Top considerations for an indoor pool

Are you interested in a stand alone indoor pool house or a pool house extension to your home?

Stand alone pool house


  • A space to escape away from the home
  • Typically most cost efficient
  • Can be a focal point of a garden design
  • Can be easy to build under permitted development rights
  • Reduced disruption to your household over the course of the build
  • Separate social hub


  • Distance from the house in poor weather

The Olympic range has four new customisable models to choose from. They vary in size and incorporate different facilities to suit your requirements.

  • Designed to meet Permitted Development criteria*
  • More energy efficient – through improved levels of insulation
  • A selection of green energy options- to further reduce energy consumption and protect the environment
  • Configurable door and window layouts
  • Choice of roof finishes: slate, clay tile or shingle
  • Choices in exterior finish: brick, painted render, horizontal weatherboard, cedar or engineered timber
  • Configurable extension modules. – looking for a little more space to entertain, train or relax
  • Wellbeing options: spa, sauna, steam room, relaxation area, gym or bar

Pool House Extension


  • Your indoor pool becomes another recreational area of your main home
  • Convenient way to incorporate swimming into your everyday life and daily routine
  • Ease of access when the weather is poor


  • Typically increased cost due to materials selection and additional work to existing property
  • More advanced dehumidification systems are essential
  • More disruption during construction
  • Usually requires a formal planning application

Will I need to get planning permission?

For a pool house in your garden it’s more than likely that you won’t need planning permission. In the majority of cases as long as the building you are going to house the pool within is freestanding, complies to the permitted development design criteria and your permitted development rights are in tact - you won’t need it.

Almost without exception, a pool house extension to your home will need planning permission. At Origin, we have a wealth of experience in gaining planning approval for indoor pools in listed buildings, areas of outstanding natural beauty, conservation areas and we’ll also manage the whole process for you so, no need to panic!

Do I start with an architect?

We are fortunate in the UK to have some of the best architects in the world. But specialist architects with working knowledge of an indoor pool environment are very rare. Architects are extremely well versed with domestic construction details, but unfortunately an indoor pool is very different. An architect can provide you with an outline design for an indoor pool, this may cost you anywhere between £1,500 to £3,000 however, many don’t have the knowledge or insurances needed to take that design further. As part of our feasibility study we provide initial design sketches and a budgetary proposal free of charge.


Which aspects of pool design have the biggest impact on cost?

Size is an obvious one, setting your heart on a 25m pool will be a significant investment. The most popular size for an indoor pool is between 8m to 10m, there are also some excellent counter current devices that you swim against making the size of the pool less important.

Covers are an important part of a pool design as they retain heat, reduce running costs and some provide a level of safety. As an example based on a 8m x 4m indoor pool, the following cost comparisons would apply:

Manual Solar Bubble Cover - £1,000 -£1,430 - Poor safety, good heat retention, manual operation.
Semi Automatic Foam Cover - £3,500-£6,000 - Average safety, excellent heat retention, easy to use.
Automatic Slatted Surface Mount Cover - £8,300-£10,700 - Good safety properties, excellent heat retention, very easy to use.
Hidden Automatic Slatted Cover - £18,000-£20,000 - Good safety properties, excellent heat retention, amazing aesthetics, extremely easy to use.
Automatic Safety Cover - £21,400-£23,800 - Highest level of safety properties, excellent heat retention, very easy to use

Condensation and Indoor Pools

Condensation occurs when the temperature of an object (e.g. glass, metal, or even grass) falls below what is known as the dew point temperature for a given relative humidity. This causes water vapour from the atmosphere to condense into water droplets on its surface.

We are all familiar with condensation on a bathroom mirror or a cold drink outdoors in the summer. Now imagine the challenge of 30m² to 40m² of warm water in a pool building on a cold winters day, if your pool company or builder doesn’t understand the effect that water temperature and humidity can have on your pool and pool building, the consequences can be disastrous.


The consequences of high humidity

The consequences of high humidity in poorly designed pool rooms are well documented;

Health issues - High humidity can contribute to health issues, it facilitates the growth of mould and mildew which can irritate respiratory infections. Inhaling or touching mould spores may cause an allergic reaction, such as sneezing, red eyes and skin rash as well as asthma attacks.

