
Sønderborg
Alsik Hotel & Spa
4-star development on Sønderborg’s waterfront
Sønderborg Municipality’s vision for its waterfront has been kick-started with construction of a 19-storey hotel. This is an important step towards transforming the waterfront into a vibrant and attractive district with homes, offices and urban spaces for activities.
Sweco served as a sub-consultant to turnkey contractor A. Enggaard A/S, and designed and supervised structures, electrical and HVAC installations, acoustics, fire protection, water treatment and geoengineering.
- Location
- Sønderborg
- Status
- Realised in 2019
- Developer
- Bitten og Mads Clausen Fond
- Client
- A. Enggaard A/S
- Area
- 24.800 m²
- Services
- Consultant engineer for all engineering disciplines and advisor on sustainability and water treatment
- Advisory role
- Consultant engineer to turnkey contractor
- Architect
- Henning Larsen Architects
- Sustainable Development Goals
- 3, 6, 7, 9, 11 og 13
Scandinavia’s largest spa
Alsik Hotel & Spa contains the largest Spa & Wellness centre in the Nordic region – about 4,500 m² in size – spread over four floors. The spa area includes four indoor pools (Main pool, Children’s pool, Hot tub and Watsu pool) as well as an outdoor heated pool.
Energy optimisation and sustainability
Alsik Hotel & Spa is designed based on Sønderborg Municipality’s ‘Project Zero’ strategy, with the aim of being energy neutral by 2029. As engineers, we have therefore worked closely with the architect and contractor in an integrated design process, with a focus on ensuring energy optimisation and sustainability.
We have sought to exploit the inherent passive characteristics in the architecture to achieve a healthy and energy efficient building. For example, the facade has been optimised in relation to function, orientation, external climate (sun and wind), and indoor climate and energy. Sun screening has been completely avoided by using the shading effects of the vertical projections on the facade. The ‘shadows’ in the facade and the building’s structure have been designed in a multidisciplinary process, which focused on reducing energy demand, optimising indoor climate and high quality architectural expression.
A number of sustainability initiatives have been implemented at Alsik Hotel & Spa, and life cycle analyses and energy calculations have been performed. Effort has also been made to reduce energy and resource consumption. A number of advanced technical and sustainable solutions have been incorporated, such as using surplus heat from the cooling systems to heat domestic water.
All technical installations such as ventilation, heating, domestic water and lighting are controlled via the SCADA system, so that the technical systems only run when needed. The booking system is also integrated into the SCADA system, so that heating and cooling are only active in hotel rooms when they are in use.


Energy optimisation and sustainability
Upon opening, the Alsik Hotel & Spa had achieved 76% carbon neutrality, which is high for a building that includes spa areas.