Approximately half the current European building stock dates from between 1945 and 1980. A large number of these buildings are now worn out and are lagging behind new constructions in terms of comfort and indoor climate. Buildings in the Netherlands are no exception. In the next ten years, at least two million of the country’s two and a half million social housing homes will be in need of renovation. This presents a tremendous challenge. But it also makes the Netherlands an excellent case for rethinking renovation.
▼ 小镇中的建筑，Building in Montfoort
De Poorters van Montfoort is a refurbishment initiative based on the Active House principles using the solar solution. It involves a range of partners from the building industry and housing sector. (read more about the solar solution on p. 10). Their vision was realised in the Dutch town of Montfoort, but it is relevant everywhere − existing buildings are in need of change: renovation is not just about maintaining the past – it is a chance to prepare for the future.
The Poorterstraat district of Montfoort is an area with social housing. The 92 single- family houses have provided affordable homes for local families since the 1970s. However, after almost 40 years, the houses had become worn and uncomfortable by the standards of the 21st century. When the residents had their say, they came up with a list of shortcomings: draughty, gloomy, soaring energy costs and a general lack of space.
▼ 建筑外观，external view
The owner, housing association GroenWest, decided to embark on a major renovation and teamed up with the VELUX Group. The renovation involved all houses, but ten homes were chosen for a sustainable transformation of greater scope. They were turned into buildings that produce energy, offer excellent living conditions and provide maximum daylight. In other words: Active Houses.
▼ 建筑外观，external view
At De Poorters van Montfoort, all parts of the building envelope were newly insulated. An entirely new roof was added; the existing facades received new insulation and a new brick facing, and the old, poorly insulated windows with their thin, aluminium frames were replaced with new, triple-glazed models with timber frames. The existing floor was replaced with a new highly insulated concrete floor.
▼ 建筑与其相邻建筑相差无几，the project’s facade is similar to the nearby building
The remodelling of the Poorterstraat houses has revitalised the design and upgraded the appearance of the buildings. But, most importantly, it has changed the lives of the residents. Edwin Hamelink is one of them. After living in Poorterstraat for 18 years with his wife and four children, he has experienced both the shortcomings of the past and the new possibilities of the future: “It would be fair to say that comfort was very bad before the remodelling. That has changed now,” he says. He especially appreciates how the remodelling has improved the daily life of his family. “We are amazed by the extra space in the attic.
Thanks to this extension, we now have four bedrooms. That is great for a family with four children,” explains Edwin Hamelink. The transformation has left him looking forward to living in Poorterstraat for a long time: “It is truly a brand new start that will hopefully go on for many years.”
The Active House renovated buildings in Poorterstraat have attained energy label A++. The renovation is expected to reduce the energy costs per house by around 130 euro a month, which is more than the rent increase needed to pay for the renovation.
▼ 阁楼上的三角墙，The triangle garble wall
Architect company BouwhulpGroep was given the task of implementing the Active House principles in the construction of the Poorterstraat houses. They decided to add extra space and light by making use of the houses’ unutilised attics. Every attic was enlarged and became an entity on its own, resulting in a new room and a rooftop terrace.
The ground floor, first floor and staircase were also remodelled to ensure that the daylight and air from above would benefit the entire house. Thanks to the abundant amounts of daylight, the rather narrow and deep buildings now feel light and spacious.
▼ 一层空间，first floor
Good ventilation in De Poorters van Montfoort is ensured in several ways: facade and automatically operated roof windows are strategically positioned on all floors of the building, from ground level right up to the roof ridge. On the one hand, they provide horizontal cross-ventilation on the different floors; on the other, opening the roof windows on the top floor creates a (vertical) chimney effect around the open stairwell that channels the stale air up from both the floors below, and allows it to escape through the roof in to the open.
▼ 二层通往阁楼楼梯，staircase to the attic floor
▼ 阁楼空间，the attic floor
Solar solution is a concept for the renovation of terraced houses and townhouses. Applying the Active House principles in existing buildings requires a different approach from that used in new build houses. In cooperation with Danfoss, the VELUX Group has developed the award-winning solar solution concept. Already implemented in a number of residential areas, solar solution inspired the refurbishment of the Poorterstraat houses.
Solar solution combines roof windows, solar-generated heat and electricity, ventilation, heat pumps and geothermal heating, with every aspect under full control. Well-proven technology makes it easy to monitor and manage indoor climate and energy consumption.
When it comes to remodelling existing houses, one size does not fit all. But solar solution can be adapted to almost every need.
▼ 光伏板与太阳能板，Photovoltaic panel and solar panel
An Active House is energy efficient and supplied by renewable energy sources integrated in the building or from the nearby collective energy system and electricity grid.
The design and orientation of an Active House, as well as the building components used in it, are therefore optimised to use as little energy as possible and to utilise renewable energy sources.
▼ 改造前后能效雷达图与对比，The Active House radar and energy performance
在荷兰等国家，燃气价格很低，因此将老旧的燃气锅炉替换为可再生能源独立系统是一项大胆而富有前瞻性的举措。客户和建筑师们希望看到的是：随着矿物燃料价格的上涨，这一举措将被证明是值得的。根据Bouwhulp Groep建筑公司的计算，改造完后每月房租约上涨115欧元，但住户每月能够节省的能源费用约为130欧元。这样算来，相当于住房空间扩大了17 m2。
Active House is a vision of buildings that create healthier and more comfortable lives for their occupants without impacting negatively on the climate – moving us towards a cleaner, healthier and safer world.
The Active House vision defines highly ambitious long-term goals for the future building stock. The purpose of the vision is to unite interested parties based on a balanced and holistic approach to building design and performance, and to facilitate cooperation on such activities as building projects, product development, research initiatives and performance targets that can move us further towards the vision.
The Active House principles propose a target framework for how to design and renovate buildings that contribute positively to human health and well-being by focusing on the indoor and outdoor environment and the use of renewable energy. An Active House is evaluated on the basis of the interaction between energy consumption, indoor climate conditions and impact on the environment.
▼ 建筑改造后，After renovation / 建筑改造前，Before renovation
“主动式住宅”的理念核心在于设计适合住户的建筑物。在蒙特福德，设计师们将这一理念归纳为阳光、空气和空间。这3个方面是所有设计的关键——无论是在屋顶平台的延伸、楼梯光线设计或是室内空气质量方面。 “以人为本”的理念使蒙特福德的项目在其他节能翻新项目（包括 “被动式住宅”翻新）中脱颖而出。在被动式住宅设计中，建筑物起着主导作用；然而，在主动式住宅中，用户则是建筑物设计的核心。因此，主动式住宅强调住户在住宅内的主动作用，主动式住宅理念只是项目执行的一个部分，而非全部目标。
An Active House is the result of efforts to actively integrate the three main principles of comfort, energy and environment in the design of a building and in the finished building.
De Poorters of Montfoort are the first houses in the Netherlands renovated according to the principles of Active House, using a sustainable renovation concept developed by the VELUX Group and Danfoss. In Montfoort for the first time ten houses are sustainably renovated with the focus on a comfortable indoor climate. The unique design based on the principles of Active House creates a good balance between energy design, indoor climate and environment, with the main focus on comfort and health of the residents.