Painting Window Frames in London Period Homes: A Complete Guide
How to paint window frames on London period homes — sash windows, casements, timber vs uPVC, draughtproofing, colour selection, and what a professional job actually involves.
Painting Window Frames in London Period Homes
Window frames are one of the most visible and most abused surfaces on any London property. They're exposed to everything the British climate can throw at them — sun, rain, frost, condensation — and they're often the first place that poor maintenance becomes apparent. On a period property, painted timber window frames in good condition look beautiful; in poor condition they can drag the whole building down.
This guide covers everything you need to know about painting window frames in London homes: different window types, paint systems, colour choices, and what a professional job looks like from start to finish.
Sash Windows: The Period Standard
The traditional sliding sash window is the defining window type of London Victorian and Georgian housing. A well-maintained sash is a thing of genuine beauty — the elegant proportions of the glazing bars, the way the window sits flush with the surrounding brickwork, the clean lines of the frame. A poorly maintained one is a draughty, paint-peeling embarrassment.
Painting a sash window properly requires care and a methodical approach. The process involves:
Preparation. Any flaking paint must be removed back to a sound surface. On older timber, particularly lower sills and the faces of parting beads, this can mean stripping back several layers. A heat gun or chemical stripper followed by sanding is the usual approach. Bare timber should be checked for rot — soft, spongy areas need to be dug out and filled with an appropriate two-part epoxy filler, or the section replaced entirely if the damage is extensive.
Priming. Bare timber must be primed before finish coats are applied. A specialist timber primer seals the wood, improves adhesion, and provides a stable base for the topcoats. Don't skip this stage — it's what makes the finish last.
Glazing compound. Where putty has hardened, cracked, or shrunk away from the glass, it needs to be raked out and replaced. Fresh linseed oil putty or a modern equivalent forms a proper weather seal and gives a clean profile. This is one of the most commonly skipped preparation steps, and one of the most important.
Finish coats. Two finish coats in a quality exterior trim paint. The choice between oil-based and waterborne formulations is discussed below. Glazing bars need careful masking or cutting in — thick paint on glazing bars blocks light and looks sloppy.
Allow a couple of days per bay window arrangement when done properly. Rushing this work produces paint failures within a year or two.
Casement Windows
Casement windows — side-hung, opening outward — are common in Edwardian and inter-war properties. They present similar challenges to sash windows in terms of preparation, but with a different set of moving parts. Pay particular attention to the rebate (the step where the casement closes against the frame): this area is prone to paint build-up from successive coats, which can cause casements to stick and ultimately prevent them from sealing properly.
When repainting casements, it's worth opening and fully working each sash to check that it opens, closes, and latches correctly. Stiff casements or casements that no longer close flush should be addressed as part of the decorating project rather than left.
Oil-Based vs Waterborne Trim Paints
The choice between oil-based and waterborne paints for timber windows is one that comes up constantly, and there's no single right answer.
Oil-based — traditional gloss or eggshell — remains a benchmark for durability on exterior timber. It penetrates the wood, remains flexible as timber expands and contracts, and achieves a very hard, smooth finish. The downsides are longer drying times, strong solvent smell during application, and slower recoating — a full oil-based repaint of a window might take two or three days from start to finish.
Waterborne — modern alkyd-modified or acrylic trim paints — have improved dramatically over the past fifteen years. They dry faster, have minimal smell, clean up with water, and many modern formulations have excellent durability. The best waterborne products (Farrow & Ball Exterior Eggshell, Little Greene's Intelligent Eggshell, Dulux Trade Weathershield) now match oil-based products in all practical performance measures for most applications.
On period properties, a satin or full eggshell finish is usually preferable to high gloss. A gloss finish on older, imperfect timber will highlight every grain irregularity and filling line; the slightly softer sheen of eggshell is more forgiving and looks more appropriate.
uPVC Window Frames
Many period properties have had original timber windows replaced with uPVC at some point — a decision that is cosmetically and architecturally unfortunate but irreversible without significant expense. If you're living with uPVC windows, they can be painted, though it requires the right approach.
Specialist uPVC paints, or a properly primed surface using a bonding primer before a conventional topcoat, will adhere to uPVC. The key is proper surface preparation — a light sanding to create a key, a thorough clean to remove any grease or mould release residues, and the right primer. Without the right primer, paint on uPVC will peel within months.
Draughtproofing and Window Maintenance
Repainting is also the right moment to address draughtproofing. Sash windows in period properties typically lose a significant amount of heat through gaps in the meeting rails, between the sashes and the pulley stiles, and at the sill. Purpose-made draught strips for sash windows — pile (brush) seals on the sides, blade seals on the top and bottom rails — are highly effective, largely invisible, and can dramatically improve comfort in winter.
A good decorator will mention this option as part of a window repainting project.
Colour Choices for Window Frames
In London period properties, window frame colour is primarily a question of what suits the brickwork and the overall facade composition. The most common options are:
White or off-white. The classic choice. Works on virtually every brick colour and period. A clean, period-appropriate white (Farrow & Ball All White or Wimborne White, or a Dulux or Little Greene equivalent) against London stock brick is a combination that has lasted two centuries for good reason.
Pale stone or cream. A warmer alternative to white, particularly effective on darker red brick or on rendered facades. Farrow & Ball Bone, Clunch, or String are options in this range.
Matching the front door. On some properties, painting window frames to match the front door colour creates a cohesive, considered look. This works better on houses where the windows are a prominent design element — a Victorian terrace with large bay windows, for example.
Heritage colours. For conservation area properties or listed buildings, specific colour ranges from Little Greene, Farrow & Ball, and Dulux Heritage offer historically-referenced options that are appropriate to the period of the building.