26.4 road miles north-west of Bournemouth
skylights & rooflights in iwerne minster
The estate mansion of 1878 and James Ismay's purchase of the estate in 1908 shaped Iwerne Minster, with Shroton alongside it and Cranborne Chase on the downs to the east. We survey every roof in the village.
the houses of Iwerne Minster and Shroton
- Estate-era cottagesRed brick, some half-timbered, built by successive owners of the estate.
- Semi-detached village homesShared walls, one roof line to match.
- Larger village housesDeeper roofs with room for a loft bedroom.
- Added kitchens and sitting roomsFlat or shallow roofs at the back.
the first look-up for an Iwerne Minster house
- planning authority
- Dorset Council
- protected landscape
- Cranborne Chase National Landscape; check the conservation area
- protected landscape
- Cranborne Chase National Landscape
- road miles
- 26.4
rooflights installed in Iwerne Minster and Shroton
estate brick and tile
an estate village under the chalk downs
Iwerne Minster has a Grade I church, a conservation area that Dorset Council lists, and a layout that owes a lot to two successive owners of the estate. Shroton lies close by, and the same planning authority covers both.
Red brick and half-timbering from the estate
The look of the village is the work of a few owners, and its roofs carry that history.
The second Lord Wolverton began a building programme in the village in red brick and half-timbering. James Ismay bought the estate in 1908 and went on to run the village as a single piece, down to its hand-painted shop signs. The mansion that Alfred Waterhouse designed for Lord Wolverton, dated 1878, became Clayesmore School in 1933. The result is a village where many houses were built to a common idea, and where the roofs on one street may share a pitch and a covering.
In a brick village the roof is the clean place for new light: the courses beside the opening are lifted, set aside and relaid, and the plain tile courses are matched to the existing line so that the finished window sits as part of the slope. On a house in a row, we match the position of the window to those on neighbouring roofs where they exist.
That helps a surveyor and it hinders one. It helps because rafter spacing and roof pitch on a row of similar houses are often similar, so a survey of one gives a good first idea of the next. It hinders because a house that looks uniform from the lane may have been altered at the back, with a rear wing or an extension that has its own roof and its own structure. We measure every roof on the building; we never carry the reading from the house next door.
A school in the middle of a village also affects the way work is planned. Term-time traffic on the main road, parking near the entrances and the timing of deliveries are things we ask about when we book the visit, so that glass and scaffold arrive when the lane can take them.
The Church of St Mary, a Grade I building, stands in the conservation area that Dorset Council lists for the village, and the conservation area contains a good many listed buildings besides. Shroton, the neighbouring settlement, has its own character and its own planning history, and we treat it as a separate address check rather than assuming it follows Iwerne Minster.
Shroton is the second name to keep in mind. It sits close to Iwerne Minster and the two are often mentioned together, but a house in one is an address check in its own right. We do not assume that a boundary, a listing or a past planning decision in the village applies to Shroton, or the other way round. The register and the heritage list answer for each address individually, and they are free to search.
The example card shows the readings we write down on a brick house with a tiled pitched roof. They are illustrative only; your own sheet carries your own numbers.
A survey visit to a village house, step by step
The sequence is the same everywhere; what changes is how long the loft takes.
A VELUX window or any other roof window is sold in a fixed range of sizes, and each model carries a pitch range from its maker. So the first job at the house is taking readings, and only then do we name a product. We arrive with a tape, an inclinometer and a torch, and we ask to see the roof void before we look at anything else.
In a village house the loft is often reached by a hatch on the landing, and the boards may be partly laid. The things we look for are the rafter spacing, the condition and size of the timbers, the position of the chimney and any water tank, and whether the loft is deep enough to build a shaft or a room. Outside, we walk round to see the slopes from the garden and from the lane, which tells us what a neighbour or a passer-by will see.
Where the house has more than one roof, the visit takes longer. A main roof, a rear wing and a porch each get their own readings, and each is listed separately on the sheet so a quote can name the one it refers to. Photographs go on the sheet beside the numbers. If a loft is full, we say so before the day and agree what needs to be moved.
The written sheet is ready after the visit. It lists the readings, the options that fit them and the checks that remain, including the planning and listing lookups. Our page on what happens at a rooflight survey covers the visit in more detail.
Allow for the weather on the survey day as well. In wet or windy conditions the roof is not climbed, and we rebook rather than rush the readings.
