Sirhowy valley, a drive of 18.3 miles to the north-west from Newport
Blackwood skylights and rooflights
- 10-year workmanship guarantee
- We handle the Building Control notification where notifiable
John Hodder Moggridge's model village and its roofs
Blackwood, Coed Duon in Welsh, is a town on the Sirhowy River in the South Wales Valleys, and it comes under Caerphilly County Borough Council. It was founded in the early 19th century by the colliery owner John Hodder Moggridge, who built the first houses in an attempt at a model village. From Newport the town is 18.3 miles away by road. Its bridge is cable-stayed, 230 m long and supported 30 m above the valley floor by a 90 m A-frame pylon. Before it, the journey was made by a detour or over a steep road through the bottom of the valley, known locally as the Rhiw.
Roofs face every way, and a window that suits a south-facing pitch in June may want a blind by lunchtime, while a north-facing slope gives a steadier light. We read the direction of each slope at the survey, so the size and the position of an opening follow the roof, not a standard drawing.
Roofs in any town come in several ages, and the age shapes the job. Terraced houses of the older kind often have a shallow loft, more use for storage than for living. Later houses more often have a loft deep enough for a room, and a rear extension of any age may have a flat roof. The table pairs the common cases with the openings worth asking about.
| Home type | The roof over it | Fitting to consider |
|---|---|---|
| Valley terrace | Pitched, with a shallow loft above the rooms | A roof window over the stairs, or a sun tunnel above the landing |
| Semi with a loft that has been boarded | Pitched, with headroom for a bedroom | Roof windows for a loft room, with blackout fitted |
| Home with a rear extension | Flat roof behind the main slope | A flat rooflight over the kitchen or dining end |
| Bathroom with no outside wall | Pitched or flat, with the loft above | A roof window if the slope allows, otherwise a sun tunnel |
What suits Blackwood houses
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Caerphilly and the Welsh planning rules
Planning applications in Blackwood go to Caerphilly County Borough Council. For a house, the question of when a rooflight needs one is answered by Welsh law, and the limits, with the cases where the right falls away, can be read in the Wales section of our planning guide.
Householder permitted development rights do not extend to a flat, and an Article 4 direction lets a council withdraw them from a street or an estate. A planning condition on the original permission can have the same effect, so it pays to ask the council about the house first.
If the house is listed, any work that would affect its character needs listed building consent, applied for through Caerphilly. Cadw recommends which buildings are listed, and the Welsh Ministers compile the list.
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Close to Blackwood
A winter bathroom under the slope
Steam, vents and a window in a cold roof.
January is when a bathroom roof window earns or loses its keep. Hot water is running before it is light outside, the room fills with steam, and the glass overhead, often the coldest surface in the room, is where the moisture can land first. A sash that opens and a fan that keeps running after the shower are the plain defences, and the window is chosen with them in mind.
Plenty of bathrooms in terraced houses sit at the back under the slope, with no exterior wall for a window. A roof window gives that room daylight and a way to air it. A sun tunnel is the alternative where the slope is awkward or the route through the loft is clear, but it brings daylight only and does not open, so it never stands in for ventilation.
Swapping an old window brings in Approved Document F (Wales), which asks that the ventilation afterwards be no poorer than before. Where the old window carried trickle vents, the new one should carry vents no smaller than those, controllable by the occupant or automatically. That detail slips out of view when two windows look alike on paper, so the vents on the one coming out are worth looking at before the new one is ordered.
Privacy is the second question. Blackwood lies in a valley, and a roof window can sit within sight of a window further up the hillside. In the evening, with the light on, anyone looking down can see in through clear glass. A blind answers it, and at the survey we stand at the window position and look at who might be looking.
The outer pane takes the weather. VELUX lists a dirt-repellent coating among its glazing options, and which options exist varies with the model, so it is a fair question to put to us when a window is being chosen.
Approval under the Building Regulations will generally be needed for a roof window that is new. Where the work is notifiable, we handle the notification with local authority building control or a registered building control approver.
| What happens | What helps |
|---|---|
| Steam on the coldest glass | An opening sash and a fan |
| Old vents lost on replacement | New vents no smaller, controllable |
| Looked down on from the hill | A blind, chosen with the window |
| Weather on the outer pane | Glazing options to ask the maker about |
From a model village to a dark hall
The inner hallway, a loft route and a sun tunnel.
