Interior Finishes: The Complete UK Guide (2026)

Interior finishes are what turn a shell of a house into a finished home, and the cost range across the category is enormous. Skimming a single ceiling costs as little as £150, while a bespoke oak staircase or a run of built-in joinery can run past £10,000. In 2026, UK homeowners are spending anywhere from a few pounds a metre on architrave and skirting to £15,000+ on a full staircase replacement, depending on material and specification.

Most of the money wasted on interior finishes is not wasted on the wrong product. It is wasted on the right product installed too early, into a substrate that was still drying, or specified without checking the one dimension or performance figure that a building control inspector will actually look at. This guide sets out those figures, and the sequence that keeps you from paying for the same work twice.

The Sequence, and the Drying Times That Set It

Interior finishing is a wet-to-dry sequence, and almost every avoidable defect in the category comes from compressing it. Screed and plaster carry a large volume of water. That water has to leave the building before anything absorbent, dimensionally sensitive or painted goes on top of it.

For a sand and cement screed, the working estimate is one day of drying for each millimetre of thickness up to 50 mm, with thicker screeds taking disproportionately longer.¹ A 70 mm floating screed therefore needs around 50 days for its first 50 mm and longer still for the remaining 20 mm, which is why floor coverings are the last thing to arrive on a well-run job. Minimum thicknesses matter for the same reason: a bonded cement and sand screed has a 25 mm minimum but is best specified at 40 mm; unbonded needs 50 mm minimum and is better at 70 mm or more; a floating screed over insulation needs 35 mm minimum and is better at 70 mm or more, with 100 mm or more preferred to avoid curling.¹ The thicker, more reliable build-up is also the slower one, which is the trade-off nobody mentions at quotation stage. Our guides to floor screed types and levelling a subfloor go into the build-ups in detail.

Plaster is quicker but the same principle applies. A skim coat is thin, but the water still has to go somewhere, and in a house with the windows shut it goes into the timber. Timber for internal joinery in a heated building should sit at 7% to 11% moisture content, corresponding to roughly 50% relative humidity; in an unheated internal space the figure rises to 10% to 14% at around 65%.² Skirting, architrave and doors delivered at the correct moisture content and then stored in a house that is still giving off plaster water will take up moisture, swell, and shrink back once the heating goes on. That is the mechanism behind opened mitres, gappy skirting and doors that bind in winter and rattle in summer.

The practical rule is simple: get the wet trades out, get heat and ventilation in, and let the building settle before the joiner arrives. Ventilation matters more than heat here, because a warm sealed house just moves moisture from the plaster into the air and then onto the coldest surface in the room. The Property Care Association is blunt that condensation is the most common form of unwanted dampness in UK homes, that it is increasing as buildings become more airtight and insulated, and that inadequate ventilation is the main reason moisture becomes a problem.³ Our note on condensation, mould and black spots covers the diagnosis, and treating damp walls before painting covers what to do when you have inherited the problem.

Walls and Plaster

Plaster and plasterboard are the base layer behind almost everything else in this guide. Plasterboard types and sizes explains when to specify standard, fire-rated, moisture-resistant or acoustic board, most sheets cost £5–£25 depending on type. Skimming that board is a separate job and a separate cost: ceiling plastering cost covers the £150–£300 skim-only price against £300–£600 for a full board-and-skim re-plaster.

The choice between board-and-skim and a full three-coat wet plaster is mostly a choice about substrate. Dry lining is faster, drier and more forgiving of an uneven wall, but it hangs the finish on dabs or battens rather than bonding it to the masonry, which is why it sounds hollow and why fixings into it need the right anchor. Wet plaster bonds to the background, handles curves and reveals better, and suits solid walls and older houses; it also puts substantially more water into the fabric. In a pre-1919 solid-wall house the answer is often neither of the modern options: lime plaster and lime mortar stay vapour-open where gypsum and cement trap moisture behind an impermeable skin. Our practical guides cover how to plaster a wall, replastering, fixing blown or cracked plaster and what a room costs to plaster.

