A permit condition requiring "obscure glazing to 1.7 metres" means the glass in that window must be permanently obscured from the floor of the room up to a height of 1.7 metres, so nobody standing inside can see into a neighbour's private space. The measurement runs from the finished floor level of your room, not from the windowsill. Permanently applied privacy film is one of the accepted ways to satisfy it.

This condition catches out a lot of builders and homeowners, almost always on the same two details. Let's deal with those first.

Mistake one: measuring from the wrong place

The 1.7 metres is measured from finished floor level, not from the bottom of the window.

This trips people up constantly. If your window sill sits 600mm above the floor and the window is 1,400mm tall, you do not need 1.7 metres of film. You need film from the sill up to 1,100mm above the sill, because that is where 1.7 metres above the floor lands. The top 300mm can stay clear.

Conversely, if you have a full height window or a sliding door starting at floor level, you need the full 1.7 metres of obscuring, which on a standard 2,100mm door leaves only 400mm clear at the top.

Get a tape measure, measure from the floor, mark 1.7 metres on the frame, and that is your line. Do this before anyone quotes.

Mistake two: assuming anything that blocks the view will do

The condition almost always requires the glazing to be fixed and obscure. Both words carry weight.

Fixed means it cannot be opened, moved or removed in normal use. This rules out:

•     Blinds, of any kind

•     Curtains

•     Internal shutters

•     Removable static cling film

•     Frosted spray, which degrades and can be scrubbed off

It also creates a problem with openable sashes. If the obscured panel is in a sash that swings or slides open to restore the line of sight, a surveyor may not accept it. Check the condition wording and check the window type.

Obscure means genuinely obscuring, not merely decorative. A light dusted film that still lets you make out a person moving on the other side is not obscure glazing. We use films rated at 95 per cent opacity for compliance work for this reason.

What actually complies

Under ResCode and the Building Regulations 2018, the accepted ways to deal with an overlooking issue are:

•     A sill height of at least 1.7 metres above floor level

•     Fixed, obscure glazing in any part of the window below 1.7 metres above floor level

•     Permanently fixed external screens to at least 1.7 metres above floor level, with no more than 25 per cent transparency

•     Permanently fixed internal screens to the same height and transparency limit

•     Relocating or reorienting the window so the sight line no longer arises

For balconies, terraces, decks and patios, the height is measured from the floor of that outdoor area rather than from an internal floor level.

Your permit condition may specify one of these explicitly. If it just says "obscure glazing", you generally have a choice of how to achieve it.

Obscure glass or film?

Both work. The question is timing and cost.

Order obscure glass if you have not glazed yet. Translucent, textured or acid-etched glass ordered with the frames costs little more than clear and is permanent. If you are still at frame order stage, this is the cleanest route.

Use film if the glass is already in, which is the situation for most people reading this. Retrofitting obscure glass means removing beads, handling and disposing of the existing pane, ordering a replacement in the right safety grade, and re-glazing. Film goes on in place in a few hours.

Film also wins when the deadline is short. Permit conditions have a habit of surfacing at final inspection, and a replacement pane can take weeks between measure, order, toughening and installation. Film can usually be done inside a week.

Will a building surveyor accept window film?

In our experience across more than twenty years of this work, yes, where the film is:

•     Permanently applied with a pressure-sensitive adhesive, not static cling

•     Sufficiently opaque to genuinely obscure, not merely decorate

•     Installed to the correct height measured from finished floor level

•     Applied across the full width of the opening, with no clear gaps at edges

Here is the important part. We do not determine compliance. Your building surveyor or the responsible authority does. We will tell you honestly what we believe satisfies the condition, and we are usually right, but the sign-off is not ours to give.

The safest sequence is: send your surveyor the film specification and the proposed height, get their agreement in writing, then install. That email takes a day and it eliminates the risk of a failed inspection.

What if a neighbour is demanding more than the permit requires?

This comes up often enough to be worth addressing.

The Victorian standards limit overlooking. They do not attempt to eliminate it entirely. The provisions only concern themselves with habitable room windows and secluded private open space within 9 metres, measured within a 45 degree arc from 1.7 metres above floor level. VCAT has consistently recognised that the framework balances a neighbour's privacy against a new occupant's right to outlook.

If you satisfy the condition on your permit, you have satisfied your obligation. Going further is a decision, not a requirement.

For the full picture of how the geometry works, read our guide to obscure glazing rules in Victoria.

Choosing the right film for a permit condition

You do not have to use plain white frost, and a lot of people are pleasantly surprised by this.

•     Plain frosted, 95% opacity. The straightforward compliance answer. Clean, neutral, unambiguous. See our frosted window film range.

•     Reeded or fluted film. Vertical texture, currently very much in favour in Australian interiors. Choose a denser grade if it is doing compliance duty, because lighter reeded patterns may not obscure enough on their own.

•     Patterned and decorative film. Works well provided coverage is continuous. Widely spaced motifs with clear glass between them will not satisfy an obscure glazing requirement.

•     Gradient film. Denser at the bottom, lifting toward the top. Looks good but be careful, because the top of the treated zone still has to be obscure at the 1.7 metre line.

Bring the condition wording to us and we will tell you which options in our range will satisfy it.

Frequently asked questions

Can I use a blind instead?

No. The screening must be permanently fixed, and a blind can be raised.

Does the film go inside or outside?

Internal application is standard. It lasts longer, is protected from weather and is easier to maintain.

What if my window is a sliding door?

The full 1.7 metres from floor level needs obscuring on the panels creating the sight line. On a standard door height that leaves a clear band at the top.

Do I need it on every window?

Only those identified in the permit condition, or those failing the 9 metre, 45 degree and 1.7 metre test. Bathrooms, toilets and laundries are generally not habitable rooms for this purpose.

How quickly can it be done?

Most residential jobs are a few hours on site. Depending on our schedule and the film required, we can usually get to you within days.

What happens if I fail inspection?

Usually you get a call-up and a chance to rectify. It is a delay and a cost, which is why confirming the specification with your surveyor in advance is worth the day it takes.

Get the condition sorted

Send us the wording of your permit condition along with photos of the windows and the floor to head measurement of each opening. We will tell you exactly what height of film each one needs and what it will cost.

We do a lot of this work for Melbourne builders and homeowners, often at short notice when an inspection is booked. Request a free quote or call 1300 204 852.

General information only, not planning or building advice for your property. Compliance is determined by your building surveyor or the responsible authority.