How Much Does it Cost to Knock Through a Toilet & Bathroom

Knocking through a separate WC & bathroom into one can make sense for many families. This article deals with the costs involved.

Knocking through?

Please see this article if you are unsure as to whether you should knock through or keep your WC & bathroom separate.

Alternatively keep reading for the costs of combining the two rooms into one.

Introduction to pricing

I have done a fair few WC / bathroom ‘knock through’ installations now and I hope that this article will help you to understand what kind of costs may be involved in this kind of work, and the factors that affect these costs.

In its simplest form costings look like this:

Labour cost is directly related to time taken (or the amount of work required) and the material cost is for things like timber, plasterboard, toilets, basins, radiators etc.

So obviously a simple job with cheaper fittings that takes less time to complete will cost less than a more complicated job that takes more materials and more time to complete.

It sounds simple and thats because it is.

Obviously removing a wall will cost more than not removing it, and it will be up to you to decide whether the benefits are worth the cost, in which case you should refer to my other article on whether you should knock through a WC & bathroom

Hopefully these case studies should help.

Case studies

Case study 1

SUMMARY:       A side by side WC & bathroom combined into 1

Costs incurred that may not always occur:

1. Fully tiled walls generally cost more than partly tiled walls.
   Please see here for more.
2. Reboarding of all the walls was required upon stripping the existing tiles.
   Please see here for more.
3. Fitted bathroom furniture is generally more costly than freestanding units but does help to reduce clutter.
4. Floor tiling is more expensive than vinyl or laminate.

5. P baths are generally slightly more costly than regular baths

Costs not incurred that may in other instances:

1. As suite fittings were to be installed in their current locations (more or less) the cast iron soil pipe outside did not have to be replaced.

Case study 2

SUMMARY:

Costs incurred that may not always occur:

1. Fully tiled walls generally cost more than partly tiled walls.
   Please see here for more.
2. Reboarding of all the walls was required upon stripping the existing tiles.
   Please see here for more.
   
3. Wall hung basins are generally more expensive to install when compared to freestanding units, and LED mirrors with shaver points cost more than plain mirrors that do not have to be wired in.
4. Floor preparation & tiling is more expensive than vinyl or laminate. In this instance long joist spans meant that deflection became an issue for the tiled floor – these had to be strengthened prior to tiling.
5. Tiled in baths are a bit more costly than baths with cheap, flimsy plastic bath panels.

6. Adding an archway was more costly than removing a regular dividing wall which is normally non loadbearing.

7. Good quality fittings are more costly (at least up front) than cheap alternatives.

8. The floor surfaces were not level so had to be levelled prior to tiling.

Costs not incurred that may occur in other instances:

1. There was no soil stack to replace.
2. Labour costs were slightly less as it was a bungalow with easy access.

Case study 3

SUMMARY:       A typical semi detached arrangement of WC & bathroom at the top of the stairs being                             knocked through into one (with a new angled entrance to suit the upstairs layout).

Costs incurred that may not always occur:

1. The fusebox had to be updated to ensure an electrical certificate could be issued.

Costs not incurred that may occur in other instances:

1. No need to replace the soil pipe as it was plastic & new connections could be easily made.
2. Vinyl floor costs less than a tiled equivalent.
3. No walls had to be reboarded prior to tiling or skimming as the old tiled came off easily.

4. Walls were only part tiled.

Case study 4

SUMMARY:       A typical semi detached arrangement of WC & bathroom at the top of the stairs being knocked through into one (with a new square doorway into the space).

Costs incurred that may not always occur:

1. Fully tiled walls generally cost more than partly tiled walls.
   Please see here for more.
2. Reboarding of all the walls was required upon stripping the existing tiles.
   Please see here for more.

3. Separate bath & shower increases material & labour costs

4. High quality combined WC & basin is more costly than stand alone units
5. Taking out an airing cupboard and re-routing all pipes and cables is more costly than not having to do so.

Costs not incurred that may occur in other instances:

1. Similar layout & drainage runs (from the previous facilities) meant that the existing soil pipe could be used without much extra work.

Summary

So you see, there are many variables to consider when determining how much a WC & bathroom ‘knock through’ will cost to fit and hopefully these case studies above will give you some ideas as to where your project lies on the spectrum.

Taking all these examples into account….

You will probably be looking at £5 – 7K to knock through a WC & bathroom and to carry out all of the other necessary work*

* Please do not confuse the costs given here for merely the plumbing costs of putting in a new bathroom suite as plumbing is only one of the several trades involved in a job of this type.

For example, the prices given above typically include several of the following costs in addition to the plumbing costs:

• Waste disposal costs
• Electrical costs – amending light switch positions (as 2 rooms become 1), fitting fans and new lighting, moving alarms & fuse boxes & issuing completion certificates
• Joinery costs – building, insulating & boarding studwork, fitting skirting boards, architraves & hanging doors
• Plastering costs – reboarding & skimming the walls & ceiling is often necessary
• Plumbing costs – fitting the toilet, basin & radiator etc, replacing cast iron soil pipes
• Decoration costs – painting the walls, ceiling & skirting boards, architraves & door
• Floor fitting costs – supplying & fitting vinyl or tiled floors with all necessary floor preparation work
• Wall tiling labour – either partly or fully tiled walls
• Building costs – removing or building walls, inserting doorways, lintels and installing windows
• The bathroom suite – up to £3K of the total prices listed above (cheaper suites available)
• Tile prices – £20/m² x 30m² (for walls & floor as in the examples above) = £600

Get in touch

Due to the many trades that can be involved in projects like this, you would probably be best getting a turnkey supplier such as ukbathroomguru.com to carry out the work so that it is completed in the quickest time possible to limit disruption and to ensure that the project runs smoothly.

We can take projects from a simple plan….

Through the work….

To completion….

With all work done to a high standard in a professional manner.

Give me a call or request a callback by clicking on the red ‘request a free site survey’ button on the site.

Many thanks

Chris