Cat hammocks, in the three ways they actually mount
Three mounts, one for each kind of window: suction cups on the glass, a wooden frame on the sill, a metal frame over the radiator. Nothing drilled, nothing glued, and every measurement published.
Why a cat picks the window over its own bed
A window ledge is rarely comfortable: too narrow for a cat to stretch out on, usually cold, and taken the moment you put a plant there. A hammock fixes all three at once — it moves the bed off the stone, insulates it, and leaves the ledge free.
It is also a question of territory. An indoor cat organises its day around a handful of lookout posts. Give it one at the right height and you often get the back of the sofa and the kitchen counter back.
One mount for each kind of window
Suction cups, straight onto the glass
Four large suction cups hold the hammock against the pane, at whatever height you choose. No sill is needed: the only thing that matters is how much glass you have.
A 45 × 30 cm bed in breathable mesh backed with plush. It folds flat when you want the window back. This is the fastest of the three to fit, and the only one that works on a picture window with no ledge at all.
Wooden frame, resting on the sill
A plywood frame clamps onto the window sill and stretches a cotton canvas between two uprights. It holds by its own weight and by two adjustable hooks under the ledge.
38 × 43 × 21 cm, washable canvas, four colors. It comes apart for storage and stands just as well on the floor against a wall when the window is taken.
Metal frame, hooked over the radiator
A metal frame drops over the top of the radiator and suspends a plush bed with a backrest. The cat gets the heat without lying directly on metal.
46 × 30 × 25 cm. It hooks just as happily onto a balcony railing or a stair balustrade — several buyers use it that way all year round.
The dimensions we publish, and why
The question people ask is never about comfort — it is “will it fit?”. So we publish the three measurements that decide, including the total footprint with the cups, which almost nobody lists.
| Model | Bed | Total footprint |
|---|---|---|
| Suction cups on glass | 45 × 30 cm | 50.5 cm / 20 in of glass width minimum |
| Wooden frame on sill | 38 × 43 cm | 21 cm of height below the hooks |
| Radiator frame | 46 × 30 cm | 25 cm of depth with the backrest |
Three numbers that explain why hammocks work
of sleep a day in the adult cat — which is why the spot it picks matters
— Lucas and Sterman (1974), as reported by Campbell and Tobler, 1984
the glass width actually needed, suction cups included
— measured by a buyer and checked against our own figures, 2026
reviews kept across our three models, rated 4 or 5 out of 5
— Sunbask, verified review corpus, 2026
Which model for which window
| Your situation | The model that fits | Check first |
|---|---|---|
| Picture window, no sill | Suction cups | 50.5 cm / 20 in of smooth glass |
| Wide, flat sill | Wooden frame | 43 cm / 17 in of sill depth |
| Radiator under the window | Metal frame | a radiator with a gap along the top |
| Frosted or filmed glass | Wooden frame | 5 cm of clearance under the ledge |
Not sure about your window? Measure the width of smooth glass between the frames — that is the only figure that decides for the suction model.
A cat is not looking for a soft bed, it is looking for a post. Height, warmth, a field of view — get all three in one place and it goes back every day without you doing a thing.Camille Ferrand — founder of Sunbask, feline behaviorist
Fitting the hammock in the right place
Where to put it, at what height, and what makes a cat adopt it
Pick the window first, not the room. A cat adopts the post that looks onto movement: a street, a garden, a bird feeder. A window onto a blank courtyard gets ignored, however perfectly the hammock is fitted.
Put it at a height it reaches without effort. A stepping stone on the way up — an armrest, a dresser, a radiator — is enough. If it has to jump for it, it will use it less, and less again as it ages.
Clean the glass before you press the cups on. This is the step that separates a mount that holds for months from one that lets go: greasy glass will not let the vacuum form. A cloth and a little warm soapy water is enough.
Give it three or four days. A cat inspects anything new before lying on it. Putting a piece of fabric that carries its own scent on the bed speeds adoption up considerably.
Specifications
| Bed material | Breathable mesh backed with plush (window) · cotton canvas (sill) · plush (radiator) |
| Structure | Plastic arms and suction cups · multi-ply plywood · metal frame |
| Assembly | No drilling, no glue. Printed instructions with the wooden model. |
| Colors | 2 on the window model · 4 on the wooden model · 3 on the radiator model |
| Shipping | Free, 6 to 10 business days |
The 50.5 cm figure includes the cups and their arms. That is the measurement to take on your window, not the 45 cm of the bed.
4.9 out of 5, across 115 verified buyer ratings
What buyers say
"Good quality, very strong suction cups, they take the cat's weight easily and my cat is not exactly small."
— Claire Z., verified buyer
"Honestly it is fairly easy to assemble, it looks solid, my cat weighs about 7 kg and it holds really well. I recommend it."
— Verified buyer
"Our kitten absolutely loves it and lies on it every day. I am very happy with this purchase; it is easy to fit and stays firmly in place."
— Sophie S., verified buyer
These come from verified buyers. The photos they sent in are on the reviews page.
Camille Ferrand · Feline behaviorist — founder of Sunbask
Camille works with households living with one or more cats in flats. Her work turns on one question: where a cat chooses to settle, and why it ignores the bed you bought it. It was measuring dozens of window sills in clients' homes that led her to start Sunbask, and to the habit of publishing the measurements nobody else gives.
