Sash, steel and slider

Why the frame, not the postcode

Claremont grew in layers, and you can still read them off the street. A village had formed on the main road by about 1840; the railway from Cape Town through to Wynberg arrived in 1864 and pulled a working village of cottages in below the line; and by 1890 the whole area, above and below the railway, held its own municipal status before being folded into greater Cape Town in 1913.¹ Then came the big subdivisions of the 1920s and 1930s — Ravensworth, Wyndover, Sanatorium Estate, Edinburgh Estate, Keurboom, Palmyra and The Vineyard among them — which is why so many houses here carry steel-framed windows rather than timber ones.¹

Below the line, the cottage grain survived. The first Harfield Village cottages date from the mid-1880s, most of them Victorian and Edwardian, many semi-detached or terraced, on streets named after English counties — Surrey, Suffolk, Norfolk.² Above it, the pattern is villas and mid-century houses on wide, tree-lined avenues, and around the commercial spine the stock turns to townhouses and low- and mid-rise blocks.

So a Claremont enquiry that starts with "I live in Claremont" tells us almost nothing about the job. One that starts with "our windows are the original timber sashes, and there's a bay in front" tells us nearly everything. Five frames cover most of the suburb. Find yours below.

The four numbers behind all of it

Whatever the frame, the sun does the same thing to it. Cape Town sits at latitude −33.93°, and four figures from the published sun-path tables explain nearly every complaint we get called about.³

There is a local correction to make, though, and it is the one thing most online sun calculators will not tell you. From Claremont the mountain stands to the west and north-west, so the printed sunset time is optimistic: the sun does not set here so much as go out, dropping behind rock while the tables still promise daylight. That has two consequences worth planning around. The hard hour is earlier than you expect — mid-afternoon rather than dusk — and it arrives fast, which is exactly the situation motorisation and a timer were invented for.

The second local fact is rain. The eastern slopes of the range — the side Claremont sits under — take more than four times the rainfall of the drier western slopes.⁴ That is why a Claremont brief is so often a double one: cut the glare in February, hold the warmth in July.

The timber sash

A vertical-sliding timber sash, usually taller than it is wide, often with glazing bars, and set in a plastered reveal deep enough to stand a mug in. It is the defining Claremont window, from the semis below the line to the villas on the upper avenues.

Two things about it govern the specification. First, the proportion: it is a tall window, so anything hung on it reads as a vertical, and a slat rhythm that fights the glazing bars looks wrong from the pavement. Second, the joinery is old and often carries a century of paint. A standard bracket screwed hard into a soft, over-painted stile is how a hundred-year-old frame gets damaged in ten seconds.

The bay

A bay is not one window. It is three or five windows set at angles to each other, which means each pane faces a slightly different bearing and takes the sun at a different time. That is precisely why so many bays end up half-solved: a single blind is fitted across the front of the recess, the room goes dark, and the two side panes — the ones actually causing the glare at four o'clock — carry on doing it.

Fit each facet separately. One blind per pane, one fabric and colour across all of them, and the bay reads as a designed set rather than three unrelated fixes. On a street-facing bay, sunscreen mesh usually wins over blockout: it takes the sting out of the low sun while you can still see who is at the gate.

The steel casement

The estates subdivided across the 1920s and 1930s left Claremont with a great many steel-framed windows,¹ and they behave nothing like timber. The frames are thin, so there is very little to fix into. The stays and handles stand proud into the room, so a blind hung tight inside the reveal fouls them the first time the window is opened. And steel is a superb conductor, which is why these windows sweat: on a wet Claremont winter's morning the condensation runs off the frame and pools on the sill.

The fix for the first two problems is geometry — mount the headbox above the opening, on the wall or the lintel, so the fabric hangs clear of the handles and nothing is screwed into a thin steel section. The fix for the third is thermal, and it is where a cellular blind earns its keep: the honeycomb traps a layer of still air against the glass, and still air is the insulator. A warmer inner face means less of the moisture in the room condensing on it.

