A Finnish green roof – 10 years of GRT

by | Mar 20, 2018

A Finnish green roof is the next stop on our celebratory green roof tour built using our online guide. Although many people around the world purchase the guide, we don’t always have a clear idea where the green roofs will be built.

Finnish green roof - biosolar

Support is part of the deal

Occasionally, however, we get an email from a far-off place. In this case, an email popped into the inbox from Southern Finland. Getting an email from anyone is always interesting. Yet one from Mikko Mononen in Finland had a real interest for us. We have always wanted to go to Finland!

The challenge for us is to take our knowledge and provide as much information as possible to get people in countries beyond the UK to take forward the project as best they can. A lot of this is intuitive but fortunately in Finland there is a nascent green roof industry developing.

Our green roof guide was the game changer

Firstly, Mikko had been planning a house in quiet rural location in Southern Finland. From the start the green roof figured in all his sketches. It was a must.


The problem they had was how to build the green roof:

‘In general it was really hard to find information about green roof construction. There were some newspaper stories of people building their own roofs (and forgetting proper root protection, etc). Then there was marketing material about all inclusive green roof solutions. The dream, budget, and growing curiosity kept us searching for right solution.’

Then Mikko stumbled across our guide.

‘The happy accidents started to happen. One night, while googling for information, we found greenrooftraining. We waded through the material in one sitting. In fact, it was a game changer. The guide helped us to demystify different bits of the green roof construction. Suddenly it was not a black box system. We finally figured out what all the different layers were there for and how to choose what types of plants to grow on the green roof (not just sedum!). The guide also gave us the info on details like gutters and chimneys. After all the struggle it started to feel like it was possible to build the green roof after all. Actually, it all started to feel more like gardening, where we can try things out and see what works for us.’


Recycled materials combined with local knowledge

The next problem was finding out how to understand the local and national context and how to source local materials. This is when the next ‘happy accident’ happened.

‘The final missing piece in our puzzle was how to apply that information locally, using the materials available over here, and whether we had to take something specific into account because of building regulations and weather.

Then the second happy accident happened. We met a local green roof specialist, Taina Suonio, while visiting a housing fair. At this point we had many questions about building the roof and she was really happy to answer. She introduced us to the green roof research that is being undertaken at Helsinki University. She was also part of the working group which was making a new version of the green roof building code in Finland. It was a pleasant surprise that many of the ideas from greenrooftraining were very much in line with the new regulations and recommendations.’

Mikko also learnt about the Swiss approach of using reeds or grasses as the drainage layer from the university. With some email support from Dusty and John, Mikko had the confidence to take forward this approach. Yet there was still a problem of sourcing the right substrate/growing medium in Finland.



The first biosolar roof in Finland?


Mikko wanted to source recycled materials for the substrate. After much research, he eventually found a supplier who had just started blending green roof soils. A local concrete company had worked with the University of Helsinki to develop the mix, which is made of locally sourced construction waste and blended to meet green roof requirements.

In fact, when the Finnish green roof was completed, Mikko had managed to use recycled materials for everything but the filter layer. He also installed solar thermal panels on one of the roofs, meaning that it could well be the first biosolar roof in Finland.

Wildflowers for a Finnish green roof

With the green roof put in place, the next step was the really important element – the wildflowers. Mikko had been planning for this. As with the Cornish coastal green roof, he and his family had started to collect seeds, seedlings, and moss from around the grounds of the property. Further, they had purchased a suitable Finnish seed mix and bought some seedlings from a local nursery. Owing to the fact that there were several roofs, Mikko felt he could experiment with the planting by varying it on each roof. 


‘Some experiments we tried failed. For our sauna roof we sowed and planted only species we found at our lot and nearby. For a long time the whole roof looked like it had died. When things started to look really bad during the dry spring we sowed some of purchased seed mix there to save it.’


The important thing here is that Mikko tried things out and adapted the planting to what was able to grow on the roof.

And finally…

Having followed Mikko’s endeavours following his purchase of our guide, his Finnish green roof has been a great lesson in persevering, researching and communicating. As Mikko says:

‘The green roof was the hardest and most rewarding part of building our house. There were so many ups and downs, obstacles, nay-sayers and doubters. But I still like to go back to that moment when we bought the guide and began to understand how things worked and how our dream started to take shape. After that it was just a lot of hard work, sweat, and patience.’

And in the spring and summer the Finnish green roof is a sight to behold.


And in the long winters of southern Finland there is a certain snowy peace to the green roof.


From Essex to Cornwall and now Finland, the next stop on our celebratory green roof tour will be to the west coast of North America.