top of page

Feel the pane

Welcome to btofloorplans’ Make You A Windower / Feel The Pane page, where we dive deep into the wonderful world of BTO windows! There’s just so much to explore, and that’s just when we restrict it to BTO windows. The world of pre-BTO HDB windows is even more varied and fascinating but much harder to find information about since most of it is pre-internet. Maybe something for me to do when I’m retired (in half a century’s time!)


On this page is everything I could find on the internet about BTO windows – from the basics like dimensions and placement, to more esoteric things like special projects with extra windows, to practical knowledge for renovation (the HDB rulebook on windows, basically). I also have a section on balconies, because what are balconies but thicc windows?


A quick note before we begin: many of these photos have been obtained from window contractor websites, or from users who have posted these photos to discuss window renovation (most commonly metal or invisible grilles). So please disregard any grills seen in these photos, they are not original features of the windows.

Explore windows

Explore windows

The standard BTO flat

The standard BTO flat

To set the stage for the windows to shine, we must first put them in context: the standard BTO flat. Counting mainly rooms with windows, every flat has a living room and master bedroom, with perhaps one or two common bedrooms, and maybe a study area. In the standard layouts, each of these areas has only one cluster of windows, with varying numbers of panes and heights, and they all face the same direction.

First, we have the 2-room BTO. There are type 1 and 2 which differ in size, but are functionally similar. The larger type 2 (47-48sqm) is shown here. This is from the 2014 project amusingly named "Golden Ginger":

2014-01 GoldenGinger 2R4.jpg

The next flat type is the 3-room BTO, usually coming in at 68 sqm. Here's a sample from Tampines Greenvines:

2018-05 Tampines_GreenVines 3R2.jpg

Here have the ever-popular 4-room BTO, commonly 93 sqm and shown here from Oleander Breeze in Yishun:

2013-01 Oleander_Breeze_Yishun 4R2.jpg

And the veritable 5-room flat, standing at 110 sqm, seen here from Keat Hong Mirage:

2012-11 Keat_Hong_Mirage 5R1.jpg

These layouts became the norm since the early 2000’s when corridor-facing units were phased out. Windows are split into multiple panes, and are generally 3 in the common bedrooms, 3 or 4 in the master bedroom, 4 in the living room, and 2 or 3 in the study.


Note that the only other windows in the standard layout are the ventilation windows in each bathroom, and the open service yard (open ledge without windows, though many buyers install windows there). There are no windows at the dining area, along the kitchen wall, or along the sides of the living room or master bedroom.

Types of windows

Types of windows

There are 4 types of windows in a BTO: casement, sliding, top-hung and louvre.



Sliding: these windows are uncommon in BTO flats except when installed by owners at the service yard, but here's an example from an older BTO (Sri Geylang Serai):


(Source: Property Guru)



(Source: Houzz)



(Source: Piggyhome)


Y-axis: window heights

There are three standard heights for BTO windows: full, ¾, and half. (I will write ½ as “half” so it is easier to distinguish from ¾.) They are determined by how high they are above the ground: 30cm or less (full), 55cm (¾) and 90cm (half). While the ¾ and half heights are quite standard, full-height may be anywhere between a full 30cm from the ground to truly starting from the floor up. Here are the three window heights in empty flats.

Full-height window (and an incredible view):


¾ height window:

Screenshot 2021-02-26 at 4.28.01 PM.png

(Source: Seedly)

Half height window:


The following two images are lucky finds showing the different-sized windows side-by-side as the owners had hacked the walls between rooms:


(Source: Gixxerfied)


(Source: Gixxerfied)

And here’s a nicely renovated unit showing the difference between a half height and ¾ height window:


(Source: Seedly)

Distribution of windows within the flat

For the purposes of windows, flats can be divided into 3 zones: living area, common bedrooms, and master bedroom. (Of course, 2-room flats only have the living and MBR.) The living area always has the largest window type within the flat. The MBR window is usually the same size as the common bedrooms, but occasionally it is as large as the living room windows instead.


