Adding a dormer to an existing loft conversion

(26 Posts)
Pickpick101 Thu 25-Jun-20 09:16:23

I'm looking to add a dormer to the existing loft we have now. I'm not sure what it would cost , anyone done a similar job ? I'm thinking about 10k . I'm not sure how realistic this is.

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Loofah01 Thu 25-Jun-20 09:46:32

No idea but you might need planning for it, and depending on distance between houses and where it points you might not be allowed it at all. Worth checking!
Best to get 3 quotes for your area tbh as the prices will vary a lot.

thinkingcapon Thu 25-Jun-20 09:47:40

Is it literally just putting one dormer window into a current room?

Pickpick101 Thu 25-Jun-20 09:56:45

Alot of the neighbours have done the same so I don't think planning will be a problem.

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Pickpick101 Thu 25-Jun-20 09:57:59


Basically yes , no electrics or plumbing needed. Looking at something around 5m across.

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thinkingcapon Thu 25-Jun-20 11:49:18

I'd hope it would be well under £10k then?!

Pickpick101 Thu 25-Jun-20 12:02:10

Okay that's sounds not too bad. It's across 2 rooms but still be 5m across.

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thinkingcapon Thu 25-Jun-20 13:48:54

So two dormers in two separate rooms?

Pickpick101 Thu 25-Jun-20 14:12:46

One dormer across 2 rooms . They are both bedrooms next to each other.

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Staringouttosea Sun 28-Jun-20 20:01:52

I had a dormer extended (doubled in size) and repairs to the roof which were able to be done without scaffolding-that alone would have added 1.5k to the cost. It cost just under 8k. I'm in the South West.

Pickpick101 Mon 29-Jun-20 07:37:06

Thanks for that , handy to see what others pay for something like this.

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FuglyHouse Mon 29-Jun-20 16:23:07

Staringouttosea, could I ask you about your dormer extension please? We're hoping to do the same. Did you need planning permission? And how long did it take?

TaleOfTheContinents Mon 29-Jun-20 18:10:01

I was thinking of asking this very question! We're buying a house that has a dormer to the back and a velux to the front. I'd love to change the velux to a dormer to get extra head height so I'll be following this thread with interest.

Yellowbutterfly1 Mon 29-Jun-20 20:00:42

If changing it means your neighbours lose all privacy then keep the velux.
I’ve seen this happen to a friend and, they would have lost all privacy so the council said the format had to have non opening opaque glass.

think it’s best to have good neighbourly relations.

Yellowbutterfly1 Mon 29-Jun-20 20:01:19

Sorry, meant to say the dormar windows had to be non opening and be opaque glass.

Staringouttosea Mon 29-Jun-20 20:13:25


Staringouttosea, could I ask you about your dormer extension please? We're hoping to do the same. Did you need planning permission? And how long did it take?

No planning required-sorry can't remember why not. Altogether with the repairs it took about 4 weeks but the builder wasn't exactly great at time keeping!

FuglyHouse Tue 30-Jun-20 16:12:24

@Staringouttosea thank you. That doesn't sound too awful (apart from builder timekeeping, and I think that's not unusual!)

katrin174 Tue 24-Nov-20 20:36:53

Did you get your conversion in the end OP? We are thinking of doing the same. How much did it cost you if you had it done?

Pickpick101 Tue 24-Nov-20 21:55:50

No didn't get it done , it's a maybe but covid has pushed it back .

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SecretOfChange Tue 24-Nov-20 22:04:12

I've been quoted 19k for a front dormer and never investigated further. My issues were with money (obvs), time needed, and headache (planning permission etc). You need planning permission for dormers on the front, but not on the back.

katrin174 Tue 24-Nov-20 23:21:08

Oh that's interesting thank you for that input. Wow 19k was that to add it to a pre existing loft conversion? Seems like a lot.

TwoLeftSocksWithHoles Wed 25-Nov-20 07:28:52

5 meters?
That could mean removing 12 or more of the rafters (depending on the spacing) and the roof would need a lot of strengthening after this to maintain its integrity. I think this is where quite a bit of your cost will go - and you'll really never see it!

Mish88 Thu 01-Apr-21 13:43:45

Interested to know if this came to fruition, regarding having a dormer addition to an already renovated loft! I'm interested in a property and have this exact thought in my mind, thinking on how we could improve it! Would be great to here how this worked out!

Midlifelady Fri 02-Apr-21 02:07:23

I want to do this too, add dormer to back about 4.5m across. It will have either one double doors on to juliet or doors and window. I'm thinking about £15k, as not only the structural work but will need to recarpeted etc inside, though scaffolding is mega so that could easily add a grand or more.
It is pd I believe, but there's building regs. Party wall agreement? All adds to it.

MrsJamin Fri 02-Apr-21 07:17:59

We looked into this, adding a dormer and en suite to a loft extension done in the 90s, the loft companies we talked to were rather scathing of the original loft job and said they had to redo the whole thing, costing £30k or so. We thought it wasn't worth the investment so we actually moved in the end!

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