How high above the window should the rail go?

Higher than you think. Halfway between the top of the window frame and the ceiling is a good default, and if the gap is less than about 30cm, go right up to the ceiling instead. Fixing the rail to the window frame is the single thing that makes a room look rented, because it draws a line across the wall at the height of the smallest thing in it.

How much wider than the window should the rail be?

About 15 to 25cm past the frame on each side, more if the curtains are heavy. That extra rail is where the fabric sits when the curtains are open, so the glass stays uncovered and the window looks as wide as it really is. Curtains that stack over the glass make a room darker all day.

Should curtains touch the floor?

They should reach it. Either just kissing the floor, about half a centimetre clear, or a couple of centimetres of fabric resting on it if you want the softer look. What does not work is stopping short. A curtain that ends above the floor looks like it shrank, and there is no length of gap that reads as deliberate.

How much fabric do I need?

Two to two and a half times the width of the rail, in total, across both curtains. This is the number that decides whether curtains look expensive, far more than what the fabric cost per metre. A cheap linen at two and a half times the width will look better than an expensive one at one and a half.

Are eyelet curtains a bad idea?

Not bad, just casual. The eyelets hold the fabric in a regular wave and read as modern and slightly practical, which is lovely in a kitchen and a bit thin in a living room. Pencil pleat and pinch pleat both gather more fabric at the top, which is what gives you the soft column of folds.

Do I need blackout lining?

In a bedroom, probably. Elsewhere it is often the wrong tool, because it also stiffens the curtain and flattens the way it hangs. A plain cotton lining blocks a surprising amount of light on its own, and interlining, a soft layer between fabric and lining, is what makes curtains hang heavy and expensive.

Guide

How to Hang Curtains

Curtains are the fastest way to make a room look rented, and it is almost never the fabric. Where the rail goes, how much wider it needs to be, and how much fabric you actually need.

Haze Homes13 September 2026

Curtains are the thing I notice first in a room, and almost always for the wrong reason. Not because the fabric is cheap, which is rarely the problem, but because they are hung too low, too narrow and too short, and all three of those are decisions made with a drill rather than a credit card.

The good news is that the fixes are free. You can hang a fifty euro pair of curtains well and they will look better than a three hundred euro pair hung badly.

The rail goes far higher than the window

Instinct says the rail goes just above the window frame, because that is where the window is. It is the wrong instinct.

Go halfway between the top of the frame and the ceiling. If that gap is small, say under about 30cm, go all the way to the ceiling and mount the track on it. The curtain then runs floor to ceiling in one line, and the room reads as taller than it is. Every room I have been in that felt generous had its curtains hung high.

A rail screwed to the window frame does the opposite. It draws a horizontal line across the wall at the height of the frame and tells your eye that the wall stops there.

And much wider

The rail should carry on past the frame, about 15 to 25cm on each side, and more if the curtains are heavy or the fabric is thick.

That overhang has a job: it is where the fabric goes when the curtains are open. Without it, open curtains sit over the glass, and a bunched curtain is not transparent. You lose light all day, every day, and the window looks narrower than it is.

If there is a wall on one side and none on the other, run the rail as far as the wall allows on the side you have. Asymmetry is not the problem here. Covered glass is.

Fullness is the whole game

This is the number almost nobody is told. The total width of fabric should be two to two and a half times the width of the rail.

So a two metre rail wants four to five metres of fabric, across both curtains together. At that ratio the curtains hang in deep, soft folds, closed or open. At one and a half times they hang nearly flat, and flat is what reads as cheap, no matter what the fabric is.

If you are choosing between a nicer fabric at low fullness and a plainer fabric at proper fullness, take the plainer fabric. It is not close.

Length: reach the floor

Three lengths work.

Kissing the floor, about half a centimetre clear. The most practical, and the one to pick if the curtains get opened and closed every day.
Resting, two to three centimetres of extra fabric sitting on the floor. Softer, slightly undone, my favourite in a bedroom.
Puddled, considerably longer and pooled. Lovely in photographs, and it collects dust and gets caught in the vacuum.

What does not work is short. Anything that stops above the floor looks like a mistake, and there is no gap small enough to read as intentional. If your measurement comes out awkward, err long.

Measure from the rail, not from the top of the curtain, and measure at both ends of the window. Floors are rarely level, and a two centimetre difference across a wide window is visible.

Heading, track and pole

The heading is the top of the curtain, and it decides how the folds form.

Pinch pleat, gathered into groups at the top. The most formal, holds its folds whether open or closed.
Pencil pleat, a gathered tape you pull to width. Forgiving, cheap, and what most ready-made curtains use.
Wave, a continuous S-curve on a track. Modern and very even.
Eyelet, metal rings over a pole. Casual and easy, and it holds less fabric at the top, so it needs a wide pole and looks best in a kitchen or a study.

A track disappears, which is what you want if the curtains are the feature. A pole is the feature, which is fine if it is a good one. Ceiling-mounted track is the quietest of all and the one I would choose for full-height curtains.

Lining, and what actually makes them hang

Weight is what makes curtains look expensive. Lining is how you get it.

An unlined linen curtain is lovely and light and will always look a bit like a sheet. A cotton lining adds body, blocks a good deal of light, and protects the face fabric from the sun. Interlining, a soft blanket layer between the two, is the thing that makes curtains fall in heavy columns and stay there, and it is what you are looking at when a curtain in a hotel looks the way it does.

Blackout is a separate decision. It belongs in a bedroom and it does stiffen the drape a little. Outside a bedroom I would almost always take a plain lining and a bit more fabric instead.

The order I would do it in

Decide where the rail goes, on the wall, with a pencil. High and wide.
Measure the rail, not the window.
Multiply the rail width by two to two and a half. That is your fabric.
Measure rail to floor, at both ends, and pick a length that reaches.
Only then choose the fabric.

Doing it in that order costs nothing and is most of the difference.

Common questions

How high above the window should the rail go?: Higher than you think. Halfway between the top of the window frame and the ceiling is a good default, and if the gap is less than about 30cm, go right up to the ceiling instead. Fixing the rail to the window frame is the single thing that makes a room look rented, because it draws a line across the wall at the height of the smallest thing in it.
How much wider than the window should the rail be?: About 15 to 25cm past the frame on each side, more if the curtains are heavy. That extra rail is where the fabric sits when the curtains are open, so the glass stays uncovered and the window looks as wide as it really is. Curtains that stack over the glass make a room darker all day.
Should curtains touch the floor?: They should reach it. Either just kissing the floor, about half a centimetre clear, or a couple of centimetres of fabric resting on it if you want the softer look. What does not work is stopping short. A curtain that ends above the floor looks like it shrank, and there is no length of gap that reads as deliberate.
How much fabric do I need?: Two to two and a half times the width of the rail, in total, across both curtains. This is the number that decides whether curtains look expensive, far more than what the fabric cost per metre. A cheap linen at two and a half times the width will look better than an expensive one at one and a half.
Are eyelet curtains a bad idea?: Not bad, just casual. The eyelets hold the fabric in a regular wave and read as modern and slightly practical, which is lovely in a kitchen and a bit thin in a living room. Pencil pleat and pinch pleat both gather more fabric at the top, which is what gives you the soft column of folds.
Do I need blackout lining?: In a bedroom, probably. Elsewhere it is often the wrong tool, because it also stiffens the curtain and flattens the way it hangs. A plain cotton lining blocks a surprising amount of light on its own, and interlining, a soft layer between fabric and lining, is what makes curtains hang heavy and expensive.