Sanding plaster and cutting plasterboard produce far more harmful dust than people assume. The HSE separates construction dust into silica dust from concrete, mortar and sandstone; wood dust from softwood, hardwood and wood-based products including MDF and plywood; and other dust with little or no silica, most commonly gypsum from plasterboard.⁴ Over 500 construction workers are believed to die each year from silica exposure alone, and the HSE specifically corrects the habit of wetting material once before starting: damping down needs enough water at the right level for the whole duration of the work.⁴ For a homeowner sanding a ceiling, that means a dust-extracting sander and a fitted mask, not an open window.

Sound: What Part E Actually Requires

Part E is routinely misquoted in both directions, so it is worth being precise about which figures apply to what.⁵

Between separate dwellings, purpose-built walls must achieve a minimum 45 dB DnT,w + Ctr for airborne sound, and floors and stairs with a separating function must achieve a minimum 45 dB airborne and a maximum 62 dB L’nT,w for impact sound. Where a dwelling is formed by material change of use, such as splitting a house into flats, those relax to 43 dB airborne and 64 dB impact.⁵

Inside a single dwelling the requirement is much lighter. New internal walls and floors within a house need a laboratory value of a minimum 40 dB Rw, and requirement E2 covers internal walls between a bedroom or a room containing a WC and other rooms, plus internal floors.⁵ Crucially, E2 does not apply to an internal wall containing a door, to a wall separating an en suite from its own bedroom, or to existing walls and floors in a material change of use.⁵ That last set of exclusions is why a new stud wall in your own house rarely triggers anything: put a door in it and the requirement falls away entirely.

The practical consequence is that if you want a quiet room in your own home, Building Regulations will not get you there. You have to specify it. Where noise between rooms is the real problem rather than the finish itself, soundproofing a room covers the mass and decoupling techniques that go on before the final plaster coat, at £400–£2,500 DIY or £1,500–£8,000+ professionally installed, and acoustic insulation for floors and walls covers the materials. Mass, isolation and sealing every gap all matter; the cheapest of the three, sealing, is the one most often skipped.

Mouldings and Trim

Skirting, architrave and coving are usually the last things fitted before decoration, and the easiest place to mismatch a period property’s proportions. Skirting board types and cost compares MDF against solid timber at £1–£8 per linear metre in materials, plus £150–£300 per room in labour. Architrave should always match or complement it: architrave and skirting profiles walks through torus, ogee and chamfered options from £0.80–£8/m. Ceilings get the equivalent treatment in coving and cornice cost and fitting, typically £200–£600 per room all-in, and where the existing coving is original rather than new, repairing Victorian coving covers patching small cracks for a few pounds versus £80–£200 per metre for a cast replacement section.⁶

The decision between MDF and solid timber comes down to three things. MDF is dimensionally stable, takes paint better than any softwood, and machines to a crisp profile, so for painted work it is the better material and usually the cheaper one. It has no grain to raise and no knots to bleed through primer. It also has two hard limits: it swells irreversibly if it gets wet, so it needs a moisture-resistant grade anywhere near a bathroom or a solid wall that has not fully dried, and it is heavy and blunt on tools. Solid timber is the right choice where the moulding will be stained or waxed, where it has to be scribed to a badly out-of-true wall, or where you are matching an existing period profile. MDF vs solid timber for joinery explains why MDF is cheaper and more stable for painted work, at £25–£45 a sheet against £4–£8 per linear metre for comparable softwood, but cannot go anywhere damp without a moisture-resistant grade.

Cutting MDF is where the dust risk in this section sits. All wood dust is a substance hazardous to health under COSHH; it can cause asthma, dermatitis and irritation, and hardwood dust can cause a rare nasal cancer. The HSE names sanding, particularly with hand-held powered sanders, and using compressed air to blow dust off work as high-exposure activities, and warns against dry sweeping.⁷ Fine dust is the biggest risk because it travels furthest and goes deepest into the lungs.⁷

Our guides cover fitting skirting boards and removing them without damaging the wall.

Internal Doors and Fire Safety

Doors are both a finish and a safety element. Internal door types and how to choose compares hollow-core flush doors from around £30 with solid hardwood panelled doors at £400+. Getting the opening right matters just as much: standard internal door sizes sets out the six standard UK widths.

