regulations

Purpose of the work

To review the impact of air tightness testing in construction in Ireland since the introduction of mandatory testing under the National Building Regulations in 2008 and the subsequent enforcement of a National Certification Scheme.

Method of approach

Review of National Building Regulations in 2008 & 2011 and implications on buildings being constructed and the industry's acceptance.

Content of the presentation

As a consequence of the sustainable politics demanding regulations that allow the use of more efficient ventilation systems, the IAQ Spanish regulations were modified and enforced in 2017. The new regulations became performance-based in order to accommodate the use of systems which are capable of adapting required ventilation rates to real needs. The new requirement is based on both CO2 concentration and a minimum ventilation rate. 

The new IAQ requirement is able to keep acceptable IAQ values and to reduce energy demand in relation to the previous IAQ requirement. 

Surface condensation risk is a fact that has to be dealt with when buildings are airtight. Airtight buildings with lower ventilation rates are the result of applying energy saving policies and criteria. Surface condensation risk depends greatly on the ventilation rates, as well as on another factors such as generation of water vapour, climate, envelope components and U value, etc.

The Spanish Technical Building Code establishes the criteria for indoor air quality fixing minimum and constant ventilation rates per local. Currently, there is a proposal to modify the regulations so that the IAQ criteria becomes more useful by setting it based on average concentrations of CO2 and accumulated CO2 in the habitable rooms. However, the indoor average concentration is not the average concentration at which the occupants are exposed.

Recently research at the Eduardo Torroja Institute for construction sciences proposes a new wording for the IAQ regulations for dwellings included in the Spanish Building Code.
The main goal of the earlier research was to adapt required ventilation rates to real needs to achieve a reduction of ventilation rates and energy demand with no negative impact on indoor air quality.

The Spanish Building Code (BC) regulates indoor air quality (IAQ) requirements in dwellings by establishing threshold continuous flow rates according to the occupancy, use of the rooms and their usable area. The implementation of this threshold flow allow adequate IAQ.
A revised IAQ requirement have been proposed. These new requirement quantifies the IAQ as a function of CO2 concentration which means an non continuous flow rates ventilation systems will be able to be used.

The ventilation required in order to maintain acceptable indoor hygiene standards results in a significant consumption of energy. Currently the Spanish regulations on indoor air quality (IAQ) require minimum rates for delivery-to and extraction-from the habitable rooms of residential buildings. These rates are not adjustable, so ventilation systems based on variable ventilation rates, are not normally deemed acceptable unless a comprehensive statement of compliance is provided, justifying the proposed ventilation solution.

Implementation of the European Energy Performance of Buildings Directive (EPBD) introduced the first legal airtightness regulations into the 2008 Polish Building Codes. Unfortunately these provisions are currently not sufficiently precise or developed in relation to testing procedures to ensure appropriate airtightness. Generally there is a low level of awareness, experience and knowledge among architects, designers, investors, contractors and there are no certification requirements imposed for measurement companies.