Building the future: The Tammela phenomenon – successful renovation of apartment buildings

VTT joined forces with the City of Tampere and local limited liability housing companies and began renovating some apartment buildings built in the 1970s and 1980s to improve their energy efficiency. The customised solutions and final outcomes far exceeded everyone’s expectations.

Four years ago, I walked with a colleague of mine in the area around Tammelantori square, getting acquainted with the blocks of flats there. The City of Tampere, in collaboration with VTT, had organised an open application process to identify local limited liability housing companies that were willing to become demonstration projects for improved energy efficiency. We felt that we were beginning the process much too late. The windows in the buildings from the 1970s had been replaced, and many of the houses had received new façades. The city, however, wanted to focus on the district of Tammela.

Energy efficiency improvement via a staged approach

From among the applicants, we were able to select eight limited liability housing companies to which we applied the principle of a ‘staged’ deep renovation of building stock included in the Energy efficiency directive. According to this principle, the energy efficiency of buildings can be improved by means of a staged renovation. Only two of the eight housing companies selected for the demonstration implemented the renovations of both façades and technical systems at the same time. Two other companies had already done some improvement measures.

On these four demonstration sites, improvements in energy efficiency were achieved by replacing the windows, installing additional insulation on the façades, renewing the lighting in the common facilities and installing a heat recovery and exhaust air heat pump. Furthermore, adjustments were made in the building’s technical systems, which included reducing the supply pressure of domestic water. The same measures, with the exception of additional insulation, were implemented in three other sites. One of the sites only invested in different types of heat pumps. In addition, all the sites implemented some other minor refurbishment measures.

Concrete turned into a real gem

Every housing company needed an active moving spirit for the project, either a chair of the housing company board or a house manager. One of these persons also happened to be an enthusiastic housing investor, who understood the financial incentive associated with the pilot. In some of the companies, choosing to join the pilot took no more than a single housing company meeting, whereas others needed several sessions before reaching a decision.

Now, subsequently, more than 90% of the housing company share owners have been satisfied with their decision to become one of the pilot sites in the EU GUGLE project. The residents of the demonstration that was the last to be completed are particularly proud of the results: they present their house as a gem among the contemporary housing stock of basic concrete buildings around it (photo).


Energy savings amounting to a significant 40%

The impact of the EU GUGLE project is not limited to the pilot projects. When we were looking for pilot projects four years ago, hardly anyone was familiar with heat recovery and exhaust air heat pump technology. The technology has made its breakthrough in the market over the last four years. The monitoring of the EU GUGLE projects and open communications about them have played a key role in this.

Cooperation with the housing companies has raised many questions about general claims. In the EU GUGLE pilots, the decisions were eventually quite easy to make. One housing investor promoted the renovations in his housing company, the senior residents in the housing companies involved were enthusiastic about the matter, and, on top of everything else, energy savings were achieved. To date, the combined energy savings calculated from the pilot projects have amounted to 40%. The monitoring of the pilots will continue for a further two years.

Further information on the pilot projects:

Terttu Vainio VTT

Terttu Vainio, Senior Scientist
terttu.vainio (a), +358 40 508 0983

From off-peak electricity to comprehensive energy saving

Over the last few weeks, it has been well nigh impossible to avoid seeing headlines about demand response, intelligent home automation and remotely readable electricity meters. Finland has been said to be a global frontrunner in the development of intelligent energy systems, which opens possibilities in the large and global market. However, consumers may remain uncertain as to whether they can benefit from this development in ways other than through the old familiar off-peak electricity.

In a recent news article, the Finnish Broadcasting Company wrote about how new intelligent meters will change everyday domestic life, while the proliferation of intelligent technology was reported in March to create entirely new kinds of electricity products on the electricity market. When reading the latter article, in particular, the famous bubble burst – it was merely about the old and familiar hourly rates for electricity. For many consumers, hourly rates have remained an alternative akin to the lottery – electricity may be cheap, or it may make a deep dent in your wallet.

Hourly rates are merely the tip of the iceberg of the changes emerging below the surface of the energy market. With regard to intelligent technology, one of the most concrete examples is Fingrid’s Datahub to be deployed in 2019. This increases the efficiency of the information exchange in the electricity retail market, offering an interface for business development. Elsewhere, according to its views as presented in the Commission’s winter package, the EU wants to shorten the imbalance settlement period to 15 minutes from 60 minutes, thus shaping the operation of the market to become much more dynamic.

