Roofs you can see from the cathedral tower
Durham was built on a tight loop of the Wear, with steep banks on most sides and hills rising round it. The council describes the setting as an outer bowl. From the peninsula you look straight across at the roofs on the far slopes. That is why the planners care so much about what happens up there.
The World Heritage Site itself is small. It was inscribed in 1986 for the castle and cathedral, and a boundary change in 2008 added Palace Green and the old buildings round it. Hardly anyone lives inside it, and it has no buffer zone. What reaches ordinary houses is the Durham City Conservation Area. That was designated in 1968 around the peninsula and enlarged in 1980 to cover much of the city, including Crossgate, Elvet, Framwellgate and Gilesgate. It now holds more than 400 listed buildings.
If your house is in it, any dormer needs planning permission, on the back slope as much as the front. A hip to gable or a mansard does too. Rooflights on most houses can still go in without an application. The exception is the group of streets in the council's 2016 Article 4 direction, which brings rooflights and dormers under control. It names Hawthorn Terrace, Crossgate Peth, Albert Street, Lambton Street, Nevilledale Terrace, Claypath and Gilesgate. If you live there, read the direction and its map before ordering a single Velux.
Student lets and the extra bedroom
Durham's other planning story is student housing. A council report placed 766 of the county's 790 registered HMOs in the city and its inner suburbs. Since 17 September 2016 a defined area of the city has needed planning permission to turn a family house into a small HMO. Framwellgate Moor, Newton Hall and Pity Me followed in 2017, then Mount Oswald, Carrville and Belmont in 2022, and a direction covering the rest of the county took effect on 17 August 2026.
Policy 16 of the County Durham Plan sets the test. A new HMO is refused where more than 10% (but under 90%) of homes within 100 metres are already student-exempt from council tax. That threshold doesn't apply to extending an existing HMO, but the plan Inspector made sure that extensions adding bedspaces still face some of its tests. Then there's the national line. Three to six sharers is a small HMO. Go to seven and it becomes a large HMO, which needs its own planning permission whether or not the roof changes.
The council's appraisal work on the city singles out attic conversions for student lets that put dormers on terraces which never had them. Expect that to colour any decision on a Crossgate or Gilesgate street.
How the conversion types fit Durham houses
Old Durham is built of sandstone and brick under Welsh slate, with the odd clay pantile rear slope on the oldest Gilesgate houses. Here is how each type tends to work.
Rooflights. Often the first thing to try on a terrace inside the conservation area, because it leaves the roofline alone. Off the Article 4 streets, a few conservation-style rooflights sitting flush in the slate are usually fine without an application.
Rear dormer. Outside the conservation area a rear dormer normally goes ahead as permitted development. Check the council's boundary map first, because it reaches further than people expect. Inside it you need an application, and a dormer clad to match the slate and kept well below the ridge stands the best chance.
Hip to gable. Suits the detached houses and semis on Newton Hall, built mostly in the 1960s to 80s. Check the original estate consent for removed rights before you assume it's permitted.
Read our full guide: Hip-to-Gable Loft Conversions: What It Involves and Which Houses It Suits →
L-shaped dormer. Fits Victorian terraces with a back offshoot, such as the workers' grids in Framwellgate and behind Claypath. Most of those sit in the conservation area, so plan on a full application.
Extra bedroom. For your own family it's a normal householder job. For a let, count heads first. One more room can take a six-person house to seven, and seven sharers is a large HMO.
En-suite. Old stone terraces rarely have a soil stack where you want one. Fix the pipe route before the drawings.
Home office. A small study lit by rooflights on the back slope is the easiest version to get past the planners in the old city, and it keeps you clear of the term-time noise on a street of student lets.
Read our full guide: Loft Home-Office Conversion: What Works Well Up There and What to Specify →
Planning. Check three things in this order. Is the house in the conservation area? Is the street on the 2016 Article 4 map? Is it, or will it be, a shared let?
Mansard. Hard to justify on a street that can be seen from the peninsula, and most of the old city can. Take pre-application advice before paying an architect.
Cost. We don't print a Durham price. A Newton Hall semi and a listed Crossgate terrace are different jobs, and three site visits will tell you more than any average.
New estates and who signs the work off
Durham keeps growing. Sniperley Park, released from the Green Belt in the 2020 County Durham Plan, has a headline figure of 1,900 homes. New houses like those are usually built with trussed roofs, so converting one later means a steel frame and a bigger bill than on an older cut roof.
Durham County Council handles planning and runs its own building control team, at buildingcontrol@durham.gov.uk. Conservation questions go to design.conservation@durham.gov.uk. Search your street on the council's planning register to see what neighbours were allowed to build.
Where these facts come from
- Durham County Council: Durham City conservation area and Article 4
- Durham County Council: conservation areas
- Durham County Council: multiple occupancy homes (Article 4 directions)
- Durham County Council: building regulation approval
- Durham World Heritage Site: site boundaries
- UNESCO: community-led planning in Durham
- Durham County Council: selective licensing evidence report
- Place North East: Sniperley Park
How FirQuote works in Durham: We connect you with local specialists who visit your property before giving you a price. You get up to 3 written quotes — no call centres, no estimates from photos, no obligation to accept any quote.
Questions people in Durham ask
I own a terrace on Western Hill or in Crossgate and want to let it to students. Can I add a loft bedroom?
Possibly, but planning comes first. Most of those streets are in the conservation area, so a dormer needs permission. If the house isn't already a lawful HMO, the Article 4 direction means letting it to three or more sharers needs permission too, and Policy 16's 10% test will apply. Take more than six sharers and you need permission for a large HMO as well.
My house is near the cathedral. Am I in the World Heritage Site?
Almost certainly not. The site is the castle and cathedral with the buildings round Palace Green. You are far more likely to be in the city conservation area, which is where the rules on dormers come from.
Can I put rooflights in on Nevilledale Terrace or Hawthorn Terrace?
Not without asking. Both are named in the 2016 Article 4 direction, which brings rooflights under control. Ask the council's design and conservation team what it will accept.
I'm on Newton Hall. Does the HMO direction stop me converting my loft?
No. That direction is about letting a family house to sharers. A loft conversion for your own household follows the normal householder rules, so check only whether your house's original planning consent removed permitted development rights.