Bathroom & Shower Room Design for Granny Annexes
Compact Toilet and Sink Areas
For garden rooms, home offices or man caves, many customers choose a simple toilet and hand basin installation.
These compact cloakroom-style spaces typically include:
• toilet
• small hand basin
• extractor fan
• compact vanity unit
This type of setup is ideal for:
•
garden offices
• leisure rooms
•
man caves
• small garden studios
Because the space requirements are minimal, these installations can fit easily within smaller garden buildings.
Standard Shower Room Layout
A standard shower room is the most common bathroom option installed in granny annexes designed for independent living.
Typical layouts include a shower tray with glass enclosure combined with a toilet and sink.
Common shower tray shapes include:
• square shower trays
• rectangular shower trays
The shower area is normally finished using either:
• aquapanels with waterproof surfaces
• tiled shower walls
A standard annexe shower room usually includes:
• electric shower (8.5kW instantaneous)
• toilet
• sink with vanity unit
• extractor fan
• electric thermostatic towel radiator
This layout provides a practical and comfortable bathroom space within a compact footprint.
Fully Tiled Bathroom Areas
For a more premium finish, some granny annexes include fully tiled bathroom walls and floors.
These bathrooms typically include:
• fully tiled shower area
• tiled floor
• toilet and sink
• vanity storage units
• electric heated towel rail
• extractor ventilation
Fully tiled bathrooms are popular because they are durable, waterproof and easy to maintain.
Wet Room Shower Areas
Wet rooms are becoming increasingly popular in granny annexes because they provide a modern and accessible shower solution.
A wet room usually includes:
• fully waterproof floor and walls
• level access shower area
• floor drainage channel
• glass screen (optional)
Advantages of wet rooms include:
• easy access
• modern appearance
• easier cleaning
• ideal for accessibility
Wet rooms are often recommended for annexes designed for elderly family members or accessibility requirements.
Disabled Access Shower Rooms
Some annexes are designed with accessibility in mind.
Disabled-access bathrooms may include:
• level-access shower areas
• wider door openings
• grab rails
• accessible toilet height
• disabled alarm system (optional)
These features allow annexes to be used comfortably by people with mobility needs.
Although most annexes include showers due to space limitations, it is possible to install a bath when the layout allows.
However, a bath installation typically requires additional space for:
• a hot water cylinder
• additional plumbing
For this reason baths are more common in larger annex layouts.
Hot Water Supply for Annexe Bathrooms
Annexe bathrooms are typically supplied with electric water heating systems.
Common installations include:
• 8.5kW instantaneous electric showers
• Ariston 2.5kW or 3kW water heaters
These systems provide hot water for:
• bathroom sinks
• kitchen sinks
• compact annexe plumbing systems
Using electric water heating is a reliable solution for garden annex buildings where traditional boiler systems are not required.
Proper drainage is esseProper drainage is essential for any annexe bathroom installation.
There are two main drainage methods used in granny annex construction.ntial for any annexe bathroom installation.
Gravity Drainage (Standard System)
Where possible, bathrooms are connected directly to the existing household drainage system using gravity-fed waste pipes.
This is the most common solution and provides reliable wastewater flow from:
• toilets
• sinks
• showers
Gravity drainage works best when the annexe is positioned at a suitable level relative to the main property sewer connection.
Mini Sewage Pump Systems
In situations where gravity drainage is not possible, a small sewage pumping station can be installed.
These systems collect wastewater and pump it to the main sewer connection.
TRJ Construction frequently installs compact systems similar to the Mini Sewage Pumping Station with 5m lift capacity.
These pumps allow annex bathrooms to operate even when the drainage level is lower than the main sewer line.
Advantages include:
• flexible installation location
• reliable waste removal
• suitable for annexes further from the main house
Every bathroom installed in a granny annexe includes proper ventilation and heating.
Typical installations include:
• extractor fans
• electric thermostatic towel radiators
• moisture-resistant materials
These systems help maintain air quality and prevent condensation inside the annexe.
Bathroom Design for Granny Annexes
Every annexe project is different, which is why bathroom layouts are carefully designed to suit the available space and the needs of the homeowner.
Whether installing a compact cloakroom, a modern shower room or an accessible wet room, our goal is to create a bathroom space that is practical, comfortable and easy to maintain.
At TRJ Construction we combine careful planning with quality materials to deliver bathrooms that integrate perfectly with the overall design of the granny annexe.
FAQs
Can a granny annexe include a full bathroom?
Yes. Most granny annexes include a fully functional bathroom or shower room with toilet, sink and shower designed to maximise space while maintaining comfort.
What type of shower is used in a granny annexe?
Most granny annexes use 8.5kW instantaneous electric showers combined with square or rectangular shower trays or wet room systems depending on the layout.
How is drainage connected for a garden annexe bathroom?
Drainage can either be gravity-fed into the main household sewer or use a compact sewage pumping station when gravity drainage is not possible.
Can a granny annexe bathroom be designed as a wet room?
Yes. Wet rooms are a popular option for granny annexes because they provide level-access showers and modern waterproof bathroom designs.
Are accessible bathrooms available for granny annexes?
Yes. Accessible bathrooms can include level-access showers, wider doors, grab rails and optional disabled alarm systems.
Still have a question?
| Bathroom Type | Best for |
|---|---|
| Toilet + sink | garden offices /rooms |
| Standard shower room | annex living |
| Wet room | accessibility |
| Disabled shower room | mobility needs |
Design Your Granny Annexe Bathroom
Our team designs compact and practical bathroom spaces that maximise comfort while making the best use of the available space.
At TRJ Construction Ltd, we carefully plan bathroom and toilet facilities as part of the overall annexe layout. Whether you need a simple toilet and sink for a garden room, a modern shower room, or a fully tiled wet room, we can help create a bathroom that integrates perfectly with the design of your granny annexe while ensuring reliability, comfort and efficient use of space.
