A space designed for human health and well-being


Castellana 81 has taken the necessary steps against COVID-19 required for WELL Health-Safety Rating certification.

The genesis of the WELL Health-Safety Rating was feedback from the International WELL Building Institute’s (IWBI) Task Force on COVID-19, a group of nearly 600 public health experts, virologists, government officials, academics, business leaders, architects, designers, building scientists and real estate professionals, which was established in late March 2020 to support IWBI’s response to the pandemic.

This certification process entails an evidence-based, third-party verified adoption and monitoring of a plan of measures to assure that the operation and maintenance of the building complies with health and safety standards required by the rating in the current COVID-19 global health crisis and in the long term.


Castellana 81 is the first WELL office building in Spain and the fifth building in Europe to obtain the Gold WELL Building Standard in the Core & Shell category.

WELL is the first global certification for buildings focusing solely on human health and well-being and is based on seven years of scientific, medical and architectural research.

WELL certification is an innovative system founded by Delos and managed by the International WELL Building Institute™ (IWBI), set up in 2015. It certifies that the design, construction and operation model of the building addresses health and well-being of persons. It evaluates on site the building’s impacts regarding seven concepts: air, water, light, nourishment, fitness, comfort and mind.


The measures taken to obtain the Gold WELL certification were:

Measures aimed at improving indoor quality:

  • Levels of radon gas in the air far from the values deemed to be hazardous for human health. Measurement performed by Arup and and GBCI (Green Business Certification Inc.).

  • Low presence of volatile substances, particles or inorganic gases. Measurement performed by Aire Limpio, Arup y GBCI (Green Business Certification Inc.).

  • Supply of an outdoor air source that guarantees good indoor air quality, compliant with the global ASHRAE 62 and Spanish RITE standards

  • Filtering of outdoor air in the building via F8 filters in the HVAC system.

  • Promotion of healthy habits for occupants and smoke-free building.

  • Use of products with low volatile organic compound (VOC) content inside the building: paint, cladding, adhesives, sealants, furniture and insulation.

  • Good practices in renovation work performed on the building to improve indoor air quality.

  • Good practices in building maintenance to avoid the use of pesticides and other chemical products.

Measures aimed at improving lighting:

  • Artificial lighting systems with low or zero glare at work stations.
  • Access to natural light and direct outside views for 95% of occupants on office floors.

Measures aimed at improving mental well-being:

  • Promoting health and wellbeing awareness for building occupants, through a digital library accessible to occupants.

Measures aimed at improving nourishment:

  • A regular offer of natural wholegrain foods for occupants, through a vending machine.

  • Healthy nutrition information through messages displayed on the big screen in the lobby.

  • A New canteen for personnel in common areas, with outdoor air and fittings aligned to the WELL standard.

Measures aimed at promoting fitness:

  • Outdoor spaces equipped with benches and other elements that promote activity and interaction among people.
  • Bicycle spaces in car park.
  • Showers and changing rooms provided for users.

Measures aimed at enhancing comfort:

  • Guaranteed accessibility for persons with disabilities, aligned with the Building Technical Code and 5-star DIGA accessibility certification.

  • Outside noise levels in the building below 50 dBA, complying with local regulations and the WELL certification. Measurement performed by Arquilav (a laboratory belonging to Madrid’s Universidad Politécnica), Arup and GBCI (Green Business Certification Inc.).

  • An HVAC system which provides appropriate comfort levels to occupants, following ASHRAE 55 requirements.

Measures aimed at improving water quality:

  • High-quality drinking water at user consumption points, complying with local regulations and WELL requirements. Measurement performed by Arup, Labaqua laboratory and GBCI (Green Business Certification Inc.).