Rackarberget, Student housing

Rackarbergsgatan 10-102

752 32

Uppsala, Svezia

architetto

a-sidan arkitektkontor ab
Olof Palmes plats 8, 753 21 Uppsala
mk@a-sidan.se
+46(0)18 64 05 90

Owner

Uppsalahem AB
Väderkvarnsgatan 17, 753 30 Uppsala
info@uppsalahem.se
018-727 36 00

Contact Details

Sharon Pulvino
Uppsala University

Other Information

Visits
For visiting the project please contact Mikael Engberg, mikael.engberg@uppsalahem.se

Building B. Source: a-sidan arkitektkontor ab
Rackarberget is one of Sweden first residential neighborhood built only for students. The area is of cultural and historical value and is included in the National Interest List for Cultural Heritage. In 2015 started a comprehensive renovation and modernization of the 13 student accommodation buildings that consists of approximately one thousand student apartments in total. The renovation has been divided in three stages with the aim to improve living standards for students and increase the energy performances of the building envelope. The following analysis will focus on results and energy performances of building A and B renovated during renovation stage 3. However, results from stages 1 and 2 will be presented in the case of calculation of the u-Value of the new windows installed as well as through a comparison of energy performances of the different stages.
Energy performance
44 kWh/m2.y

Climate Zone Dfc

Altitude 15 s.l.m.

HDD 3158

CDD 18

Protection level Listed

Conservation Area:
Si

Level of Protection:
Uppsala stad C 40 A Riksintresse för kulturmiljövården

Building age 1960-1969

Year of last renovation:
1980

Year of previous renovation:
0

Building use Residential (urban)

Secondary use:
NA

Building occupancy:
Permanently occupied

Number of occupants/users:
186

Building area Net floor area [m²]: 3550,0

Building typology:
Student apartments

Number of floors:
4

Basement yes/no:
Si

Number of heated floors:
4

Gross floor area [m²]:
6388,0

NFA calculation method:
Sverige

Construction type
Brick masonry wall

External finish:
Plaster

Internal finish:
Plastered (on substructure)

Roof type:
Pitched roof

+ MORE - LESS
Building B. Source: a-sidan arkitektkontor ab
Building B. Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
SEE MORE +
A student apartment in building G after renovation. Source: a-sidan arkitektkontor ab
Building A during renovation. Source: a-sidan arkitektkontor ab
Building A during renovation. Source: a-sidan arkitektkontor ab
Building A during renovation. Source: a-sidan arkitektkontor ab
Building A during renovation. Source: a-sidan arkitektkontor ab
Building A- Original windows upgraded with an extra insulation glass on the inside. Source: a-sidan arkitektkontor ab
Building A- Original windows upgraded with an extra insulation glass on the inside. Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
Building G with new windows with same material and appearence as the original ones (Stage 1). Source: a-sidan arkitektkontor ab
Building A. Source: a-sidan arkitektkontor ab
Building A. Source: a-sidan arkitektkontor ab
Building G. Source: a-sidan arkitektkontor ab
Building G. Source: a-sidan arkitektkontor ab
Building B and G. Source: a-sidan arkitektkontor ab
Building B and G. Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Source: a-sidan arkitektkontor ab
Section external wall. Source: Uppsalahem
Section external wall. Source: Uppsalahem

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

Rackarberget is one of the first student residential neighborhood in Sweden. It was designed by the famous Swedish architect Arthur Von Schmalensee and built during the 1960s. The area is characterized by 3 different architectural typologies for a total of 13 buildings and spacious green spaces with trees, rocks and gardens between the buildings. The renovation has been divided in three stages. The first and second stage took place between 2015 and 2018 for buildings G,K,L, F, E,D,C. In these two steps all windows and doors have been substituted, a new ventilation system with heat recovery has been installed as well as LED-lighting in the common areas. The third stage started in 2022 and it is not completed yet. It involves building A and B where both the existing windows and doors are being upgraded and renovated instead of substituting them with new ones. A new ventilation system with heat recovery is installed as well as LED lighting in the common areas. Furthermore, solar panels will be installed on the southern and western roof of the two buildings and an extra insulation layer with loose wool will be added to the roof joists. A further stage will take place in the next years in order to renovate the remaining buildings (N,O,P,J).
Urban context
The urban environment around the buildings has been renovated and upgraded with new equipments such as bicicle stands, recycle bin and new plants and trees.

