Energy neutrality

Multiple design decisions were made to minimize the energy required to realize this project, both operational and embodied energy.

New buildings

In collaboration with mainly the structural design discipline, the choice was made to use a lightweight timber structure that consisted out of timber stud walls and Lignatur floor elements in the new buildings. These materials have a low embodied energy density.

The façade of the new development has a modern character with thermally hardened timber cladding. On the Vestdijk the use of the original masonry wall respects the traditional heritage of the site. Movable timber louvers create an element of depth in the façade, while also preventing overheating in the summer. In the summer an additional sun shade sail can span the two main buildings to provide shade, thus preventing overheating and creating a more enjoyable environment in the courtyard.

HVAC

The residential apartments use mechanical extraction ventilation with CO2 sensors and Invisivent NL ventilation grilles to prevent draught. In the retail spaces and communal spaces on the ground floor, a balanced ventilation system provides fresh air, additionally, heat recovery (from the atria) reduces heat losses due to ventilation and reduces initial heating temperature differences.

On the roof PV and PVT panels supply electricity and thermal energy, furthermore, an ATES system acts as a storage and heat recovery system. The green, sedum roof improves water retention and creates a gradual drainage system for water recovery. Rain and greywater from the water collection system are used to flush toilets. This can reduce the water demand of the building up to 15%.

NEW BUILDINGS

Section for ATES & PVT + green roof-1.jp

One of the technical problems that was encountered during the design process was the difficulty of acoustic insulation of a timber structure. Due to the low mass of the timber structure, particularly contact noise could cause noise disturbances for residents on floors below. To prevent this 30 mm of Fermacell honeycomb infill was added to the floor system to increase the mass, on top of this 20 mm wood fiber board provided acoustical and thermal insulation. In the Fermacell dry screed board layer of 25 mm, floor heating pipes are applied to provide heating for the spaces above.

Monumental building

In the monumental building, most of the structure and façade has been reused to preserve the original character of the building and to reduce the need for additional building materials. To lower the operational energy demand, the inside of the building is thermally insulated. Due to the thickness of the exterior walls, a traditional insulation method will result in the accumulation of moisture in the building envelope.

Therefore a capillary active insulation system with wood fiberboards was chosen. Capillary active systems are vapor open, so during the summer moisture can evaporate on the inside of the façade.

To improve moisture control and reduce energy costs, a central ventilation system with heat recovery is applied. Floor heating provides thermal comfort for the occupants in the different offices and exhibition halls. The different modules are using the PVT panels and the ATES system that provide warm water for the floor heating.

MONUMENTAL BUILDING

ENERGY NEUTRALITY

All these different design decisions have resulted in three distinct buildings with different operational and embodied energy values.

The monumental building has a high operational energy, but a low embodied energy. 74% of the mass of the building consists of concrete, but this accounts for only 1% of the embodied energy. The HVAC and solar panels account for 57% of the total embodied energy.

The second building, a combination of the old brewery and new building on top of it has a higher embodied energy density. Some steel and concrete structural elements were required to create the structure, however the embodied energy was reduced by reusing steel from the old site.

Buiding 3, the main building, has a low operational energy demand and a higher embodied energy demand. Both timber and finishing materials contribute significantly in terms of mass as well as embodied energy.

All of these buildings will be climate neutral by 2050.