What are kitchen corner posts and why are they needed?


When constructing a kitchen, you can never butt up units that meet in a corner, right up to each other, as you will have problems opening doors or with doors hitting handles and getting damaged. That’s where corner post comes into effect.

The solution to this issue is to fit corner posts in each corner where the units go off at right angles. For example, if you had an L shape kitchen then you would have just the one corner post, if you had a U shape kitchen then you would have 2 corners posts, as shown in the diagrams below.

Kitchen Corner Posts

How big should the corner posts be?

We recommend that your corner post should be at least 40mm x 40mm, although this can increase or decrease depending on the kitchen that you choose to fit. Considerations that will affect the size of the corner posts are:

  • The size of the handles and how far the protrude from the doors
  • Appliance doors that open downwards
  • Door thicknesses

All the corner posts that we sell come in 2 sizes:

  • 720mm high by 100mm wide (Cabinet Material)
  • 715mm high by 70mm wide (Door Material)

to be cut down as necessary to exactly fit the gap that is left between the units. You can see an example of a base corner post here.

Here is an example of a corner post being fitted.  Corner posts can also be constructed from leftover door material, as used in this example.

Fitted Corner Post

As you can see in the image above, enough clearance has been given so that when the door is opened, the handle will not collide with the approaching door.

Moving the blanking panel on the corner unit

If you are buying all the pieces required (unit & corner post) then the blanking panel on the corner unit would need “moving” backwards. This is done by undoing the 4 screws that hold the blanking panel on and moving it back as required. (See above image and you can see why a service void is needed to accommodate this as the end of the panel goes into the free space).

Read What is a kitchen unit service void for more information on service voids.

Once the  blanking panel has been moved backwards, this allows you to fit in a corner post like the one shown on the page below (Some of these corner posts do come as 2 separate pieces of material that are fitted together to create the right angled corner post).

When you have the units and corner post in position, you then butt the  blanking panel back up to the corner post and screw it back in.

Remember, corner units have the blanking panel attached from the inside with 4 screws. This panel is removed and refitted once the corner post is in position.

How not to fit a corner post

The image below shows a corner post that has been fitted but only 1 side of it has been done. Although the door on the left opens, there is only a small 2mm gap between the door and the front of the door on the right. This corner post causes your kitchen to lose symmetry as well as the possibility of trapping your fingers as the door is closed and banging your knees as you have to stand out of the way to actually open this cupboard.

Ideally the handle on this door should really be placed on the other side to allow for easier access.

Bad Corner Post

Straight Corner Base Unit Planning Tips

This is a short kitchen planning video, which explains how to plan your kitchen with a straight corner unit. The video also covers corner posts and service voids, which are essential in the planning of your kitchen, as they all take up space in your kitchen run.


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52 thoughts on “What are kitchen corner posts and why are they needed?”
  • Matthew Robertson says:

    High line corner units have a hinge post and a blanking panel making fitting the 100mm cornee post a simple case of moving the blanking panel. However I have received my kitchen yesterday which includes a 2150 tall corner unitbut the 4 hinges are mounted on the blanking panel making it impossible to fit the supplied full hight corner post flush with the door and fitting it on top of the blanking panel will increase the overall length and kitchen will not fit in. What am I not seeing, what is the average diy fitter supposed to do please.

    July 11, 2024 at 10:42 pm
    • DIY Kitchens says:

      Hi Matthew, the tall corner larders, work the same was as the corner wall units. With these particular units, the fitter would need to set back the blanking panel and then install the corner post. The base plates would then need to be transferred from the blanking panel and fitted to the corner post. Our telephone support team will be able to offer further advice if needed.

      July 15, 2024 at 2:30 pm
  • Fab says:

    Could you do 2 x 150mm open face units (wine rack) instead of a corner piece?

