Truss and tile
Estate roofs, village lanes and a lot of building
Kingston Bagpuize, with Southmoor alongside it, stands in the Vale of White Horse west of Oxford. There is an older village core and a great deal of housing from recent decades. Roofs run from hand-cut timber under old tiles to factory trusses under concrete, and the planning story differs just as much, so each job begins by establishing which kind of house it is.
Stage 01 · Truss roofs
What a modern truss roof will allow
Newer houses are roofed with trusses, and in Kingston Bagpuize that covers a large share of the village, built in successive phases over recent decades. In place of loose rafters over a hand-cut frame, a row of factory-made triangles spans the house at regular centres, each sized for the job and nothing more. That regularity helps with planning, but it limits what may be cut. A truss is structural, and a roof window cannot simply go where one stands.
The usual answer is a unit sized to sit in the gap between two trusses. Gaps vary with the roof design, so a window listed as suitable for the house next door may not suit yours. That is easy when the size is chosen at survey stage and awkward when a unit is picked first and the trusses discovered afterwards, which is why measuring comes before ordering.
A wider opening means trimming trusses, and in some roofs there is no sensible way to do it at all, and that is a structural change needing proper design and careful handling under the Building Regulations. Many modern lofts are also crowded with the diagonal web members of the trusses, leaving little room to convert, and a loft with a water tank or ductwork adds further obstacles that the survey will record. You are told whether a loft room is realistic before a quote is written for the windows that would light it.
Unit between two trusses
- Sized to the gap at survey
- No structural cutting
- Simpler Building Control route
- Delivery time set by the size
Opening that trims trusses
- Needs structural design first
- Allows a larger window
- More work inside the roof
- Fixed in the plan before ordering
Stage 02 · Older lanes
Cottages near the village centre
Away from the estates, Kingston Bagpuize keeps an older core of cottages and houses built in brick and stone, quieter than the main road and often reached by short lanes. Their roofs are tile or slate over hand-cut timber, so spacing and size change from one rafter to the next. These are also the houses most likely to be listed or to stand in a designated area.
On roofs like these a slim, flush conservation rooflight often looks best, and it is the unit we point owners towards when a house has real age. Rafters are measured at the exact spot, the covering is read for pitch and condition, and the survey notes whether matching spare tiles or slates exist.
The village also contains Kingston Bagpuize House, a large historic house, and older buildings near it. Even in a small place, the age of a building can differ sharply between neighbours. A neighbouring address tells you nothing, though. Each house is checked on its own, because listing and planning status do not follow from how a building looks.
| Home | Roof | First check |
|---|---|---|
| Older cottage | Hand-cut rafters | Spacing and soundness |
| Estate house | Factory trusses | Truss centres and webs |
| Garage or extension | Flat, membrane | Deck, falls and kerb |
| Flat or maisonette | Varies | No householder rights |
Stage 03 · Estate conditions
Reading the decision notice for your estate
Planning decisions in this village come from Vale of White Horse District Council, whose officers answer to its elected members. On an ordinary house a rooflight may be allowed without an application. Our planning guide for rooflights deals with where that stops, which is why this page does not. The question for your house is whether the right still exists.
Newer estates are where they may not. Permission for a development can carry a condition removing householder permitted development rights, so that any change to the roof needs an application. The condition sits on the decision notice, which should be on the council's online planning register under the address or the estate's name. Reading it takes minutes, and it can save a wasted order.
An older house raises different questions: is it listed, does it sit in a conservation area, does a direction apply? Any alteration to the character of a listed building needs consent of its own. Conservation pages on the council's website, and the register, answer the rest.
The job plan records what turned up and the route we suggest: nothing to apply for, a planning application, or consent for a listed building. We check and advise; the council decides.
Checked for a Kingston Bagpuize address
- Conditions on the estate's original permission
- Is the house listed
- Conservation area or direction nearby
- Whether the home is a flat
- Points for the council before ordering
Stage 04 · Garage and extension roofs
Flat tops on kitchens and converted garages
Many homes here have gained a rear extension or a converted garage, and nearly all of these have a flat roof. Some of the extensions are recent and well insulated; others are older and thinly built, and the difference matters for the choice of unit. These roofs sit over the darkest rooms, because depth leaves the middle of the space far from any window. Light from above is what helps: a flat rooflight or lantern lets daylight drop in from overhead, where it can reach the centre of the floor and the work surfaces.
Before one is chosen, the roof beneath is examined. The deck, the falls to the drain, the height of the upstand and the type of membrane all bear on the choice. A new kerb has to be tied into the existing covering, so the unit is specified to the real opening and never guessed.
Lantern glazing and frames are heavier than anything in a flat unit, so the opening may need extra support, and lifting them takes care. A roof lantern suits a wide kitchen or dining area, whereas a flat rooflight suits a narrower room or a conversion.
Sun tunnels earn a place here too, especially in family houses that grew a room at a time and left a dark corner behind. Where a gloomy hall or landing lies just beneath a pitched roof, a sun tunnel pipes daylight down through a tube, and the roof needs only a small hole.
Insulation differs from one flat roof to the next. Older extension roofs may have little, while newer ones are built to current standards, and a rooflight changes the heat balance of the room beneath. The survey notes what the roof already has, including the depth of the build-up above the ceiling, and the unit chosen is one whose glazing performance suits the way the room is built and used.
What stretches a Kingston Bagpuize fitting day
| Drive and gate | Where the van waits, and how the glazing is walked round to the garden |
|---|---|
| Roof type | Fitted from the loft when pitched, from above when flat |
| Scaffold or tower | Arranged early for higher roofs |
| Unit size | Larger frames and glass need more people |
| Inside lining | Boarding and finishing round the opening |
Each item above has a place on the survey sheet, and the written quote draws on that sheet.
Stage 05 · Plan to sign-off
From notebook to a signed-off roof
When the survey is finished, the findings become a job plan, and that arrives before anyone asks for money. It names the product and its dimensions, sets out what the planning register showed and how Building Control fits in, gives the waiting time for delivery and fixes a date for the fitting.
Taking a saw to a roof for a new unit is building work. If a job is notifiable, our office lodges the Building Control notification and tells you in writing which body receives it, either the council or a registered approver. Exchanging a whole rooflight or roof window counts as well, though exchanging only the sealed glass does not.
On the day, the team shows up at the hour the plan gives, cuts the opening, fits the unit and leaves the roof closed and made good. Once the work is signed off, the 10-year guarantee on workmanship applies.
Product, permission answer and day: all in writing, before a penny is asked.