Clear SkylightsCrawley

West Sussex · 9 miles from Crawley by road

Rooflights and skylights for Horsham roofs, from stone to new build

From the Causeway to Mowbray, Horsham's roofs range from medieval frames under Horsham Stone to trussed new builds. We fit rooflights and skylights to each, and write down the glass we choose for the railway and the rain.

Get a quote What is a quiet spec?

An opening rooflight in a plastered light well above a bathroom
Planning
Horsham District Council, with West Sussex County Council above it
Homes
Re-fronted medieval Causeway, Victorian and Edwardian streets, new estates at Mowbray and Kilnwood Vale
Roofs
Clay plain tile and Horsham Stone, some laid where thatch once was
Setting
Low Weald at about 50 metres, on the Arun Valley Line

Stone slabs, old frames and a railway through town

  • Stone that cannot be replaced

    Commercial quarrying of Horsham Stone at Tower Hill ended in 1876, so every slab around a new opening is lifted, numbered and relaid in its place.

  • Trains near the Arun Valley Line

    Loft rooms facing the line near Horsham or Littlehaven station hear passing trains through thin glass before they hear them through the roof.

  • Downpours on extension glass

    Flat panes and barred lanterns on Horsham kitchen extensions ring under Wealden rain unless the outer sheet and the upstand are chosen for it.

  • Loft windows past their best

    Roof windows from earlier Horsham loft conversions mist between panes and close loosely, letting in cold air and outdoor noise alike.

A sample quiet spec for a Bishopric loft room

A written quiet spec for a Victorian house in Horsham could read like this. Every quote carries one like it, drawn up for the room we stood in at the survey.

Room:
second-floor loft bedroom in a Victorian house off Bishopric, rear slope in clay plain tile
What we would listen for:
trains on the Arun Valley Line with the old window shut, and rain on the glass
Glazing:
laminated acoustic inner pane, outer and inner panes of unequal thickness, widest cavity the frame takes
Seals and upstand:
continuous compressed gaskets on the sash, plain tile flashing with soakers, lined and insulated reveals

Noise out hereStill in here

The survey file

Rooflights in Horsham

Horsham has a medieval street at its heart and thousands of new homes rising around its edges. A rooflight installation in Horsham can mean cutting through clay plain tile on a Victorian villa off Bishopric, or fitting a skylight into a truss roof at Mowbray that was finished last year. The glass, the flashing and the paperwork change with the house, so this page follows the town street by street, from the Causeway to the new estates, and sets out what we would specify for each.

Three ages of house

Horsham's houses, from the Causeway to Mowbray

Medieval timber behind later fronts, Victorian streets and new estates each take a rooflight differently.

Horsham's housing runs from medieval timber hidden behind later fronts to estates still being built. Each age of house takes a rooflight differently, so the survey starts by reading which age you live in.

The oldest fabric sits in the Causeway. Its medieval buildings were re-fronted in later fashions, so a house that looks Victorian from the pavement can carry a far older frame under its roof. That matters to us before anything else. A rooflight means trimming rafters, and an old frame is rarely square, rarely regular and sometimes pegged rather than nailed. We open a small area first, look, and then size the opening to what the timbers allow.

Horsham's Victorian and Edwardian buildings sit mainly within its conservation areas. The council's appraisal names Park House and Manor House, along with buildings in Queen Street, Bishopric, Worthing Road, London Road and Brighton Road. On these roofs a loft conversion or a back extension brings the rooflight question together with the planning question, and the planning position needs the most care. More on that further down.

The new Horsham still arriving

  • 2,500Homes permitted at Kilnwood ValeOutline permission came in March 2010, in Colgate parish.
  • spring 2027Highwood Village completionA development due to finish by the date shown.
  • about 1,100Homes at Highwood, approximatelyBuilt with trussed roofs to recent Building Regulations.

Then there is the Horsham that is still arriving. Kilnwood Vale, in Colgate parish between Horsham and Crawley, received outline permission in March 2010 for 2,500 homes. Highwood Village is a development of about 1,100 homes, due to finish by spring 2027. North Horsham is now known as Mowbray, with Legal & General as master developer and the new Bohunt Horsham School. Homes like these are built with trussed roofs and to recent Building Regulations, which changes the job completely: the question is not the age of the timber but which members may be cut at all.

