From Roof Replacement to Urban Renewal Demonstration Project

From yellow brick building to sustainable property: A four-part renovation project

What began as a necessary replacement of a worn fibre-cement roof in the housing cooperative AB Ålholmhus ended as a four-part sustainable renovation project, encompassing solar panels, insulation, a green façade, and a sedum roof. The project will significantly change the appearance of the cooperative while positioning it as a local example of how aesthetics and sustainable solutions can be combined.

In Valby lies the housing cooperative AB Ålholmhus, consisting of 96 apartments across three buildings from the 1950s, as well as four commercial units in a ground-floor building. When the maintenance plan in 2020 revealed that the old fibre-cement roofs needed replacement, it did not just mark the beginning of a necessary renovation – but the beginning of a much larger transformation that has highlighted the cooperative’s commitment to the green transition.

Ole Vinkler, chairman of Ålholmhus, shares insights into the four-part renovation project, which will not only significantly change the cooperative’s appearance but also position it as a local example of how aesthetics can harmonise with sustainable solutions.

From roof replacement to urban renewal demonstration project

It was the maintenance plan from 2020 that set the four-part renovation project in motion. The plan showed that the old fibre-cement roofs needed replacing – a major task in itself.

Whenever roof work is undertaken, scaffolding is almost always required – and anyone familiar with construction knows that scaffolding often makes up a significant part of the total project cost. Ålholmhus’ consultancy firm, A4 Arkitekter, therefore advised the cooperative to investigate whether it would be beneficial to combine the roof project with other renovation tasks to get more value for the money. It turned out that it would.

The cooperative’s buildings had been poorly insulated for many years. Apart from the replacement of all windows 10–12 years ago, no major façade renovations had taken place since the 1950s. It quickly became clear that insulating the façades while replacing the roofs was the obvious solution.

“Because we were now looking at renovating both the roof and façade, we were advised to think in sustainable solutions – that way, we could apply for financial support from the urban-renewal fund,” explains Ole Vinkler.

The cooperative took this advice to heart and added as many sustainable initiatives as the budget allowed – enabling them to apply for and receive support from the urban-renewal fund. With its many sustainable elements, the renovation supports the municipality’s goal of creating a greener and more climate-friendly city. This means the cooperative will receive:

Solar panels on the roofs

“We discovered that it would ‘only’ cost us an extra 1 million DKK to install solar panels on the roofs instead of just replacing them,” says Ole Vinkler, adding that choosing solar panels was therefore an obvious decision.

The old fibre-cement plates have been removed, new roofing felt has been laid, and solar panels installed on top. The solution comes from Solartag and consists of integrated solar cells. The system is modular, allowing the cooperative to easily add more solar modules later if needed.

“Only two of the buildings will actually have solar panels. A solar consultant determined that in summer we would produce so much electricity that we could not possibly use it all – and might even struggle to get rid of the excess. The system would simply be oversized if we installed panels on all roofs. So on the block where I live, there are dummy plates. They look like solar panels but aren’t,” says Ole Vinkler. “The craftsmen are installing them now. They look like slate, and they’re really beautiful – both the dummy plates and the actual solar panels.”

Ålholmhus specifically chose a modular system so the dummy plates can easily be replaced with real panels later if needed.

Insulated façades

It quickly became clear that insulating the façades while replacing the roofs made perfect sense. The façades were virtually uninsulated, so adding insulation would reduce heat loss, improve indoor climate, and make use of the scaffolding already being erected.

“We chose external insulation so we wouldn’t have to enter the apartments and take up space there. Many apartments are small, around 45 m², and losing 20 cm on all walls would make a big difference – so we chose to put the insulation on the outside,” explains Ole Vinkler.

“And since we were advised to think in sustainable solutions to obtain funding, we chose to use as many recycled materials as possible to reduce our CO₂ footprint.”

The exterior cladding consists of recycled aluminium plates with wooden slats. This is also a modular solution, allowing the plates to be easily removed later if adjustments behind them become necessary.

A similar insulation system has been used on very old buildings in the Klimakarréen area on Østerbro, but the City of Copenhagen wants more data on the solution. The parties therefore agreed to install a similar insulation system on Ålholmhus’ buildings – enabling the cooperative to receive funding and allowing the municipality to test the system on a newer building type.

Sedum roof

Ålholmhus consists of three parallel buildings connected by the roof of the ground-floor building housing the four commercial units. This is the roof that will receive sedum, planned for planting next spring.

