Basements built since 1980


Pooling your leisure ideals

Basement space into leisure space

Der Pool im Untergeschoss


The creation of leisure space is becoming a priority in many self-build projects. The importance of health and well-being are better understood, and Glatthaar Keller are increasingly being asked for sport and wellness space as part of the clients’ basement projects.

The simplest ideas utilise a basement room for home gym or studio, but when the objective is to replicate some of the more luxurious features found in hotels and spas then clients are including saunas, Jacuzzis and indoor swimming pools.
An outdoor swimming pool is the simplest option, but its availability is thwarted by the British weather, limiting use for half of the year. An indoor swimming pool delivers 365 days swimming time but comes with an exceptionally large footprint eating into the available space. A big challenge for prospective self-builders relates to finding a suitable building plot in a desirable area. Unfortunately, this is normally a compromise, where cost, size and plot suitability has to be traded. Therefore, getting smart with the design will deliver against your desired requirements. The relationship between cost size and availability is well understood, and more and more frequently smaller building plots are the only available options. When a building plot is on a slope, the addition of a basement can be seen as an advantage rather than a negative. Digging out the space for the basement and locating the wellness centre aligned to the bottom of the building plot and building the house aligned to the top, provides the wellness centre with access to the garden and a source of natural light. By using sliding glass doors, the indoor pool is seamlessly connected to the garden in summer. Even if the building plot is level, a subterranean terrace or light well can be created allowing natural light into the leisure space.

We have completed several basement swimming pool projects and there are a few things we’ve learnt along the way. Really, the swimming pool should be included as part of the design process right from day one. A litre of water weighs exactly 1 kg and a relatively modest swimming pool has in the region of 15000 litres of water. It is probably a good idea to include some additional strength to support the weight. We make the foundation slab thicker, and include extra reinforcing steel, not something which can really be retrofitted later. All of the elements which make up the swimming pool sit below ground level, which means a standard 2.4 m high room requires the depth of the pool and some extra space for services. We recommend including a double height AquaSafe® basement to house the swimming pool and supporting plant equipment. Finally, if you’re going to create a subterranean level lower than the height of the building plot or the drainage system, extra groundwork planning is needed to make sure any flood risk is mitigated. Fortunately, with a little bit of planning the creation of a wellness centre with swimming pool should not be seen as a huge challenge.


The self-builder Matthias had always intended to include a swimming pool as part of any housing project he undertook. A chance encounter when out on a weekend walk started the process. The building plot, although in a great location, was a slightly awkward shape and it had passed hands several times without any development occurring.  Our client had the vision to see how the project could work. After tracking down the owner and agreeing a sale the project was on. So that most of the garden would not be lost, the swimming pool could only really fit in the basement. While researching possible options the client came across Glatthaar Keller and the idea of the basement swimming pool started to take shape.

“Sometimes I feel a bit like a house technician when I walk through my basement and see the different components in front of me - be it those for the heating or the battery system or those for the swimming pool technology. It's fun to acquire the necessary specialist knowledge and to understand what kind of technology is built in there. Of course, the largest part is made up of the swimming pool with a width of 2.80 m a length of 12 m and a water depth of 1.40 m. In addition to this, we have included a steam bath and a fitness room. There is additional storage space to keep those things that we do not want in the house”. – Matthias

The basement was designed using Glatthaar’s AquaSafe® technology because it has excellent thermal insulation and optimal protection against penetrating moisture, which made it ideal for the spar room environmental conditions. The basement is about 200 m² and is not only used as a wellness area, but also hosts all the building technology. There are four technical areas, pool and control, building and heating systems, as well as the steam bath technology. The building systems contain the Air source heat pump, battery storage of 15 kWh and the control systems for a 13 kw photovoltaic system. The building filter and ventilation technology can also be found here. The pumps for pool filters, counter-current swim systems and whirlpool massages are housed in the crawl space under the swimming pool.


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