Summer 2020 - we now offer high quality garden gates! Use code GATE15 for launch savings and receive 15% off the whole gate range.

How to measure for a Juliet balcony

How to measure for a new Juliet balcony

There’s a lot of jargon out there - openings, recesses, centres, flanges and sills - but you shouldn’t need to be an expert to buy a balcony with confidence.

So we’ve kept things simple; the only measurement you need for a Forjj Juliet balcony is the aperture. This is the horizontal measurement of the structural opening you want to cover with a balcony. Order based on this size (you’ll see below that there are only 6 standard choices) and we will automatically make the balcony slightly wider (around 350mm [or 1ft] overall) to ensure a secure, safe & suitable fit.

Tips for Measuring

  1. Use a metal tape measure as cloth ones can stretch and give you an inaccurate reading.
  2. Measure at 2 different locations [at the base and roughly mid height].
  3. Don’t worry if you get two different measurements. As long as they aren’t wildly different (something is wrong with your tape measure or your building if that’s the case!] use the larger of the two measurement as your aperture size.
  4. Measure twice, order once. It’s best to be confident about the size you are ordering so double-check your measurement or have someone else verify it.
  5. Don’t worry about millimetre accuracy - most window and door openings in the UK are a standard size and you will see below that each balcony design covers a range of aperture values.
  6. If you’re in any doubt about what to measure or what to order, just drop Forjj a line for more advice.

Should I look out for anything else?

Inspect the walls / surfaces to a distance of 1ft (30 cm) around your window aperture. The balcony won't extend this far, but any obstacles in this area may be important. Look out for any protruding features such as over-sized window sills, drain pipes, electrical cables or stonework that might clash with the balcony frame. Be aware too if you have less than 1ft (30 cm) of space around the balcony area which might cause problems for fixing. Don’t panic if you see any such issues as we can (and have) worked around all sorts of unusual obstacles in the past. Just get in touch or even send us a photograph if you would like any advice.


Which size do I choose?

Apertures do vary slightly so each of our standard Juliet balcony sizes will suit a maximum and minimum aperture range:

I've measuredAperture size to order
between 890 and 940mm 900mm
between 1190 and 1240mm 1200mm
between 1490 and 1540mm 1500mm
between 1790 and 1840mm 1800mm
between 2090 and 2140mm 2100mm
between 2390 and 2440mm 2400mm
Something else! See below

My measurements don’t match any of your standard sizes?

If your aperture measurements fall outside of these ranges please contact us and we will be happy to help. We can accommodate any other size that you require, sometimes at little or no additional cost.


I don’t have the windows or doors yet, can I order the balcony anyway?

Yes, even if the opening hasn’t been made in the building yet, your window or door manufacturer should be able to advise the aperture size of your new windows or doors and that’s all you need to be able to place your order.

See also our FAQs for more measuring and selection advice.