Full House Window & Door Replacement guide: 1930s semis in Caerphilly
Every 1930s semi-detached in Caerphilly has its own quirks, but the recurring six are: cavity brick construction with a rendered or pebble-dashed upper; curved or angular front bay across two storeys; a small canopy or porch over the front door, often with a stained-glass toplight; along with the usual interwar-property reveal detail. When full-house replacement land on this spec, we default to A+ uPVC or aluminium frames, one consistent foil/RAL across every elevation. Oil-heating running costs make triple-glazing an easier upsell on barn conversions than on urban stock. Render around the frame edge is often 60s scratch-coat — patch and re-paint the same visit rather than mask. The porch canopy fixings are usually one bolt into masonry and one into the fascia — we test both before removing the old door. Chimney breasts eat a foot of internal width on both sides — bay window quotes account for it in the survey. Estate roads are wide and van-friendly — we can leave the truck in one spot for the whole day without moving. Bay ceiling drops usually have a beam boxed in above — we route silicone around the boxing edge rather than through it. Rural cottages often have limited off-road parking; the van sits on the road and the crew boards through the front door. Rural access often includes a farm gate and a narrow lane — we check turn-in width at survey. Original Crittall frames still exist on some ex-council properties — check the perimeter for lead-paint before disturbing. Original stone reveals need a resin anchor rather than plug-and-screw — the dressed face crumbles under mechanical fixings.
Local context — Caerphilly
- Council
- Caerphilly
- Postcodes
- CF83
- Main route
- A468
- Nearest town
- Cardiff (7 mi)
Neighbourhoods we cover: Bedwas, Trethomas, Machen, Energlyn, Llanbradach. Easy in via the A469, and we're 10 minutes from the A470 for vans loaded with full-house glass.
Who's asking
Second-time buyers extending or refurbing family homes, and long-time owners finally replacing 90s installs that are now on their second failure.
In Caerphilly specifically that reads as young families upgrading first homes, long-time owners replacing original 90s uPVC. The recurring driver for a full-house replacement enquiry is: Homeowners looking to fix the bay-window mismatch and warm the property up as one job.
What makes a 1930s semi-detached its own thing
- a small canopy or porch over the front door, often with a stained-glass toplight
- curved or angular front bay across two storeys
- cavity brick construction with a rendered or pebble-dashed upper
- hipped tile roof, usually red clay
Common 1930s semis problems we quote full-house replacement for
- 1The two-storey bay has been cheaply re-glazed with an under-sized profile that reads visibly wrong.
- 2Back kitchen extension has 90s uPVC with fogged units and dropped hinges.
- 3Porch canopy timber has rotted at the fixings.
Planning & permissions
Not usually protected, though estates with consistent bay-fronts read better when replacements match neighbours in colour and sightline.
Locally in Caerphilly, Caerphilly County Borough Council covers this area. Market town with the castle as the centrepiece — a mix of stone period stock and modern estates. We check any conservation or Article 4 status against the address before quoting rather than after.
What we typically find on survey
- ·The letterbox opening is not draught-proofed at all — a candle held two feet away flickers in a light wind.
- ·The internal beadwork has been painted so many times the mitres are unrecognisable.
- ·The internal glazing bead across the top of the bay lifts out completely with fingernail pressure.
- ·Condensation runs down the inside of every north-facing pane between October and March.
- ·One of the sealed units carries the previous installer's phone number etched on the aluminium spacer bar.
- ·There is no drip groove on the underside of the cill — water tracks straight back onto the brick face.
- ·The composite front door skin has a shallow dent from a delivery bike handlebar and it has ovalised the door.
- ·One kitchen unit has a defrost trace across the low-e coating — the argon fill has been gone a while.
- ·The concrete cill under the door has heaved by 3mm across the two-metre span, tilting the whole threshold.
- ·One handle turns freely through 180° with no engagement — a snapped internal cam.
- ·The letterplate has a hinged internal flap that has snapped off and is currently held in place with masking tape.
- ·The old timber sub-frame under the current uPVC unit is still in place and is soft at the bottom left corner.
- ·One patio-door interlock has a bent alignment lug — the door jams shut half of the time.
- ·The internal window board has swelled at the sink end from years of splash and is delaminating along the front edge.
- ·The letterplate is a straight through-plate with no anti-snap flap — visible from outside in the hallway.
- ·The multipoint lock still throws but the internal handle has 40° of dead travel before engaging.
- ·One sash locks by lifting a nail out of the frame — a bodge from a decade ago that everyone forgot about.
- ·The window opens fine on a cold morning and binds by 3pm on a hot afternoon — classic thermal-expansion bind.
- ·The bay-window front elevation has a visible smile — the middle mullion has sagged and taken the head with it.
- ·The transom bar has a live crack in the plastic, opened up by summer expansion cycles.
- ·The kitchen window has a defrost line across the low-e coating — argon gas long gone.
- ·The front door has been painted three times without stripping — the paint film is now stopping the door closing at the top.
- ·The bay-corner post has bowed by about 4mm across two metres — visible only if you sight along it.
- ·The cylinder on the front door still has the builder's key stamp, meaning it has never been changed since handover.
Why residents are enquiring right now
- ·The resident wants the front door lock to be re-keyable if a set of keys goes missing in year three.
- ·The buyer wants the property to be quieter after 11pm — the street noise is fine, the bass from next door is not.