How we survey an Iwerne Minster roof
- Into the roof voidWe measure the rafter centres, check the timbers and look for anything in the way of an opening.
- On the roof or the ladderWe read the pitch on a rafter and note the covering, the condition of the battens and the position of the chimney.
- Around the houseWe look at each slope from the lane and the garden, and note which way each faces.
- The address checksWe search the conservation map, the heritage list and the planning register for the house.
- The survey sheetEvery reading and every option goes onto one written sheet you keep.
Cranborne Chase and what it does to a rooflight application
The designation matters, but less than most people expect.
Iwerne Minster lies inside Cranborne Chase National Landscape. Planning rules for householders are a little different in designated land: the dormer window right is withdrawn, for example. The rooflight right is not taken away by the designation itself. Two things can remove it: a council Article 4 direction, or wording attached to an earlier permission, and it does not apply to flats or maisonettes.
People who hear the words National Landscape tend to conclude that nothing can be added. The card sets that belief beside what the rules say.
A few practical points follow for an Iwerne Minster owner. First, read the decision notice for the house if you have one, because a condition attached years ago may govern the roof. Second, look at the roof of the house next door in the same row: if it already carries a rooflight, find out whether it was approved or built under the general right, since that tells you something about the street. Third, ask us to include the lookups in the survey, and the findings are written down.
For a house inside the conservation area, a conservation rooflight is the product that tends to fit the street. For a house that is listed, anything cut into the roof means listed building consent, applied for through Dorset Council.
Apply the same thinking to Shroton. Nearby protected land may follow a different boundary from the village, and a landscape designation can extend beyond the conservation area that sits within it. Searching each address separately, as the council's maps allow, keeps the answer correct.
Myth
Nothing can be added to a roof in a National Landscape
Many people in Cranborne Chase villages assume the designation rules out any new rooflight, so they never ask.
Fact
The designation alone does not remove the right
A rooflight is judged by the same rules as elsewhere. A listing can change the answer for one address, and so can a council Article 4 order or a condition left from an old permission. The planning guide has the conditions in full, and the council's own records show whether any of them reach you.
Lighting the kitchen and sitting room added behind the house
The rear of a village house is often where the roof is flat and the glass is large.
Walk round the back of a village house and you often find a single-storey addition: a kitchen, a utility, a sitting room, sometimes a garage turned into a study. The roof over it is flat or very shallow and the room beneath tends to be deep, with windows only along one side. Over the dark end, a flat roof rooflight lights the whole width, and on a wider room a roof lantern spreads the light further in.
Two measurements shape the product. One is the height of the kerb, the raised frame around the opening, above the finished roof. The other is the fall, the slope that lets water run off. Both go on the sheet before anything is ordered.
Access to the back of the house varies a good deal. A side path may be wide enough to carry a lantern in one piece, or the unit may have to be brought through the house, or lifted over. We check the route at the survey and say so on the sheet, since it affects the day the work is planned and the type of lifting kit that is needed.
A roof window in a pitched part of the house is a different calculation. For a bedroom above ground level, the width code and the escape rules come into play together: the code tells you how wide the glass is, and the rafter gap tells you whether it fits or one rafter must be trimmed.
Fontmell Magna lies a short way north up the A350 and Child Okeford over the hill to the west, and owners there raise the same questions.
Inside the extension, the same survey notes the ceiling height and what is above it, because a lantern needs a deeper well than a flat unit. The depth of the existing roof build-up, from the ceiling lining to the covering, sets how much of the unit shows inside and how wide the splayed lining can be.
- Commonly quoted minimum kerb height; each maker sets its own
- 150 mm
- Width of a C-size roof window, the narrowest code
- 55 cm
- Highest floor level from which a roof window can serve as an escape
- 4.5 m
faq
questions from Iwerne Minster and Shroton
Is Shroton treated differently from Iwerne Minster?
It has its own address checks, because conservation boundaries and listings differ from one settlement to the next. We search each address on its own.
My house is on a street of matching brick cottages. Will the roof be the same as next door's?
Perhaps not. Rear alterations, changed timbers and different extensions mean each roof gets its own tape and inclinometer.
Is a rooflight allowed in the Cranborne Chase National Landscape?
The designation does not remove the right in itself. A listing, a council direction or a condition left on an old permission can, so we check the address and put the answer on the sheet.
Can I light a dark kitchen at the back of the house?
Yes. A flat unit or a lantern both suit a deep kitchen. We measure the existing kerb or roof first, so the new frame sits correctly.