Heritage Flush Casement Windows for Period Homes
Overview
The window that finally lets period homes have both the warmth of modern glazing and the elegance of true timber. Our flush casements sit perfectly level with the outer frame — with mechanical corner joints, monkey-tail handles, pencil-round edges and dummy sashes that would fool a joiner at three paces.
Mechanically-jointed 70mm flush uPVC profile · Heritage foil finishes · Argon-filled A+ rated glazing · Solid brass monkey-tail furniture · Q-Lon compression seals
Mechanically-Jointed Corners
True 45° mechanical joints (not welded seams) at every corner — the single detail that separates a heritage flush casement from a standard uPVC window at a glance.
Timber-Look, Zero Maintenance
Deep-grain foil finishes in Painswick, Chartwell Green, Anthracite, Cream, Rosewood and Irish Oak — colour-fast for 25+ years, no sanding, no repainting, no rot.
Conservation & Listed Building Ready
Accepted in the majority of conservation areas across London and the Home Counties. We prepare planning drawings and finish samples for your officer at no charge.
Monkey-Tail & Peardrop Hardware
Solid brass monkey-tail handles, peardrop stays and traditional casement fasteners in polished chrome, antique brass, pewter or black — chosen to match the era of the house.
Heritage Style, 0.9–1.4 W/m²K
A six-chamber profile, warm-edge spacer and argon-filled glazing provide energy-efficient whole-window performance behind traditional Georgian proportions.
Georgian Bars & Astragal Options
Internal, external and through-frame Georgian bars in 18mm or 25mm, with authentic astragal profiles and duplex-butt jointing. Lead-effect and stained glass upgrades available.
uPVC vs Aluminium vs Flush Casement
Compare whole-window U-values, energy ratings and frame performance for uPVC, aluminium and flush casement windows installed across London and the Home Counties.
uPVC
- Best for
- Every home — modern & period
- Frame sightlines
- Standard (~70mm)
- Maximum pane size
- Up to ~1.8m tall
- U-value (as low as)
- 0.9 – 1.4 W/m²K
- A+ energy rating
- Yes
- PAS 24 security
- Yes
- Colour choice
- 20+ foil finishes
- Dual inside / outside colour
- No
- Conservation-area friendly
- Case-by-case
- Mechanical (not welded) joints
- No
- Maintenance
- Wipe-clean, none
- Guarantee
- 10-year insurance-backed
Aluminium
- Best for
- Contemporary builds, large apertures
- Frame sightlines
- Slim (~55mm)
- Maximum pane size
- Up to ~3m tall
- U-value (as low as)
- 0.9 – 1.4 W/m²K
- A+ energy rating
- Yes
- PAS 24 security
- Yes
- Colour choice
- Any RAL, dual colour
- Dual inside / outside colour
- Yes
- Conservation-area friendly
- No
- Mechanical (not welded) joints
- Yes
- Maintenance
- Wipe-clean, none
- Guarantee
- 20-year finish + structural
Flush Casement
- Best for
- Period, cottage & listed homes
- Frame sightlines
- Slim, timber-look
- Maximum pane size
- Up to ~1.8m tall
- U-value (as low as)
- 0.9 – 1.4 W/m²K
- A+ energy rating
- Yes
- PAS 24 security
- Yes
- Colour choice
- Heritage foil palette
- Dual inside / outside colour
- No
- Conservation-area friendly
- Yes
- Mechanical (not welded) joints
- Yes
- Maintenance
- Wipe-clean, none
- Guarantee
- 10-year colour-fastness
Not sure which range fits your property? Book a free survey and we'll bring samples of all three to your door — no obligation, just honest advice.
uPVC vs aluminium vs flush casement — the answers we're asked most.
- Which energy-efficient windows are best for London and Home Counties homes?
- Our uPVC, aluminium and flush casement ranges achieve a whole-window U-value of 0.9 – 1.4 W/m²K. uPVC has naturally low frame conductivity, thermally broken aluminium combines slim sightlines with the same approved range, and heritage flush casements suit period and conservation homes across London and the target counties.
- When should I choose aluminium windows over uPVC?
- uPVC is a strong all-round choice for standard-sized apertures. Aluminium comes into its own on large panes above roughly 1.8m, contemporary builds where slim sightlines matter, and projects needing a bespoke RAL or dual inside/outside colour. For modest openings focused on thermal performance, uPVC is usually the natural fit.
- Will flush casement windows suit a conservation area or listed building?
- Yes — flush casements are our go-to for conservation areas, AONBs and listed properties. The sash sits flush with the frame (mimicking traditional timber joinery), corners are mechanically jointed rather than welded, and heritage foil finishes replicate painted timber convincingly. We regularly get them approved where standard uPVC would be refused.
- Can I mix window types on the same house?
- Absolutely — and we often recommend it. A common combination is flush casements to the front elevation for kerb appeal and standard uPVC or aluminium to the rear where a contemporary look and larger glazed openings take priority. Colours can be matched across ranges so the house reads consistently from every angle.
- How long do each type of window last?
- Modern uPVC frames are engineered for 35+ years of service and come with a 10-year insurance-backed guarantee. Aluminium frames outlast the building in most cases and carry a 20-year finish guarantee. Flush casements share uPVC's core structure with heritage foils that carry a 10-year colour-fastness warranty. All three use the same locking systems and Q-Lon seals.
- Which range offers the widest colour choice?