So one town gives three quite different starting points. The table further down matches rooflight types to each.

NextClay plain tile, Horsham Stone and what sits between them

Tile and stone roofs

Clay plain tile, Horsham Stone and what sits between them

Clay plain tile and Horsham Stone can both take a rooflight, but each asks for its own flashing and its own patience.

The appraisal describes Horsham's older roofs as clay plain tile or Horsham Stone, sometimes laid where thatch once was. Both can take a rooflight, but each asks for its own flashing and its own patience.

Clay plain tile is small and double lapped. A rooflight in a plain tile roof needs a flashing kit made for deep, small-format tiles, with soakers worked in course by course up each side of the frame. Cut tiles at the edge of the opening are set so their nibs still hang on a batten, and the courses above and below are lifted and relaid rather than trimmed back hard. Done this way, the rooflight sits into the roof instead of on top of it.

Horsham Stone is a different matter. It was quarried commercially at Tower Hill from 1830 to 1876, so the slabs on a Horsham roof today are the ones already there. Every slab we lift is numbered, stacked on the scaffold and set back in its place. Where a stone roof meets a rooflight frame, the flashing has to allow for the depth and uneven profile of the stone, and the frame is often set a little lower to sit in plane with the slabs.

What each older roof asks for

  • Clay plain tileA flashing kit for small tiles, with soakers worked in course by course up each side.
  • Horsham StoneSlabs are numbered and replaced, and the frame is set a little lower to sit in plane.
  • Former thatch pitchThe pitch can be steeper and the rafters lighter, so both are checked before a size is proposed.
  • The stone quote lineSlabs expected, where they are stored and how they go back, all listed before booking.

Some of these roofs replaced thatch. On a roof that was once thatched, the pitch can be steeper than the tile or stone now asks for, and the rafters were cut for a lighter covering than stone. We check the pitch against the rooflight maker's minimum and the timbers against the load before proposing a size. A roof window that suits a 40 degree tile roof is not automatically right on a steeper former thatch pitch.

NextHorsham District Council and the four character statements

Council and consent

Horsham District Council and the four character statements

Most rooflights need no application, but a listing, an Article 4 direction, a flat or a condition can change the answer.

Planning in Horsham sits with Horsham District Council, with West Sussex County Council as the county authority. Whether your rooflight needs consent depends on the address, and we check that address before the quote is final.

Horsham District has 39 conservation areas. In the town itself the council has adopted character statements for London Road, Richmond Road, Park Terrace Gardens and Horsham Town Centre. You can read each one on the council's conservation area maps and character statements page, and we read the relevant one for any job in or near those streets.

On a house, the national permitted development rules usually let a rooflight go in without an application, provided it stands no more than 150 mm proud of the roof slope and stays under the ridge. Horsham addresses can fall outside that for a handful of reasons:

  • a listed house needs listed building consent, inside and out;
  • on some streets an Article 4 direction has taken the permitted rights away;
  • flats and maisonettes never had householder permitted development to begin with;
  • a planning condition attached to a newer estate home can restrict changes to the roof.

Numbers behind the planning check

  • 39Conservation areas in Horsham DistrictThe town has character statements for four of its areas.
  • 150 mmPermitted rise above the roof slopeThe national limit, with the unit staying under the ridge.
  • Part LStandard for heat lossWhat any new or replacement rooflight must reach.

We assume none of them. The address is checked against each. Where the house is in one of Horsham's conservation areas, a conservation rooflight is the usual starting point on a street-facing slope: a steel or cast-style frame with a slim profile, set flush into the tile or stone. Our guide to planning permission for rooflights explains the national rules in more depth.

Building Regulations are a separate question from planning. Opening up a roof alters its structure, and Part L sets the heat loss standard that any new or replacement rooflight must reach. Notifiable jobs are registered with Building Control by us, and the completed rooflight meets current Building Regulations.