Examples of living room ¾ window combinations:

LR ¾ + CBR half + MBR half (standard)

LR ¾ + CBR half + MBR ¾ - eg. Tampines Greenweave

LR ¾ + CBR ¾ + MBR ¾ - eg. Senja Ridges, Clementi NorthArc


Examples of living room full window combinations (premium flats):

LR full + CBR full + MBR full – eg. Woodleigh Village

LR full + CBR ¾ + MBR ¾ - eg. Waterway View, Alkaff Courtview/Lakeview, Woodleigh Glen

LR full + CBR ¾ + MBR full - no examples found yet

LR full + CBR half + MBR half – eg. Northshore StraitsView


Other interesting combinations:

LR ¾, CBR1 ¾, CBR2 half, MBR ¾ – Kallang Breeze


The story is a little different for 2-room flats. Many 2R units in standard projects have ¾ windows in both the living and bedroom, which really helps maximise the spaciousness and light in a small space. But equally often a project will have the standard ¾ in the living area and half in the bedroom (eg. East Lace Canberra, West Crest/Valley/Terra Bukit Batok, St Georges Towers).


2R units in premium projects may have full height window in at least the living room (eg. Bedok Beacon, full height living room and ¾ height bedroom) or only ¾ windows throughout (eg. Alkaff Courtview/Lakeview).  


What are the pros and cons of each window height?


While some may fret about not getting a flat with full-height windows or at least ¾ windows in the bedrooms, there really are benefits and drawbacks to all types. Larger windows let more light in and are lovely if you have a beautiful and private view. But if you’re facing the street or towards the town centre with lots of foot traffic, these windows are also a privacy hazard if you are on a low to mid floor because passers-by on the street level can see more of your flat’s interior. Picture this: Let’s say you stay on the fifth floor and have just stepped out of the shower. Pedestrians on the ground floor 50m away are unlikely to be able to see more than your head and shoulders if you have half windows, but will probably enjoy the full view of you (wrapped chastely in your towel) if you have ¾ or full windows.


Another aspect to consider is space planning. Larger windows hog the whole wall, and it’s tougher to use the wall for anything else because you need to make space for the curtains or blinds. While still possible if done creatively, you can’t simply push your bed or study desk up against a ¾ or full height window. In contrast, the wall space under a half window is easily usable for a desk, storage or a bed.


So fret not if your project isn’t blessed with large windows. And remember that we’ve come a long way from ye olden days when HDB windows were tiny and facing the corridor!


What are the heights of my BTO unit’s windows?


You can find out what type of windows you have from your BTO brochure, but not within the floor plan itself. Go to the level/block plan for your flat and look in the bottom left corner. It will mention the height of any windows labeled. Often half height windows are not labelled, while ¾ or full windows are labelled either W1 or W2.

2016-11 Bedok_Beacon.jpg

This level plan from Bedok Beacon illustrates this perfectly. The main windows are labelled either W1 or W2, and the legend is written in the bottom left corner. In the above example, W1 indicates full height and W2 ¾ height. Like all brochures, this legend also says, “Unless otherwise indicated all windows will be standard height windows.” You may be wondering, all windows here are labelled W1/W2, so why is this written? Well, look closely at unit 38 – there’s an extra window in the master bedroom! This window will be half height. More on extra windows in a later section.

Interestingly, HDB hasn’t standardized which of W1/W2 refers to full and ¾ height. In the above example W1 = full and W2 = ¾, but in the example below from Tampines Greenweave it’s the other way around (W1 = ¾ and W2 = full), likely because W1 is the primary window and W2 is a secondary offering, in this case as an extra window in the MBR.

2015-05 Tampines_GreenWeave.jpg

Case studies: window variations

Be careful and pay attention to the windows on all floors and blocks, because sometimes different units within the same block or even floor can have different window sizes!


Case 1: Northshore Residences

This Punggol project illustrates just how important it is to comb through the brochure carefully. If we look closely at the 4R units (coloured in yellow), we see that units 140, 160 and 162 have full height windows in the living room and ¾ windows in all bedrooms. But stacks 150 and 152 only have ¾ windows in the living room and half height windows in the bedrooms, without any full height windows. That’s easy to miss!

2015-05 Northshore_ResidencesI_II window

Case 2: Bishan Towers

Below is another example from Bishan Towers. HDB did something really interesting here. Both stacks 130 and 132 face the same direction. Privacy of the two units are comparable. But stack 132 got the balcony, so isn’t that the obvious choice? Upon closer inspection we see that unit 130’s MBR has a ¾ window, and a corner window no less! (There’s a whole section on corner windows later on.) Whereas unit 132 has all half height windows. Which would you choose, especially considering the extra price you pay for the square footage on the balcony? I don’t know, but it’s a happy dilemma to have! 