Building issues - Humidity can also have effect on the pool building, and if left can have catastrophic results including roof collapse, destructive condensation within the building structure and deterioration of the internal finishes.

How to avoid this:

Building design - The design of your building structure is critical and your architect & builder should be familiar with how a building will perform in such high levels of humidity. The important aspects to remember are:

  • Construction methods – avoid steel structures and cavity walls, timber framed structures are much better suited to a pool environment
  • Roof design - a warm deck roof is essential. If your architects design incorporates a cold deck roof then alarm bells should be ringing!
  • Cold bridging is critical on an indoor pool, this can include extra insulation around the lintels/posts or solid structural members
  • A bespoke design will be needed for dehumidification, air circulation and distribution
  • Material selection for internal finishes - there is a long list of do’s and don’t’s, the right company will guide you through and make the right decisions.

What must an indoor pool design include?

There are the obvious aesthetics around external and internal finishes, building style and colour schemes but there are some far more important aspects which will fundamentally influence the success of a project. Input from an experienced professional will be vital for each area.

Design parameters

How will the pool be used? The design and size of your swimming pool will factor heavily on your answer to this question, some further elements to think about are:

  • Will the pool be used for swimming practice?
  • Or for recreational use?
  • Water temperature?
  • Air temperature?
  • How many hours a day will the pool be uncovered?
  • How many people will be using the pool at once?

These items are the foundation for pool design as all these aspects will have impact on other design considerations further into the project. A pool designed for light family use between 2-4hrs a day will be completely different to one that will be used for regular swimming practice and longer durations.

Pool circulation design

This element of the pool may be hidden from view but this part of the process will keep the water crystal clear all year round.

  • It’s important to remember that any reputable pool company should be a member of SPATA, therefore working to British and European standards and abiding by a specific code of ethics to ensure the design and construction of your swimming pool are the best that they can be.
  • Safety standard audits are put in place so you can be safe in the knowledge your pool has been designed to the latest standards.
  • Temperature, bathing load and turnover are all essential elements to take into account to ensure the pool system is designed correctly.

Tailored dehumidification design

Ever wondered why some pool houses either smell badly of chlorinated pool water or are dripping with condensation - this vital part of the pool process will make or break a project.

  • We talked about the dangers of condensation in your pool house and the damage it can inflict.
  • For every individual project a tailored design should be put in place to take into account the dehumidification load, fresh air introduction, air circulation and distribution.
  • Key parameters and variables which influence the design are pool size, glazed areas and building volumes.

Building design

Planning permission isn’t always necessary to construct indoor pools as buildings which house indoor pools are generally classed as ‘permitted development’, however elements of the design and building will be subject to certain conditions:

  • The building itself must be single storey
  • There are restrictions on roof height that your pool company should be aware of
  • The location of your pool house will need to comply with certain regulations (distance from the house and not be placed at the side of the property)
  • Different regulations will apply if your property is situated near or in a National Park, World Heritage Site, Conservation Area, Greenbelt Land or an Area of Outstanding Natural Beauty.

Choosing the right structural solution for your size of pool and building generally informs the design process with the parameters to ensure the correct insulation values are included. This in turn will provide the necessary information for the right vapour control barrier placement in order to protect the longevity of the building. The buildings applied finishes such as; ceiling, wall and floor finishes will all need to be robustly considered for the pool environment in both a health and safety and aesthetically pleasing sense to make sure the building has an elegant form which is also functional.

All of these components and processes put together may seem overwhelming and restrictive, however if you work with a swimming pool company that has years of experience and a dedicated team of experts who will help you through every step and be there from concept to completion, like Origin, it’s plain sailing.

The team at Origin have 40 years of experience specialising in the construction of indoor pools. We have architects experienced in everything from archaeological requirements through to listed buildings and conservation. Our construction specialists lay down the detailed design for each project to ensure your pool building is trouble free. Having built in excess of 1500 indoor pools it’s safe to say, we know what we’re doing and we’ll be there for you from concept to completion.

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