NextTrains on the Arun Valley Line, and rain on a flat roof

Rail and rain

Trains on the Arun Valley Line, and rain on a flat roof

A house near the line hears trains through the glass, and every flat-roofed extension hears the rain.

Horsham's noise is its railway and its weather. Horsham station is on the Arun Valley Line, Littlehaven station opened in 1907, and every flat-roofed extension in the town hears the rain.

Across most of a roof, rafters, insulation and plasterboard muffle what happens outside. The rooflight is where that stops. A house near the line or either station therefore hears a train pass most through the glass, particularly in an attic bedroom whose opening faces the track.

Rain is the second source, and it falls on every address alike. Horsham stands in the Low Weald, at about 50 metres, with the River Arun cutting through the south of the town. On a flat rooflight or lantern a downpour strikes the glass a few feet over your head. Thin outer glass rings. A lantern cut up by many bars can sound like a garden shed in a storm.

Two sounds the glass lets in

  • TrainsHeard most in an attic bedroom whose opening faces the track.
  • Rain on a flat rooflightA downpour strikes the glass a few feet over your head, and thin outer glass rings.
  • Rain on a lanternMany bars give the drops more to ring against.

Neither problem needs anything unusual to solve. It needs the right glass, the right seals and a properly built upstand.

NextWhich rooflight suits which Horsham home

Matching product to home

Which rooflight suits which Horsham home

A stone roof, a Victorian back extension and a new-build loft each point to a different product.

The roof decides the rooflight. A stone roof in a conservation area, a Victorian back extension and a new-build loft each point to a different product.

Causeway or town centre house

Roof
Stone or plain tile, pitched
Likely rooflight
Flush conservation rooflight

Victorian or Edwardian house, rear slope

Roof
Clay plain tile
Likely rooflight
Roof window, centre pivot or top hung

Rear kitchen extension

Roof
Flat roof
Likely rooflight
Flat rooflight or lantern

Kilnwood Vale, Highwood or Mowbray home

Roof
Trussed, pitched
Likely rooflight
Roof window between trusses, or a sun tunnel
Horsham homeRoofLikely rooflight
Causeway or town centre houseStone or plain tile, pitchedFlush conservation rooflight
Victorian or Edwardian house, rear slopeClay plain tileRoof window, centre pivot or top hung
Rear kitchen extensionFlat roofFlat rooflight or lantern
Kilnwood Vale, Highwood or Mowbray homeTrussed, pitchedRoof window between trusses, or a sun tunnel

On a Victorian terrace or villa, the rear slope usually takes a standard roof window without trouble, and a loft bedroom gains both light and ventilation. Where the room is a kitchen extension, a roof lantern lifts the ceiling and floods a gloomy rear room with daylight, while a flat roof rooflight stays quieter under rain, because one broad pane leaves no glazing bars for drops to hit.

New-build homes need a lighter touch. Trussed rafters are engineered as a set, and a truss is never cut without a design from an engineer. Most roof windows come in widths that fit between standard truss spacing, so a skylight in a new Horsham home is usually sized to the gap rather than the other way round. If the truss layout leaves no open stretch of roof over a landing or bathroom, a sun tunnel brings daylight down a slim tube instead.

NextWriting a quiet spec for a Horsham room

Writing the spec

Writing a quiet spec for a Horsham room

A single written page arrives with the quote and opens with two questions: is the railway audible, and how does rain sound?

The quiet spec is a single written page about your room, and it arrives with the quote. In Horsham it opens with two questions: is the railway audible, and how does rain sound on the roof today?

The survey is partly listening. In an attic bedroom near the line we note which slope looks towards the track, and whether trains carry through with the existing window closed. Over a kitchen extension we examine the current glass, its bars and its kerb, and ask what a downpour does to the room. Whatever we hear is written on the spec plainly.