2020-08 Bishan_Towers windows.jpg

Case 3: Waterfront @Northshore

And finally, here’s a project where the windows vary not just between stacks, but between floors! And we don’t have just W1 and W2, but also a W3! See if you can spot the difference between the odd and even storeys:

2015-11 Waterfront_I_II@Northshore windo
2015-11 Waterfront_I_II@Northshore windo

In this project, W1 and W2 both refer to full height windows, but W2 is “full height window with railing”. Now I’ll admit I have no clue what that means, and I can’t wait for images of this project to emerge on the internet so I can find out. W1 and W2 are used on alternate storeys for the living rooms of stacks 549 and 551. These stacks have full height windows (W1/W2) in the living room and ¾ height windows (W3) in all other rooms. However poor stacks 553 and 555 face away from the seaview and have only ¾ windows in the living room (W3) and half height in all bedrooms.

Moral of the storey is (pun), if windows are important to you, please go through your BTO brochure with a fine-tooth comb and a keen eye!


X-axis: window-wall ratio, split windows and 5-room splits


Windows also vary greatly in the horizontal axis. For example, sometimes windows are inexplicably off-centre. Here’s a ¾ window that is nicely centred within the wall (as you’d expect):

Screenshot 2021-02-24 at 8.03.25 AM.png

(Source: Qanvast)

And here’s a window that is frustratingly not (camera angle alone cannot account for this):


(Source: Gixxerfied)

Honestly I have no clue why it’s done this way, but like many decisions made by HDB we will never know. (The above two images also demonstrate other common design variations, like the multipled louvred windows on the left side in the first picture which I don’t think anyone prefers over the normal full panel in the second picture but HDB still does it all the time. Maybe it’s safer for cats? Lol.) 

Window-wall ratio

All the windows featured so far are standard BTO windows in their shape and size. But some projects just have less window compared to wall in the x-axis, or what I call a lower “window-wall ratio”. The Dawson projects in the Queenstown area are a great example of this.


Here is a 4-room living room from a Dawson project, and compare it to the other 4R windows in previous images:


(Source: Home and decor)

Here’s a Dawson bedroom:


(Source: iProperty)

And here is a 5-room living room, also from a Dawson project:



Compare that to standard 5-room windows:

standard (1).jpeg

(Source: Qanvast)

What’s interesting about Dawson is that the windows, even if narrow, are all full height. That creates a totally different vibe from the usual wide, stout windows. Dawson projects are incredibly tall (up to 40 storeys) so if I were to hazard a guess, the narrower windows may have been chosen to reduce the heat of the unit. The marked asymmetry does free up wall space for artwork or a display shelf and presents different opportunities for interior design.


The windows in many upcoming Tengah projects are also similarly asymmetric and narrower than usual, which we can see from the floor plan from Tengah Plantation Grange (although not nearly as pronounced as Dawson). All the windows in this project are ¾ height. (An aside but I am SO excited for Tengah to be developed!)

2019-11 Plantation_Grange 4R1.jpg

Split windows

Sometimes the total width of window is the same, but the window is split into multiple segments. This is what it looks like on the floor plan (this example is from Waterway View):

2013-09 Waterway_View 4R2.jpg

And this is what it looks like in person:


(Source: Renonation)


(Source: endogrilles)


(Source: SRX)

Again, I have no clue why this is done. The windows will probably share one set of curtains like the photo above, but if you go for blinds instead, do you do a single long blind across both clusters, or do you do a big one and a tiny one separately? If anyone actually likes this split-window configuration, do let me know because I’d love to learn what I’m missing!


5-room window splits 


5-room flats in the BTO era include an extra 10 sqm over 4-rooms, most of which goes to a “suggested study” area which is often used instead to enlarge the living room. This study area has its own dedicated windows which are almost always the same height as the living room windows, but narrower.


Living rooms usually have 4 panels of windows, whereas the study may be 2 or 3.  Here are the most common window splits:


Here’s a 4+3:


(Source: fixfixsg)

Here’s a 4+2 (most common):


(Source: sweetmelody06)

And my personal favourite, 2+2+2, which is not only the most visually pleasing, but also the most versatile:


(Source: Renonation)

Many owners who need a study space encase it in glass like the photo below. Only the 2+2+2 allows owners to build it on whichever side of the living room they please without interrupting the windows.


(Source: Renonation)

We can see this even more clearly by comparing the floor plans of the various splits.