The idea of the sedum roof arose because the City of Copenhagen strongly focuses on solutions that slow rainwater drainage to the sewers. Sedum turned out to be a simple and effective solution that both delays runoff and contributes to biodiversity. These qualities made it possible for the cooperative to receive support from the urban-renewal fund.

“The roof does not allow for a very lush layer of sedum, but it will still be able to retain a certain amount of water,” says Ole Vinkler.

Green façade wall

The green façade wall is the fourth part of the project.

The idea did not come out of nowhere – it emerged from dialogue with the municipality’s urban-renewal team. Through these discussions, the cooperative was invited to join a pilot programme. They accepted and are now part of a demonstration project in the urban-renewal scheme. In practical terms, almost the entire façade facing Ålholmvej will be planted.

“It’s a very busy road. If you look at an air-pollution map, it’s almost as red as H.C. Andersens Boulevard. So we’ll be planting the entire wall. The University of Copenhagen has been involved and has placed air-quality sensors here since August last year – both facing the road and inside some of the apartments. We’ll see whether the green wall reduces particle pollution. Results won’t be available for about half a year,” says Ole Vinkler.

Behind the façade: Large projects quickly become everyday life

Today, scaffolding surrounds all buildings, and the workers are busy with solar panels, façades, and the green wall. The first building is nearing completion, meaning the green façade should be uncovered just before Christmas. The second building is expected to be finished around the turn of the year, and the third in spring. Once the three buildings are complete, work on the sedum roof will begin next spring.

However, it has taken time to get this far – large projects require planning, patience, and many steps.

“We held countless informational meetings leading up to the vote. Our consultant A4 Arkitekter prepared three different project proposals, and we voted on them sometime in 2021/2022. Then it went out to tender,” explains Ole Vinkler.

Municipal support requires that projects follow formal tender procedures. The cooperative received bids from three or four contractors and chose the lowest offer that met all requirements.

Ole Vinkler and board member Martin Borelli have been the project’s key coordinators, while the rest of the board has handled other tasks. From the moment the project started taking shape until construction began, the two have spent many hours each week on everything from construction meetings to consultations with the municipality and advisors – all to ensure proper planning and execution.

“We held countless weekly construction meetings even before starting – just to get through the urban-renewal application. And we’ve had many meetings with the municipality and various consultants. I think Martin and I still easily spend 5–10 hours a week on this. And that’s on top of everything else,” says the chairman.

Experiences along the way: The chairman’s advice

Even though the project isn’t finished yet, the chairman has already gained valuable experience and offers some advice:

Ensure you have a well-functioning board

Not all cooperatives can easily manage a project of this scale. Major renovations require time, energy, and cooperation.

“It’s only been possible because we have a truly well-functioning board. We’ve been lucky that the rest of the board has been extremely good at handling all other tasks in the cooperative,” he says.

“If there is friction in the board, meetings can quickly turn into day-long events – and that doesn’t work.”

Get professional advice

“It’s extremely important to get proper advice for projects of this size,” says Ole Vinkler.

The cooperative has worked with several advisors: construction consultants, solar consultants, lawyers, etc.

“A project of this scale can’t be handled by laypeople. Get consultants involved from the start – before the first scaffolding is erected.”

Investigate funding opportunities

“Look into whether you can get funding. It’s worth it. The green façade wall made the project more complex, but it will end up costing the cooperative nothing because the city covers it.”

A consultant can help identify and apply for support schemes, making sure opportunities aren’t missed.

Create a separate email address

The simplest and most important advice:
Create a dedicated email address for board business to avoid mixing it with your private life.

“When the project was at its peak, we received 15–20 emails a day. It becomes overwhelming if it mixes with your personal inbox.”

From brick to modern expression – and solar power that pays off

The many projects naturally change the building’s appearance. The old yellow brick façades will be covered with aluminium plates and wooden slats for a more modern look, while the green wall and sedum roof soften the expression.

“Nothing will look the same when we’re done. The only thing unchanged will be the balconies. But residents have known this – and we’ve had a mock-up displayed for years so people could see how the materials age.”

Looking ahead: The future with solar power

Residents and the chairman look forward to completion – and to seeing how the solar panels perform. While calculations show that solar power will reduce electricity costs, only time will tell how everything balances out.

The Solartag system is expected to produce 83,596 kWh of green electricity per year, of which around 49,000 kWh will be used directly in the building.

“There are calculations showing it will be cheaper – and naturally, some electricity will be free. But payback time and similar factors are harder to predict,” says Ole Vinkler.