    October 28, 2022 at 8:15 pm
    • DIY Kitchens says:

      Hi, there is nothing stopping you using a small unit in the corner, instead of a corner post. Some people use tray space units there to really maximise the storage space in the kitchen.

      October 31, 2022 at 10:03 am
  • Jamie says:

    There doesn’t seem to be any blanking panel or brackets in the corner post that arrived with my kitchen, just 2 720mm filler pieces. Is this correct? If so what is the best way of fitting the 2 pieces together? Should there have been brackets or do I cut one to size and then screw through from the other?

    November 13, 2021 at 12:28 am
    • DIY Kitchens says:

      Hi, the blanking panel is attached to the corner base unit. A corner post is created on site and attached to your units as you see fit. People tend to use modesty blocks (example here).

      The filler panels should be the same height as the doors and the plinth is then returned at the bottom to cover any gap. The recommend size for a corner post is 70mm x 70mm (outside measurement, example here). If you need any further advice with this then our aftersales team will be able to help on 01977 608 418.

      November 15, 2021 at 10:03 am
  • Astrid says:

    How do I fit the two corner post pieces? There are no screw holes. Do I glue one to the standard corner unit? How will the other one be fitted?

    October 27, 2021 at 5:42 pm
    • DIY Kitchens says:

      Hi, the corner posts are supplied in two separate 100mm pieces to be cut and mitered into an L shape corner post. The size of the corner post depends on the layout of the kitchen but the standard size is 70 x 70. In order to fix the two pieces together, we would recommend them to be screwed together through the back and then use modesty blocks to fix them to the units (example here).

      October 28, 2021 at 1:55 pm
  • Elena says:

    I need a 50mm corner post – can Luca corner posts be easily cut down to this size? will this work even with the gloss finish?

    April 18, 2021 at 12:02 am
    • DIY Kitchens says:

      Hi, the Luca corner posts are pre-formed meaning they arrive as a full piece, already pre-mitered. If you need to make modifications then we would recommend purchasing a door and cutting this down on-site, to form the corner post to the dimensions you require.

      April 19, 2021 at 4:30 pm
  • agnieszka says:

    Buying L shape corner unit , do I need corner posts as well?
    also, I wonder if the unit dimension are 900 x 900 what accrual space we need to fit it ?

    February 2, 2020 at 2:18 pm
    • Diy Kitchens says:

      Hi, no corner post is needed with an L-shaped unit. When you fit a 900×900 unit in the corner, it will stick out 900mm exactly, on each of the 2 walls it butts up against.

      February 3, 2020 at 1:03 pm
  • James D says:


    Does a corner post always consist of two 70mm pieces for a Malton bespoke corner unit which are included or do I need to get separately?


    April 30, 2018 at 12:19 am
    • Diy Kitchens says:

      Hi James, corner posts are supplied with all our corner base units. The Malton corner post measures (715 x 70 x 20mm).

      April 30, 2018 at 6:25 am
  • Dave Gibson says:

    Hi – just planning our kitchen now and wish to have an ICBU-PWS internal curved unit in the corner of our kitchen (very similar to the layout on the front page of your kitchen planner pdf).
    Can you advise whether corner posts are required with this? Im assuming not as there is no corner as such since it is taken up by the curved door?

    March 28, 2018 at 9:16 pm
    • Diy Kitchens says:

      Hi Dave, no corner post is needed with these types of units as the door curves around the area where a corner post would sit.

      March 29, 2018 at 8:27 am
  • Adam Scott says:


    I’m almost at the ordering stage but one question:

    We are having a 950 mm LeMans unit in one corner. Next to that there is approx. 110 mm space before the integrated dishwasher space. We were originally thinking of having a 100 mm corner post and setting the units off the wall by 10 mm.

    If instead I put in a 100 mm open base unit (BT10-30) then would I still need a full corner post or could I get away with only one side of a corner post? I can’t see that the 100 mm open unit could cause any issues with the Lemans drawer (though might affect the look).

