The second part of the net-zero carbon equation is the operational carbon, for which there are currently fewer benchmarks.
The layered nature of engineered timber can improve acoustic compartmentation and if properly designed, does not need the same mass as concrete to achieve the same airborne sound resistance.However, detailing is the main challenge and if not properly resolved it can generate sound flanking at the joints which is difficult to resolve without the use of wet trades.
Creating reliable diaphragm action through slabs when trying to achieve acoustic separation and control movement is also fraught with issues.. Other acoustic considerations include the noise from building services and potential increased reverberation time due to smooth surfaces.. Our response is to:.- Engage in early discussions with specialist timber contractors and acoustic engineers to address all potential acoustic difficulties.. - Use additional mass (increase the thickness of the slab) and acoustic ceiling and wall panels.. - Decouple floor finishes from the slab with additional insulation.. - Use alternatives to wet screeds, slab breaks above partitions, and resilient strips between CLT panels.. - Coordinate with engineers to reduce noise transmission caused by HVAC systems.. - Use in smaller size, lower buildings to reduce acoustic transmission and complexities.. Durability, rotting, installation in wet conditions.Significant volumetric changes can occur to timber exposed to changes in moisture, including swelling perpendicular to grain direction, warping, and bending of straight elements.
With engineered timber overall deformations are less likely due to the controlled material use and grain directions, but it is still sensitive to swelling if exposed to moisture and water.This makes it necessary to adequately waterproof the envelope of the building and protect the material during transportation and construction.. Due to high demand, timber sold in the UK is typically not dried out properly.
As it dries it changes geometry losing original accuracy.
This is a problem as connections cannot be relied on geometrically and presents a challenge particularly for DfMA solutions and other situations where small tolerances are required.. Our response is to:.The operational carbon emissions are based on the assumption that at the current rate of decarbonisation, the emissions by 2040 will be 67gCO.
/kWh (BEIS 2040), and that by 2050 they will be zero carbon..The charts below show the total accumulated carbon emissions and the detailed 60-year projection of the three cases.
Looking at the total emissions after 60 years, light refurbishment is the most advantageous adaptive reuse option (26% less carbon than new construction), followed by a full refurbishment (23% better than new construction).A red dotted line in the graphs below identifies the potential additional embodied carbon reduction from materials due to the decarbonisation of the grid.