We strive for an architecture that finds its inspiration in the state of being in between, between urban and rural, but always in relationship to both; between a deep respect for tradition and an appreciation of the contemporary; rooted in the local and yet part of a larger international context.

Periphery as a space of possibility
For us at OOPEAA, the notion of the peripheral is an important starting point for creating architecture. It emphasizes the fact that what one sees as the center or as the periphery is always relative to ones own position, and that there is always a distance between the two. We understand the notion of periphery to mean a space of possibility on the borderline between two different worlds. It is about a perspective and about an approach. It is about a space and a moment of transition, of having been something and of being about to become something more. It implies a sense of looking at things from an outside position while embracing the knowledge and understanding offered by an insider. Therefore, the peripheral is not about a geographical position but rather about an attitude that combines experience with a sense of openness and curiosity towards experimentation.


Regardless of scale or context, architecture is always about creating spaces for people and for life. We want to create architecture that is close to people, and also in dialogue with its context.

Creating spaces for people and for life
For us at OOPEAA, the goal in architecture is to create better life. In our work at OOPEAA, a sense of care, an attitude of curiosity and an understanding of the context are key guiding principles. For us at OOPEAA, care means taking responsibility for creating a sustainable foundation for a good life. Curiosity is about being open to new ways of seeing and learning while allowing knowledge from the past to serve as a foundation for creating something new. Context, be it social, cultural, economic or the site itself, is the place where the roots of the past meet the potential of the future growth and development.


Architecture is about communication and collaboration, from the very beginning of the process all the way to the final completed building. It is about learning from past experience and about building for the future.

A dialogue between the old and the new
In our approach to architecture we combine new ideas with experience and a sense of respect for tradition and locality. Our objective is to create architecture and milieus that are functional, technically and ecologically sustainable, of aesthetically high quality, and committed to the location. A willingness to courageously explore new ways of doing things and solving challenges is at the core of achieving sustainability. While appreciating the value of the past, we need to be open for new ways of seeing things.

Learning from each other
Sharing knowledge between different parties involved in a building project is essential to creating successful architecture. Collaboration as a way of learning from each other is at the core of the practice of OOPEAA. We have had the great opportunity to learn the appropriate methods of working with wood from the masters of craftsmanship and enjoyed the seamless cooperation with the most skillful of structural engineers.

Range of Work


The portfolio of OOPEAA covers a wide range of projects of varying scales from churches and public buildings, to housing, office buildings and private houses to town planning and urban visions for future development. We have also had the opportunity to do some quite demanding renovations and extensions to historically valuable landmarked buildings. There is a strong emphasis on the development of sustainable solutions on all scales, from individual buildings of to blocks of affordable housing and entire neighborhoods all the way up to the scale of visions for cities.


The work of OOPEAA and of Anssi Lassila personally has been recognized with some of the highest merits achievable, including the Pro Finlandia Medal in 2021, the Finlandia Prize for Architecture and the Wood Architecture Award in 2015, the Alfred Kordelin Prize and the State Prize for Architecture in 2017, the Rice Design Alliance Spotlight Award in 2017, and the Canadian Wood Design and Building Award 2016, as well as the American Architecture Prize 2016 in two categories. The work of the office has also been selected for the shortlist for the Mies van der Rohe Award, European Prize for Contemporary Architecture in 2005, 2011, 2017, and 2022, and nominated for the 2019 edition of the prize.


The Kärsämäki Shingle Church, completed in 2004, was the international breakthrough of the office. Since then, OOPEAA has realized four more churches, with the Tikkurila Church completed in 2021 as the newest one. In addition to public buildings, housing, and affordable housing in particular, has also been near to our heart.

We have been commissioned to design several housing blocks, which has given us a chance to test and develop innovative approaches. For example, the Puukuokka Housing Block (completed in three stages between 2015 and 2018) is an apartment block of three buildings with a fully wooden structure and a system of volumetric modular units made of CLT. The Risuviita Housing (2018) combines affordable housing with apartments tailored to meet the special needs of people with autism specter. In the Pihapetäjä Housing in Joensuu (2017), we were able to apply the method that was developed for the Puukuokka Block. Currently, we have also several new projects on the drawing board in which CLT is the chosen material. We have also designed daycare centers and school buildings, like the Taika Kindergarten (2017), or the Järvenpää Campus, currently under design.


The building industry is responsible for about 40% of emissions and harmful impact of human activity on the environment. That is more than the share of any other sector. That is why we as architects have a big responsibility in taking seriously the potential that we have in influencing decisions regarding material and structural choices related to the building’s design. The materials we use for building and how we use them make a big difference to sustainability. As a natural, locally available, renewable and recyclable material wood has a great potential in our effort to find ways of reducing the burden on the environment.