    Many thanks,


    February 14, 2018 at 1:32 pm
    • Diy Kitchens says:

      Hi, good question. I’ve not seen a kitchen with a 100mm open tray space in the corner but it technically it would work. You just need half a corner post the other side, so that the door can open without clashing onto the corner unit but in principle it will work.

      Depending on your carcase colour and door colour, you may want to bring the open unit forward so that it lines up with the doors. Obviously, this may look a little strange if you have a white matt carcase and a white gloss door.

      February 14, 2018 at 2:00 pm
  • Steven Shipton says:

    Hi, I’m planning an L-shaped bespoke painted kitchen. What material should I choose for the corner post in that case to match the painted doors?

    November 13, 2017 at 2:12 pm
  • Ian says:

    I understand the principle of the “corner post”, but I cannot understand why the corner unit blanking plate requires “moving backwards” by 10mm.

    Can you clarify this requirement please.

    August 3, 2017 at 8:43 am
    • Diy Kitchens says:

      Hi, the blanking panel, in unit material is there to prevent items from falling out of the unit. When you use a corner post, the blanking panel needs taking off and pushing backwards to give space for the corner post to fit into. Once you have the corner post in position, you can then reattach the blanking panel. The 2nd image on the page above shows this. The 2 pieces with the light tops are the corner post being created. The dark bit is where the blanking panel has been pushed back. The amount you move the blanking panel back by will differ depending on the size of the corner post.

      August 3, 2017 at 9:02 am
  • Sara says:


    When fitting a 600 mm corner wall unit with a blank panel, do you need a corner post? I see with the base corner units the corner post is automatically added but they don’t for the wall unit, nor does the planner cut out of the corner wall unit show a void to allow for the post? Does the other wall unit which fits perpendicular to the wall unit with the blank simple fix to the blank?

    Thank you

    May 5, 2017 at 4:23 pm
    • Diy Kitchens says:

      Hi, a 30mm filler is required for the unit to correctly match a corner base unit with a corner post. We would advise either using pelmet or a cut down door to create the door finished filler.

      May 7, 2017 at 8:05 pm
  • brian heslop says:

    we have ordered an inframe kitchen with corner posts but the hinges for both of the highline units are hinged in the corner, hence the handles are not being obstructed. Do we need the corner posts, or will the width of the inframe be enough ?

    March 1, 2017 at 8:25 pm
    • Diy Kitchens says:

      Hi, when ordering a straight corner unit, you always need a corner post.

      March 2, 2017 at 9:19 am
  • Andrew Knight says:


    The end wall of my U-shaped kitchen is 2360mm wide. I am hoping to fit two Le Mans units in the corners, and a central 600mm oven unit with two 300mm units (with doors), one either side. This adds up to 2320mm leaving only 40mm in total for corner posts. As I don’t have any drawers nearby for opening doors to interfere with, would I be ok to cut the corner posts down to 20mm by 70mm?

    February 14, 2016 at 10:13 pm
    • Diy Kitchens says:

      Hi, it is really hard to answer this without seeing a plan/sketch of the kitchen. If you can send your plan/sketch with your question on a support ticket below then the sales team will be able to have a look at it for you and get back to you.


      February 16, 2016 at 7:43 am
  • lucas says:

    Hi there, I’ve got all units, but struggling with corner posts.
    Should they be leveled with door units, or with base units?

    I do understand that one post goes in the gap which appears when blanking panel is moved,

    I don’t understand which to make the second right. Level it with the doors? or not?

    December 10, 2015 at 3:50 pm
    • Diy Kitchens says:


      The corner post goes level with the doors.

      December 11, 2015 at 8:27 am
  • Kingsley Robbins says:

    Hi, please could you advise if it is possible to purchase a corner post for your 900mm tall wall units. If not, what is the best way to make one up.

    Many thanks.

