Keynsham Civic Centre and One-Stop-Shop

The building has allowed the council to rationalise its office buildings from 12 down to 4, with the majority of staff now based in Keynsham.

Four wings are arranged around a central atrium at the heart of the space.

Prioritising people’s health and wellbeing and fostering connections between different departments were key to the council’s brief. By considering the space and voids in the atrium, somebody must cross this central space to get anywhere. This encourages people to move around more, increasing creative collisions, impromptu meetings and spontaneous interactions.

There is a 3:2 desk sharing ratio and the departmental mix was unknown at the outset of the project. This has ensured that there are a variety of types of spaces that can cater for different team sizes. Some of the areas are enclosed, offering space for seclusion and privacy, while others encourage openness and collaboration by facing outwards into the atrium.

It was very important that people had opportunities to work away from their desks and that they could work in any environment which suits them. The breakout space and touchdown ‘decks’ have proved popular as informal meeting spaces.

There are stunning long-distance views across the town and local countryside, which gives a connection to the outdoors, improving productivity and efficiency.

A passive first design approach was used as this is an effective and cost-efficient way of achieving a low-carbon building in the long term. We adopted the passive first approach early at the concept stage, which fundamentally influenced building massing and internal arrangement.

1. Structure - An innovative hybrid structure of a cross-laminated timber (CLT) frame, steel and concrete, was designed which offered quick site erection and good airtightness. This solution provided significant programme savings, and drastically reduced the amount of embodied carbon produced. The building achieved many of the sustainable benefits of a timber building with the structural efficiency of a steel frame.

2. Daylight - Larger north-facing windows maximise daylight without increasing heat. Light shelves on the south facade bounce light deeper into the building improving daylight uniformity. Blinds can be used to control daylight without cutting out ventilation.

3. Orientation - Deliberately narrow floor plans, 15 m wide, ensure the greatest cross-ventilation.

4. Form - Pitched roofs create space for warm air to rise before being ventilated through high-level windows. The roofs are pitched south to enable photovoltaics to be incorporated into the design. Opening windows are set back from the facade which shields them from traffic noise.

5. Ventilation and cooling - Alongside the pitched roofs, voids have also been used to drive passive stack ventilation. These are next to the fully glazed areas of the facade, letting daylight penetrate deeper into the building. We avoided air conditioning throughout, instead using natural ventilation, controlled heat gains and exposed concrete thermal mass.

6. Acoustics - There is some level of noise pollution due to being in the heart of the vibrant town centre. To reduce this, we incorporated a bespoke window solution with a deep acoustic louver into the window system with an inward opening ventilation door behind.