes full advantage of the potential and specifics of this technology.
Here are the key aspects worth considering before deciding to invest in CLT.
TYPES OF MULTI-FAMILY BUILDINGS SUITABLE FOR CLT
Contrary to common belief, structural timber is not limited to single-family houses. CLT technology is successfully used in the construction of:
• low- and mid-rise apartment buildings (typically up to 4 storeys)
• terraced and semi-detached housing (based on prefabricated wall and floor modules)
• apartment complexes with varied functional layouts
• mixed-use buildings (often combining residential and commercial spaces), where some floors are made of concrete (e.g. underground garage levels) and others of CLT (e.g. above-ground levels)
Based on our experience, CLT technology offers great design flexibility, enabling the creation of customized apartment layouts, shared spaces, or even unconventional building forms, all while meeting the requirements of prefabrication.
LEGAL AND CERTIFICATION REQUIREMENTS
In Poland, there is no ban on using structural timber in multi-family buildings, although certain height limits and fire safety requirements must be met. The key aspects include:
• number of storeys – while regulations do not define strict height limits for CLT buildings, in practice most are low- or mid-rise. Taller buildings require individual approvals and additional fire protection measures
• fire resistance – CLT components can achieve fire resistance classes REI 60, REI 90, or even REI 120, making them suitable for residential and commercial applications
• CE and KOT certificates – our CLT panels meet both European and national standards
• acoustic and thermal insulation – compliant with technical requirements for residential and commercial buildings
We assess each project individually for compliance with local regulations and support our clients in obtaining all necessary approvals and documentation.
WHAT TO CONSIDER WHEN DESIGNING A MULTI-FAMILY BUILDING WITH CLT
To fully benefit from prefabrication, it is important to consider the following factors at the architectural concept stage:
• modular apartment layouts – a simple, repeatable structural scheme minimizes the number of custom elements, reducing production costs
• installation and service shaft solutions – these should be planned in advance, as CLT is not a material that can be easily modified on-site
• early cooperation with the prefabrication supplier – in our case, we can engage already at the concept stage, helping to avoid design errors and optimize assembly
• acoustic and expansion joint details – particularly important in multi-unit residential buildings
THE CLT INVESTMENT PROCESS
In our experience, the best results are achieved when investors plan for prefabrication as an integral part of the project from the outset. The standard process includes:
• joint review of the design with the architect and structural engineer
• preparation of a BIM model and optimization for prefabrication
• production of CLT panels in controlled factory conditions
• transport and on-site assembly, typically much faster than traditional construction
• finishing works in line with the investor’s schedule
Depending on the scale of the project, prefabrication can shorten construction time by several months, reduce the number of workers on-site, and simplify material logistics.
WHY DO INVESTORS CHOOSE CLT
In development projects, time and predictability are key. As a prefabricated technology, CLT:
• reduces the risk of delays (factory production, on-site assembly regardless of weather conditions)
• limits noise and disruption during construction, which is important for urban developments
• makes it possible to distinguish the project – CLT timber serves as a hallmark of modern and eco-friendly residential developments
Our company has supported many investors who previously had no experience with CLT. Today, many of them are planning further projects using this technology.
SUMMARY
CLT technology opens up new possibilities for multi-family construction, provided that it is properly planned and implemented. Careful project preparation, knowledge of legal requirements, and good cooperation with the prefabrication supplier are key to success. CLT LUX HOMES, with years of experience in cross-laminated timber projects, supports investors at every stage – from feasibility analysis to design and assembly. CLT is not the future – it is a technology ready to meet today’s residential market challenges.
