This article is the third part of series about Swegon Air Academy seminar in Estonia and this article describes the nZEB application in Sweden and Marko Granroth´s experience with Swedish building regulations during Swegon Air Academy seminar in Tallinn on November 22, 2013, with topic on Modern and energy-saving concept in a small residential buildings.
In past Marko Granroth worked as Inspector & Design Team Leader HVAC&R for Sweco Systems AB. Currently Marko Granroth is a lecturer at Division of Building Service and Energy Systems, School of Architecture and the Built Environment at Royal Institute of Technology (KTH) in Stockholm, Sweden. You can read more about Marko Granroth at his profile page.
Marko stared with saying that it is already possible – technologically and economically – to build houses with energy consumption of 40-70 kWh/(m2.a), so Sweden has already reached the goal of 2015, and thus, there is a need for more solid basis for near-zero energy buildings to 2016.
In 2012 Sweden has the most stringent energy requirements in Europe said Stefan Attefall, Housing Minister. In 2009, the energy use in residential and commercial buildings amounted to 216 kWh/(m2.a) compared to the requirements of 89 kWh/(m2.a) by 2050 (or 142 kWh/(m2.a) by 2020 respectively). As for today (year 2013) the requirements in Southern Sweden are 90 kWh/(m2.a) and in Northern Sweden are 130 kWh/(m2.a). Therefore it seems to be technically possible to build more energy efficient buildings today (40-70 kWh/(m2.a)).
Marko said: “Swedish Parliament has allocated 12.86 million EUR for investments in the evaluation of nZEB in period of 2014-2016. The project plan is to collect measurement data (short and medium term) and by 2015 have a solid information and assumptions for decisions to specify a specific level of what a near-zero energy building is. The boundary conditions and mistakes must be identified and the mistakes made during previous energy efficiency (for example like sick building syndrome in 1970s) must be avoided.”
As for specification, even the Swedish regulation does not explicitly say “how you should design the building systems” and also what is “good air quality in rooms when people are present”.
The building regulation in Sweden states: “Ventilation systems shall be designed for a minimum outdoor air flow corresponding to 0.35 l/s per m2 floor area. When in use, rooms shall be able to have a continuous air exchange. In residential buildings where the ventilation can be controlled separately for each dwelling, the ventilations system is allowed to be designed with presence and demand control systems. However, the flow of outdoor air must not be lower than 0.10 l/s per m2 of floor area when the dwelling is unoccupied and 0.35 l/s per m2 of floor area when the dwelling is occupied.”
Picture by Akademiska Hus.