Today, intelligent technology and dynamicity are most visibly connected on the electricity market in the form of demand response, the idea of which is pretty simple on paper: based on hourly electricity rates, demand is moved from expensive hours to cheaper hours, which is seen on the consumer’s electricity bill as savings. Fortum is currently running a commercial electricity demand response trial, in which a virtual power plant with a capacity of over 100 kW has been formed from the hot water boilers of 70 electrically heated detached houses and utilised in maintaining the power balance of the network. Examples of demand response can also be found in the heating sector: Fourdeg connects a weather forecast and a cloud service to a thermostat, allowing the apartment’s temperature to be adjusted room-specifically, saving energy and therefore also money.

Fingridin Tuntihinta-mobiilisovellus

Consumers can already use, for example, Fingrid’s Tuntihinta (Hourly rate) mobile application to monitor the hourly spot rate on the electricity market and receive alerts if the hourly rate exceeds the alert limit set by the user. Demand response requires an electricity agreement tied to the market rate. However, the savings remain marginal when consumption is controlled manually.

In the future, electricity is not merely a commodity going from the wall socket to an appliance; instead, electricity and heat will be fundamentally linked with each other, with homes featuring small-scale production of both, and storage solutions as well. Furthermore, these different components of the system must be governed in a controlled manner so that it is comfortable to spend time at home. Understanding all this requires combining many different areas of competence and points of view into a single whole, which may appear to the consumers as an insurmountable obstacle for participating in the active control of the energy consumption at home.

Every consumer is different and wishes to participate in controlling the energy consumption of their home in different ways. In order to make this participation easier, we have launched a project called DyRES (Dynamic platform for demand RESponse) in which we will create a dynamic calculation platform for the optimisation of flexible use of electricity and heat. Our approach is slightly topsy-turvy: by making the models more complex, we can simplify things and bring them closer to practice. This complexity comprises the operation and characteristics of each individual appliance utilised in the demand response, building models, control circuits and the system’s control logic in accordance with the consumer’s behaviour, and at lot more besides. However, we will conceal all this complexity behind a clear user interface that suits the consumer’s needs. The concept will be demonstrated first by simulating residential areas, but the developed platform will suit the implementation of demand response for complex industrial processes as well, thanks to the Apros® modelling tool we use.


DyRES combines analytic calculations, dynamic simulation and a consumer interface into one, single whole. This enables the transparent utilisation of algorithms and optimisation in practical applications intended for consumers. We will discuss the benefits offered to different user groups by the calculation platform in more detail in the next part of the blog.

The purpose of the platform we have developed is ultimately to guide a consumer’s use of electricity and heat in such a way that the energy consumption and related costs are reduced without compromising living comfort. This is enabled by the home automation and intelligent electricity meters so often mentioned in the news. A visual interface between the automation and the consumer enables the consumers to participate according to their own level of activity – or they can just be passive participants. However, the burning question is who is motivated by what to participate in the demand response: money, environmental impacts or something else entirely?

VTT is involved in the Energy Efficiency 2.0 in Building seminar on 22 May 2017 at Heureka in Vantaa, Finland. So please, come and discuss with us what demand response services should take into consideration from the perspectives of the consumer, developer and service provider.

Tomi Thomasson VTT

Tomi Thomasson, Research Scientist 

Elina Hakkarainen VTT

              Elina Hakkarainen, Research Scientist
Twitter: @e_Hakkarainen

Mikko Jegoroff VTT

Mikko Jegoroff, Research Scientist

Energy efficiency is the key component of sustainable development in cities


The UN Habitat New Urban Agenda was released a few weeks in Quito, Equador. The task to write a new urban agenda has not been easy, given that pre-conditions and interests are different in different UN countries. At the same time, there is an urgent need to act in favour of sustainable development in cities.

The striking fact is that urban settlements covers roughly 2.7% of the surface area of the globe, but consume 70% of resources and hence produces 75% of CO2 emissions. Moreover, we face many challenges if we are to transform our cities into healthy, safe and comfortable living and working areas.