State of repair

Conditions of the envelope
The existing buildings were in need of extensive renovation due to a high degree of deterioration of the original windows, doors and ventilation system. In addition to upgrading the windows, it was initially planned to improve the energy performance of the buildings by insulating the external walls on the inner side. Further analyses showed that the existing walls already had 100 mm of insulation between the two brick layers, so no additional insulation was needed.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION
During renovation stage 3 the existing windows were considered of cultural value so that they were preserved and renovated. All the original wooden entrances were preserved, renovated and adjusted.
Heritage Value Assesment
Rackarberget is an area with both cultural and historical value and it is included in the National Interest List for Cultural Heritage “Uppsala stad C 40 A”. The existing buildings were in strong need of renovation and adaptation, both in terms of general maintenance and current functional and energy consumption requirements so that the architects were asked to find good and satisfactory solutions that also considered the cultural and historical value of the buildings. The result was that most of the exterior building details were renovated instead of substituted. During renovation stage 1 and 2 the original windows and doors could not be renovated so that new ones were made with both same dimensions and colors of the existing ones in order not to alter the appearance of the original facades. In stage 3 the original windows were renovated.

Aim of retrofit

Renovation
The aim of the renovations was to improve the comfort standards of the students living in the student accommodations without compromising the historical and cultural value of the buildings but preserving it. Every apartment has been refurbished with new kitchens, toilets and permanent furnitures as well as new floors and wall painting. The energy efficiency of the building was improved thanks to an upgrading of the original windows, new ventilation system, better insulation of the roof structure and installation of solar panels on the roof.
Lessons learned
Working with existing buildings can be unpredictable at times.
Stakeholders Involvement
Private Sector
Uppsalahem AB - contact person Mikael Engberg, project leader
Väderkvarnsgatan 17, 753 30 Uppsala
mikael.engberg@uppsalahem.se
Tel.+46(0)708 24 89 80
Architect
a-sidan arkitektkontor ab
Olof Palmes plats 8, 753 21 Uppsala
mk@a-sidan.se
Tel.+46(0)18 64 05 90
Tools used
Was the renovation process done following a specific methodology? No
Energy calculation IDA Indoor Climate and Energy
Hygrothermal assessment IDA Indoor Climate and Energy
Other Life Cycle Cost

RETROFIT SOLUTIONS



Windows

Substitution of existing windows

Uppgrading of the existing windows with insulation glass

Substitution of existing windows

Existing windows were replaced with triple-glazed windows with same appearence as the original ones.

During stage 1-2 the energy efficiency of the buildings was improved by replacing existing windows with new triple-glazed windows. The original windows consisted of wooden double-glazed windows that were clad on the outside in aluminium during a first renovation in the '80s. Renovating the existing windows was not considered a feasible option by the property, partly because the energy gain was less than replacing them and partly because wooden windows required continuous maintenance. It was therefore chosen to install windows with an inner frame of wood and an outer frame of aluminium. The ambition was to recreate the original architecture of the houses by using the same dimensions of the frames and sashes and maintaining the window sizes and the distance between the sash and the façade.

Existing window U-value Glass [W/m2K]: 1,4 New window U-value Glass[W/m2K]: 1,12 Existing window U-value Frame [W/m2K]: 0,0 New window U-value Frame [W/m2K]: 0,0
More Details
Existing window type Casement window
Existing glazing type Double
Existing shading type NA
Approximate installation year 1962
New window type Casement window
New glazing type Triple
New shading type NA
New window solar factor g [-] 0,52
Uppgrading of the existing windows with insulation glass

An extra insulation glass was added on the inner sashes of the existing windows.

In stage 3 the existing windows were not replaced but they were upgraded with a insulation glass. This choice was due to the will of the owners to reuse and preserve as many building parts as possible in the renovation process.

Existing window U-value Glass [W/m2K]: 1,4 New window U-value Glass[W/m2K]: 0,9
More Details
Existing window type Casement window
Existing glazing type Double
Existing shading type NA
Approximate installation year 1962
New window type Secondary glazing
New glazing type Single
New window solar factor g [-] 0,52

Other interventions

ROOF

OTHER

ROOF

In stage 1 and 2 the original roof construction was not altered but extra insulation (180mm wood chips, 25mm mineral wool felt) was added on the attic floor. The new U-value for the attic floor is 0,33W/m²K. In stage 3 additional insulation was added to the roof joists. The existing cavities have been filled with 300 mm loose wool and 180 mm wood chips. New U-value 0.09 W/m²K

More Details
Original roof build-up
Tiles :
50 mm
Wood :
120 mm
Dry-lining :
25 mm
Retrofitted roof build-up
Tiles :
50 mm
Insulation - Mineral wool:
300 mm
Dry-lining :
25 mm
OTHER

Living standards for students were improved by providing them with private toilets in their rooms, kitchens were modernised and corridors could be furnished for various activities. Accessibility requirements were waived in order to protect the cultural and historical values and to be able to maintain the number of existing student rooms.

The renovations did not compromise in any way the original plan structure of the buildings, on the contrary it improved the quality standard of the students living in the apartments.