- ·The resident wants the crew to remove and re-hang the internal curtains as part of the job, not leave that step to them.
- ·The resident wants the patio door to slide with one finger — not the two-handed heave the current one takes.
- ·The owner wants the crew to talk to the neighbour before scaffold goes up on a shared party wall.
- ·The homeowner wants matt black hardware because everything inside the house is matt black — no chrome to argue with.
- ·The resident has already lost one composite door to a courier boot and wants the replacement rated for impact.
- ·The resident is done with condensation-driven mould at the sill line every February.
- ·The owner wants the property to look less like a rental and more like a home, and the front door does most of that work.
- ·The resident wants the whole property warm to bare feet on a January morning — the frames are the last variable.
- ·The buyer wants the frames to still look right in twenty years, not just at handover.
- ·The buyer wants a genuine Which? Trusted Trader install, not a subcontracted crew running the badge.
- ·The owner is dealing with a partner who works nights and needs the bedroom acoustically watertight before summer.
- ·The owner has scaffolding booked for a re-render and wants the frames sequenced around the render trades.
- ·The buyer wants the frames branded with the manufacturer's paperwork stapled to the frame chamber for the next owner.
- ·A recent break-in on the street has moved security up the priority list ahead of aesthetics.
- ·The homeowner is on holiday half the year and wants a security spec they can leave for weeks without worrying.
- ·The owner is preparing the property for a rental switch and wants glazing to hit HMO fire-escape spec.
- ·The homeowner has watched the neighbour's job go in and knows exactly what they do and do not want.
- ·The buyer wants a composite door slab that a courier's boot cannot dent when a delivery is fumbled.
- ·The owner is done paying to service failing 90s uPVC every couple of years and wants the whole set replaced together.
- ·The homeowner has an infrared thermometer and has been point-checking the frames — they want the readings up by ten degrees.
- ·The homeowner wants the composite slab to be paintable without voiding the manufacturer warranty.
- ·The buyer wants a full set of the same colour across every elevation, not the current mixed collection.
How we actually fit it
- ·Fixings are always at the reinforcement points — a screw through the chamber alone loosens within a year.
- ·The perimeter airtight tape is applied over the frame flange in a single unbroken run around all four sides.
- ·Cylinders come out of the box, get numbered, and are the last thing fitted, so a lost cylinder does not stall the day.
- ·The wall around the frame is Hoovered before the client sees the room again — brick dust ages a first impression.
- ·The new frame is stood in the reveal dry before any fixings go in — a final chance to catch a wrong-hand delivery.
- ·The client is walked through the operation of every lock, every vent, and every restraint before the crew leaves.
- ·The old frame's fixing holes in the brick are filled and made good before the new outer frame beads up to the reveal.
- ·The reveal is brushed down and vacuumed before any sealant runs, so the bead adheres to substrate, not dust.
- ·The frame drainage slots are checked and blown clear before the beads go in — a plugged slot fills the chamber.
- ·The head of the frame is packed dry before the sides are fixed, so the frame does not distort during installation.
- ·The keeps for the multipoint are set with the door open and the position marked, not adjusted by eye once the door is closed.
- ·The gasket is dressed into every corner with a specific gasket tool, not a screwdriver, so the corner stays sharp.
- ·The reveals are photographed on arrival so any pre-existing damage is on record before the crew touches them.
- ·The client is walked through the finished job with a printed operation card, not a rushed verbal handover.
- ·The multipoint hooks are lightly greased after fitting, before the door is closed for the first time.
- ·The frame reinforcement is chosen for the wind load exposure of the elevation, not the smallest steel that fits.
- ·The bay assembly is squared with a laser diagonal, not a tape measure and eye.
- ·The client's Wi-Fi router near the door is checked for a signal drop after the composite slab is fitted — a rare case, but worth confirming.
- ·The client is left with the manufacturer's paperwork in a labelled envelope, not a folded receipt tucked inside a drawer.
- ·The door hinges are set with the correct rise before the frame is finally fixed — retro-adjustment on cheap hinges is limited.
- ·The van carries a set of dust extraction attachments and uses them on any grinder work in occupied rooms.
- ·The fitting van is stocked with the specific spare parts likely to be needed on the day — not a return trip on a missing hinge.
- ·The manufacturer's serial-number label on the new frame is peeled off, not left to yellow on the glass for years.
- ·Sealant is a single continuous bead run at the perimeter, not overlapped in six-inch runs.
Free full-house replacement survey — 1930s semi-detached, Caerphilly
Book a 30-minute visit. We walk every reveal, sample the one consistent foil/RAL across every elevation against the elevation, and email a written figure inside 24 hours.
Summary — full-house replacement on a 1930s semi-detached in Caerphilly
Book a survey and you'll have a full-house replacement figure for your 1930s semi-detached inside 24 hours. Coastal render is often painted in bright colours that mask sealant discolouration — colour matching at the frame perimeter matters. Estate roads loop back to themselves — the crew's van sits in one spot all day without moving. No pressure sell, no deposit until a date is confirmed. Non-square reveals mean every frame is bespoke-scribed — templates rather than standard sizes. Front door threshold sits on a York stone step in most cases — level it back to the tile line before the frame lands. Party wall proximity means neighbours hear the removal — we knock ahead and time the noisy hour to mid-morning. Timber-frame construction means fixings go into studs; we probe before drilling to locate them.
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