Sustainable buildings – fair rents

The municipal enterprise, Wohnungsbau Ludwigsburg GmbH, have built five apartment buildings in Ludwigsburg, Germany with the aim to create sustainable and cost-effective housing that is also affordable.

Affordable apartment buildings Germany

The developer wanted the five new apartment buildings – comprising 42 rental apartments, 18 owner-occupied apartments and two underground car parks – to fit harmoniously into the Sonnenberg district of Ludwigsburg and was impressed by a design by ARP ArchitektenPartnerschaft Stuttgart GbR. Their design positioned the five-storey buildings in such a way that the single-family housing development in the north of the district would have views of the open spaces to the south. Wohnungsbau Ludwigsburg GmbH (WBL) had a well thought out plan to create a mix of owner-occupied and subsidised private rental apartments, thereby giving them the financial freedom to focus on architectural design, sustainable construction and good quality fixtures and fittings.

An example of social commitment

WBL defined clear criteria which the construction project had to fulfil. One such criterion was to meet the KfW55 standard, another was to avoid a typical solid construction of polystyrene ETICS. Ecology and durability were key considerations for the client when choosing the building materials. “As a municipal housing association, we see ourselves here in the role of social pioneer,” says Achim Eckstein, Head of Project Management at WBL.

„We looked at timber construction, lightweight construction and thermal insulation bricks, and it was clear that brick was the most economical construction method.“ - Julia Diez - Architect

A comparison of construction methods

The first step for the architects at ArchitektenPartnerschaft Stuttgart GbR was therefore to evaluate a variety of potential construction systems. “We looked at timber construction, lightweight construction and thermal insulation bricks, and it was clear that brick was the most economical construction method,” says architect Julia Diez.

The perlite-filled, Poroton S9-P brick was chosen to build 42.5 cm-thick walls, allowing the client to achieve the structural requirements for the five-storey buildings and simultaneously ensure that the masonry had good thermal insulation. The client was particularly impressed by the insulating filling of perlite, a naturally occurring volcanic rock, for which the product has received the German “Blue Angel”s ecolabel. A healthy indoor climate was another requirement for the project, and this brick has been certified free from pollutants and emissions by the German eco-INSTITUT.

A social charter for affordable, high-quality homes

WBL’s main aim with this construction project was to create affordable rental accommodation those on middle to low incomes, in accordance with WBL’s own ‘fair housing’ model. The model makes provision for owner-occupied apartments and for both standard and subsidised rentals. Income from the privately-owned apartments is reinvested in the subsidised rental apartments, which are for tenants with a certificate of eligibility to live in apartments at reduced rent. If such tenants get a pay rise, their rent protection is reduced accordingly.

The “fair housing” model thereby creates a better social mix and stable communities. By taking all these factors into account, those involved in the project have achieved their goal of building a forward-looking, sustainable and social residential district. This achievement is underscored by the award to the project of the NaWoh [Sustainable Housing] Seal of Quality 2020 and the Stuttgart metropolitan region ImmobilienAward [Real Estate Award] 2019 in the housing category.