The concept of sustainability was integrated into the project from the outset, by carefully selecting the location – on the edge of the city, circled by a cluster of seven homes. Despite providing multiple housing units for seven families, the floor area of the constriction remained nearly the same (increasing from 30 % to 33 % of the land).
The first step was to create the optimal building envelope. The next elements to be considered were energy-efficient devices and renewable energy. So far, the houses have performed significantly better than expected. With E7/E12 and K16/K19 ratings (for mid-terrace and end-of-terrace homes respectively) the houses are ‘future-proof’ and achieve the passive house standard of 15 kWh/ m2/year.
For rainwater, the goal is to achieve water neutrality. This means that as much rainwater as possible is collected and reused. The houses have sloping roofs with ceramic slates. Each home has a 5000-litre rainwater, which is connected to the toilets, a maintenance faucet, and a pipe for the washing machine. Excess water leaves through an overflow to a common, gravel-filled, filtration basin in the communal garden.
The final cost of construction was 1,100 euros per m2 plus VAT for the mid-terrace houses and 1,210 euros per m2 for the two end-terrace homes. Almost a quarter (24 %) of this cost was spent on the superstructure, which has a big impact on the performance envelope. The conclusions are clear: opt for a sustainable, yet affordable, building envelope, and prioritize collective heating, with specific consideration given to a renewable energy plan.
Traditional building methods, using typical clay building materials, are perfect for affordable projects with a long service life, and do not compromise on quality or aesthetics.
HIGH QUALITY LIVING OVER GENERATIONS
Living comfort was paramount. The solid construction minimiz- es fluctuations in temperature via its thermal buffering capacity. To achieve optimal sound insulation, the houses are separated by a concrete slab and there are double partition walls between the houses, which are filled with acoustic insulation. In addition, a flexible joint separates the exterior façades.
To allow the homes to evolve over the lifespan of the residents, detailed consideration was given to accessibility and adaptability, including minimized thresholds at the entrances, wide doors, turning space for wheelchairs, a staircase suitable for a stair lift, and more.
The project achieved BREEAM (Building Research Establishment Environmental Assessment Methodology) certification with a rating of “Excellent”. It is only the second residential project in Belgium to achieve such a high score.
Facts & Figures
Project nameDe Duurzame Wijk’ – The Sustainable Neighbourhood, Waregem, Belgium
ArchitectWielfaert Architects, Landscape architect: Fris in het Landschap
Terca Eco-brick Linnaeus, Koramic Bellus slate engobe, Koramic Fleece Plus underlay, Porotherm PLS 500, Penter customized water-permeable pavers
Primary energy consumption for heating: 7,436 kWh prim/year
Net energy consumption for heating: 9 kWh/year
CO2 emissions: -477 kg CO2 / year
Year of completion2016