Starting from these pre-conditions, the New Urban Agenda for the first time highlights the importance of energy. As is well-known, energy production is the main source of CO2 emissions and air quality problems in cities. Energy is needed in cities for transport, heating, cooling, lighting as well as for water and sanitary systems. We also need energy to run equipment and appliances. To transform ourselves into low carbon society, we need to de-carbonise our energy production, but also, very importantly, we need to use energy more efficiently. Energy that does not need to be produced is the most environmental friendly. Energy efficiency is not only beneficial in preventing pollution but is also a key component for resilient cities. Energy efficiency entails reducing overall demand and more importantly reducing peak demand. In combination with smart technologies, demand can be controlled based on self-learning and adaptive algorithms to reduce and shift the demand even more efficiently without compromising users’ well-being, but rather in ways that can also further enhance well-being.

Smart cities and efficient resources

In addition to energy, the concept of smart cities was for the first time raised onto the agenda. The concept of smart cities is quite unique, since it is applicable both to industrialised cities/districts and to developing economies. The benefit of smart cities is that by using easy-to-install and adaptable sensors and self-learning control algorithms, existing infrastructure can be made more efficient. Moreover, new methods allow for generating urban services more efficiently in developing countries, without heavy and costly infrastructure requirements. Good examples for this are the implementation of renewable energy sources for cities and communities. In addition, smart communications enable citizen engagement and ownership within their own living areas, which evidently improves the perceived living quality and attractiveness of the area.

Smart systems enable us to use our resources more efficiently. This can be done by using and combining data from different sources. Currently, in modern buildings, there are typically over 20 000 data points, and hence in cities there exists an unimaginable amount of data; it is evident that no-one has the capacity to process all the data. We need, therefore, smart self-learning and predictive systems to make the most of the data available. One of the leading principles in smart cities is to enrich data to create meaningful information that supports our decision-making and helps in making our everyday lives run smoothly and that helps us to achieve environmental sustainability. More importantly, this saves time for the most important things in our lives.

Miimu Airaksinen
Research Professor
UN Habitat Policy Unit 9

Miimu Airaksinen was nominated in 2015 as an expert for the United Nations Policy Unit 9 on Urban Services and Technology to prepare the UN urbanization strategy.

Twitter: @MiimuAiraksinen

VTT supporting energy planning in Namibia

The moment you land on Hosea Kutako International Airport next to the capital of Namibia, Windhoek, you quickly realise you’re in a special place. Surrounded by a savannah landscape, rolling hills and an occasional wild animal you can’t help but feel a sense of adventure. This feeling grows stronger when you get an opportunity to explore the vast country more; Places such as Etosha National Park, the sand dunes in the Namib Naukluft National Park or simply the rough but beautiful wilderness everywhere in the country will impress even a more experienced traveller. But behind these amazing landscapes, serious challenges arise and many of them relate to climate change.


According to the Intergovernmental Panel on Climate Change (IPCC) southern Africa is one of the most vulnerable regions to the impacts of climate change. Climate change vulnerability is especially high concerning extreme events such as increased drought causing water stress, land degradation, desertification and loss of biodiversity. As a major part of the population is reliant on climate-sensitive sectors such as agriculture, livestock management and fishing, these events can endanger the food security and the overall development of the region.

At the same time, among other development challenges, many of the countries in the region are facing big decisions concerning the development of their energy sector.  For example, the Namibian energy sector has seen very little investment on electricity production capacity, making the country very reliant on energy imports. As other countries in the region are also experiencing difficulties in securing their electricity supply due to aging energy infrastructure and growing consumption, major investments would be needed.

Namibia is situated on shores of the Atlantic Ocean north from neighbouring South Africa. It is a vast, dry country with a population of only 2.3 million.

Namibia is truly at a crossroad concerning the development of its energy sector, and the decisions made now will have a major impact for several decades. Fortunately, Namibia possesses a significant potential for utilising renewable energy sources, especially solar.

Sunset in Swakopmund, Namibia

Informed decisions about future sustainable energy system

During recent years, VTT has been involved in energy policy development in Namibia by supporting the work of Ministry of Mines and Energy of Namibia. Currently, VTT works on a project related to energy efficiency and renewable energy options for the Namibian fishing industry.

Project manager Miika Rämä with Mr. Peya Hitula, the General Manager of fishing company Tunacor.

Interest on energy issues has been high, not least because of rising price of electricity: a 65 % increase on average during past 5 years for commercial and large power user consumers. In general, concerns on the electricity supply are currently a hot topic of public discussion.

The need for the capacity building on energy issues in the region is high. For example, the changes in electricity system operation and management due to increasing solar based electricity production would benefit from smart grid and electricity storage solutions. Currently, the country is moving towards a highly distributed electricity system with a significant number of relatively small scale power plants in development. Namibia’s fist photovoltaic power plant of 4.5 MW in capacity was inaugurated in 13th May 2015.