From there, the spec names the build. A typical Horsham example might read:

  1. Glazing: the inner pane laminated for acoustics, the two panes cut to unequal thicknesses so they never resonate in step, and as deep a gap between them as the frame permits.
  2. Outer pane: toughened glass, with a laminated version over a flat rooflight or lantern where rain is the chief worry.
  3. Seals: unbroken compression gaskets round the opening sash, and the frame bedded hard onto the upstand so sound finds no gap.
  4. Upstand: a lined, insulated kerb finished from inside, in place of a bare timber box.

A typical Horsham build, outside to room

  1. 1Outer pane Toughened glass, laminated over a flat rooflight or lantern where rain is the chief worry.
  2. 2Gap As deep as the frame permits.
  3. 3Inner pane Laminated for acoustics, cut to a different thickness from the outer pane.
  4. 4Seals Unbroken gaskets round the sash, and the frame bedded hard onto the upstand.
  5. 5Upstand A lined, insulated kerb finished from inside.

None of this is exotic. It is a choice among products that already exist, written down so you can see what you are buying. Our page on the quiet spec shows the full format, and the glass itself is chosen with the same care whether the room faces the railway or only the rain.

NextRenewing older rooflights in Horsham homes

Signs of age

Renewing older rooflights in Horsham homes

Roof windows from old loft conversions and flat rooflights on extensions both show when they are near the end.

Older rooflights in Horsham come in two kinds: roof windows from past loft conversions, and flat rooflights on extensions of every age. When either begins to fail, we replace the unit and use the change to improve the glass.

A tired rooflight tends to show itself in a few ways. Mist forms between the panes. A dark line of mould gathers along the bottom of the frame. The sash no longer closes firmly against its seal, and the room is colder and louder than it used to be. On a flat rooflight, water may sit on the glass because the upstand has settled and the fall has gone.

Replacing a roof window in a plain tile roof is usually a like-for-like opening: the frame comes out, the new unit goes in, and the flashing is renewed to suit. That is the moment to specify a laminated acoustic inner pane, which the original often lacked. On a Horsham Stone roof the same stone care applies as for a new opening, and every slab we move goes back.

How a tired rooflight shows itself

  • Mist between the panes The sealed unit has let go.
  • A dark line of mould It gathers along the bottom of the frame.
  • A sash that no longer closes firmly The room is colder and louder than it used to be.
  • Water sitting on flat glass The upstand has settled and the fall has gone.

A flat rooflight often deserves more than a straight swap. If the upstand is short, uninsulated or rotten, we rebuild it before the new unit goes on, so the fall on the glass is right and the kerb stops being a cold bridge. Our misted and failed rooflight replacement page sets out how we assess an old unit, and the costs page explains what moves the price of a replacement.

NextHorsham Stone, new estates and the railway: questions from local homeowners

Stone, estates, trains

Horsham Stone, new estates and the railway: questions from local homeowners

Answers to what Horsham's own mix of stone roofs, new estates and a railway tends to raise.

These are the questions Horsham's own mix of houses tends to raise. Each answer is short, and the fuller reasoning sits in the chapters above.

Can a rooflight go into a Horsham Stone roof?

Yes, with care. The stone is lifted and kept, the opening is framed, and a flashing suited to the depth of the slabs is worked in before the stone goes back around the frame. A conservation-style rooflight usually suits the look of the roof best.

My house is on London Road. Do I need planning permission?

London Road has an adopted character statement, so we check the address closely. Many rooflights still fall within permitted development, but a listed building, an Article 4 direction or a street-facing slope can change that. We confirm the position before the quote is final.

Can I add a skylight to a new home at Kilnwood Vale, Highwood or Mowbray?

Usually, yes. We fit a roof window between the trusses without cutting them, or propose a sun tunnel where the roof above the room does not allow a window. We also check whether the estate's planning permission carries any condition on roof alterations.

Will I still hear the trains through a new rooflight?

You will hear far less of them with the right glass. A laminated acoustic inner pane, good seals and an insulated upstand make the rooflight much closer to the rest of the roof in how it handles sound. The quiet spec sets out exactly what we would fit.

Horsham has neighbours with their own roofs and rules. See our pages on rooflights in Southwater and on Rusper. For the full range of rooflight and skylight work across the area, start at the homepage, or get a quote and we will arrange a survey of your Horsham roof.

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