Client: City Of Helsinki Library
Size: Footprint 150 x 32 x 25m (H)
Location: Helsinki, Finland
Inspired by the traditional farmer hat, the scheme has a continuous big roof above the two lines of office blocks. On the roof is a series of upward and downward cones which carry a wide range of sustainable performances. The adjacent water park has similar cones. Upward cones forms pavilions with passing ventilation. Downward cones are atriums connecting down to the retails below and sub-surface car parks. The proposal aims to minimize energy consumption in various ways. Surplus renewable energy generated on site is sold to adjacent developments or back to national grid. The modulating roof also gives the development a distinct architectural character while conveying green message to the area.
Settings - A continuous roof above the office blocks has a series of sustainable performance such as passive cooling, rainwater harvesting and solar water heating. Shallow floor width allows good daylight penetration and cross ventilation. Precast concrete main structure forms good thermal mass to minimize cooling load. Southeast breeze across the site together with the shading from Big Roof make the deck a pleasant spill out space of the office blocks. The large water surface by the means of evaporation enhances the southeast across the site. It also reflects ample light into the periphery office space and thus reduces artificial lighting. The water park is built upon a shallow layer of water. The Park slopes from the deck level (4m above grade) down toward the botanical gardens and towards the north side of the site.
Recycled timber - The Big Roof is constructed by recycled wood composite. Timber rib members are digitally laser cut from the composite board to minimize waste. Left over is then ground and recycled to form new boards. Same materials were used for sliding panels and the deck. The composite wood is 100% recyclable, resistant to rot and wood eating organisms and also more durable than normal wood. Prefabrication construction is applied in every possible way to reduce on site works and waste transportation. Slabs and columns of the office blocks are pre cast concrete modular units.