Building physics

CECB energy certificate

The Cantonal Energy Certificate for Buildings (CECB) is a diagnosis of the current state of the building and its energy performance, including recommendations and indications for a possible renovation. This certificate is standardized for Switzerland and includes two energy labels; the first one reflects the efficiency of the thermal envelope; the second one reflects the global energy efficiency of the building.

In the cantons of VD, GE, NE, FR, the establishment of a CECB is mandatory:

• For all real estate transactions.
• When replacing a heating system with a new one using fossil fuels, for residential, administrative and school buildings.

In Geneva, it is used as a reference in the calculation of subsidies for energy renovation. The establishment of a CECB certificate must be carried out by a recognized expert and according to the state of the art.

Contact us now for more information.

CECB Plus consulting report

A CECB Plus consulting report is established in addition to the CECB and is a real decision-making tool. It includes the study and the energetic, economic and environmental comparison of 2 to 3 concrete variants of energy renovation of the building (thermal envelope, replacement of installations and technical equipment, use of renewable energies, etc.).

The investment costs, the eligible subsidies for the works as well as the achievable savings on the operating costs are estimated by the expert. Finally, a profitability calculation is used to compare the economic impact of the renovation options with the current state.

The CECB Plus is regularly used as the basis for studies in the context of energy renovation projects. As certified experts, the engineers of BIFF SA are accredited to establish the CECB and the CECB Plus for your property.

An energy renovation not only saves money in the long term, but also maintains the value of the property while improving thermal comfort.

Please note :

Most cantons or municipalities subsidize this study.

The CEBS Plus is required when the subsidy for energy renovation reaches CHF 10,000. In this case, the request for a subsidy as well as the CECB Plus report must be made well in advance of the work.

Performances Energétiques

Infrared thermography allows, through a survey of heat radiation, to highlight possible disorders in the envelope, from the thermal point of view, the physics of the building (protection against moisture) and also electrical problems.

Why a thermography?

Thermography is a unique diagnostic tool that allows, without destructive probing:

• Before the work: to detect weak points of the envelope invisible to the naked eye, for example during an inspection of the building envelope and energy audits (CECB and CECB Plus report).
• After the work : to verify the quality of the work.
• To determine the probable cause of dhygrothermal disorders (e.g. condensation, mold, rising damp).
• By its visual aspect and as a tool of sensitizing near owners, communes and cantons, of communication and understanding between the actors of a project.

As a member of the Swiss Association of Thermography, the CH and certified ITC level 1 and 2, we apply, in the realization of our mandates of thermography, the Standard of quality building published by the Association.

Discover our video on thermography here !

Please note: "For obvious reasons of clarity, the images were redone at daybreak. Indeed, a thermography is always done in the early morning before the sun rises."

Illustration thermographie

Risque de condensation et moisissures

Each project is unique; whether it is a new construction or a renovation, the concept and the energy solutions can vary greatly from one case to another given the intrinsic specificities of each project, its location, its use and the objectives of the client.

For this reason, it is very useful to establish a concept or an energy feasibility study upstream of the project in order to provide the most suitable solution according to the owner's expectations.

In concrete terms, this study makes it possible to determine the level of performance to be achieved, to list the inventory of possible energy resources and to propose the optimal solution based on an analysis of economic, environmental and technical criteria.

Contact us for more information.

Within the framework of a construction project (new, renovation, extension...), the establishment of an energy file is required. This energy file is the last opportunity to plan an efficient and adapted global energy concept. It includes in particular :

• Description of the project and the energy objectives (SIA 380/1, Minergie/-P/-A).
• Calculation of the heat balance and materialization of the thermal envelope of the building (adapted to the requirements of the building physics).
• Establishment of the cantonal energy forms (thermal insulation, heating, hot water and ventilation concepts, minimum share of renewable energy, etc.).
• Checklist of thermal bridges and calculation of special thermal bridges as an option.
• Calculation of surfaces and measurements using adapted software.

 Minergie-P-A and ECO

Since 1998, Minergie is the Swiss label dedicated to the comfort of buildings, energy efficiency and the maintenance of the value of real estate. Priority is given to the comfort of the residents, for both new and renovated buildings. Three Minergie/-P/-A labels can be combined with the complementary product ECO for ecological and healthy buildings. The SQM construction supplement is available for superior quality during the construction phase.