    November 19, 2015 at 5:18 pm
    • Diy Kitchens says:


      Sorry but there are no corner posts available in that height, you can order an end panel or an extra length of plinth to create one.

      November 20, 2015 at 10:14 am
  • Lydia says:

    I am fitting a hob into the corner using diagonal 900 x 900 corner unit next to a dishwasher on one side and a pull out larder on the other. Do I need to use fillers to allow the door to open, and if so, what type of filler and are they needed on both sides of the unit.

    July 16, 2015 at 9:46 am
    • Diy Kitchens says:

      We would advise using a 22 degree corner post but it would be dependent on the kitchen style as to whether this can be made for you.

      July 16, 2015 at 9:47 am
  • Ray says:

    I’m planning on fitting a Luca Matt White kitchen and have a question regarding the corner post. I know that the corner post in door material comes in at around 700mm by 700mm but the space that I have to fill will be 400×400. Is it ok to cut this corner post down to size as it looks like it’s pre made and stuck together at 90 degrees already? If I did cut it to size, how would I get the outside edges white again as I imagine the wooden interior of the post would show through?

    May 28, 2015 at 11:09 am
    • Diy Kitchens says:

      Hi, you are correct the corner posts are already joined. You can order some touch up paint to fix this issue, just add this in the comments section at the checkout.

      May 28, 2015 at 11:10 am
  • Shana says:

    Hi there,
    On your Downloadable kitchen planner the voids are 130mm while on the above picture they are 100mm. Does that mean we can allow a void between those mesures?

    May 12, 2015 at 11:25 am
    • Diy Kitchens says:

      The minimum service void that we used to recommend was 100mm, that would give a corner post of 40mm. But, we have since updated our recommendation to leaving a service void of 130mm to give a corner post of 70mm to ensure that handles on doors do not clatter when opened. The corner post can then shorten if necessary to allow the kitchen run to fit from left to right.

      May 18, 2015 at 11:06 am
      • lucas says:

        I prepared 100mm service void for 1000mm corner unit and It is NOT possible to get 40mm space. Once I moved the unit to 120mm I got it. Unless Im doing something wrong, and corners should be attached to line up doors, not units…
        Im confused!

        December 11, 2015 at 1:23 am
      • Diy Kitchens says:


        The service void will grow and contract based on the space that you have available in your kitchen run. The corner post is then cut down to suit.

        December 11, 2015 at 8:40 am
  • Michael Holt says:

    I am doing a makeover of my kitchen units, already got the tops, and now changing all the doors to a different colour (white). As the blanking panel on my base unit is same colour as the doors now ( wood effect) will I able to get a white blanking panel without buying a base unit?

    December 10, 2014 at 7:09 pm
  • bob cavendish says:

    When fitting a 1000 base corner unit I need to leave a 100mm void at the corner (so effectively a 1100mm unit) so how can the 1000mm wall unit that is to be fitted above the corner unit be made to line up so wall and base doors line up vertically unless a 100mm filler piece is attached to the side of the wall unit going to the corner ? Have I answered my own question ? Bob.

    September 17, 2014 at 7:27 pm
    • Diy Kitchens says:


      A good question. Hopefully the page below will answer your question.

      You may also find this page useful as well.

      September 18, 2014 at 1:57 pm
      • bob cavendish says:

        Hi, that’s a great help and had I looked harder would have found these answers were already available. Its going to be tight as the width of the kitchen is 1782mm and with the 600 and 1000 wall units plus a 150mm wine rack allowing 30mm for corner post will leave me 2mm. Walls are never plumb in an old cottage is there any way I can squeeze a few mm in my favour on the corner post ? If not will have to scrap the wine rack and infill the difference. Thanks for your prompt reply to my original question. Bob.

        September 19, 2014 at 7:57 pm
      • Diy Kitchens says:


        A good kitchen fitter can usually make things fit but I would be unable to comment as to whether you should remove the 150mm wine rack. It might be a good idea to get your kitchen fitter to have a look inside the kitchen first and see what they think to be 100% sure. Apologies that I could not help you any further.

