Small Extension estimate - roof type

g0009348

Hello,
could somebody please help me with an estimate for a small extension to square off between the end of the current kitchen and dinning room.  Estimate would be a 4 x 3 m. The current kitchen has an apex roof running front to back.  Would it look strange to extend but with a flat roof to save costs?
 


Thanks for your thoughts

tacpot12

I don't think it will look strange, unless the neighbours have also had extensions and have pitched roofs. 
Personally I would never install a flat roof by choice. In my experience, they don't save money as they need leak and cause damage, and need to be replaced more often than tiles/slates.

g0009348

Apologies I did mean a slopping tiled roof, just not the apex which is above the kitchen at the moment

FreeBear

If the existing roof slopes away from the house, then extend it over the new extension. It will cost a little more initially, but you will save in the long run by not having to repair/recover a flat roof. Might even save a few quid on insurance.

A sloping roof also gives you the option to install Velux windows without having to compromise the roof covering.

Jeepers_Creepers

Nothing wrong with a 'flat' (ie, gentle anti-pooling slope) roof. If it's GRP'd, it should last decades. Also easy to add sky lanterns and stuff.

Rough ballpark figure for your extension, ready to move in to? £30-40k? (should include nice bifolds, a sky lantern, flooring.)

Where are you?

DevilDamo

So the current Kitchen has a gable roof and you are still wanting to retain some type of pitched roof once you’ve extended? If so, you could probably still have a gable roof but at a shallower angle due to the increased width and relative to the size/positions of the first floor rear windows. If that doesn’t work, you may be able to accommodate a lean-to roof providing you achieve a minimum roof angle of 15 degrees. This roof would be better to come below the first floor window cills or you could cut out around the windows. Failing that, you could have a dummy pitched roof, which is mainly flat but has sloping elements on the perimeter walls to achieve that pitched roof look. Or you go for a flat roof of which you’re not restricted by the size of the extension along with first floor windows. You can put rooflights into any roof.

Just a side note, your extension will require Planning, so assuming you’ll have an architect/designer on board to take you through that and the Building Regulation processes?

g0009348

To try make it easier to explain, the rear currently looks like this.

I'd like to extend bring the patio doors up level with the kitchen, making open plan inside. Would the extension be made more difficult by the type of roof put on the kitchen and blending it into what I guess would be a sloping roof out from under the bedroom windown with a skylight.

DevilDamo

It may be tight to get under the first floor Bedroom window. Unless you’d consider raising the Bedroom cill to match the Bathroom, may give you enough room? Or as mentioned before, re-pitch a new gable roof from new side to existing side wall. If you go for a re-pitched gable roof, you may have to bring in the new side wall in order to accommodate the soffit and gutter. If you do manage to get a lean-to roof to work (which is what you’re talking about), then the overhang on that new side wall will not be as much. Obviously take into account your new foundations, etc...

g0009348

Thanks, maybe a flat roof maybe the best option then, assuming any other type of roof work would considerably add to the potential cost.  

DevilDamo

Flat roofs are generally cheaper than pitched (lean-to or gable) roofs. Costs could start increasing depending on the size and position of rooflights or lanterns. If you’d like the large and vaulted feel, a gable roof would be your best option. If you don’t mind having a flat ceiling at the same level as existing, then go got a flat roof. A flat roof does also mean your new side wall can go a little closer to the boundary with your neighbour as there’s less of any overhang.

Bear in mind something I mentioned earlier that you’ll need Planning. As a result of that, the neighbour will be notified. Planning will also review and asses the potential loss of outlook or daylight to the neighbours’ habitable room(s).