Depending on the level of performance targeted and to ensure that the objectives are met, a design and an airtightness test called "blower-door" of the building must be performed.

Our engineers, specialists in the building envelope and Minergie partners, will advise you and take care of the establishment of all the energy proofs until the acceptance of the latter by the competent authorities and Minergie certification office.

Diagramme de Sankey - Déperditions énergétiques

As eco-counsellors accredited by the State of Geneva, our specialists can assist you in your projects related to environmental and sustainable development issues.

Thanks to various calculation tools (thermal balance, CECB report, thermography, BlowerDoor test, etc.), we calculate and determine the energy potential of your site in order to guide you towards adapted and energy-optimized measures.

We analyze and optimize the feasibility and profitability of the remediation measures while remaining in accordance with the environmental criteria and the requirements in force.

The advice of BIFF SA engineers guarantees:

• A good planning according to legal requirements or desired objectives.
• A valorization of your building.
• A reduction in energy needs.
• A better durability.

The profitability of energy renovation projects depends heavily on cantonal and communal financial contributions. These subsidies can cover from 30 to 50% of the basic investment. Therefore, the conditions and the obtaining of these subsidies imply a rigorous planning and follow-up throughout the renovation project in order to reach the planned energy performances and subsidies.

BIFF SA advises you from the planning phase in order to evaluate and even optimize the eligible financial aid according to your project, and then assists you throughout the procedure, until the financial aid is paid.

Our knowledge of the general regulatory framework of the building industry, specific cantonal requirements, the market, raw materials and energies allows us to have a mastery and a global vision of construction projects.

Cooking, drying clothes and showering are all activities that generate moisture in the home. Humans themselves release large quantities of water in the form of steam, even when they are at rest. Surface condensation occurs when the relative humidity near the surface is 100%.

Mould can appear when the relative humidity reaches 80% for a prolonged period in the vicinity of a surface. These moulds must be treated, as they can lead to health problems such as chronic respiratory tract infections.

The employees of BIFF SA have the appropriate tools to make the necessary observations and analyses. The analysis of the readings taken will make it possible to define the origin of the development of mold: bad management of humidity, serious thermal bridge, lack of ventilation.

Very simple actions ensure good air quality. Thanks to an optimal ventilation, you will avoid damages due to humidity in the living rooms.

Courbe de saturation

Condensation et moisissures

The hygrothermal simulations 2D or 3D allow to evaluate the risks of condensation and moulds on interior surfaces or through construction elements. The methods or the calculation softwares such as Glaser, WUFI, Flixo, and Trisco, allow to verify theoretical hypotheses. The critical analysis of the results is however essential in order to propose constructive measures adapted to each case.

WUFI for hygrothermal transfer through walls

The WUFI software allows to check the risk of condensation inside a wall according to the hygrothermal transfers which take place. Compared to a so-called static method such as "Glaser," the WUFI software is particularly interesting in the context of complex construction (wood structure, renovation from the inside, multi-layer facades...). This method takes into account the characteristics of the building, the interior and exterior hygrothermal climate and the materials (porosity, water content, hygroscopy, water vapor permeability, thermal resistance, etc.).

FLIXO and Trisco for thermal bridges

Thermal bridges can occur at interruptions or dimensions of the insulation or at particular geometrical connections. Thermal bridges are generally found at the connections between the different parts of the thermal envelope (facades, floors, roofs, embrasures, balconies, head of slab, etc.).

Simulation 2D WUFI

Simulation 2D du pont thermique

With the evolution of construction techniques in the building industry, the use of glass for various applications has become very accessible in modern architecture. However, its use as an essential component of the building envelope is not always well mastered in architectural concepts. Some very glazed buildings have high temperatures in their rooms, causing thermal discomfort for the residents. Our findings and analyses allow us to avoid this by proposing adapted architectural measures.

The low inertia of some buildings also implies important risks of overheating and discomfort. The variations of outside temperatures are then transmitted to the interior with little damping and little phase shift. For example, rooms with little or no insulation on the roof often have excessive temperatures and a risk of discomfort.

Our engineers advise you both for on-site measurements and through dynamic thermal simulations for your construction projects in order to provide adapted solutions to ensure summer thermal comfort. In some cases, we can also design a prototype to evaluate the improvements made.