The dimension that actually gets checked is the clear opening width, measured from the face of the door stop to the face of the open leaf, not the leaf width. For a new dwelling, Approved Document M pairs doorway width with corridor width: a 750 mm clear opening needs a 900 mm corridor if approached head on, or 1200 mm if not; a 775 mm opening needs 1050 mm; an 800 mm opening needs 900 mm.⁸ Usefully, the guidance states that a standard 826 mm door leaf up to 44 mm thick is deemed to satisfy a requirement for a 775 mm clear opening.⁸ That is why 826 mm is the size to specify if you want an accessible route without a bespoke frame. Door linings and frames explains the difference between the two and why specifying the correct lining width for your wall thickness avoids costly on-site alterations, and hanging an internal door covers the fitting.

Fire doors are where the specification gets strict, and where most retrofits fail. Approved Document B’s Table C1 sets the domestic cases: a door between a dwellinghouse and an integral garage needs a minimum E 30 Sa, the modern designation for FD 30 S, a smoke-sealed thirty minute door; doors within fire-resisting construction inside a dwellinghouse need a minimum E 20, that is FD 20; and doors onto a protected stairway need E 30 Sa.⁹ A dwellinghouse with a storey more than 4.5 m above ground level, which is the trigger a loft conversion pulls, must have a protected stairway separated by fire-resisting construction of a minimum REI 30 at all storeys, or an alternative escape route.⁹ FD 60 is essentially not a domestic house product; in Volume 1 it appears for shafts, not for the doors in a two or three storey home. Our note on FD30 and FD60 fire doors sets out which rating applies where.

A certified fire door only performs as a doorset, and the installation tolerances are tight enough that a homeowner can check them. The gap between leaf and frame at the head and along both sides should be 2 to 4 mm, the threshold gap should follow the manufacturer’s instructions and is typically around 8 to 10 mm, and voids between frame and structural opening must be tightly packed with mineral wool rather than expanding foam.¹⁰ Intumescent seals are sized to the rating: 15 mm by 4 mm for most modern thirty minute doors, and 20 mm by 4 mm, or two of 10 mm by 4 mm, for sixty minute doors.¹¹ Gaps around the leaf should not exceed 3 mm on the two long edges and across the top, and the bottom gap is usually around 10 mm where smoke is not a consideration but 3 mm where smoke seals are required.¹¹ Cutting a glazing aperture or an air transfer grille on site invalidates the certification outright, and may only be done by a certificated licensed processor.¹⁰ The commonest expensive mistake here is trimming a certified leaf beyond the permitted allowance to fit a wonky opening: it voids the certificate and the door has to be replaced.

If a door is binding or dropping rather than failing, fixing doors that stick or drop covers the adjustments.

Staircases and Balustrades

A staircase is one of the highest-value single joinery items in a house. Staircase types and costs compares straight flights from £1,500–£3,500 against winders at £2,500–£5,000 and spirals at £2,000–£8,000. If yours is structurally sound but tired, staircase renovation cost covers refurbishing treads, spindles and handrail for £1,500–£4,500 rather than the £3,000–£15,000 a full replacement can reach.

The geometry is fixed by Approved Document K and it is worth knowing before you measure anything. For a private stair the rise must be between 150 mm and 220 mm and the going between 220 mm and 300 mm, the maximum pitch is 42 degrees, and the normal relationship is that twice the rise plus the going equals between 550 mm and 700 mm.¹² Maximum rise and minimum going cannot be combined, because the result exceeds 42 degrees. Minimum headroom on the access between levels is 2 m, with a reduced allowance for loft conversions.¹² Handrails should sit 900 mm to 1000 mm above the pitch line or floor.¹² Guarding in a single family dwelling must be a minimum 900 mm to stairs, landings, ramps and the edges of internal floors, rising to 1100 mm for external balconies, Juliette balconies and the edges of a roof, and where children under five may use the building a 100 mm sphere must not pass through any opening in the guarding.¹² The British Woodworking Federation adds the trigger point most people miss: guarding is needed at the sides of flights and landings wherever there is a drop of more than 600 mm.²

Short on floor space specifically, spiral staircase sizes and Building Regs covers the 1,500mm minimum compliant diameter and £2,000–£10,000+ price range. Whatever the stair type, newel posts, spindles and balustrades covers the £800–£2,000 softwood balustrade against £3,000–£8,000+ oak or glass upgrades. For a loft, loft conversion staircase options covers the space-saving layouts that still comply, and fixing squeaky floors and stairs covers the commonest complaint about an older flight.

