Högsbo 20:22 office building, Gothenburg, Sweden

The Högsbo property consists of two office buildings divided into four building sections: A, B, C and D. Total heated area of the buildings is 14 543 m2. Besides the office areas there is also a lunch restaurant and an underground garage in the property.  The main objective of the renovation in Högsbo office building was to incorporate energy performance improvements to the general upgrade of the building for upcoming tenant adjustments.  Total measured energy use before renovations was 121 kWh/m² per year (including tenants’ electricity). This is rather low energy use compared to other similar office buildings in Sweden and can be explained by the relatively high vacancy level in the buildings and low occupancy rate in the used premises. Due to planned tenant adjustments in Section C, the energy use of the building was estimated to increase to about 128 kWh/m² per year. This was set as a new baseline for energy efficiency measures.

The proposed action package in Step 1 contained six energy saving measures for building Sections C and D, which were planned to be carried out as part of the upcoming renovation for the tenant adjustments.  The total energy saving potential with the proposed action package, with measures for sections C and D, was approximately 14 % compared to the new baseline.  The internal rate of return of the proposed action package is 5.5 %.

Five measures were carried out in Step 2 with some modifications to the initial plans. The total building energy use was estimated to decrease about 7% compared to the new baseline. The measured outcomes in Step 3 show the savings to be about 8%. The energy use for building operation (BBR) decreased about 11 % compared to the baseline. Actual internal rate of return for the action package is 8 % and fulfils property owner’s profitability demand.

Read more about the outcomes of Step 1

Read more about the outcomes of Step 2 and 3

 

Segevångsskolan school building, Malmö, Sweden

The Segevångskola is an elementary school locating in Malmö. The property consists of six buildings: Building A, B, C, D, E and F. Most of the buildings were built in the 1960s. Two of the buildings were built or fully renovated in 2006 (Buildings E and F). The buildings incorporate classrooms, gymnastic hall and a canteen for about 260 students in total. Measured total energy use of the building in 2011-2014 was in an average about 186 kWh/m²per year inclusive tenant’s electricity. According to the energy audit, it can be difficult to meet the indoor climate requirements set for the school premises with the current system solutions in Buildings B, C and D. Therefore, upgrading of ventilation systems is recommended leading to abaseline of 167 kWh/m² per year.

The total energy saving potential with the proposed action package is approximately 12% down to 147 kWh/m² per year compared to the new baseline. Annual district heating use of the property can be reduced by 12% and electricity use by 13%. The internal rate of return of the proposed action package is 2%which fulfilling the property owner’s profitability demand.

According to the property owner the proposed action package will not be carried out now, but it is planned for the future.

Read more about the outcomes of Step 1

 

Norrtälje prison Building 9, Norrtälje, Sweden

The Norrtälje prison is a high security institution for male prisoners. The building of interest – Building 9 – is with its 8 030 m2 heated floor area and holds several activities. The greater part of the building is for stock-keeping, carpentry and mechanical work were wood furniture and all sorts of sheet-metal work is carried out. The rest of the building is for office and educational use. Based on the calculations, the specific annual energy use for the building is today ca 121 kWh/m² per year, including electricity for tenants.

According to the energy audit in Step 1, it was difficult to meet the indoor climate requirements set for the premises. For improving thermal comfort the room temperature set points needed to be increased in some areas of the building. The new baseline for the total specific annual energy use for Building 9 will be 128 kWh/m² per year. The proposed action package in Step 1 contained five energy efficiency improvement measures. The total energy saving potential with the proposed action package was approximately 26% compared to the new baseline.  The internal rate of return of the proposed action package was 11%.

Up till now (Nov 2016) some of the measures have been partly carried out and some of the measures are ongoing. Therefore only partial results of the outcomes will be presented in this project. With the action package carried in Step 2 the total building energy use is estimated to decrease about 15% compared to the new baseline which will lead to a total specific energy use of the building of about 110 kWh/m² per year. The energy use for building operation (BBR) will decrease about 23%. The calculated profitability for the package in Step 2 is 8.1%.

Read more about the outcomes of Step 1

 

Read more about the outcomes of Step 2 and 3