By the end of 2020, all new buildings must be nearly zero-energy. This means that they must consume very little energy, most of which should be renewable. However, Senior Scientist Satu Paiho and Research Team Leader Jari Shemeikka of VTT say that compromising on comfort is not on the cards.
The design idiom of the buildings, their orientation, interior ambient light levels, the location of regional renewable resources in relation to local energy needs: these are just a few details which can be optimised to improve the energy efficiency and comfort of densely built areas.
Regional energy plans involve holistic management. When the EU issues a directive on almost zero energy building, the issue can be approached in a number of ways.
– In the future, it looks as though detached buildings will often need their own equipment, such as solar panels, for generating renewable energy. In the case of dense urban structures, it would make more sense to design the energy supply on the basis of entire areas rather than single-home investments, says Satu Paiho.
Vartiosaari a model district?
In 2015, the City of Helsinki, the Housing Finance and Development Centre (ARA) and Helen Oy ordered background materials to assist architects participating in the Vartiosaari design competition. The aim is to create an island district which combines an energy-efficient urban structure with recreational activities for Helsinki residents and comfortable living. Traditional design competitions do not take a stand on energy solutions.
In the planning of Vartiosaari, the aim is ecologically, socially and culturally sustainable building. The district energy solutions will be based on the utilisation of local renewable energy sources and alternative energy production methods. Another aim is to take account of construction with a low environmental impact and sensible choices of materials at the planning stage.
The City Planning Board has approved the proposed master plan for Vartiosaari, which will be submitted for consideration by the City Council this autumn.
– Although VTT's analysis and the design competition arranged alongside ARA focused on Vartiosaari, the results can be regarded as generally applicable and would benefit affordable housing project planning elsewhere, says the Project Manager of Vartiosaari, Ritva Luoto of the Helsinki City Planning Department.
– In Helsinki, we are trying to make the best possible, customisable, durable residential areas. Energy solutions are an important part of a functional whole – as are traffic arrangements. The planning of Vartiosaari, which will be built around a new rail connection, emphasises public transport, cycling and walking, says Luoto.
Storage of solar heat
In its Vartiosaari report, VTT addressed the importance of solar heat production.
If excess solar heat in the summer were stored for use in the winter using BTES (borehole thermal energy storage) or tank-based storage, the result would be a 60% self-sufficiency rate in heat production, a 50% reduction in carbon dioxide emissions, and an up to 70% reduction in sulphur dioxide and fine particle emissions compared to non-storage.
Plans for people, not technology
VTT utilised the results of its previous SunZeb project.
– In the SunZeb project, we used various simulations to investigate how, say, the orientation of buildings affects living conditions and the capture of energy. For the Vartiosaari project, we applied the results to an entire residential area, says Research Team Leader, Jari Shemeikka, of VTT.
Based on the SunZeb model, each building is connected to a local system which distributes the building's surplus energy to other buildings in the area.
– Energy integration is still a new feature in town planning. It is not easy, because the optimum situation for each of the many actors may not be the same as the optimum for all.
The SunZeb model can also be applied to renovations.
– Office premises based on the SunZeb principle have lower lifecycle costs than other types of buildings. For residential buildings, the lifecycle costs remain at about the same level. The additional costs can be recovered within a couple of decades. Better living conditions can also be bought with the same money.
– In SunZeb, the focus is on the comfort of interior living conditions. In particular, the elderly, who tend to suffer more from draughts in the winter and heat in the summer, could benefit from this, Shemeikka points out.
What's coming up, VTT?
Regardless of regulation due to climate change, construction must not be too expensive. This makes the development of cost-effective solutions highly topical at VTT.
Shemeikka comments that the boundaries between actors will blur when energy companies expand into service provision due to efficiency requirements. In the future, energy companies will offer wellbeing, i.e. comfort of living, as well as energy.
New practices will reduce the risks
Municipal planning decisions have a significant impact on how energy-intensive new districts are. Town planning involves far-reaching decisions that affect district solutions.
– The solution is sub-optimal if the area is not holistically considered in collaboration with various businesses and the municipality. The introduction of new technological solutions via collaboration is particularly important now, when business models are in transition, states Shemeikka.
Shemeikka refers to the experiences of planning Härmäläranta in Tampere.
– This involved the creation of new types of town planning partnership models, where cost-effective and comfortable solutions were created based on a goal set jointly by the city, industrial players and residents.
Paiho and Shemeikka point out that Finland is a pioneer in living conditions.
– The Nordic countries have always had sharp frosts. But this does not affect life in Finnish homes, where district heating is sufficient in even the coldest weather. This provides an excellent basis for developing into an exporter of district energy solutions, he says.