A stair is also the biggest single piece of joinery in the house, so the moisture content rule bites hardest here. Delivering a new flight into a house that is still drying out is how you get squeaks and gaps in a stair that was perfect in the workshop.²

Built-in Storage and Joinery Materials

Alcoves either side of a chimney breast are the most common built-in storage opportunity in a UK home. Alcove cupboard cost and ideas compares £400–£900 flatpack units with £900–£2,500+ bespoke carpentry. Doing it yourself is realistic for a competent DIYer: how to build an alcove cupboard and shelves covers a materials-only build for £80–£250 over a weekend.

The choice between flatpack and bespoke is usually decided by the walls rather than the budget. A period alcove is rarely square, rarely plumb and rarely the same width top and bottom, so a carcass built off-site has to be scribed in, and the scribing is most of the labour. Where the alcove is close to square, flatpack plus a bespoke face frame gets you most of the look for a fraction of the cost. Where it is not, bespoke is cheaper than paying a joiner to fight a carcass that does not fit.

Paint, VOC and Ventilation

Paint is the cheapest finish in the house and the one where the coverage figure on the tin decides your shopping list. A typical interior matt emulsion covers up to 14 m² per litre, needs two coats, and is touch dry in two to four hours with the same interval between coats.¹³ That is a manufacturer’s figure on a prepared, sealed surface: new plaster drinks the first coat, which is what a thinned mist coat is for, and a strong colour change adds a coat regardless. Our guides cover how much paint you need, filling cracks before painting, painting woodwork and skirting, choosing colours, the best paint for kitchens and bathrooms and what decorating costs per room. BS 6150:2019 is the code of practice for painting buildings, covering preparation, initial painting and maintenance, and is the document a specification should call up if you want workmanship defined rather than assumed.¹⁴

VOC content is capped by law, and the limits explain why water-based and solvent-based products behave so differently. The maximum VOC content of a ready-to-use product is 30 g/l for interior matt walls and ceilings, whether waterborne or solventborne; 100 g/l for interior glossy walls and ceilings; 130 g/l waterborne against 300 g/l solventborne for interior trim and cladding paints for wood and metal; and 30 g/l waterborne against 350 g/l solventborne for primers.¹⁵ A solvent-based gloss can legally carry more than twice the VOCs of its water-based equivalent, which is the whole of the smell, the headache and the long recoat time in one number.

That makes ventilation part of the job rather than an afterthought. Approved Document F sets minimum intermittent extract rates of 30 l/s for a kitchen with a cooker hood extracting outside, 60 l/s for a kitchen without one, 30 l/s for a utility room, 15 l/s for a bathroom and 6 l/s for sanitary accommodation, with extract terminals no more than 400 mm below the ceiling.¹⁶ Background ventilators should provide at least 8000 mm² equivalent area in habitable rooms and kitchens, and where windows are being replaced the new ones must carry background ventilators no smaller than the originals.¹⁶ A freshly decorated room with the trickle vents painted shut is a room that will grow mould on the coldest wall by February. Bathroom ventilation and extractor requirements covers the wet-room case in detail.

Fixings, Adhesives and Final Fix

None of the above stays up without the right fixing. Wall plugs and anchors explains matching the plug to brick, block, plasterboard or stud at £3–£6 per 100, and screws and fixings covers thread, drive and material choice from £2–£5 per 200. For bonding rather than mechanical fixing, grab adhesive runs £3–£10 a tube, silicone vs acrylic sealant explains which of the £3–£12 tubes suits a wet room versus a skirting gap, and tile adhesive and grout covers standard and rapid-set mixes from £8–£25 per 20kg bag.

