A steel town built in waves
Corby's houses arrived in bursts. Stewarts & Lloyds, the Glasgow tube makers, set up their steel plant here in 1932 and built about 2,200 houses through the 1930s for the workers who came south, many of them from Glasgow. Bessemer Grove was the first road finished. In April 1950 Corby became a New Town, and the Development Corporation carried on building until it was wound up in 1980.
The town is growing again. Priors Hall Park is planned for more than 5,100 homes, Weldon Park for 1,000, and West Corby has outline permission for up to 4,500 off the Uppingham Road. Each wave left a different roof. Older houses usually have rafters cut on site, the newest have factory trusses. Both convert, but trusses need more steel.
The Lloyds estate and its hipped semis
Between 1934 and 1939 the steel company laid out the Lloyds estate on both sides of Rockingham Road, a garden suburb running from Rowlett Road down to Occupation Road. It has been a conservation area since 1981. The council's appraisal sorts the houses into types: pairs of semis under hipped roofs, U-shaped groups of four, blocks of three with a gable in the middle, and some storey-and-a-half semis that already have paired dormers breaking the eaves.
For a loft, the conservation area changes the rules. North Northamptonshire Council lists roof enlargements such as dormers among the works that need planning permission inside one. A hipped semi on Studfall Avenue can't simply go hip to gable the way a similar house outside the boundary might. Squaring off half of a matched hipped pair is exactly what the appraisal was written to watch. Rooflights on the back slope are the easier sell.
Which conversion suits which Corby house
How each type fits the town's houses, with a full guide for each.
Hip to gable. The obvious move on a hipped semi, because the sloping end of the roof is where the lost headroom is. Outside the Lloyds boundary it often comes under permitted development. Inside it, plan on an application and a careful design.
Read our full guide: Hip-to-Gable Loft Conversions: What It Involves and Which Houses It Suits →
Rear dormer. Sits on the back slope where the street can't see it, which suits the new town terraces and semis.
Rooflights only. The one most likely to get through in the Old Village, on the Lloyds estate or in Gretton and Rockingham. It only works if there's standing room under the ridge already, so measure before you get excited.
Extra bedroom. Turning a three-bed semi into a four-bed is the usual brief. Building control will check the fire doors, the protected route down the stairs and the linked smoke alarms before it signs anything off.
Home office. Since 2021 Corby has had two electric trains an hour to St Pancras, which makes a split week between London and home workable. A room at the top of the house keeps work away from the kitchen table.
Read our full guide: Loft Home-Office Conversion: What Works Well Up There and What to Specify →
En-suite. Decide where the soil pipe goes before anything else. The Lloyds appraisal names plastic bathroom pipes on front walls as harming the estate, so route it inside or keep it to the back.
L-shaped dormer. Needs a house with a two-storey back wing. Corby grew mostly after 1930, so it has far fewer of the Victorian terraces this type was made for.
Mansard. Rare here, and nearly always a planning application. On a listed cottage in one of the stone villages, forget it.
Planning. Outside the nine conservation areas, most rear dormers go ahead under permitted development. Newer estates can be the exception, where the original consent removed those rights. The planning conditions are on the council's register.
Cost. We don't print a Corby price. A 1930s hipped semi and a new trussed house at Priors Hall are different jobs, and a figure on a web page would only mislead you. Three site visits will.
Stone villages, and estates on old quarries
Before the steelworks Corby was a stone village, and the Old Village around High Street and Tunwell Lane still shows it. One listed house there carries a 1609 datestone under a thatched roof. Others nearby are coursed limestone under Collyweston slate, the local split stone roofing. Rockingham's cottages are local ironstone and limestone, and Weldon gave its name to a freestone used in college buildings at Oundle and Uppingham. A listed roof needs listed building consent too.
The newest houses sit on very different ground. The NHBC records that Priors Hall was quarried for ironstone from the 1950s to the 1980s, then backfilled, and that the backfill had to be re-engineered and loaded before raft foundations could go on it. If you live there, give your structural engineer the original foundation design. A loft adds weight, and they'll want to see what's carrying it.
Who handles the paperwork
Corby Borough Council went in 2021. Planning and building control now sit with North Northamptonshire Council, which runs a building control office for Corby and the villages around it, from Gretton and Rockingham to Little Stanion and Priors Hall. Planning applications for the whole area are on the council's online register. Search your street first. What the neighbours were allowed is the best guide to what you'll get.
When the job is finished you'll get a completion certificate. Keep it. Copies can be bought from the council later, but Corby records from before September 2025 aren't online and have to be requested by email.
Where these facts come from
- Conservation areas (North Northamptonshire Council)
- Lloyds Conservation Area Appraisal, March 2008
- Northamptonshire HER: Lloyds Estate, Corby
- Kingswood Article 4 direction (North Northamptonshire Council)
- Building control, Corby office (North Northamptonshire Council)
- Priors Hall and Weldon Park (North Northamptonshire Council)
- NHBC: Priors Hall Park case study
- Historic England listing, 1609 thatched house in Corby Old Village
- TCPA: Corby new town
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Questions people in Corby ask
I'm on the Lloyds estate. Can I still convert my loft?
Usually, yes, but expect to apply for planning permission for anything that changes the roof's shape. The estate has been a conservation area since 1981. A rear dormer or rooflights on the back slope stand a better chance than a hip to gable on a hipped pair.
Does the old quarry under Priors Hall Park matter for a loft?
It can. The estate was built on backfilled ironstone workings on engineered raft foundations. A loft puts extra load on the house, so the engineer doing your steel calculations should see the original foundation details.
Does the Kingswood Article 4 direction stop loft conversions?
No. It came into force on 24 April 2024 and removes only the right to turn a family house into a small house in multiple occupation without permission. Your householder rights for dormers and roof work aren't affected by it.
Corby Borough Council doesn't exist any more. Who signs off my loft?
North Northamptonshire Council, through its Corby building control office, unless your builder uses a private building control company. Either way you should end up with a completion certificate to keep with the deeds.