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Appoaches to Residential Retrofit around Europe

Posted by: Maeve on June 04 2019 | Tagged: Industry News, Retrofit Scotland News

According to a new study, the only way for the UK to achieve its carbon saving goals is to establish a nationwide programme to upgrade the existing housing stock. The ‘Scaling Up Retrofit 2050’ report by the Institution of Engineering and Technology and Nottingham Trent University highlights that, alongside environmental benefits, retrofit offer a lasting solution to tackling fuel poverty. To achieve the required goals, a great increase in the rate and level of retrofit interventions is needed. In light of this challenge we’re sharing four examples of different approaches to retrofit from around Europe.


Lacaton and Vassal - Social Housing Transformation

Parisian architects Lacaton and Vassal have made a namefor themselves through their skill with working with what already exists. They have created an innovative approach to the re-use of existing buildings that has been applied to a range of building types. But is their approach to social housing transformation which is particularly notable. In 2004 they coauthored the manifesto Study Plus which rallied against the French government’s programme to demolish much of its postwar housing stock; Lacaton and Vassal instead called for an approach to “never demolish, never remove or replace, always add, transform, and reuse!’

The transformation of the Tour Bois-le-Prêtre towerblock, completed in 2011, was their first opportunity to put this in action. The perimeter of the 16 storey towerblock was encased with lightweight self-supporting glazed winter gardens and prefabricated balconies. This increased the overall floor area by around 40% which made it possible to accommodate new typologies more suitable to modern living arrangements.

Lac Vass Before After

In addition to creating new light-filled space, the winter gardens passively heat and cool the flats – as a result energy consumption has halved. The project was delivered with half the budget which would’ve been required had the block been demolished and new housing built. Prefabrication and careful phasing of works means there is minimal disturbance
to existing communities as inhabitants were able to stay put during construction works.

Lacaton and Vassal has since applied this approach to a number of further towerblocks. Grand Park in Bordeaux has been one of their largest projects to date. It consists of works to three separate towerblocks containing 530 apartments between them.

Lacaton and Vassal’s work shows the value in altering and remodeling when demolition is not an absolute necessity. It is less disruptive, more economical, and more and environmentally friendly compared to demolition.


LV Grand Philippe Puault Lacaton Vassal Grand Parc Bordeaux France

© philippe puault lacaton & vassal grand parc

 Lvdruot Lacaton And V


Energiesprong - Carbon-neutral Homes

Energiesprong (‘energy leap’) is a carbon-neutral housing retrofit scheme pioneered in the Netherlands. It started as a government-funded innovation programme. This scheme uses a ‘wrapping and capping’ approach where external walls are clad with insulated panels while roofs are insulated and topped with PV panels. Speed and minimal intrusion during works are key, with refurbishments being carried out in just 7-10 days. Affordability is also central. Energy efficiency upgrades are paid for via energy bill savings and loan repayments. The homes are designed to pay for themselves over 30 years. Households renovated using Energiesprong recieve an energy performance guarantee: the construction company provides a 30-year warrantee meaning that if the real-life performance fails to meet the promised energy reductions then they are liable to a financial penalty.

After successful improvements to social housing in the Netherlands, Energiesprong has now been brought to the UK. The ‘Nottingham City Homes 2050 pilot’ project which consists of 10 terraced homes is the first to be completed using the scheme. New highly insulated external cladding and roofs were prefabricated and craned into place – all while the residents stayed put in their homes. The reduced energy load of the terrace is complemented by renewable energy generation  from PV roof panels and ground source heating systems.

This project is one of a number made possible by a £5million fund which Nottingham City Council secured through the European Regional Development Fund (2014-20) to roll out its Energiesprong.

While Energiesprong is in early development stages in the UK, the Dutch example suggests that economies of scale will come with an increased take-up. According to Energiesprong, there are currently plans for 14400 houses in the Netherlands to be renovated using the scheme - this figure is at 225 for the UK.

Energisprogdonald Chambers



Panelak - Easter European Prefabrication

'Panelák' is a colloquial Czech and Slovak term used to describe the type of prefabricated residential urban blocks typical of the Soviet era. When first built, Paneláks were a way of providing a large volume of housing quickly and cheaply. Now, the former Czechoslovakia has more of this type of housing than anywhere else in what was Soviet Bloc. The prevalence means that widescale demolition and replacement is economically unfeasible.

The Slovakian architects GutGut worked on the renovation and reconfiguration of a Panelák block using a methodology it has termed ‘Paneláky.’ Their design removed the internal partitions of the block’s uniform apartments, and reconfigured the layout to create apartments of varying sizes. An extra penthouse storey was also added. The exterior appearance was improved with a new insulated façade which eradicated the prefabricated appearance; steel balconies were also added. The storage warehouse on the ground floor was replaced with communal facilities: a café, gym and sauna which are connected to a new external terrace

Panel Gutgut Merged


Achieving the Passivhaus Standard with refurbishments of existing buildings is difficult aim. The building’s orientation, and structural approach are already set and existing thermal bridges are particularly challenging to eliminate.

EnerPHit is the standard developed by the Passivhaus Institute which focuses on retrofit projects and sets a more relaxed and realistic bar. Benchmarks to achieve EnerPHit certification include:

  • A space heating and cooling demand of ≤ 25kWh/m2/ year (compared 15kWh/m2/year for Passivhaus)
  • An airtightness performance of ≤ 1.0 air changes per hour (compared to 0.6 for Passivhaus)
  • A Specific cooling load of ≤10 W/ m2
  • Primary energy demand of ≤ 120 kWh/m2. yr + heat load factor

The standard can be implemented with a phased strategy including intermediate certification if a whole-house retrofit approach is not viable.

Cedar Court in Glasgow is an example of a project in Scotland which has been renovated using Enerphit standards.

Enerphit 2014 The Process Of Step By Step Enerphit Certification PHI

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