With efficient joinery, you reduce risk to natural and climate hazards: the building is more comfortable in winter and summer. Energy needs for heating and air conditioning are reduced. It is therefore energy bills that will decrease, which will reduce fossil-fuel dependency and contribute to reduce GHG emissions.

Joinery for low-energy houses are directly related with other stationary energy integrated solutions (mainly at building level, such as positive energy houses/buildings, nZEB, energy renovation or retrofitting of existing buildings...).

Project governance and implementation modalities

A bioclimatic design framework for the city where strategies to optimise the design of joinery can enable the passive energy design of the buildings taking into account local climate, orientations of the buildings and other factors to optimize building energy efficiency and comfort.

Technical aspects/infrastructure

In terms of joinery design, the framework should consider how to capture heat in the winter and prevent excess heat from entering the building in the summer. For example, in the winter, it may be important to design windows and other joinery to allow for maximum solar gain, while in the summer, shading devices or other methods may be necessary to prevent excess heat gain. The framework should also consider the orientation of the building and the specific exposures of sensitive walls to the sun: in the North hemisphere its common to limit losses in the North walls, whereas in the South walls (East and West too) the challenge is to limit the losses at the same time the solar flux is optimized according to the season.

If a building is located on a classified site or has heritage interest, there may be specific requirements or guidelines for the design of joinery in order to maintain the appearance of the building. In these cases, it is important to find a balance between preserving the historical appearance of the building and optimizing its energy efficiency through modern joinery design.

Other enabling conditions include: right skills of the workforce and awareness of the citizens; energy certificates promotion; building regulations promoting joinery and passive techniques; etc.

Technically speaking the framework should take into account which surfaces should be exposed or not to the sun, and how to prevent heat from entering in summer.

Identify the exposures of the sensitive walls, in the North the issues will be to limit the losses by the joinery. In the south (East and West also) the challenges will also be to limit the losses, in addition to optimize the capture solar flux according to the season.

It is also needed to identify if the building is located on a classified site, or of heritage interest, ...). In this case possibility to have to respect specific appearance (of old joinery for example).

Joinery is an element of the envelope with opaque walls, their replacements, or even their implementation in a new project, must be integrated into a global reflection of thermal improvement of the building envelope: the continuity of the insulation must be treated, for example work on the junction between wall insulation and joinery can limit thermal bridges.

Humidity in homes comes largely from human activity inside (breathing, showering, cooking, etc.). As part of a renovation of the joinery, we will improve the airtightness, and thus reduce the evacuation of this humidity. So special consideration of ventilation is necessary because it allows humidity to be evacuated effectively.

In renovation, a bad change of joinery can cause humidity problems that degrade the building and air infiltration that limits energy performance.

To ensure good summer comfort it is recommended to equip the windows with horizontal masks. Without reflexion it's possible to have thermal discomfort and more climatization consumption. When the masks are correctly sized, it is possible to significantly reduce direct radiation in summer without compromising solar gains in winter. They are especially useful on south facades.

Reference of the text: 

• https://www.programmepacte.fr/tags/fenetre
• France: http://maisons-paysannes.org/wp-content/uploads/2013/07/ATHEBA-ouvertures-dans-le-bati-ancien.pdf

Energy savings

Energy savings due to the use of joinery in buildings depend on the climate (therefore, location), on the type of joinery and on the number (generally joinery represents a small part of losing surface on building). Indicative numbers are: triple glazing saves 1-1,5 times more energy than double glazing, which saves 2-3 times more energy than single glazing.

GHG emissions avoidance (removing energy consumption in buildings)

Emission reductions due to the use of joinery in buildings depend as before on the climate, the type of joinery, the number, but above all on the energy used in the building. The more carbon-intensive the energy used (gas for example), the greater the reduction in emissions will be with good joinery.

User engagement for energy efficiency: Final users need to know this efficiency in the context of their building to accept Investment (overall calculation of the energy performance of the building).

Incentives: Needed to stimulate construction stakeholders to invest in this technology for new and existing buildings.

Data strategy: Needed to collect data on energy savings and GHG emissions.