Green Building Forum - Best design for a dormer

Best design for a dormer

joe90 — Sun, 12 Jul 2015 10:32:58 +0100

Well we have had some bad news, our planning application has been refused because my design is to high, local planning policy requires a room in roof or dormers to restrict ridge height. Judging by next door I think I can get away with dormers and a dwarf wall of 1660mm. I think this is an exceptable compromise (watch this space!) .

I didn't want dormers (tho I think they are pretty and cottagy) because they are more difficult to insulate and make airtight, the last thing I want is chunky cheeks etc. Also I will have to use plastic insulates rather than natural to reduce insulation thicknesses.

So the question is, how best to build well insulated dormers.

Best design for a dormer

tony — Sun, 12 Jul 2015 16:54:15 +0100

See comments in the other place, best plan is to design them out.

Best design for a dormer

Chris P Bacon — Sun, 12 Jul 2015 18:01:52 +0100

I'd suggest this type of dormer which I used on my house. Gives you full head height and straightforward to insulate.

Best design for a dormer

djh — Mon, 13 Jul 2015 13:40:45 +0100

We went with a barrel-vaulted roof to keep the ridge height low enough whilst giving us a full upstairs without dormers. I expect dormers are cheaper though!

Best design for a dormer

fostertom — Mon, 13 Jul 2015 14:10:48 +0100

an02ew of this forum was builder. Velux on top of one, for that full fishbowl effect, solar (wet) panels on top of the other - invisible from ground (LIsted Building)

Best design for a dormer

fostertom — Mon, 13 Jul 2015 14:21:41 +0100

30o tiled pitch to top

Best design for a dormer

owlman — Mon, 13 Jul 2015 15:55:35 +0100

Posted By: tonySee comments in the other place, best plan is to design them out.

I tend to agree tony.
Joe, You could make one elevation in a single pitch right up to permitted height with rooflights if you wish. Then at the ridge drop a full length 3G "glazed wall" e.g. 1M down to another lower same or different pitch roof.

A bit like this.
http://www.bing.com/images/search?q=Slant+Roof+House+Design&view=detailv2&&&id=A22DC1306F91028F0741B1C84A8FF8B911F3080E&selectedIndex=64&ccid=nlOViZp7&simid=608002077937762724&thid=JN.tuoQX%2bprQPmGcwgTyWs8KQ&ajaxhist=0

Best design for a dormer

richardelliot — Mon, 13 Jul 2015 16:24:03 +0100

Could the house from this Grand Designs episode also be an option to keep the overall roof height down? I seem to remember it was built in an area of bungalows so they needed to do something interesting to get a two storey house past planning:

https://www.google.co.uk/search?q=grand+designs+wood+bridge&safe=active&rls=com.microsoft:en-gb:IE-Address&tbm=isch&tbo=u&source=univ&sa=X&ved=0CDYQsARqFQoTCK66vMq02MYCFUwWPgodiLwL0w&biw=1255&bih=814

Best design for a dormer

joe90 — Wed, 15 Jul 2015 16:30:41 +0100

Unfortunately swmbo and I want a "cottage" . We have been to the architects And they are submitting plans for skeilings and dormers ( looks pretty) as it will get us planning permission to get the garage workshop built and get the footings for the house in before the winter. I will then decide during the winter whether to challenge the council to get a design that gives us passive levels of insulation. I can't afford to not get on with the ground works.

Best design for a dormer

fostertom — Wed, 15 Jul 2015 17:07:44 +0100

owlman and richardelliot, actually both those designs lead to a higher topmost, than a simple ridge. owlman's one I do like but the Grand Designs one (which a client enthusiastically forwarded to me and keeps cropping up!) I think is quite perverse and v costly for what it gives. Despite that I really liked how the architect described his process with the clients.

Best design for a dormer

djh — Wed, 15 Jul 2015 17:22:33 +0100

How do you work that out for the Hoo House design, Tom? Clearly, extending the two halves of the roof until they meet in a ridge will result in a taller design, so I suppose you must be thinking of something else.

Best design for a dormer

fostertom — Wed, 15 Jul 2015 22:03:07 +0100

It only makes sense if you really want steeply sloping room walls rising from floor level, and a bit of level ceiling (quite lofty, as I remember). Then yes, do this. But if the intention was to minimise height, why extend the slopey walls up enormously? - actually just styling. If really wanting to minimise height then some kind of room-in-roof on vertical walls with lowish eave edge internally and a bit lofty at the ridge, would minimise heights.