A side return extension is one of the most effective ways to provide extra space in an older property, but homeowners often overlook one powerful addition when they plan the extension – a well-designed toilet or bathroom. Incorporating either in your designs can boost convenience and enhance your family’s comfort.
Planning a side return extension? This guide explains how to design a functional and attractive WC that will fit seamlessly into your modern side return extension. We discuss layout options, utility integration and the latest design ideas for 2026.
Why Should I Include a WC in a Side Return Extension?
Adding a WC to your side return extension plans brings several long-term benefits to your family. With a growing family, an extra toilet will reduce the morning queue for the bathroom and improve the ease of daily routines.
- A downstairs WC is practical if you entertain, as it keeps visitors away from your private family areas.
- A downstairs WC is easily accessible by children, older family members, and those with mobility problems.
- Adding a downstairs WC to your extension adds value to your home too, as house buyers look for multiple bathrooms/ toilets.
Minimum Space and Layout Considerations
A well-planned layout is essential when adding a WC to a side-return extension, especially in compact spaces.
1. Building Control Requirements
Exact minimum measurements do vary with the different local authorities, and when you are at the planning stage, it is best to check with your local authority. The minimum size that comfortably accommodates a WC is 800 mm x 1400 mm.
To meet with building control approval, there must be adequate circulation space and good door clearance so that it opens easily.
2. Where to Place a WC in Your Extension
There are several ideal places to locate a new WC when planning your side return extension.
- Under the stairs, this is a great way to use wasted space.
- At the back of the extension, this provides ease of ventilation
- Within the utility area, efficient plumbing is easy to achieve.
3. Layout Options
Each layout offers a different way to use the space effectively:
- Straight layout: The toilet and basin can be aligned lengthways, which is ideal for compact layouts.
- L-Shaped layout: Fixtures are placed around corners to maximise floor area
- Integrated WC and Utility: This is a combined room with a zone for appliances and another for toilet facilities.
How to Work Around Obstacles
Consider how to manage any problems you may have well in advance so that the new WC is as practical as possible. These can include:
- Think about where pipes need to be located
- Low head heights
- Narrow corridors
- Adequate ventilation requirements
- Restrictions for the WC door- it should open easily and widely.
Choosing the Right WC Fixtures
Selecting the correct fixtures is essential when dealing with confined spaces, as they really can make all the difference when you are trying to maximise floor space.
Space-Saving Toilet Options
These options reduce bulk and keep the room streamlined.
- Slimline toilets to reduce projection.
- Wall-hung toilets save floor space, are minimalist and are easier to keep clean.
- Concealed cisterns help to streamline the room visually.
Clever Basin Options
Compact basins free up space in tight layouts.
- Corner basins make good use of tight corners.
- Wall-mounted sinks free up valuable floor space.
- Small rectangular basins are perfect for sleek modern lines.
Good Storage Ideas
Smart storage keeps essentials tidy without crowding the room.
- Floating shelves are versatile for storage and don’t make the room look smaller.
- Narrow-depth cabinets offer storage but maintain floor/ wall space.
- Recessed niches can be adapted to store spare toilet rolls and cleaning products.
Modern Features for new WCs
These modern additions enhance efficiency and hygiene.
- Dual-flush eco systems for toilets.
- Anti-bacterial coatings.
- Soft toilet seats for extra comfort, especially for older family members.
- Minimalist, easy-wipe designs for easy cleaning.
Utility Room Integration
Part of a side return extension is often designated to be a utility space, and this can be successfully combined with the addition of an extra toilet.
Planning this as the location for a new WC brings benefits as it frees up valuable space elsewhere and ensures that the utility space is truly multi-purpose.
Smart Use of the Utility Space
Simple planning helps appliances and storage fit efficiently into the layout.
- A washing machine can be stored side by side or stacked
- A drying area can be created with pull-out clothes racks.
- Storage facilities can be created for household appliances and cleaning products.
Ventilation and Lighting
Good airflow and bright lighting are essential for comfort and hygiene.
- Good natural ventilation or efficient extractor fans are needed for combined WC/utility rooms
- LED lighting helps to brighten any areas lacking in good natural daylight and is essential for night-time use of the toilet.
Space Optimisation
Light colours, mirrors and slim fixtures make the combined space feel larger and more open.
- Use mirrors to enhance light and space.
- Pale colour palettes brighten narrow rooms and create a feeling of space.
- Incorporate glass or opening shelving for an airy feeling.
- Underfloor heating, a slim radiator, or towel rails all maximise floor space.
- Use floating shelving, as this keeps the floor area clear.
2026 Design Trends
These are proven and tested design ideas that help to create a beautiful downstairs toilet that feels welcoming and surprisingly spacious.
- Use clean and minimalist contemporary lines
- Choose natural calming fabric and paints
- Opt for multi-functional fixtures and fittings.
- Subtle mood lighting helps to give the room a spa-like quality.
Practical Tips and Checklist
Once you have decided to create a downstairs WC in your new side-return extension, check these points before proceeding:
- Determine who will use the WC (children, elderly or guests).
- Choose the optimal location and layout based on space and current plumbing.
- Select toilet and sink models designed for small rooms to maximise space.
- Decide whether to integrate or locate the WC close to the utility room.
- Plan for efficient ventilation, lighting and heating.
- Ensure door widths and circulation areas meet accessibility considerations.
- Future-proof your design by choosing durable, easy-clean fixtures.
Including a new toilet in your new side return extension is a clever way to streamline family living and increase property value.
With the right layout, fixtures and storage solutions, even the tightest space can become an efficient and stylish new WC. This will make a great addition to your home and complement your new extension perfectly.
If you are ready to update your bathroom or need expert advice on layout, fixtures and finishes, we are here to help. Contact us today for personalised advice and support that will bring your renovation plans to life.
- BuildTeam, 342 Clapham Road, London SW99AJ. Telephone 020 7495 6561
