Pablo highlighted Passivhaus as a rigorous standard for energy efficiency in a building, reducing its ecological footprint.
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:.
- Transport and store timber in waterproofed flat stacks.. - Engage early with contractors to produce an on-site maintenance plan with special attention to timber elements.. - Enable sufficient drying periods within the project programme.. - Use preservative natural treatments to prevent woodboring and avoid the use of toxic chemicals such as chromium, chlorophenols or arsenic.. - Use preservative natural treatments on all sides to prevent water ingress.We cannot wait 20 or 40 years for the benefits of more efficient new buildings.
This is the main reason why it is important that we prioritise refurbishment, reusing buildings that already exist..If we account for the decarbonisation of material manufacturing (red dotted line), the difference between the adaptive reuse of buildings and new construction is even greater.. As part of this analysis, we calculated the WLCA using different performance benchmarks to prove that the conclusions would not depend on a specific baseline selected.
The results below on the left, are based on LETI 2020/RIBA2025, and the ones on the right are based on LETI 2030/RIBA 2030.In both cases of adaptive reuse, the light-touch refurbishment and full refurbishment are more advantageous than new construction..
(Editor: Adjustable Baby Monitors)