The sealant choice is a genuine decision, not a preference. Silicone is waterproof, flexible and permanent, but it cannot be painted, so it belongs in a shower, around a bath and at a worktop joint. Acrylic caulk is paintable and takes decoration, but it is not waterproof and it will crack if the joint moves much, so it belongs at a skirting-to-wall or architrave-to-plaster line. Using the wrong one in either direction is the single most visible finishing error in a decorated room.

The last jobs before a room is finished are usually electrical: LED downlights covers spacing and the fire-rated fittings required beneath a converted loft, at £8–£60 per fitting, and sockets and switches sets out the standard 450mm/1,200mm heights and £80–£180 per outlet fitted cost. Those heights come from Approved Document M, which requires wall switches, socket outlets, stopcocks and controls to have their centre line between 450 mm and 1200 mm above floor level, with consumer unit switches at 1350 mm to 1450 mm and boiler timer controls and thermostats between 900 mm and 1200 mm.⁸

What Things Cost

Sequence Your Finishes in the Right Order

Plaster and board first, then let it dry out fully before fitting skirting, architrave and coving, moisture from wet plaster will bow MDF and open up mitre joints within weeks. Hang doors and fit sockets and switches last, after decoration, so the trim isn’t marked during painting.

How to Choose a Specification

Work backwards from three questions and most of the decisions make themselves.

Will it get wet, or be near something that does? If yes, that rules out standard MDF, standard plasterboard and acrylic caulk, and rules in moisture-resistant grades and silicone. This is the question with the highest cost of getting wrong, because the failure appears months later and is not repairable in place.

Will it be painted or shown? Painted work favours MDF and engineered materials, which are cheaper, more stable and give a better paint finish than softwood. Anything to be stained, waxed or oiled needs solid timber, which costs more and needs the moisture content controlled.²

Does a regulation set a number for it? Doors, stairs, guarding, socket heights and separating walls all have figures attached; everything else is taste. Spend the specification effort on the regulated items, where getting it wrong means doing it again, and spend the money on the visible ones.

The trade-off that catches most people is between speed and stability. Every shortcut in this category buys time at the cost of movement: dry lining instead of wet plaster, a thin screed instead of a thick one, joinery fitted before the building has dried. Each is a legitimate choice. Each also has a predictable failure mode, and it is always the same one, a gap opening up where two materials meet.

The Expensive Mistakes

Fitting joinery into a drying building. Skirting, architrave and doors delivered at the right moisture content, into a house full of plaster water, will move once the heating goes on.² The result is opened mitres and binding doors, and the fix is refitting, not filling.

Trimming a certified fire door to fit. Cutting a leaf beyond the manufacturer’s permitted allowance, or cutting an aperture on site, voids the certification.¹⁰ The door then has to be replaced, and a building control officer or a buyer’s surveyor will spot it.

Assuming Part E gives you a quiet room. Internal walls in your own house need only a laboratory 40 dB Rw, and the requirement drops away entirely once a wall contains a door.⁵ If you want quiet, buy it deliberately.

Painting over trickle vents and skipping extract. The VOC limits explain the smell.¹⁵ The extract rates and the 8000 mm² of background ventilation explain the mould.¹⁶ A newly airtight, freshly decorated room with no working ventilation is the classic condensation case.³

Sanding without extraction. Gypsum and silica dust are covered by COSHH,⁴ wood dust from MDF and hardwood is too, and hand-held powered sanders are named by the HSE as a high-exposure activity.⁷ A dust-extracting sander and a fitted mask cost less than one visit to a doctor.

Laying a floor covering on a screed that is not dry. One day per millimetre up to 50 mm is the estimate, and it is a floor, not a wall, so the consequence of ignoring it is a lifted covering rather than a stain.¹

Where to Start

If you’re planning a full room refit, start with ceiling plastering cost to budget the base layer correctly, then move on to skirting board types and cost for the trim that ties the room together. Replacing a tired staircase is usually the single biggest-ticket item in this guide, staircase renovation cost is the fastest way to see whether a refurbish or a full replacement makes more sense for your budget.

The rules in this note are those that apply in England. Scotland, Wales and Northern Ireland have their own building standards and permitted development rights.