Building renovations offer considerable potential for reducing energy consumption and carbon emissions. The comprehensive white paper shows how large-scale property owners can implement energy-efficient renovations in a way that’s environmentally sustainable, economically viable and socially responsible.
Much of Switzerland is already built up. About 80 per cent of the 1.8 million or so residential buildings date from before 2000 and fall short of current requirements for thermal insulation and energy efficiency. It is hardly surprising that the building stock remains responsible for around 40 percent of Switzerland’s energy consumption – more than three quarters of which is used for heat generation. And buildings still account for a quarter of total emissions. To effectively reduce the energy consumption and CO₂ emissions of the building stock, we need to leverage renovation of existing buildings.
Framework conditions
Despite the considerable potential for reducing energy consumption and greenhouse gas emissions, the renovation rate has been stagnating at just over 1 per cent for years now. To get buildings on track to achieve net zero by 2050, the federal government and the cantons are promoting investments in renewable energy and energy efficiency through the Building Programme. You can find an overview of the available funding on the platform www.energiefranken.ch. The Model Cantonal Regulations in the Energy Sector (MuKEn) serve as a basis for energy legislation. The revised version – MuKEn 2025 – is set to be incorporated into cantonal law in the coming years. It sees buildings as energy hubs that consume and produce energy. In comparison with the previous version, it also sets out tighter requirements for in-house electricity production, heat supply from renewable sources, and grey energy. Standard 390/1 ‘Climate Path – Greenhouse gas footprint over the life cycle of buildings’ is another instrument aimed at transforming the building stock. Building labels such as the Swiss Sustainable Building Standard (SNBS), Minergie, Minergie-ECO and the cantonal building energy certificate (GEAK) are also important tools for renovation projects.
An analysis systematically records the current state of a property and identifies potential optimisation with regard to energy efficiency, greenhouse gas emissions, cost-effectiveness and comfort, as well as potential risks. The following aspects are key:
- Market potential: location, tenants, potential use, public transport connections, infrastructure and tax rate of the municipality. Further elements to consider are building regulations, options for extension and requirements for listed buildings.
- Building fabric: the characteristics of the building with respect to architecture, urban planning and spatial qualities, flexibility of the building structure, supply of daylight, accessibility, spatial structure and fit-out standard. Since every component has a different service life, a value retention plan helps to optimise replacement planning.
- Energy: heating, the energy quality of the building shell, roof, facade, windows and the efficiency of building technology. If the plan is to switch to a renewable heating system, it is important to clarify which renewable energy sources are available at the location. It is also worth verifying whether the property can be equipped with a photovoltaic system or charging stations for electromobility in the future, or at least be prepared accordingly.
Service life of components using the example of a building constructed in 1990
Renovation measures need to be planned with a view to the entire life cycle of a property and in accordance with the portfolio or corporate strategy.
Replacement new build or renovation?
Does it make sense to renovate an existing property, or would a replacement new build better meet long-term targets for the environment, cost-efficiency and user requirements? A poor building fabric and high market potential speak in favour of replacement. But if the focus is more on environmental and social factors, there is much to be said for retention.
Value retention, partial renovation or comprehensive renovation?
Value retention makes sense if the building has structural defects and low market potential. Measures that require little investment can maintain living standards and the building fabric. Additional useful life: 10 to 15 years.
Partial renovation is an appropriate option if the building fabric is fundamentally sound and the layout meets contemporary needs but the market potential is somewhat low. Additional useful life: 20 to 25 years.
A good building fabric, high market potential and the option of extending all speak in favour of comprehensive renovation. Investments pay off, as they increase the value of the property and allow for greater rental income. Additional useful life: 40 to 50 years.
Complete or phased renovation?
A complete renovationreduces the duration and costs of construction. It also offers much greater scope for planning and coordinating measures, although it requires significant investment up front.
Dividing the project into stages spreads the investment over several years, which can be an advantage for owners with limited resources. However, construction costs will generally be a little higher overall and the energy savings gains will only be achieved in stages.
Decision matrix
Engage experts to help you determine the structural measures that will ensure optimal future utilisation of potential in terms of energy, the environment and cost effectiveness.
Building shell and structure
Improved insulationof the facade can save 10 to 20 per cent of total energy consumption. Similar savings can be achieved by insulating the existing roof and screed floor. Roof renovations also offer an ideal opportunity to think about installing a photovoltaic system to produce solar power. Replacing old windows with the current standard of triple thermal insulation can significantly reduce the loss of energy through windows. To reduce resource consumption and the associated grey energy, the ‘FenSanReuse’ study suggests that reinforcing windows can be a better option than replacing them.
Building services
More than half of all residential buildings in Switzerland are still heated with fossil fuels such as oil and gas. One obvious solution for reducing carbon emissions and operating costs for heat generation in the long term is to switch to renewable sources of heating and cooling. Replacing heating brings potential savings of between 5 and 10 per cent of total energy consumption. Connection to a district heating network, a joint network solution with the owners of neighbouring properties or an integrated energy solution with heat pumps can also be good options.
Since buildings will have to generate part of their electricity> themselves in the future, owners should already be thinking about installing a photovoltaic system. Self-consumption models (e.g. ZEV, vZEV and LEG) ensure that as much of the locally produced electricity as possible is consumed directly on site. To optimise self-consumption, solar power is also an ideal complement to electromobility.
In calculating the costs incurred by a building during its ‘lifetime’, it is important to consider not just the investment costs but also the capital, maintenance and operating costs over an assumed life of 50 years and the increase in value resulting from the renovation measures. The initial investment only amounts to around 20 per cent of these ‘life cycle costs’ – the remaining 80 percent is incurred while the property is in operation, in expenses for things like energy supply, cleaning, maintenance of the surrounds and administration, as well as upkeep and repair work.
Cost-effectiveness is one of the main obstacles to a higher renovation rate. In regions with low land prices in particular, it can be difficult to recover the investment costs through higher rental income and/or an increase in the value of the property. According to the Wüest Partner study ‘Cost-effectiveness of energy-efficient renovations of residential building stock’, around 54 per cent of potential renovation projects for rental properties can now be implemented cost-effectively. But without government support in the form of subsidies and indirectly through tax breaks, this figure would be much lower.
Reducing risks
Regular upgrading of properties also helps to minimise risks. This can prevent loss of value through poor building fabric, loss of income due to vacancies, inadequate living conditions and reputational damage due to non-compliance with sustainability standards.
Financing renovations
How a renovation project is financed depends heavily on the financial resources available to the owner. By making provisions in good time you can finance the project from your own resources. For self-financed renovations, energy-related measures can be partly tax-deductible. For third-party financing, banks will grant preferential loans under certain conditions, for instance if the property has a GEAK Plus certificate.
For owners of larger property portfolios, it makes sense to start by renovating poorly insulated buildings that are heated with fossil fuels. The top priority is to switch to renewable heating. If it proves impossible to insulate the entire building envelope, it is a good idea to conduct a cost-benefit analysis that shows where insulation would be most efficient. Agile planning methods such as integrated project delivery (IPD) and integrated planning (IP) help keep renovations on schedule and up to quality standard through early engagement of the various stakeholders.
However, a project does not end with successful commissioning. Many properties consume more energy than they need to in operations. Experience shows that operational optimisation can reduce energy consumption by up to 15 per cent. The costs are low and can often be amortised within two years.