- Aluminium is the clear winner — any RAL colour, matt or satin, plus different colours inside and out. uPVC comes in 20+ foil finishes including anthracite grey, Chartwell green, cream and popular woodgrains. Flush casements share the heritage end of the uPVC palette (painted-timber creams, sage, off-black) and are limited to a single colour throughout.
- Are all three ranges equally secure?
- Yes — every window we install is PAS 24 tested and fitted with multi-point locking, laminated glass options and Secured by Design compatible hardware. The frame material doesn't change the security rating; the locking system, glass specification and installation quality do.
- How do I choose between the three ranges for my home?
- Start with the property's character. Period cottage or listed home in a conservation area → flush casement. Contemporary new-build or large glazed opening where sightlines matter → aluminium. Everything else, where value and long-term thermal performance are the priority → uPVC. Book a survey and we'll bring samples of all three so you can compare them at the house.
The homeowner's guide to uPVC vs Aluminium vs Flush Casement.
An 8-page PDF you can read in ten minutes. Side-by-side specs, clear performance comparisons, range-by-range detail and the six questions we're asked most. No email required — download and share freely.
- Full specification table — U-values, sightlines, guarantees, design suitability
- Which range suits period, contemporary and conservation-area homes
- Six FAQs and a checklist for booking your survey
Instant download · No email required · Share it with your architect, builder or partner.
Engineered to the millimetre.
Every frame we install is made to your survey sizes with the following performance envelope as standard.
- U-value (whole window)
- 0.9 – 1.4 W/m²K
- Corner joints
- Mechanical 45° (not welded)
- Frame projection
- Fully flush — sash sits level with outer frame
- Colours
- Painswick, Chartwell Green, Anthracite, Cream, Rosewood, Irish Oak, Agate Grey + full RAL
- Hardware
- Monkey-tail, peardrop, traditional casement fasteners · brass, chrome, pewter, black
- Bar options
- 18mm & 25mm Georgian · astragal · lead-effect · stained-glass upgrades
- Security
- PAS 24:2016 · Secured by Design · Doc Q compliant
- Guarantee
- 10-year insurance-backed · 10-year colour warranty
The flush casement windows family.
Every one of the following styles is available in the flush casement windows range — mix, match and specify at survey.
A calm, predictable process.
No sales calls, no pressure, no surprises. Every project follows the same six steps — with a named surveyor from start to finish.
- 01Day 0
Enquire
Send photos of the front elevation — we advise on planning-friendly specifications within one working day.
- 02Week 1–2
Planning support
For conservation areas and listed buildings, we prepare drawings, finish samples and a written spec for your planning officer at no charge.
- 03Week 2–3
Survey & sign-off
Detailed heritage survey — sightlines, cill projections, bar arrangements and hardware finalised on site.
- 04
Manufacture
Mechanically-jointed and hand-finished in the UK. Typical lead time 4–6 weeks including hardware.
- 05Fit week
Installation
CERTASS-registered fit team experienced with period brickwork and stone reveals. Lime mortar-safe methods on request.
- 06Ongoing
Aftercare
CERTASS certificate lodged, insurance-backed guarantee registered, hardware serviced free in year one.
When flush casement windows isn't the right answer.
We'd rather lose a job than sell the wrong window. Here's when to consider the alternatives.
Flush Casement Windows across London
and the Home Counties.
We install flush casement windows across six counties — every project surveyed, made and fitted by our in-house team. Choose your county to read local knowledge, planning notes and recent work.
See all areas coveredHeritage flush casement windows — fitted to period homes.
See timber-look flush casement windows fitted to a thatched cottage and red-brick rectory, plus a close-up of the cream interior frame and locking handle.
Practical answers.
Everything homeowners ask us about flush casement windows — survey, lead times, guarantees and coverage.
Do these really look like real timber?+
Closer than any window we've fitted. Mechanical (not welded) corner joints, deep grain foil, pencil-round profile edges and traditional hardware — walk past one at three paces and you would not know.
Will they be accepted in a conservation area?+
In most cases yes, particularly with timber-effect finish, Georgian bars and monkey-tail handles. We prepare planning drawings and finish samples for your officer at no charge and have secured approvals across London, Herts and Bucks conservation zones.
Are they allowed on listed buildings?+
Sometimes — listed-building consent is at the discretion of the local authority. Where uPVC is refused, we can supply the same profile in painted aluminium or timber-composite. We advise honestly on your chances at survey.
How do they compare on thermals to a standard uPVC casement?+
Identical — same six-chamber 70mm profile, same A+ glass, same warm-edge spacer. The mechanical joints and flush appearance are purely aesthetic; thermal and security performance is unchanged.
What Georgian bar option looks most authentic?+
Through-frame 18mm astragal bars with duplex-butt jointing at the intersections — the bar physically passes through the glass unit rather than being applied internally or externally. It is the most convincing option and the one most likely to secure planning consent.
What makes flush casements different from standard casements?+
The sash sits level with the outer frame, while mechanical joints and heritage hardware create a timber-like appearance. They suit period properties and conservation-sensitive elevations particularly well.
Can I mix flush casements with standard casements?+
Yes — many clients specify flush casements to the front elevation (for kerb appeal or planning) and standard uPVC to the rear (to suit the character of each elevation). We match colour, glass and handle finishes across both.
How long is the lead time?+
4–6 weeks from signed order for standard heritage colours and bar arrangements. Bespoke arched heads and non-standard RAL sprays add 1–2 weeks.
Enquire about
Flush Casement Windows.
Speak with our design team, book a home survey, and receive a fixed written quotation — all with no obligation.
Call · 020 3633 0405