In Baar, right on the edge of Zug and adjacent to the agricultural area, Allreal owns the Baarermatte office building. The massive construction, built in 1981, has outdated building technology, no ventilation or conditioning. However, it does have a semi-sunken basement that extends halfway above ground, offering a clear ceiling height of over 3 metres and is situated on a plot with approximately 8,000 square metres of undeveloped potential.

At the end of 2020, we decided to breathe new life into the property and transform the Baarermatte into a flagship project for sustainability. The highly ambitious goal: to ensure that the construction and subsequent operation of the property generate no more than 6 kilograms of CO₂ equivalent per square metre of energy reference area (ERA) per year. The requirements for the study, conducted later with four invited architectural firms, were therefore clear: the building should be constructed primarily from wood, use minimal concrete, include photovoltaics and incorporate an innovative parking solution without an underground garage. Additionally, the study needed to demonstrate how parts of the existing building could be reused and how the undeveloped potential could be utilised.

The four project submissions were evaluated not only on architectural and economic criteria. The engineering firm Basler & Hofmann used a specially developed tool to check compliance with the sustainability goal. The surprising outcome at first glance: the winning project by Lucerne-based office Roman Hutter Architektur achieved the lowest CO₂ value by using only 5% of the existing structure. In comparison: the project that reused 80% of the existing structure had the highest value. Ursina Caprez, Team Leader of Project Development at Allreal and Project Manager for Baarermatte, emphasises the importance of this insight: “A precise analysis and objective comparison of options is the right approach to achieving the goal of low greenhouse gas construction. In the case of Baarermatte, a complete or substantial retention of the existing structure would not allow us to achieve the ambitious target of 6 kg CO₂e/m²a ERA. Therefore, retaining a building or parts of it does not necessarily lead to an advantage in terms of sustainable development, and this shows that an ideological stance can even hinder sustainable development.”

The four key pillars that, in addition to the low CO₂ value, make Baarermatte a sustainable flagship project:

Timber construction

Timber construction is not automatically sustainable. The wood used for Baarermatte comes from sustainably managed forests in Central Switzerland. It will largely be dowelled, not glued.

Re-use

Parts from the existing building are given a new lease of life in the new building. Whether concrete slabs now serving as staircase walls or pillars will be reused in the new buildings: the less the building components need to be processed and the shorter the transport distance, the better the CO₂ balance compared to new production.

Mobility tower

In Baarermatte, cars will be parked in a fully automated high-bay storage system. This space-efficient solution eliminates the need for an underground garage, hereby saving a significant amount of concrete and therefore grey energy.

Sponge city

The accumulating surface water can flow openly under the buildings into the retention basins. The water flow is thus slowed down and the water can be released into the stream at a slower rate. An environment designed with as few sealed surfaces as possible promotes biodiversity and ensures a pleasant local climate through the slow evaporation of stored rainwater.

The result, as of mid-2028, will be a liveable residential and work environment with a pioneering character. Baarermatte will feature 110 rental apartments, 10 studios and around 6,600 m² of office space, with 137 parking spaces available in the mobility tower.