The project carried out in Alingsås (Sweden) is a successful example of social housing refurbishment. The Brogården area (built in 1973) was extensively renewed (both interior and exterior) and the flats completed in 2013. The aim was to create a good and sustainable living environment.
The Brogården area consists of blocks of flats arranged around large courts. The area after refurbishment comprises a total of 265 flats, divided into 16 houses with 2-4 floors each. All flats have a balcony or a patio (Alingsashem, 2011).
Figure 1: Site Plan of the Brogården area (Alingsås – Sweden) (Alingsashem, 2013)
The size of flats available ranged from 35 to 112 m2 and from 1 room and kitchen to 5 rooms and kitchen. The defects of the flats before the refurbishment were the thermal bridges by indented balconies, crumbling bricks, draughty flats, high energy consumption and poor sound proofing. The refurbishment operations dealt with (Alingsashem, 2013):
- Easily resolved obstacles
- Flats with high accessibility
- The need for larger flats
- Installation of lifts
- Improving laundry rooms
- Shared premises
- Complementary buildings
- Car parks
- Design issues
- Cultural historical value
- Planning for passive houses
- Simplicity, repetition, rationality, effective building
- Redress the technical defects
An important aspect when the refurbishment of the flats was planned was to ensure the opportunity of social interaction for elderly people thanks to flats with high accessibility and common areas for recreation activities, meals and hobbies.
The refurbished was carried out with the aim to achieve the passive house standard in the flats. The old bricks and all the old curtain walls were removed. A completely new wall with 44 cm mineral wool insulation (U value 0.09 W/m2K) was installed against the existing concrete frame. The roofs were also better insulated with 40 cm insulation (U value 0.1 W/m2K) (Alingsashem, 2011).
On the new facade tiles were mounted on horizontal support profiles, which gave a back-ventilated and damp proof construction. The tiles consisted of a hard-burnt light yellow clinker stone or brick that aesthetically gives an impression similar to the original. The original indented balconies caused thermal bridges and draughts, because of this they were replaced with externally mounted balconies with screens on the short sides and a roof even on the topmost balcony. All windows installed comply with passive house standards (U value 0.85 W/m2K) and the ground slab was insulated with 20 cm insulation. The flats refurbished achieved the passive house standards for refurbished buildings (25 kWh/m2yr and the energy consumption was drastically reduced (Table 1) (Alingsashem, 2011).
Table 1: Comparison of energy consumption in one of the flats at Brogarden, before and after renovation (Alingsashem, 2011)
|
|
Before renovation |
After renovation |
|
|
[KWh/m2yr] |
[KWh/m2yr] |
|
Heating |
115 |
19 |
|
Hot water |
42 |
18 |
|
Household electricity |
39 |
28 |
|
Residential electricity |
20 |
21 |
|
Total consumption |
216 |
86 |
The difference of the exterior aspect of the buildings before and after renovation can be seen in Figure 2.
Figure 2: After and before renovation of one of the buildings in Brogarden (Alingsashem, 2011)
The break-down of the energy savings achieved and the share of the costs between Ahem (Alingsåshem, the company in charge of managing the social housing on behalf of the municipality) and tenants are presented in Figure 3.
Figure 3: Break-down of energy consumption and cost share between tenants and the company managing the social housing (Alingsåshem, 2011)
A continuous contact with the tenants was upheld during the entire refurbishment at Brogården. Information to the tenants was distributed throughout the project. A show apartment was established in the area since before the building works began. The tenants were invited to the show apartment to receive information on what would have happened to the area and their flats, as well as practical and economic issues concerning evacuation and resettlement. The show apartment was also used for regular and well attended “open house”-arrangements. It was an appreciated social activity that offered an opportunity to share information and give feedback to the tenants. The show apartment had made evident that there was a need for shared social premises (Alingsashem, 2011).
The total cost of renovation was approximately 48,000,000€ (Alingsashem, 2011).