Here’s a 4+3 (Hougang ParkEdge, with a lovely corner window in the MBR as well):

2013-01 Hougang_ParkEdge 5R1.jpg

Here’s a 4+2 (Oleander Breeze):

2013-01 Oleander_Breeze_Yishun 5R1.jpg

And here’s a 2+2+2 (East Crown Canberra):

2014-03 EastCrown@Canberra 5R2.jpg

However, one drawback of this symmetric layout is that there is no obvious way to split the curtains, so it’s either two big curtains on either side of the room, or 3 little blinds.


(Source: Renonation)

Corner windws

Corner windows

If there’s one particular thing I love about BTO windows, it’s the corner window. Only found in flats with a good view, it just makes me feel a certain type of way, giggly if you would, like meeting a cute puppy or licking a delightful cone of candy-flavoured ice cream. That’s not because I find these windows particularly appealing, but more because I’m delighted that HDB chooses to include something so unnecessary, so extra, in something so sterile as public housing. (We’ll get to the extra bit soon.)

A corner window (named by HDB, abbreviated “CW”) is a window that wraps around the corner of the wall, often just by one pane. They’re designed to give you a peek of a different view while not compromising privacy. And of course, they let in more light than just the standard three or four panes.

Here’s the terrible low-res photo off the HDB website:


(Source: HDB)

Just like other windows, corner windows come in half, ¾ and full heights. It’s really difficult to find photos of them by deliberately searching, so here’s what I’ve stumbled upon and saved to my collection over the past year.

Standard half height corner window:


(Source: Pang Giap)

¾ height corner window:

Screenshot 2021-02-27 at 10.11.33 AM.png

¾ + full height corner window… if this isn’t extra, I don’t know what is!


(Source: Pang Giap)

One Punggol project (Northshore StraitsView) even has a full-height corner window attached to a half-height bedroom window. The project was just completed at the end of 2020 and I haven’t found any renovation photos online yet. Please, if any readers stay in a flat with this corner window, please get in touch. I’d love to add a photo of your window to this collection!


The funniest thing about corner windows is that I don’t know how I feel about them. Maybe I’m just jealous that my own flat isn’t one of those within my project with a good enough view to be granted a CW, but I also imagine that they’re a bit troublesome since they either have to have a separate curtain or blind, like the L-shaped curtain below that basically covers the corner window:


(Source: humanrace)

On the other hand, you get a whole other view which you can choose to enjoy if you want by having a cup of coffee by the window. And even if the corner window faces west (oh the dreaded west sun!) you’ll get to see a lovely sunset and have some of that evening glow enter your room without having the sun glare directly in your eyes. 


Corner windows are almost always found in the master bedroom, such as in this 5R floor plan from Fernvale Acres:

2018-11 Fernvale_Acres 5R1.jpg

Or in this slightly unusual 4R floor plan from Kebun Bahru Court:

2013-01 Kebun_Baru_Court 4R1.jpg

Here’s a rare 3-room corner window at Northshore Straitsview:

2015-11 Northshore_StraitsView 3R1.jpg

There’s also this incredible corner window in the living room, in some 3-room and 4-room units from the 2015 Bidadari project Alkaff CourtView:

2015-11 Alkaff_CourtView_Alkaff_LakeView
2015-11 Alkaff_CourtView_Alkaff_LakeView

Sometimes they’ll be marked with a delightful “CW” in the level plan, like in this Punggol BayView 3-gen unit:

2014-01 PunggolBayView.jpg

But most of the time they will not, like in this level plan from Woodleigh Village (note that all the units have corner windows in their MBR):

2016-11 Woodleigh_Village.jpg

And we already saw in the previous segment on window heights about the corner window in Bishan Towers, where the corner window was just marked with an additional “W1”. Here’s the image again:

2020-08 Bishan_Towers windows.jpg

Sometimes there may be corner windows hidden in the project, buried deep within the brochure. So if it’s a feature you think you’ll enjoy, make sure to look closely at each and every page!

Extra windows

Extra windows


Back in the pre-BTO era when corner units frequently had different layouts from corridor units, the bedrooms and living room often faced different directions and “fanned out”, offering the opportunity for multiple window facings in a single room. Now most BTOs follow a standard linear layout with all windows facing the same way, and the main exterior walls are only those of the master bedroom and occasionally living room. Therefore extra windows are rare; whenever I stumble upon them I get extremely excited!


