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: Rudry, Energlyn, Machen, Trethomas, Bedwas, Nelson. 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.
- ·The reveal internally has been skimmed over the old plaster edge, hiding a 6mm gap behind the architrave.
- ·Wet-set fixings through the outer frame have rusted and stained the surrounding brick.
- ·The georgian bar between the panes has come detached from the top spacer on one unit.
- ·The cill end-cap has fallen off and the cill chamber is now a home for insects.
- ·The front-door hinge screws are 25mm chipboard fixings, not the manufacturer's 60mm hinge screws.
- ·The seal at the beading corner has shrunk enough to expose the mitre on the internal white finish.
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.
- ·The customer wants a specific hardware colour to match a kitchen renovation booked six months out.
- ·The owner has an electric car on the drive and wants the front to say the whole property has been kept up.
- ·The owner is done with the biannual repaint of the timber back door and wants a paint-free equivalent.
- ·The homeowner wants a warranty they can pass on to the next owner without a fee or a form.
- ·The owner is done with the sliding door drag and wants one that closes with a single push.
- ·The buyer is moving in with two dogs and needs a back door that will not degrade with claw scrape.
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.
- ·Cavity closers get inserted where the old frame's cavity closer has failed — not omitted because it is unseen work.
- ·The internal reveal is masked before any silicone runs, so the finished bead is a clean line against the plaster.
- ·The multipoint gearbox is thrown by hand before the frame goes in — a factory fault at that point is a five-minute fix.
- ·The install date is stamped inside the frame chamber for future reference — a decade later a client can still date it.
- ·Fixings are set at the manufacturer's spacing, not evenly spaced by eye — the corner loads matter.
- ·The frame is protected with a low-tack tape at any point a tool might scrape it during the fitting hour.
Owner occupiers doing the whole property in one go
Why full-house replacement look different to owner occupiers doing the whole property in one go
Written for owners who want the job over with in one visit. The questions we get asked at this stage are about dust, security overnight, and whether the quote can be itemised so the budget can be trimmed elevation by elevation.
What we build into the quote for you
- Old frames, sashes and glass taken away rather than left in the garden
- A programme that keeps the house lockable and weathertight every night
- The internal cill is scribed with a coping saw against the reveal plaster, not butted flush with a caulk joint.
- The perimeter foam goes in in two passes so the second lift meets the first without a void in the middle.
Full public liability insurance and a written two year fitting guarantee on the package
Get the whole house priced in one quote in Caerphilly
One visit, one written figure, every opening listed separately so you can see exactly where the money goes. Full-house replacement for 1930s semis properties in Caerphilly, typically 2–4 days depending on count, with a final snag visit a week later, with a written price inside 24 hours.
Questions we get on 1930s semis jobs like this
Is it worth upgrading the whole elevation rather than one opening?+
On a 1930s semis it often is, because the frames were fitted at the same time and tend to fail together. Homeowners looking to fix the bay-window mismatch and warm the property up as one job. We price both options so you can compare them properly.
Will planning rules affect full-house replacement on this kind of property?+
Not usually protected, though estates with consistent bay-fronts read better when replacements match neighbours in colour and sightline. We check the position with Caerphilly County Borough Council before anything is ordered so there is no surprise after manufacture.
What tends to push the price up on a 1930s semis?+
Three things, in order: the state of the timber or brick behind the old frame, whether the opening has been altered at some point, and glass size. The two-storey bay has been cheaply re-glazed with an under-sized profile that reads visibly wrong is the one that catches people out. Around Caerphilly we quote the making good in writing rather than treating it as an extra on the day.
Do you fit full-house replacement on 1930s semis around Caerphilly?+
Regularly. Bedwas, CF83 is where most of this work lands, and we also cover Cardiff, Newport, Pontypridd. Easy in via the A469, and we're 10 minutes from the A470 for vans loaded with full-house glass.
Will the house be secure overnight during a full replacement?+
Yes. Only one elevation is open at a time and every opening we start is finished, glazed and locked before we leave for the day.
Can I stage a whole house replacement over two visits?+
Yes. Front elevation and front door first, rear later is a common split. It costs slightly more overall than doing everything in one visit and we will show you the difference in writing before you decide.
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. Around Caerphilly that usually means wind-driven rain off the mountain ridge on stone-fronted terraces, post-war semis around the castle and newer estates out toward Bedwas, with Bedwas and Trethomas the streets we are on most. 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.
Let's make your house feel more like home.
Fill in a few details and we'll come back within 24 hours with a clear quote — no callout fee, no pressure.