Simulation thermique dynamique (DIAL+)

With global warming, air conditioning is becoming more and more important in the housing sector. Administration, industry, and commerce have always been sensitive to this phenomenon, given the important part of internal gain (by heat loss from appliances) and external gain (by sunlight through the windows).

As air conditioning is not recommended by the current energy policy, architectural solutions are most often implemented in order to inhibit summer overheating in housing:

• Solar protection (blinds, shutters, etc.).
• Caps, sunshades, eaves.
• Protective film (reduces the g-value).
• Materials with good thermal inertia (reinforced concrete, stone, etc.).

According to the current requirements in the canton of Vaud, 50% of the need for comfort air-conditioning must be covered by renewable energies (e.g. photovoltaic, heat pump, heat recovery). Some cantons even require that the need for air-conditioning be proven by an energy certificate (e.g. Canton of Geneva).

We are equipped with tools (DIAL+) to determine the need for air conditioning based on internal and solar energy gains. Thanks to an assessment of the thermal envelope, the energy need for air conditioning is determined. Then practical solutions are proposed for the envelope in order to reduce or eliminate the need for air conditioning.

Résultat simulation heures de surchauffe

Thermographies luminaires et vitrines

Why a BlowerDoor test?

• Mandatory for obtaining the Minergie-P^® label.
• To analyze sources of thermal discomfort caused by air infiltration.
• To quantify the air permeability of an enclosure (villa, apartment...).
• To locate air inlets or parasitic infiltrations.

The infiltrometry test, the BlowerDoor test or the test of the blowing door allows to evaluate the airtightness of conventional buildings to passive buildings (Minergie P or equivalent), for new constructions as well as for renovation. This test makes it possible to target and treat uncontrolled air infiltrations that could lead to condensation in the structure and significant energy losses.

BIFF SA's strengths:

• Our engineers are recognized experts and specialists in building envelope and physics.
• With their experience in the field, the waterproofing concepts that we propose are adapted to each case to help achieve the objectives set (whose level of requirement is, moreover, increasingly high according to the sustainability labels).
• BIFF SA is a member of the Swiss Blower-Door Association, theCH and a Minergie partner. In the realization of our concepts and BlowerDoor tests, we apply the Building Quality Standard published by the Association.
• We have the necessary and adapted material to treat also big buildings and we have adapted material means (several blower doors and fans).
• During the tests, we carry out leakage research in order to directly propose improvement solutions.

Test Blowerdoor

Test Blower-door 2 ventilateurs

Recherche de fuites

Recherche de fuites

In Switzerland, according to the OFEV and SUVA  :

• 1.1 million residents are exposed to harmful or annoying noise.
• 200,000 workers are exposed to a noise level above the authorized limits.

Noise has multiple effects, the frequency and intensity of which generally increase with the noise level. The main effects are:

• Health: e.g. discomfort, sleep, cognitive performance, hypertension, heart attack, etc.
• Economic: devaluation of buildings, costs of noise protection, health costs.
• Territorial and social: decline in quality of habitat, built environment and landscape, social segregation.

In order to avoid significant nuisance and to offer protection against noise such that a majority of the residents of a building are satisfied, the SIA 181 standard sets requirements for protection against:

• Exterior (envelope) and interior (slab and partition wall) airborne noise.
• The noise of shocks.
• Noise from technical equipment and fixed installations of the building.

Our engineers and acousticians will work with you throughout your construction or renovation project to:

• Define the level of requirement or acoustic performance desired.
• Evaluate the current acoustic quality of your building (diagnosis by acoustic measurement).
• Dimension and materialize the construction elements.
• Ensure the good execution of the constructive measures particularly sensitive from the acoustic point of view (uncoupling of the elements, lining, etc.).
• Receive the work.

Today, green building is a worldwide paradigm; an environmental necessity that has become both a part of the mores and the law. We talk about "green buildings" and sustainability.

In order to attest the sustainability of a building, different standards, labels, certifications, norms and prescriptions such as BREEAM, LEED, DGNB, MINERGIE, SNBS, etc. have been created and are becoming essential.

At BIFF SA, environmental and social responsibility is an integral part of our values. Our engineers, specialized in energy and sustainable development, will advise and assist you, whatever the label you are looking for.