Working with wood and mass timber to explore its potential for developing ecologically and socially sustainable solutions to the contemporary needs of urban housing and public buildings is a key focus in the work of the office. We are also interested in developing new systems of flexibly customizable modularity. The Puukuokka Block by OOPEAA is an illustration of the potential of a system of volumetric modules made of CLT in creating multi-story apartment buildings with a fully wooden frame and structure. The Global Concept for the Allas Sea Pool Family developed by OOPEAA is an example of the applying the modular principle in a scalable concept with the capacity for flexible adaptation for sites in different parts of the world.


There is an active focus on research and development at OOPEAA. We are interested in exploring the potential of finding optimal solutions that support both the social and ecological aspects of sustainability while simultaneously being economically efficient in a long-term perspective. In recent years, our interest in finding ways to optimize the use of material and to create solutions that are architectonically and technically sustainable has led to our involvement in research projects with a focus on sustainability.

Most recently, we have completed a research and development project to create a web based evaluation tool, JOKOTAI Material Impact Screener, to assess the impact of the material and structural choices on the ecological sustainability of a building project that could be used already in the early stages of concept design in order to help to guide the design process. The working name for the tool was Life Cycle Visualizer. There is also an ongoing focus on exploring the potential of modularity and the application of mass timber as a sustainable solution to the needs of urban housing and public buildings.



The OOPEAA team is a multinational group of highly motivated young professionals who are excited about the potential of architecture in making spaces and places for people and for life. The interactive way of working in small groups that vary from project to project supports a process of continuous learning from each other in the team. Thanks to the strong local and international networks of the office, it is always possible to create new teams and to invite additional members to join the office according to the needs of the projects at hand.

The office has two locations in Finland, one in Helsinki, the capital of Finland, and the other in Seinäjoki, a regional center in the middle part of Finland. The working languages in the office are Finnish and English.


Anssi Lassila (b. Soini Finland, 1973) is the founder and director of OOPEAA Office for Peripheral Architecture. His international breakthrough was the Kärsämäki Shingle Church in 2004. Lassila’s architecture displays his interest in combining a sculptural form with traditional materials and innovative techniques. For him, peripheral sensitivity is a vital part of the creative process. His work is characterized by a strong interest in the way materials behave and experimentation with innovative solutions. It is about venturing into borderlands and identifying new possibilities where tradition meets the new.

Anssi Lassila has a keen interest in exploring the potential of using the new wood products as a sustainable solution to urban housing and in developing new systems of flexibly customizable modularity. His personal experience in working with wood as an architect covers a broad range from applying the traditional method of building with hand carved logs, as in the Kärsämäki Church and in the Lonna Sauna, to the use of CLT, as in the Puukuokka Block, the Pihapetäjä Housing and in the Global Concept for the Allas Sea Pool family.

Anssi Lassila is a sought after speaker at international symposia on architecture and he participates actively in international forums focused on matters of architecture, sustainability and the development of the use of timber in building and construction.


  • Anssi Lassila

    Founder and Director of OOPEAA Office for Peripheral Architecture.
    Architect SAFA, M.Arch.
    Professor of Contemporary Architecture (POP) at the Oulu School of Architecture, University of Oulu, Finland.

  • Tuuli Tuohikumpu

    Team Leader of the OOPEAA Helsinki office (member since 2018).
    Architect SAFA, M.Arch.

  • Timo Etula

    Team Leader of the OOPEAA Seinäjoki office (member since 2016).
    Architect SAFA, M.Arch.

  • Iida Hedberg

    Team Leader of Helsinki office (member since 2012).
    Architect SAFA, M.Arch.

  • Isaac Edmonds

    Member of Helsinki office since 2022.
    Architect, M.Arch.

  • Annamari Haapasaari

    Member of Seinäjoki office since 2022.
    Student of Construction Architecture.

  • Liisa Heinonen

    Member of Helsinki office since 2017.
    Architect SAFA, M.Arch.

  • Otto Heinonen

    Member of Seinäjoki office since 2021.
    Architect, B.Arch. Visualization specialist.

  • Havu Järvelä

    Member of Helsinki office since 2022.
    Architect, M.Arch.

  • Markus Keisala

    Member of OOPEAA office since 2019, Helsinki office since 2022.
    Architect, B.Arch.

  • Katharina Leinonen

    Member of Helsinki office since 2017
    Architect, M.Arch.

  • Teemu Leppälä

    Member of Seinäjoki office since 2014.
    Architect SAFA, M.Arch.

  • Aki Markkanen

    Member of Helsinki office since 2019.
    Architect SAFA, M.Arch.

  • Juha Pakkala

    Member of Seinäjoki office since 2008.
    Project Architect.

  • Ella Pitkäkoski

    Member of Seinäjoki office since 2022.
    Architect SAFA, M.Arch.

  • Tanja Vallaster

    Member of Helsinki office since 2017.
    Architect, M.Arch.


Seinäjoki Office

Kauppakatu 19 A
FI-60100 Seinäjoki
tel. +358 (0) 6 4141225

Helsinki Office

Eteläinen Hesperiankatu 8
FI-00100 Helsinki
tel. +358 (0) 50 3648305