airtightness

Even though air leakage assessment is key towards a better energy performance of buildings, Spain has still not established limitations regarding airtightness. National building regulations in Spain are gathered in the National Building Code (CTE), which was first released in 2006 and updated several times so far.

The situation in Switzerland is as follows: Neither the Swiss Energy Act nor cantonal energy acts/energy regulations stipulate a legal measurement of airtightness. The current standards of the Swiss Engineers and Architects Association (Schweizerischer Ingenieur- und Architektenverein, SIA) are the latest standards for architecture. The 2014 edition of SIA Standard 180 defines requirements for airtightness with limit and target values. The limit values are to be complied with in a voluntary measurement.

Purpose of the work

I have already talked about the issue of airtightness designs in Swiss standards at the Buildair Conference in 2015. What are the challenges we are facing two years later, regarding airtightness in Switzerland? And which of the issues in this context could be of interest for other countries?

Purpose of the work

For several years, multifunctional tapes have increasingly been used for the airtight installation of windows in new buildings or renovation projects. The adhesive tapes are wrapped around the window on three or four sides. After the installation of the window, the tape expands and closes the joints between window and reveal. Their manufacturers sing the praises of these self-expanding joint-sealing tapes made of foam plastic. However, BlowerDoor tests frequently reveal faults. Accordingly, experts vary in their evaluation and discussion of the products.

Purpose of the work

Purpose of the work

Windows according to the Passive House Standard 2016 require a ten times more airtight airtightness class (EN 14351) [1] than around 1990. The installation layer of the windows is constantly moving closer into the area of the insulating layer with possibly moisture-sensitive materials. Therefore, joint sealing of construction and connection joints must also be evaluated by applying parameters related to building physics like thermal conductivity, diffusion behavior, heat and moisture storage capacity, and the capacity for movement absorption.

Purpose of the work

With the German Energy Savings Regulation EnEV 2014 the legislators have qualified the requirements for large apartment buildings (V_L > 1.500 m³). In addition to the air change rate (n₅₀ ≤ 3,0 h^-1 or n₅₀ ≤ 1,5 h^-1 depending on the ventilation technology used) the envelope-based air permeability (q₅₀ ≤ 2,5 m³h^-1m^-2) is now also required.

According to the legal regulations and the rules of technology (as generally accepted) new buildings are to be constructed permanently airtight.

Environmental control (heat, air and moisture flows and their effects) started 90 years ago on Prairies of Canada and USA. It has always been based on occupant’s interest in a better indoor environment and driven by builders. More recently, when energy efficiency and durability considerations became part of socio-economic requirements of the society this part of building physics was shifted to the interests of governments.