Knocking through a kitchen and dining room creates an open space much more in line with modern living. 20+ years ago it was normal to have a separate dining room to gather as a family and eat meals together whereas today, kitchen diners are far more popular and useful.
Kitchen diners have now become key rooms in the house and often provide the wow factor. Having a friend round for coffee? The kitchen diner is the perfect place for it. Even more formal gatherings like dinner parties are made more enjoyable because it offers a far more sociable experience.

Buyers much prefer this open type of space for cooking and eating and so creating a kitchen diner could add value to the property. Or certainly make it easier to sell.
If you currently have a kitchen and dining room that are separated by a wall and you’re interested in knocking it through, here are some tips and suggestions.
How much does it cost?
One of the main considerations when knocking through a kitchen and dining room is the cost and understandably so. There are a number of costs associated with this project and it’s important to factor them into your budgeting. Prices tend to range from £2000 to £6000 depending on the complexity of the job and your location.
Structural engineer
Approx. £500
A structural engineer will visit your property and listen to what you plan on doing. They will then assess the structure of your house and take measurements so they can calculate loads and work out what will be required to remove the wall.
Some people skip this step either because they didn’t realise it was necessary or because their builder encouraged them to. A structural engineer is a worthwhile investment because they will accurately determine what is needed to support the rest of the house should you be removing supporting walls. A builder will use his experience and knowledge and offer a best guess.
If you ever want to sell your house, the buyers solicitor will almost certainly want to see proof that the correct procedure was followed when knocking down the wall and it could prove to be a problem if the necessary paperwork can’t be shown.
Case study
We decided to knock down the wall between our kitchen and dining room, which also included a small dog leg (see image) which offered the entrance to both rooms. I knew that the dog leg wasn’t supporting any weight and was just a stud wall, so the main job was to remove the load bearing wall separating the kitchen diner.
After shopping around we hired a local structural engineer to come in and give us an idea of what would be required, at a cost of £495. He took a lot of notes and measured both downstairs rooms and upstairs rooms and also had a quick look in the loft to see if and how the roof was resting on the wall.
He confirmed that our idea was well within the realms of possibility and told us he’d be back in touch with guidance and calculations for the beam.
About 2 weeks later, he emailed through his recommendations, including which RSJ to use to hold the rest of the wall up. He noted that because the RSJ would need to sit next to two door openings (the door to the lounge and the kitchen) we’d need a second lintel placed above the entrance to the kitchen resting on a purpose built nib. This would help spread the load across and reduce the stress on the wall the RSJ is landing on.
The steel beam required turned out to be relatively heavy loaded and in technical terms was a 203x133x30kg universal beam (UB). The measurements mean that the beam would need to be 203mm deep with horizontal flanges 133mm wide, weighing 30kg per metre (just over 100kg in total).
Interestingly, not one of the builders I spoke to recommended this sized beam, or the arrangement that the structural engineer designed. In fact some of them told me this was overkill and a smaller beam would suffice.
Hiring a structural engineer is a cost some people don’t account for or try and swerve entirely but I’d strongly recommend hiring one to make sure the project is set out correctly from the start.
Architect
If you’re doing something more complicated than knocking down 1 wall, for example creating an entirely open plan first floor, an architect would be able to advise on design and offer expert advice on creating the most functional and usable space.
Builder
£2000 – £7000
The majority of the project cost will be spent on a builder who will prop up the joists, knock down the wall and install the steel beam.
Choose your builder very carefully and if possible, go off recommendations from people who’ve had the same job completed to a high standard.
Speak to as many as you possibly can to get a good range of prices and to get a feel for whether you get a good vibe from them. If you have engineers drawings, show them the plan and ask them what they think.
Case study
Once we’d had the recommendations through from the structural engineer we immediately got to work finding a builder. The general advice is to speak to family and friends for recommendations but we didn’t do a lot of that! Instead, we looked through sites such as My Builder and Rated People and read through all of the reviews. These sites are great and you can quickly get a feel for the builders that are doing a good job.
We spoke to 6 different builders to tackle the job and to my amazement, the prices ranged from £1500 to £7000. In the end we went with a local builder that had completed hundreds of these knock throughs and does them all day every day. He charged £2500 to knock down the wall, install the steel beam, build a nib and install a concrete lintel over the kitchen door.
He consistently fought with the idea of having to install a beam which was over 100kg and didn’t have a lot of good things to say about structural engineers in general, but he did the job to a very high standard in the end.

Here are some tips when employing a builder to knock through a kitchen diner:
- Get a range of quotes and keep going until you find someone you’re happy with
- Make sure the price includes a skip (most likely 8 ton) to remove the rubble
- Make sure the price includes all materials such as steel beams, bricks, padstones etc.
- Agree upfront that any additional work must be discussed before going ahead (although there shouldn’t be any surprises here
Plasterer
£300 – £1000
Once the steel beam is in place, the builder will have left it clad with plasterboard to adhere to the fire regulations. This will need making good and so a plasterer will be needed to skim the beam and any other areas affected by the building works.
A lot of people completely re-renovate when they do this type of work and so a plaster would be required later on, probably to skim the entire room. If you’re feeling brave you can give plastering a go yourself with some of our tips here.
Decorator
£200 – £500
If you don’t plan on decorating yourself once the knock through is complete, you’ll need a decorator to apply the finishing touches. This is a great area to do some DIY though whether it’s to save some costs or because you have a particular passion for decorating. We have guides to help you whether you are painting the room or choosing to hang wallpaper.
Knocking through a kitchen diner FAQs
Do you need planning permission?
Planning permission is not generally required when knocking through a kitchen diner. If your house is leasehold, you will need to contact the lease owners and ask their permission. Some will have itemised costs for this type of work whereas others are less organised and may just let you get on with it.
How can you tell if a wall is load bearing?
You can get an idea if a wall is load bearing by giving it a good knock in a few different places. If its brick, which would produce a dull sound, it might be a load bearing wall. If the sound is more hollow when you knock, it’s probably a stud wall and it might be possible to remove it without the need of any steel work.
You can also check upstairs and into the loft. Does the wall you wish to remove run all the way up the house? If so, it’s a supporting wall and would need a structural engineer to work out the best way to remove any part of it.
Could you knock through a kitchen diner yourself?
Many people feel competent enough to tackle the building aspect of this type of project and it probably depends on your level of expertise and experience. If you’re completely new to DIY this would be a huge undertaking which could have big consequences if you got it wrong. If you have experience doing this type of project and have all of the different skills needed to complete the job, it’s certainly possible but you will need a helping hand, especially to lift the beam into place.
If you’re in two minds about whether you could take this on or you have big gaps in your knowledge, perhaps get the pros in this time. There’ll almost certainly be another project round the corner you can tackle.