Background
Peabody‘s St John’s Hill Estate in London is a former 1930s development near Clapham Junction, Wandsworth. Originally the site of a Royal Masonic School, Peabody Estates bought the land in 1934 and built 334 affordable homes for local residents.
In 2012, after almost 80 years, these properties were no longer deemed fit for purpose and presented with damp problems, so Peabody engaged Hawkins Brown Architects to redesign the site. Planning permission was granted in 2012 for a 3-phase project; phases 1 and 2 have since been completed.
The Problem – ventilation without noise
Clapham Junction is one of the busiest parts of the British railway system with 17 platforms and around 2000 trains passing through on a daily basis. The newly built Peabody Estate – Burridge Gardens sits adjacent to the noisy railway line. In order to keep running costs low, whilst meeting regulations for ventilation and to prevent overheating, natural (non mechanical) ventilation was the preferred option of the architect and developer. The potential problem was that it could allow noise from the train tracks and the busy road nearby to enter the property.
The Solution – Sound ventilation
Tek was approached by Hawkins Brown to design, manufacture and supply a total of 135 naturally ventilated, attenuated units for the properties backing onto the railway lines. 70 AV03 acoustic ventilation units went into the first phase and 65 into the second. The units were required to provide a free area of 0.6 sq metres and a noise reduction of 32dB, whilst being able to be manually operated by residents.
The approach: to design a unit to fit the prescribed window opening and incorporate:
- Decorative external cover
- Storm louvre
- Acoustic casing
- Type QS attenuator
- Internal decorative acoustic doors
Tested performance – Sound Ventilation
Three samples were constructed and taken for independent testing at the leading UK Acoustic laboratory. The results were collaborated and a final design manufactured and retested. A full thermal and acoustic report confirmed the brief was met.
“We installed the first three units free of charge and also supported the installers with a full method statement and training. We also provided a video of us installing the unit to aid the process,” James Cartland, Sales Director recalls.
The acoustic performance was also checked by an on-site independent consultant to ensure it performed well in situ.
Since phase 2 was completed in 2020, the issue of overheating and ventilation has come to the fore with the updates to building regulations in 2022. Approved document O (Overheating) and F (Ventilation) are designed to address the issue. These requirements also specify that mechanical cooling solutions should only be used where passive cooling means cannot remove sufficient heat. Proof should be provided that all passive cooling solutions have been considered before mechanical solutions can be used. In situations like Clapham Junction, natural ventilation can be used when an acoustic attenuator is incorporated to allow occupants to enjoy natural fresh air and quiet.
