use of wood in construction has resurfaced due to growing concerns for the environmental impact of materials such as concrete. Wood, being a biobased material, is carbon dioxide (CO 2 ) neutral and has been shown to have a lower total CO 2 equivalence and better recycling possibilities compared to concrete in construction. [1][2][3] Although wood has many advantageous properties, it is a hygroscopic material, meaning that it will absorb ambient moisture. High levels of absorbed moisture can lead to growth of mold, with health hazards to people, deformation such as bending, or rotting which can cause structural damage. For this reason, there is a need to monitor both the humidity in the surrounding air and the moisture inside the wood to prevent such degradation at an early stage. Monitoring moisture in wood is important even earlier in the value chain, as timber or boards need to be dried for long time (often 6-24 months) before they can be further processed. The method and kinetics of drying can also have a big impact on the quality of the final product. [4] By directly sensing the water content in the timber, this process could be made more efficient. With modern technology, this is becoming reality, as connected internet-of-things (IoT) devices can sense various physical and chemical parameters and communicate the information. [5,6] IoT devices are exponentially growing in numbers, and they can play vital role in making our society more sustainable and safe. This includes buildings, where IoT can be used to collect Wood is an inherently hygroscopic material which tends to absorb moisture from its surrounding. Moisture in wood is a determining factor for the quality of wood being employed in construction, since it causes weakening, deformation, rotting, and ultimately leading to failure of the structures resulting in costs to the economy, the environment, and to the safety of residents. Therefore, monitoring moisture in wood during the construction phase and after construction is vital for the future of smart and sustainable buildings. Employing bio-based materials for the construction of electronics is one way to mitigate the environmental impact of such electronics. Herein, a bio-graphene sensor for monitoring the moisture inside and around wooden surfaces is fabricated using laser-induced graphitization of a lignin-based ink precursor. The bio-graphene sensors are used to measure humidity in the range of 10% up to 90% at 25 °C. Using laser induced graphitization, conductor resistivity of 18.6 Ω sq −1 is obtained for spruce wood and 57.1 Ω sq −1 for pine wood. The sensitivity of sensors fabricated on spruce and pine wood is 2.6 and 0.74 MΩ per % RH. Surface morphology and degree of graphitization are investigated using scanning electron microscopy, Raman spectroscopy, and thermogravimetric analysis methods.