The more common type of extra window is in the master bedroom, where the window may either face the side of the flat or toward the back. This is sometimes done when this extra window faces a nice view that the rest of the flat cannot, but equally often it doesn’t have any apparent reason.


An example floorplan here from Bedok Beacon, where the extra window faces the road Bedok North Ave 1:

2016-11 Bedok_Beacon 4R2.jpg

There’s also Anchorvale Parkview, where the extra window is not shown in the floor plan section of the BTO brochure, but only in the level block plan. Not only that, the window faces a park and is ¾ height unlike the half height main MBR windows.

2014-03 AnchorvaleParkview 4R2.png

And here’s an image I found of a 4R flat in Dawson with this side window in full height:


(Source: iProperty)

It is much rarer to find an extra window in a 3R, but here’s one from Tampines Greenvines:

2018-05 Tampines_GreenVines 3R1.jpg

And a rare find of a 2R flat with an extra window in Dakota Breeze:

2017-05 Dakota_Breeze 2R1.jpg

The MBR extra window may also open up to the back of the unit instead, such as in this floor plan and photo from Compassvale Mast with a half-height window:

2012-11 Compassvale_Mast 5R2.jpg

To mix things up, here’s an extremely non-standard “fanned out” floor plan from Tampines Greenvines that allows an extra window in the master bedroom and one common room, and with a balcony too:

2018-05 Tampines_GreenVines 5R8.jpg
Screenshot 2021-02-27 at 10.59.17 AM.png

(Source: PropertyGuru

A much less common variation is the extra window at the dining area! These two featured projects were launched in 2017 and are not yet completed, so floor plans are all we’ve got.


This Fernvale Glades 5R flat has a lovely double-panel window over the intended dining area, which looks out to the corridor and lift area (also note the MBR corner window, bathroom orientation and wardrobe delightfully flush with the wall):

2017-11 Fernvale_Glades 5R1.jpg

While this Woodleigh Hillside 5R has a small window with a breathtaking view of the clothes rack:

2017-05 Woodleigh_Hillside 5R1.jpg

There’s this image of a HDB living room that a user posted on a hardwarezone forum to illustrate different window heights. It looks like a BTO living room based on the window architecture, but I’m unable to identify the location of project. If anyone knows where this is or owns the original image, please get in touch!


(Source: Gixxerfied)

And finally, here’s an extra window in the kitchen at Sun Sails in Sembawang, an absolute rarity in the usually windowless BTO kitchen:

2020-11 Sun_Sails Sembawang 5R2.jpg

And another in Fernvale Acres:

2018-11 Fernvale_Acres 5R2.jpg
Thermochromic windows

Thermochromic windows

BTO units are positioned away from the west sun whenever possible, which isn’t always. . In terms of pricing, west-facing units are sold at the same price as their non-west facing counterparts, even though resale prices are lower, so they’re often the least popular units in any project.


There’s a project in Bidadari (Woodleigh Hillside) that attempts to counteract that with an interesting offering: thermochromic windows.


In this level plan, units 501 and 503 face west, and have “W2” windows which are thermochromic windows according to the legend. The rest of the units have “W1” windows. Amusingly, there is no further information given on these thermochromic windows, so we have no clue what they actually are or if they successfully reduce the heat from the sun.

2017-05 Woodleigh_Hillside windows.jpg

Also note that both W1 and W2 ¾ windows start from 65cm above the ground, compared to 55cm in most projects!

Renovation rules (windows)

Renovation rules


(coming soon)

Wishlist (windows)



Thank you for reading to the end! I am always eager to expand this collection, so if you are in possession of any interesting BTO windows, please send over some photos and I’d love to feature them here. The following are some specific things that are missing:


Sliding windows

LR full + CBR ¾ + MBR full

Full-height corner window

Full-height corner window attached to half-height standard windows

Extra window at living area

Extra window at dining area


Your contributions are very much appreciated!



I do not own any of the images used in this post. All images were extracted from various sources around the web (property listings, personal blogs, forums, news outlets, renovation platforms, window contractors etc). I have not sought explicit permission to use any of them. However, they are being used for educational purposes and not for personal gain; I spent many months aggregating them and writing this post purely for the benefit of BTO hunters out there (and a strange sort of personal enjoyment in the process). I gain nothing financially from this website either directly or indirectly (my career is in healthcare, not interior design or anything related). However, if you own any of these images and would like me to remove them, please get in touch and I will do so immediately. Thank you.

bottom of page