The slider and the balcony door

Closer to the commercial spine the frame changes completely: aluminium sliders, stacking doors and full-height balcony glass in townhouses and blocks of flats. Three things make this a different job. The openings are wide, so whatever is fitted has to stack clear of the door or it becomes a daily irritation. The glass usually faces the street with nothing across it to filter the sun. And nobody is home at two o'clock to draw anything.

Wide vanes that draw fully aside — panel glides or verticals — clear a stacking door properly, and on a run of sliders one continuous system reads better than four separate blinds. Then motorise it. Not as an upsell: on a balcony door three metres wide, or a window above a stairwell, a motor and a timer are the difference between shading that gets used and shading that stays up all summer.

The new glazed extension

Almost every older Claremont house that has been worked on in the last two decades has gained the same thing: a rear extension with far more glass than the original building ever had. It is the best room in the house for ten months of the year and the worst for two, because a single-glazed box facing the afternoon collects heat all day and holds none of it overnight.

If the ceiling is still open, this is the moment to specify a concealed box — a slim recess that the fabric drops out of, with every bracket hidden. Once the ceiling is closed and skimmed, it is a much bigger job to retrofit. If the extension faces west or north-west, though, read the next section first: on that elevation the answer is not inside the room at all.

When the wall is the problem, not the frame

Everything above assumes the frame is the deciding factor. On one elevation it isn't. West and north-west glass in Claremont takes the sun from mid-afternoon onward at a falling angle, arriving from underneath any overhang, and no interior blind can fully answer it. This is simple physics rather than salesmanship: an interior blockout only absorbs solar energy after it has come through the glass, so the pane and the fabric warm up and radiate that heat straight back into the room. Stop it outside the glass and the pane never warms in the first place.

A blind inside the room manages light. A blind outside the glass manages heat. They are not competing products — they are answers to different questions.

That is why, on a hard Claremont west wall, we lead with external systems rather than talking anyone into a heavier curtain.

Old houses, shared buildings

Two rules decide what may be fixed to the outside of a Claremont building. The first is national: under the National Heritage Resources Act, no person may alter or demolish any structure — or part of a structure — older than 60 years without a permit from the relevant provincial heritage resources authority, which in the Western Cape is Heritage Western Cape.⁵ A great many Claremont houses are comfortably older than that. The second is local and contractual: in a sectional-title block, anything visible on the facade needs the body corporate's agreement before it is ordered, not after.

The practical line is easy to hold in your head. A blind fitted inside the reveal is a furnishing decision — it changes nothing about the structure. A roller-shutter headbox, an external venetian rail, an awning cassette or a zip-screen channel is fixed to the outside of the building, and on an older house or a shared block that is a permission question first and a product question second.

We will help you check the scheme rules, supply slim profiles, quiet colours and the product data an application needs, and put the whole thing in writing. What we will not do is tell you an approval is a formality, or submit it on your behalf. That belongs with the authority, the trustees and, where the house warrants it, your own heritage architect.

What only a measure settles

Everything above can be worked out from a plan and a compass. These cannot, and each one has changed a recommendation of ours on the day:

1. The true depth of the reveal, measured in three places. Old openings are rarely square, and a 15 mm difference decides whether a headbox sits inside the joinery or proud of it.
2. What the wall is actually made of. Solid brick, cavity work, a later stud wall or thin steel — the substrate decides the fixing, and whether an external system is viable there at all.
3. Which way each room really faces. Streets curve here, and extensions get built onto whichever wall had space. Aspect gets read room by room with a compass, not off the street name.
4. Where the handles and stays sit. On steel casements this alone decides inside-fit versus above-the-opening, and it cannot be judged from a photo.
5. Power, and permission. Whether there is a plug within reach of a motor, whether a battery tube can be recharged without a ladder, and whether the trustees or the heritage authority have a say in what shows from the street.

That is the honest reason the measure exists and why it costs nothing: it is far cheaper for everyone to find these out before a quote than after a fitting.