According to the European Parliament and the Councils
directive (2010/31/EU) all EU member states must tighten
their energy consumption requirements for buildings to
ensure a sustainable development and an energy-efficient
union. The directive requires all member states to introduce
directives so that all newly built constructions will be near‑zero energy‑buildings by the end of 2020.
Boverket has developed directives (BFS 2017: xx BBR (A);
BFS 2017: xx BBR (B); BFS 2017: xx BEN 2) to determine how
energy consumption should be calculated and what
requirements will apply to near‑zero energy‑buildings in
Sweden.
This report will analyse what these new directives mean for
two standard wall system solutions from two suppliers of
prefabricated solid wood walls. The wall systems are applied
to a reference building where the ceiling, foundation,
windows and doors are predetermined, the only parameter
that varies is the wall systems.
The wall systems analysed are Isotimber'ʹ wall Per‑Albin 2.0
and Martinsons wall YV-16-01. Isotimber has a product
consisting of solid woodblocks with milled slots for
increased insulation (Isotimber, 2016). Martinsons
manufactures cross‑laminated timber elements that makes
form‑stable sheets of solid wood (Martinsons, u.å.a).
In order to achieve results, hand calculations of U‑values,
energy consumption and primary energy have been
performed. Calculations are based on legal texts, formulas
and standard values from the workplace as well as literature
studies, for example energihushållning och värmeisolering
(Elmroth 2015), byggnaden som system (Adel, E., & Elmroth,
A. 2012) among others.
The result shows that none of the wall systems will meet the
new requirements for near‑zero energy buildings with this
design on the reference building and with these wall
systems.