Stakeholders

Designer

Christensen & Co Architects
Michael Christensen

Contractor

Hellerup Byg
-

Other consultancy agency

COWI
Peter Lawaetz
Energy design

Others

Municipality of Copenhagen
Anne Skovbro
Strategic Partner

Others

University of Copenhagen
Lykke Friis
Strategic partner & Building Owner

Contracting method

Public Private Partnership

Owner approach of sustainability

The Green Lighthouse is meant to be a lighthouse in more than one sense. It was built as a green lighthouse for CO2-neutral buildings up to the UN Climate Conference in Copenhagen in 2009 (COP15); it as meant as a lighthouse for efficient public-private cooperation; and last, but not least, it stands as a lighthouse for the Faculty of Science at the University of Copenhagen, which will see its student services consolidated under one roof.

Every element in Green Lighthouse was chosen for its energy efficiency and for the well-being of those working in and visiting the building. An open, inviting space that is full of natural light, Green Lighthouse certainly stands out amongst the traditional buildings in the neighbourhood.

Architectural description

A round, sculptural building, Green Lighthouse features high ceilings and an open, spacious floorplan. It is designed in a way that reduces energy consumption by 70 % utilising renewable energy, natural ventilation and light – and with a highly efficient climate envelope. Its circular form ensures the inner atrium is awash in uplifting natural light from the roof’s many roof windows. The central space is also crucial in terms of ventilation as fresh air from the façade windows is channelled through the atrium before it leaves through the room’s roof windows.

The sun is the building’s main energy source, providing passive solar gain, hot water and electricity. Efficient windows minimise the heat loss while maximising passive solar gain. Green Lighthouse’s angled roof plays an active role in the building’s energy profile. It acts as a power plant, capturing the sun’s energy using both solar panels and solar cells.

The façade is made from Swissfiber, a 30 % glass, 70 % polymer composite material that is extremely light and strong. In fact, the entire façade weighs only six tonnes. By comparison, a similar solution in tile would have weighed more than 175 tonnes and been considerably thicker.

A solar clock motive for the shape of the building, the renewable energy sourcing and the integrated art piece

If you had to do it again?

We commissioned the first year into the turnkey contract, this was a good experience. For next projects, it should be commissioned for 3-5 years.

Building users opinion

Very good indoor climate, cf interviews made for "Green Buildings Pay" book written by Brian Edwards & Emanuele Naboni, ed. 3, Routledge

Energy consumption

• Primary energy need : 3 kWhpe/m².year
• Primary energy need for standard building : 60 kWhpe/m².year

Other

Breakdown for energy consumption :

14 heating;
8 lighting;
5 ventilation;
3 hot water;
27 production - solar thermal & PV

Envelope performance

• Envelope U-Value : 0 W.m^-2.K^-1
More information :

prefabricated; thermoactive slabs ground and first floor

• Building Compactness Coefficient : 1

EN 13829 - n50 » (en 1/h-1)

• Air Tightness Value : 1
 report from COWI consultants

Real final energy consumption

44

2 010

Systems

Heating system :
• Urban network
• Heat pump
• Others
• Solar thermal
Hot water system :
• Urban network
• Heat pump
• Solar Thermal
Cooling system :
• Solar cooling
Ventilation system :
• Natural ventilation
• Double flow heat exchanger
 WindowMaster control system

Renewable systems :
• Solar photovoltaic
• Solar Thermal
• Energy recovery from waste
• Renewable energy production : 90 %
 district heating in CPH is partly carbon-neutral


heat pump from Sorttech, fluid/fluid, connected to the grid, and to a seasonal storage

Solutions enhancing nature free gains : heat pump COP 1,6 on district heating

Smart Building

BMS :

Window Master system combined with BMS classic

Easy and adaptive - works from every work station

GHG emissions

Indoor Air quality

Based on the relative comfort principle, according to EN 15 251. User is connected to outdoors visually, and also in terms of comfort. During winter, the IAQ is stable based on mechanical ventilation and heat exchange, during summer the users enjoy natural ventilation, combined with night cooling.

Health & Comfort

The architectural concept of the house is the sun dial; the house follows the sun, also by its window design, where the facade windows and exterior sunscreening follow the path of the sun. The users can follow the seasons changing, and adapt the indoor climate individually. The house is flooded with daylight on all floors, and there is a "cathedral effect" through the central atrium, where users benefit from a 2500+ lux experience, to benefit their well-being and productivity.

Calculated indoor CO2 concentration : 700 ppm

Measured indoor CO2 concentration : 650 ppm in average

Calculated thermal comfort : Class 2 in EN 15251

Product

Heat pump and seasonal storage and district heating in combination

heat pump designed for solar cooling, used reverse; taking in hot water from the roof - solar thermal, by use of seasonal storage from summer to winter, and then adding the district heating. http://www.sortech.de/en/

worked well - only few problems with vacuum

Construction and exploitation costs

• Cost of studies : 50 000 €
• Total cost of the building : 5 000 000 €

Energy bill

• Forecasted energy bill/year : 2 000 €

Real energy cost/m2 : 2.11

Real energy cost/Work station : 54.05

Urban environment

High density, inner urban Copenhagen

Land plot area

1 000 m²

Built-up area

20 %

Parking spaces

20 spaces

Building Environmental Quality