The demonstration in Halmstad, Sweden, is a multi-storey building from 1963 with typical features from that period e.g., reinforced concrete load bearing frame and facade elements. The building contains 91 flats and is owned by the private housing company Apartment Bostad.

The retrofit action for the building aims at lowering the energy use by approximately 130 kWh/m2y.


Retrofit concept

The retrofit includes a complete exchange of main pipes (water and sewage) as well as new kitchens and bathrooms, energy efficient measures such as new, highly inulated windows, improved adjustments of control systems and increased airtightness etc. Residents will remain in their apartments during the retrofit construction work.  Therefore, this demonstration investigates and evaluates tenant-host communication during extensive renovation work. This demo also focuses on creating (economic) win-win situations between stakeholders through, e.g., partnering.


Brief facts

Year of construction: 1963

Property type: Multi-storey building

No. of dwellings: 91

Project owner: Apartment Bostad Väst, private housing company

Energy demand befor retrofit: 174 kWh/m²y

Estimated energy demand after retrofit: 53 kWh/m²y

Construction works: November 2010- January 2012


Participating E2ReBuild partners: NCCSE, Apartment Bostad Väst, White, SP Technical Research Institute of Sweden

Demonstration leader: Stephen Burke, NCCSE, stephen.burke@ncc.se


Final inspection in Halmstad

(December 2011)

In December 2011 Giganten 1 & 7 is in the final stages of its renovation and the building has its final inspection. The renovation has included a complete exchange of main pipes (water and sewage) as well as new kitchens and bathrooms and energy efficient measures such as new, highly insulated windows, improved adjustments of control systems and increased airtightness etc.
Read more >> 


Partnering for Sustainable Renovation

(June 2012)
Giganten 1 & 7 has finished its renovations, however, work is still on-going to adjust and program the control and logging systems which are key elements for determining the energy use of this project. An important part of this project is reducing the energy use of the building in a cost effective way. NCC used a business model they developed called ‘Hållbar Renovering’ or Sustainable Renovation, which is based on this idea.

Air permeability in Halmstad

(December 2012)
One part of the strategy on how we plan to save energy was to decrease the uncontrolled air leakage through the building envelope by increasing the air tightness of the building.
The way that this is measured is described in standard EN: 13829 – “Thermal Performance of buildings – Determination of air permeability of buildings – Fan pressurization method”. A short description of the method used in Halmstad is:
• Define the area to be measured. (The standard says that you should use the external surface area of the area you are measuring.)
• Seal all the holes which are placed there on purpose.
•  Install a calibrated fan and differential pressure meter in a door opening. For example, a Minneapolis blower door fan kit, Figure 1, can be used to both install the equipment and seal the door opening.
• Measure the amount of air you need to remove to create a constant pressure difference between indoors and outdoors. (You need to measure this flow for at least 5 different pressure differences.)
• Finally, you reverse the fan flow and blow air into the area and repeat the above procedure.


National seminar

On 4 December NCC arranged a national seminar, titled “Information about energy efficiency and renovation!” in Halmstad, Sweden. The seminar addressed 29 participants representing local and national stakeholders such as; Building associations, contractors etc.

Presentation >>

Invitation >>


E2ReBuild – Industrialised energy efficient retrofitting of residential buildings in cold climates. Contact info@e2rebuild.eu