Foster’s sustainable office project creates a milestone for Madrid

A transformative scheme to breathe new life into an old industrial building sets new standards in reducing carbon while creating a green space for outdoor working

At a time when sustainable workplace development has never been higher on the business agenda, a new office building for Spanish infrastructure and energy company Acciona has been hailed as a sustainable exemplar of building reuse following its official opening in Madrid.

Designed by architects Foster + Partners, the Ombú project is described as breathing new life into a historic industrial building, helping to revitalise the surrounding area. With more than 10,000 square metres of new office space, the project unifies both private and public land with green landscaping, which extends to the adjoining Méndez Álvaro station.

New garden for city

According to the architects, Ombú has a 1.0 Planet Ecological Footprint, which means its carbon emissions will be absorbed by the current capacity of the earth. This is said to achieve the balance of sources and sinks required by the Paris Agreement, with its environmental impact compatible with the original +2°C target.

Sir Norman Foster, founder and executive chair of the design practice explains: ‘Ombú brings an industrial wasteland back to a new garden in the city. Madrid’s benign climate allows workspaces to be outside as well as inside, creating a flexible and desirable lifestyle. Natural materials are brought into the existing building, contributing to biophilic spaces that are good for wellbeing and productivity.’

Retrofit design

Originally built in 1905 by architect Luis de Landecho, the building once supplied energy to the surrounding areas. It later fell into disuse and would likely have ended up being demolished, until Acciona acquired it in 2017.

A retrofit design capitalising on the existing load-bearing structure that supports the pitched steel trusses, has resulted in the transformation of the building, with the retaining of its historic envelope conserving more than 10,000 tonnes of original brick and mitigating the environmental impact.

‘Lightweight structure inserted in the space is made from sustainably sourced timber …’

The lightweight structure inserted inside the space is made from sustainably sourced timber from local forests and allows for spatial flexibility, while lighting, ventilation and other services have been integrated.

Foster + Partners believes that the timber structure, which is recyclable and demountable, will save more than 1600 tonnes of carbon dioxide. A central skylight brings natural light to the interior, reducing the need for artificial lighting, while the glazing features photovoltaic technologies that generate electricity.

Outdoor working

Taking advantage of Madrid’s temperate climate, a new courtyard offers the option to work in comfort outdoors. The courtyard connects to a large 12,400 square-metre park with 350 trees, and it features outdoor working spaces and areas for informal meetings sheltered by a green canopy of trees. Local species have been carefully selected to reduce water consumption.

The new green, public space connects the building with the surrounding community and generates a positive social impact. Located in the lively Arganzuela district, Ombú also benefits from direct access to rail and bus networks, encouraging employees to travel by public transport.

Ecological footprint

Lauded as one of Foster + Partners’ most sustainable projects, the scheme was presented by the firm’s head of sustainability, Chris Trott, as a case study at COP26, in Glasgow, for the World Green Building Council.

Using the concept of ecological footprint, the impact of the project was quantified and improved across all aspects of the development, with its carbon footprint carefully measured and controlled.

The design is said to reduce embodied carbon by 25 per cent when compared with a new build over the whole life of the project, while making allowances for future refurbishment. Furthermore, the operational energy is calculated to be 35 per cent below normal expectations.

In delivering the project, Foster + Partners worked closely with the client and with local design studio Ortiz León architects.

Andrew Sansom is editorial director of SALUS Global Knowledge Exchange. Salus is a content partner of WORKTECH Academy.
Find exclusive content in the


Premium content for Global Partners, Corporate and Community Members.
The latest analysis and commentary on the future of work and workplace in five distinct themes: Research & Insights, Case Studies, Expert Interviews, Trend Publications, and Technology Guides.