Moggridge built Blackwood's first houses in an attempt at a model village. In terraced plans generally, hallways are often dark for a plain reason. Stairs rise through the middle, the hall runs between two rooms, and the landing above has nothing on the outside wall.
A sun tunnel is built for those places. It has three parts: a dome that catches daylight on the roof, a tube that carries it across the roof space, and a diffuser set in the ceiling that releases it into the hall. It carries daylight and nothing else, so on a dull afternoon the hall stays dim, and once the sun is down the ceiling shows only a pale circle.
The route is the question. Anything stored up there, and any beam or pipe in the way, has to be cleared or worked around between the roof and the ceiling below. Our page on rigid and flexible tubes explains what each type does with a bend.
The difference between a sun tunnel and a roof window is the difference between a lamp and a window. A sun tunnel brings a patch of light to a small space that cannot have a window. A roof window changes a room: the view of the sky, the air and the sense of height. Hallways take sun tunnels well, bedrooms and studies take windows, and a house can happily have both.
Up top, the dome sits on the covering, whether that is slate or concrete tile, and the slope chosen is the one with the most open sky. We note both at the survey. If the loft holds a cold tank or a bundle of cabling, the diffuser may land a little off centre, since it goes where the stairs and doorways gain most.
A fixed written quote follows once the free survey is done.
One hallway, one sun tunnel
- 08:00MorningDaylight reaches the hall from a roof the household never sees.
- 13:00MiddayThe diffuser is at its brightest and the landing stays lit without the switch.
- 16:30Late afternoonThe tube carries less as the sky dims.
- 20:00EveningThe hall light takes over from a dim, cool circle overhead.
The kitchen at the back
A flat rooflight where the old wall used to be.
Start with the room underneath. A kitchen added behind a terrace or a semi often pushes the daylight away from the middle of the plan, because the old back wall, with its window, now stands inside the house. The table end of the room then relies on a garden door at the far side and nothing else.
A flat rooflight is built into the extension roof on an upstand and gives light from above, so the middle of the room becomes the brightest part. Approved Document L (Wales) describes a rooflight as a glazed unit set out of plane with the roof surface on a kerb or upstand, and it gives 2.2 W/m²K as the figure a new or replacement rooflight in an existing home should meet.
The measure is taken over the unit's full surface, which can exceed the opening cut in the roof, and a kerb that arrives with the rooflight as a single assembly is counted in the same limit.
Fixed or opening is the next decision. A fixed pane is simplest. An opening rooflight lets heat and cooking smells leave through the top of the room, and an electric one can be worked from the wall beside the worktop. The fixed or opening page compares them.
Once the sun has gone, the pane turns black and holds a copy of the room. That is a feature of any glass above a lit space, and a neat plasterboard lining makes it look intentional, while a rough one shows every shadow. The depth of the lining is therefore settled with the opening, well before plastering.
Flat rooflight, rear kitchen
- Sits on
- An upstand above the flat roof
- Warmth
- A rooflight should meet 2.2 W/m²K
- Kerb supplied with the unit
- Counted in the 2.2 limit
- Open or fixed
- Chosen with the room's air in mind
Asked about Blackwood
Does the survey cover Blackwood, or Coed Duon?
Yes, whichever name you use. Heading north-west from Newport, Blackwood is 18.3 road miles on, and the survey costs nothing. The quote form takes an address and a room, and a WhatsApp message to 07880 284133 does the same.
Who decides planning for a house in Blackwood?
Caerphilly County Borough Council. What a rooflight needs depends on the house, and the Wales section of the planning guide covers it.
My bathroom window has trickle vents. Do they go when it is replaced?
They should not. Approved Document F (Wales) asks for replacement vents at least as large as the old ones, which the occupant can adjust or which act on their own.
Which is better for a hall, a sun tunnel or a roof window?
A sun tunnel suits a small, windowless space with a clear loft route. It brings daylight only, so a bedroom or a study usually gets more from a roof window. Our pages on sun tunnels and roof windows go through both.
Is a rear extension rooflight covered by Building Regulations?
Fitting a rooflight where there was none will generally need approval, since the opening usually calls for changes to the roof structure. Where the work is notifiable, we handle the notification through local authority building control or a registered building control approver.
What if the house in Blackwood is listed?
Work that would affect a listed building's character as a building of special architectural or historic interest needs listed building consent. You apply for it through Caerphilly County Borough Council, and it is needed for work inside as well as outside. Even a small job can need it, so ask before the order goes in.
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10-year workmanship guarantee.
Building Control notification handled where notifiable.