        September 22, 2014 at 9:08 am
  • Graham Hobson says:

    As the blanking panel on a corner base needs to be “moved backwards” to fit the corner post, and then screwed back in after the corner post is fitted do I need to order a Corner Base ‘dry assembled’ or is the blanking panel already fitted without glue?

    August 31, 2014 at 6:11 pm
    • Diy Kitchens says:

      Hi, the blanking panel is just screwed in, no glue.

      September 1, 2014 at 8:40 am
  • Matt says:


    I am looking at ordering a kitchen but have a question about the corner posts. It looks like we are 15mm short of being able to fit a 70mm Door material corner post. It says above:

    715mm high by 70mm wide (Door Material)
    to be cut down as necessary to exactly fit the gap that is left between the units.

    How do you cut this down without leaving a rough edge? Do they come in 2 pieces of door material that you cut down then screw together in an L shape? Would I be better off buying another door and cutting that down instead to make a corner post?


    May 3, 2014 at 4:22 pm
    • Diy Kitchens says:


      The corner post comes in two pieces, so that you can cut them to size and hide any rough edges so that they face inwards and will never been seen.

      May 6, 2014 at 9:48 am
  • George Gibbins says:

    I’ve a technical question regarding corner posts that I hope you can assist me with.

    I’ve been trying to measure up my kitchen but always get stuck when it comes to how much clearance to leave for the corner post. After researching this on your site and visiting many stores. I’m trying to find out if I have understood this correctly, so that I can size up and order a kitchen.
    If I have understood it correctly; fitting a corner post is to facilitate the easy opening of doors on both sides of a corner, allowing for handles etc, so these will determine the actual size of the post.
    Secondly, the corner post can be made up to be the same colour and flush with the carcase doors or it can be the carcase colour and flush with the carcase, am I correct?
    The reason for my question is, I have been measuring up using your 900 highline base unit and I noticed that it has a 400mm door and a fixed 500mm panel.
    Would the 500mm panel require reducing so that one side of the corner post would be flush with the 400mm door?
    Maybe I’m just not seeing it, but it would appear that this would be the only way that the corner post (when made up), would be flush with the 400mm door.Obviously if this is the case then I would have to order a dry assembled carcase.
    I’m afraid this issue has had me puzzled for some time and when viewing your diagram showing the side and service void. It appears that one section of the corner post is set into the corner carcase, therefore this would require the fixed panel to be reduced.

    Many thanks for any assistance you can give me on this subject.


    January 15, 2014 at 6:14 pm
    • Diy Kitchens says:


      I’ll try answer each individual question separately.

      (1) You are correct that the corner post is needed to facilitate the opening of doors in the corner area and at least 4cm is recommended for the corner post.

      (2) The corner post can be made of carcase or door material if they are both a similar match. If you were having a high gloss door on your kitchen units then you would need to use door material for your corner post so that the post blends in.

      (3) A very, very good question as there is more than one way of making a corner post.

      The page below shows an example where 2 parts of the corner post were hand cut from door material and the 500mm panel set back to accommodate the 2 cut pieces, which might be confusing matters for you.


      If you are buying all the pieces required (unit & corner post) then the 500mm blanking panel on the 900mm unit would need “moving” backwards. This is done by undoing the 4 screws that hold the blanking panel on and moving it back as required. (See above image and you can see why a service void is needed to accommodate this).

      Once the 500mm blanking panel has been moved backwards, this allows you to fit in a corner post like the one shown on the page below (Some of these corner posts do come as 2 separate pieces of material that are fitted together to create the right angled corner post).


      When you have the units and corner post in position, you then butt the 500mm blanking panel back up to the corner post and screw it back in.

      I hope this makes things a little clearer. It racked my brains a little thinking about this one!

      January 16, 2014 at 9:03 am
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