HVAC

VENTILATION

VENTILATION

The exhaust fan ventilation system has been upgraded with heat-recovery

The intervention did not compromise the cultural value nor the original structure of the existing buildings

More Details
Original roof build-up New ventilation system
Type ventilation system Centralized
Type flow regime LB01 – 1 000 l/s (zone 1), LB02 – 1 620 l/s (zone 2 and 3), LB03 – 1 020 l/s (zone 4)
Heat recovery Si
Humitidy recovery No
Nominal power kW
Electric power 0,0 kW
Control system Control system according to a day and night schedule

RENEWABLE ENERGY SYSTEMS

Photovoltaic

Photovoltaic

The renovations in stage 3 includes 112 m2 solar panels on the southern and western sides of the roof in building A and B. The energy collected from the solar panels is mainly use for providing electricity to ventilation fans (13462 kWh of 19000 kWh).

The installation of solar panels on the roofs during stage 3 leads to a visual alteration on the façades that is reversible and well justified for other reasons, including technical requirements. The measure has a significant visual impact, but not to the extent that it can be considered to alter the character of the buildings or the area. The solution is therefore considered compatible.

More Details
Photovoltaic System
Type NA
Collector area 112,0 m²
Overall yearly production 19000,0 kWh

Energy Efficiency

Energy Performance
Energy performance certificate: The certification is based on the requirements from the National Board of housing, building and planning (Boverket). The groups used in the IDA system are: studentroom/apartment, corridor with kitchen and WC, staircase, laundry and storage/technical room. The parameter that shows the primary energy for the buildings during the three stages of renovation did not fulfill the requirements from the National Board (80 kWh/m², year, for stage 1-2 and 75kWh/m², year, for stage 3) nonetheless the renovations led in both cases to a reduction of the specific energy use factor. The energy consumption pre-intervention was about 156 kWh/m2 for all the buildings. In stage 1-2 ( replacement of original windows and doors+new ventilation system+extra roof insulation+ new led lightning) the post-intervention energy consumption was 101 kWh/m2 while in stage 3 (renovation of existing windows+extra roof insulation+new ventilation system+solar panels) the energy consumption post-intervention was 78 kWh/m2.
Voluntary certificates: No
Energy Use
Heating
Primary Energy 78 kWh/y
Documents:
Energirapport Rackarberget hus G BH 190116.pdf
Source: Uppsalahem
Boverkets krav_BFS2017-6.pdf
Source: Uppsalahem
Energirapport Rackarberget E3 Hus A.pdf
Source: Uppsalahem

Consumption_estimation_Before: 113 kWh/m2.y
Consumption_estimation_After: 44 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: IDA
Consumption_estimation_Including_DHW: Si
Consumption_estimation_Before: 156 kWh/m2.y
Consumption_estimation_After: 78 kWh/y
Measured Parameters
Internal Climate
Type_of_monitoring: Punctual
Description: The monitoring includes the energy used for fans, heating pumps (heating system and dometic water). lighting both indoor and outdoor, CO2 emissions.

External Climate
Type_of_monitoring: Punctual
Description: Solar shading monitoring according to Boverket's data, solar factor of windows according to NCC "Teknik och Hållbarhet" documentation.

Construction
Type_of_monitoring: Punctual
Description: The calculation includes U-value monitoring of walls over the ground (YVB02 plan 10: 80mm isolation - 0,36W/m²K, YV service room: 150mm - 0,16W/m²K, YVB01 plan11-13: 100mm isolation - 0,31 W/m²K, wooden list 0,89W/m²K ), walls under the ground 0,18 W/m²K, joists and roof 140mm concret+500mm lose wool 0,9W/m²K, joists and roof service room 150mm 0,16W/m²K, floor close to the ground (80 concretemm+100mm gravel) 0,34W/m²K, windows and doors 1,40 W/m²K, basement doors and windows 3W/m²K.

UserBehavior
Type_of_monitoring: Punctual
Description: Heating/domestic electricity and human heating (personvärme) according to Boverket's data

Costs

Investment Costs
Total investment costs
Stage 1 - 90.429.000 kronor (7.621.316 euros) + taxes, Stage 2- 61.801.000 kronor (5.208.561 euros) + taxes, Stage 3 - not available yet (total)
Amount includes: Planning, consultants work, material costs, renovation work
Running Costs
Annual heating cost
0,70 kr/kWh (0,06 euro/kWh) (per m2)
(includes DHW) No

Annual electricity cost
1,10 kr/kWh (0,09 euro/kWh) (per m2)

Lifecycle cost
The results of the LCC of renovation stage 1 and 2 shows that most of the interventions did not lower the life cycle cost of the building over 20 years.

Lifecycle documents:
Rapport LCC Rackarberget SH.pdf
Source: Uppsalahem