En-Suite Conversion: Adding a Bathroom to Your London Home
Adding an en-suite increases convenience and property value. Here's everything you need to know about creating one in your London home.
An en-suite bathroom is one of the most requested home improvements in London. It adds convenience, privacy, and property value. But converting bedroom space into a functioning bathroom requires careful planning. Here's our complete guide.
Space Requirements
The minimum practical space for a shower en-suite is approximately 1.5m x 2m (3m²). This accommodates a shower, toilet, and basin in a tight but functional layout. A more comfortable en-suite needs 4-6m², which allows a larger shower and better proportions.
Common space sources:
- Corner of the master bedroom: The most common approach. A stud wall partitions a corner of the bedroom. Works when the bedroom is large enough to lose the space without feeling cramped
- Adjacent cupboard or boxroom: Ideal if available — the bedroom loses no space. Even a cupboard as small as 1.2m x 2m can accommodate a compact WC and basin
- Bedroom reorganisation: Sometimes repositioning the bed and wardrobe reveals usable space that wasn't obvious initially
Plumbing Considerations
The biggest challenge in en-suite conversions is drainage:
- Soil stack proximity: The toilet needs a connection to the soil stack (the main vertical drain pipe). The closer the en-suite is to an existing soil stack, the simpler and cheaper the installation. Maximum recommended distance is approximately 3m with adequate fall.
- Macerator option: If the en-suite is far from the soil stack, a Saniflo-style macerator toilet can pump waste through small-bore pipes. They work reliably but are noisier than standard toilets and add a maintenance consideration.
- Floor void: The shower waste and basin waste need routing through the floor. In houses with accessible floor voids, this is straightforward. In flats with concrete floors, surface-mounted or wall-hung drainage may be needed.
Design Ideas for Small En-Suites
- Wet room layout: Eliminating the shower tray and enclosure saves space and creates a seamless look. The entire floor is tanked and graded to a drain
- Wall-hung fixtures: Wall-hung toilet and basin free up floor space and make cleaning easier
- Pocket or sliding door: A standard door swing takes up valuable floor space. A pocket door (slides into the wall) or sliding door is the space-efficient alternative
- Large-format tiles: Fewer grout lines make small spaces feel larger. A single tile colour on floor and walls enhances the effect
- Glass shower panel: A fixed glass panel (no door) keeps the space visually open while containing water
Costs
| Component | Cost Range |
|---|---|
| Stud wall construction | £300 – £800 |
| Plumbing (first and second fix) | £800 – £2,000 |
| Electrical (lighting, fan, mirror) | £400 – £800 |
| Waterproofing/tanking | £500 – £1,000 |
| Tiling (supply and fit) | £1,200 – £3,000 |
| Fixtures (toilet, basin, shower) | £800 – £3,000 |
| Vanity unit | £300 – £800 |
| Total | £4,300 – £11,400 |
Property Value Impact
An en-suite to the master bedroom typically adds 4-5% to a London property's value. On a £500,000 property, that's £20,000-25,000 of added value — comfortably exceeding the renovation cost. Estate agents consistently list an en-suite as one of the top features buyers look for.
Thinking about adding an en-suite? Get in touch and we'll assess your space and provide a detailed plan.
Frequently Asked Questions
Will adding an en-suite make the bedroom too small?
It depends on the bedroom size. As a rule of thumb, the bedroom should remain at least 10-11m² after the en-suite is taken. We assess proportions carefully and can create 3D layouts to visualise the result before committing.
Do I need planning permission for an en-suite?
Usually no — it's an internal alteration. However, if it involves structural changes (removing load-bearing walls) or affects a listed building, approvals may be needed.
How long does an en-suite conversion take?
Typically 2-3 weeks from start to finish, including stud wall construction, plumbing, electrical, tiling, and fixture installation.
Can I add an en-suite in a flat?
Yes, but drainage can be more complex. Concrete floors may require surface-mounted drainage or a macerator system. We assess the specific requirements during our initial consultation.
2026 Update
Refreshed for 2026. Costs, timelines and lead times change year to year, so treat figures as a guide and ask for a current fixed-price quote. Get yours here.
