Guest Post: How To Measure And Install Perfect Fit Venetian Blinds*

A few years ago, my brother-in-law showed me and my fiance his new Perfect Fit bathroom blinds and we instantly fell in love.  We didn’t need any at the time and had no idea what they were called or where to get them.  And after four years of not knowing what to do with our not-so-pretty loft dormer conversion, our neighbours suggested that if we just paint the roof tiles using Sandtex masonry chestnut gloss, it would look fine.

I’ll give you a hint, this dormer is one of the main reasons we were able to buy it at an affordable price.  So we did a little test with a tile sample and loved it.  It’s not something we’d considered before, and then went on to photoshop to superimpose some white double glazing to match the house and everything looked instantly better.

If we could pull this off, it would save us from paying a builder 20k to 30k to have it altered or put on the back and here’s what the result looked like below.

Before and After


Notice that our new double glazing matched the rest of the windows.  Originally we had a few companies give us quotes for the same window design in he dormer.  It looked great on paper drawings, but I’m so relieved we also used photoshop to mock them up too.

They just didn’t look right, so instead, we asked for them to match the rest of the house.  So now we were happy with them, there was just one problem we had with our newly decorated room.  It was an unbearably hot sun trap and as this is our new entertainment room, it was insufferable in there, but I didn’t want to put just any old blind up and drill or screw in to our new framework if I could help it.

So after much consideration, we decided to seek out the blind we saw in our Brother in law’s bathroom again.  And now we discovered they were called Perfect Fit Blinds.

So what are perfect fit blinds and how do they work?

Perfect Fit blinds are an integrated blind that clips to your existing double glazed window frame, providing your windows have an internal trim like the one above (ticked in red).  If you just have a rubber seal trim like our bathroom window in the cross picture, it won’t work.

The internal frame section is important as the blinds come with clips that slide behind them, trapping themselves between the trim and the glass itself.

Once they’re in place, the blind frame itself fits to the clips and that is it.  No drilling, no screwing and can be easily removed without any damage, leaving no trace behind.  And from start to finish, each blind took around 10 minutes to build and fit.

How to measure & install step to step guide


Glass size

To get the right size, you’ll need to measure between the exposed glass that you see and not include the frame work.

   - Take three measurements of the width (top, middle and bottom) and only jot down the smallest measurement.
   - Take a measurement of the drop.
   - Treat each section of your window as a completely new window.
   - And ALWAYS double, or in my case, triple check your measurements to be safe.



Measure the depth of your internal trim

Trims vary from size to size, so you’ll need to hold something straight, like a credit card, against the corner of your window across.

Now hold a tape measure against the glass and take note of where the credit card edge starts.  In my case, it was 22mm.  This meant I needed to order 22mm clips to slot behind the glass to be a secure, safe fit.

I also had to pick my colour (every was white in my occasion), and which side I wanted my blind contols to be.  I picked right hand side for all as that meant they’d be easier to access.


What if you get your measurements wrong?

For me, there’s nothing more embarrassing than getting my measurements wrong.  Sometimes it does happen, but do stress again to double or triple check.  I would have been even more embarrassed as I was kindly gifted these from Swift Direct Blinds for honest review purposes, so didn’t want to have to email them and say I’d messed up from the get go.

However, if you have miss measured your blinds, they offer a SizeSure guarantee where they can alter or replace them.  But, as with any company, they do not offer full refunds on made to measure orders, so you need to choose your colour and design carefully first.  I prefer using photo editing software, such as Microsoft Paint or Photoshop to prevent any unwanted surprises.  Just as we did with our double glazing.


Save your blind measurements

One of my biggest time saving things, although it may be obvious to most, is to save my measurements with window drawings and keep them safe.  All of my blinds were clearly marked with their measurements and as I had ten very similar ones, I could see myself getting in a pickle.  So I sat down and took time to number each one, cross matching them with my window drawings.

Avoid my mistake


One thing I couldn’t find were the instructions.  The boxes was really well packed, but I expected to find the installation guide loose inside.  However, it wasn’t until I went to fit my tenth blind when I found them attached to its packaging.  Had I started on that one first, I would have found them.

Luckily, these blinds are so easy and self explanatory to fit, I didn’t really need them and had no need to call the company.

How to fit perfect fit blinds

First, lay your blind on a flat clean surface with the good side facing down.


Slot the pieces together as shown in the picture below.

Fit the corner cover pieces in to place from underneath and press in to place until you hear them click.

Now, using the only tool you’ll need which is a small handheld screw driver, screw down the protruding screws that are already placed here for you.

Then using the screws that come with the corner piece, screw them in to place too.

And that’s all you need to build the frame which took me about 5 minutes!

Fitting the clips in to the window frame



The clips need to be positioned where they line up with the window frame’s oblong slots.  Many YouTube videos will show you how to place them using the long side of a credit card as a measurement.  However, trying this method was quite awkward for me as trying to hold  card while slotting them was quite stiff.

My alternative method


Hold the window frame against the window and using a pencil, mark where the oblong slots line up.

The pencil markings are easily wiped off and because the oblong is bigger than the clip, it means you don’t have to be accurate to the mm.  There’s some allowance if you’ve got it ever so slightly out.

Lubricate the clips with washing up liquid or hand wash, which was closer to me.

Push in the clips until they go all the way in, making sure the pencil mark is in the centre of your clip.

Place your frame in to position, lining the clips up with the oblongs and press until the clips hook in to the oblong holes.


Finally, hook on the venetian opening and closing control which works with a twisting motion and you’re all done.  In total, the whole process took ten minutes per blind.

Other types of perfect fit blinds

The reason I picked venetian blinds is because we can partially open them to bring day light with but still keep our privacy.  The can also be angled up to allow more light in while those from outside can only see the ceiling.  This was important to us as these windows are on the front of a main road.

If they were on the back on the house, we may have considered Perfect Fit blinds in pleated or roller blind (which also offer blackout options).  However, if opened, people would have been able to look straight in.  So it just depends on your needs.  I’m extremely happy with them.

My video measure and fitting guide


* This blog post was written by an award-winning DIY blogger The Carpenter's Daughter.

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