CITU, a purpose-driven developer, used SMARTPLY AIRTIGHT and SMARTPLY SURE STEP DB to construct 200 homes built to Passivhaus principles in Leeds. The highly engineered OSB panels from MEDITE SMARTPLY, a market-leading manufacturer of sustainable timber construction panels, allowed the houses to achieve airtightness levels of 0.6 Air Changes per Hour (ACH), the best scores in Citu’s history. These prefabricated kits replaced the previously used vapour-control (VC) foil, offering airtightness, greater durability, easier installation and detailing, as well as consistent quality.
Citu is committed to tackling climate change by creating exemplary places that prioritise people and the planet. Taking responsibility for every stage of the process, from land acquisition to design and fit-out, the company ensures that all materials used align with its sustainability goals.
As a part of this commitment, Citu has chosen to incorporate MEDITE SMARTPLY products, which provide a value contribution to creating energy-efficient developments.
Citu opted for SMARTPLY panels that are suited to modern methods of construction, maintaining their integrity after transportation to the construction site and during installation. The two products outperformed competitive solutions, offering superior airtightness properties, unparalleled machinability and ease of use.
SMARTPLY AIRTIGHT, the world’s only certified airtight OSB, played a role in this project. It is ideal for structural inner sheathing in timber frame wall and ceiling assemblies in low-energy buildings. Combining structural strength (OSB/3) with integrated vapour control and an air barrier, it removes the need for separate VC membranes. This streamlined the installation process while ensuring consistent vapour resistance across the panel’s surface. Additionally, SMARTPLY AIRTIGHT is easy to cut and fix, further speeding up the process. The rigid panel design reduces susceptibility to damage compared to flexible membranes.
Manufactured from FSC certified timber with no added formaldehyde, it contributes to healthier indoor environments and aligns with sustainable building objectives.
SMARTPLY SURE STEP DB, a durable tongue-and-groove OSB/3 panel, provided an effective solution for floor decking. Independently tested and certified airtight by the Passivhaus-Institut in Germany, this panel not only ensures airtightness but also offers safer working surfaces thanks to its low slip risk.
The use of SMARTPLY panels enabled Citu to achieve consistently low airtightness levels, ensuring minimal air leakage and reducing energy loss from heating or cooling systems.
“We are excited to offer a better way of achieving airtightness and vapour control for the construction industry, especially at a time when the sector is facing numerous challenges. It’s not just about meeting the standards but also about addressing the clear need for more efficient solutions, making installation easier and getting houses completed faster,” said Tim Price, commercial sales manager at MEDITE SMARTPLY.
See page 29 of our August/September 2025 issue on our Back Issues page.