The Namibians also face the problem of evaluating which technology providers actually can guarantee reliable systems, and do not just try to sell their product for buyers with limited knowledge and experience on the technologies and their profitability. Thus capacity building by a neutral party such as VTT has been highly appreciated by the stakeholders met in the projects.

There is a lot of room for very important work in the region, and the expertise of VTT’s energy systems specialists can serve the Namibians for making better decisions for future sustainable energy system. This work can also contribute in tackling the challenge of climate change adaptation. Not perhaps by the scale of activities, but by setting an example that with given resources and careful planning a 100 % renewable electricity system is a realistic target.

Current project team (from the left): Kati Koponen and Miika Rämä from VTT, Nils Hauffe from NWV Market Discovery, Inc.

Kati Koponen, Research Scientist

Miika Rämä, Research Scientist


See also:

Research report: Development of Namibian energy

The Energy and Environment Partnership (EEP)

International Renewable Energy Symposium (IRES) – NAMIBIA

Embassy of Finland in Windhoek


It is more sensible to renovate entire residential districts than individual buildings

According to Statistics Finland, there are more than 20,000 blocks of residential flats in Finland built between 1960 and 1979, which have a total of approximately 0.5 million apartments with permanent residents. Within the next 10 years, many housing companies will face different repair needs as the structures and technical systems begin to show signs of deterioration. In connection with such repairs, it is also natural to consider energy-efficiency improvements to the buildings.

Ecological energy efficiency will be faster and cheaper by means of district renovation

With a view to energy efficiency, it would be advisable to repair entire residential districts rather than individual buildings. This would include renovating both the buildings and the adjacent energy, water and waste management infrastructures. This is the only way of ensuring that the building-specific measures aimed at improving energy efficiency would also affect the entire residential district and its energy production. If renovation is limited to an individual building, that particular site may save energy and water, but the measures will not necessarily have any impact on the energy production and water needs within the district.

Residential districts typically have many building characteristic of a specific era, and the renovation solutions needed are therefore quite similar. Even though there is a wide range of different renovation techniques, and new ones are being developed all the time, elevating the prefabrication level of renovation solutions would speed up the process significantly. This would also require the development of renovation processes, practices and services. When moving from one staircase and building to the next, it would speed up the renovation work if the same solutions could be employed extensively in similar buildings and lessons could be learned from earlier sites and their repairs applied to the next. This would also lower the price of renovation construction.

Often, when examining the emissions caused by heating and other energy consumption of buildings, the focus is only on carbon dioxide emissions, even though they constitute only part of the harmful emissions. However, when the impact of renovation on the harmful emissions of energy production is examined at district level, the conclusions drawn may differ from those that would seem most sensible for an individual building. For example, it is usually more advantageous to use renewable energy in district solutions than in building-specific solutions.

The idea of demolishing and reconstructing old buildings rather than renovating them to meet the current requirements emerges in public debates every now and then. In scientific literature, relatively few comparisons have been made between renovation of buildings and demolition and reconstruction. However, examples from Western Europe show that, from the viewpoint of sustainable development, demolition and reconstruction can only be recommended if the buildings are in extremely poor condition.

New operating methods are required – decision-making is a challenge

District renovation requires new operating methods from the actors involved. From society’s point of view, district-level energy renovation has clear benefits, such as certainty of improved energy efficiency and reduced emissions throughout the energy chain. The renovation of entire residential districts could also be more interesting from the viewpoint of companies, because it would lead to bigger building contracts. In housing companies, decision-making is often the challenging factor. District repair projects would require consistent decisions from several housing companies, but, on the other hand, it would mean lower unit costs for renovation.

I presented the idea of comprehensive energy-efficient district renovations in my dissertation, in which I studied how the energy efficiency of Russian suburbs built in the Soviet era could be improved by renovating the buildings to make them more energy efficient and by reducing the losses from energy infrastructure. The topic was examined from the perspectives of energy savings, the energy needs of a residential district, emissions from energy production, investment costs, and business models of district renovation. Even though the cases studies were in Russia, the same methods and solutions could also be applied to Finland. The benefits would be the same, although not as big as in Russia.

Satu Paiho

Senior Scientist

Dissertation: Energy-efficient renovation of residential districts Cases from the Russian market