Reviewed and updated on 31 August 2026. See how we test.
What an elevated post actually changes
An indoor cat has the same floor area available to it every day of its life. What it does not have, and misses most, is volume: levels, vantage points, places to watch from without being watched. A flat is not small for a cat because of its floor plan, it is small because everything happens at one height.
That is why a window hammock is not a comfort accessory but a change to the room. It adds a storey to a space that had one, without taking an inch of floor — which, in a studio, is not a detail.
A window post also answers two separate needs at once: height, which reassures, and a view, which occupies. A cat that spends its days alone finds enough there to fill hours that neither a toy nor a cat tree against a blank wall will fill.
The three reasons a hammock stays empty
When a hammock does not find its cat, it is almost always one of these three causes — and none of them is about the product.
1. The location. A window facing a wall, a busy hallway, a door that slams: the post is technically perfect and nobody gets on it. Before concluding the model is wrong, move it. That is the most common cause by a distance.
2. The approach. Very few cats will jump four feet onto a narrow surface they do not know. They need an intermediate step — an armrest, a dresser, a radiator — to halve the climb. Without one the hammock is visible and unreachable.
3. Patience. A cat sizes up a new object for two or three days before lying on it, and puts on a thoroughly convincing show of indifference meanwhile. The classic mistake is to place it there by force: it then associates the object with being handled.
A fourth case is worth naming because it has no fix: some cats never sleep up high, whatever you install. They are a minority, but they exist, and no lookout will change their minds.
Give it a week before you judge. Our buyer reviews describe the same sequence every time: suspicion, then adoption.
What wears out, and what does not
On all three models the part that ages is the same one: the fabric. Mesh, plush or cotton, it gets dirty, it gets washed, and eventually it slackens. Every model has a removable, washable sleeping surface, precisely because that is the piece you handle most.
What does not wear out is the structure: the plywood of the sill frame, the metal armature of the radiator model. There are no wearing parts, no springs, and no foam to collapse.
That leaves the suction cups, which are a case apart. They do not wear out either, but they do get dirty: an invisible film of grease is enough to let air past. A cup that slides a few millimeters a day is not dead, it is dirty. Take it off, wipe the disc and the glass with a damp cloth, and it holds again. That, every two or three months, is the only real maintenance in the range.
Our 30-day cover is for changing your mind, not for wear: if the hammock does not suit — wrong measurement, cat that will not have it — it goes back at our expense, with no reason required.
What happens after you order
Your order is packed within 1–2 business days and arrives within 6–10 business days in total. That is the time we actually measure on our own shipments. Shipping is free, with no minimum order.
We ship to the United States, the United Kingdom, Canada, Australia and New Zealand. Tracking is sent to you as soon as the carrier takes the parcel.
On returns, you have 30 days from delivery — our own policy, on every market we ship to. No reason is required: a cat that will not get on its hammock is reason enough. Sending it back costs you nothing, and the refund is issued within 14 days of the parcel reaching us, to the payment method you used.
A question about a measurement to check, a doubt about your type of radiator or glazing — goes to [email protected]. We answer within one business day, and a straight answer about fit saves you a return.
Answers by question
Each of these takes one question the others do not.
- Comparing the three mounts
- What makes it a bed, not a ledge
- How many perches a home needs
- Fitting one to the sill you have
- Shelf height without drilling
- Clamping to furniture
- What suspension changes
- Which surfaces a cup holds on
- Perches for large cats
- The radiator bed for a big cat
- Double-panel radiators
Frequently asked questions
How much glass does the suction model need?
50.5 cm — just under 20 inches — of smooth glass, measured across the cups and arms. The bed alone is 45 cm, but it is the total footprint that decides. Measure between the frames first: it is the one thing no adjustment rescues.
Do the suction cups hold over time?
Yes, provided you press them onto clean, degreased glass. Every buyer who reports good long-term hold describes the same habit: wipe the pane, let it dry, then press the centre of each cup. A cup that starts creeping is dirty, not worn out.
Does the radiator model fit every radiator?
It is made for radiators with a gap along the top, which the frame drops over. A buyer reported that it does not work on solid cast iron, where the hooks have nothing to grip — so we say so on the page.
How many cats can one hammock take?
Several buyers describe two cats settled on the suction model at the same time, around 11 kg / 24 lb between them. That is a reported use, not a rated capacity: no maximum load is published for this model.
Do I have to drill or glue anything?
No, not on any of the three. The window model holds by suction, the wooden frame clamps onto the sill, the metal frame hooks over the radiator. All three come off without leaving a mark, which is what makes them work in a rental.
Can the hammock be washed?
The cotton canvas on the wooden model comes off and goes in the machine. On the window and radiator models the bed is cleaned in place, with a brush and a damp cloth.
Will my cat actually use it?
Give it three or four days of watching before it settles. Putting something on it that already smells of your cat helps, and so does facing a busy window rather than a closed courtyard: what a cat wants from a lookout is something to look at.
How long does delivery take?
Six to ten business days, shipping free. You get a tracking number by e-mail as soon as the parcel leaves, and you have 30 days to change your mind.
Give it a lookout of its own
Three mounts, nine colorways in all, free shipping and 30 days to change your mind.
Add to cart →The three models in detail
What each one solves, in pictures.
