Loft extension planning advice

[Pdp16]

Morning all

Wondering if I can draw on the collective wisdom of this forum to ask for some advice.

I’ve submitted planning permission for a rear extension and a loft conversion/extension to a semi detached house I have purchased. My understanding was that planning permission was required because the house had already been extended by the previous owners - single storey rear extension and a first floor side extension over the garage.

My original planning application (pictures attached) for the roof included a full width rear dormer across the back (7.08m wide) and a hip to gable extension. Other dormers on the same road that have gone through under permitted development on similar semi detached properties have been around 6m wide. The dimensions of the loft alteration came in under 50m3 but I thought it would be best to include it as part of the planning rather than seek a lawful development certificate. But having read on here maybe that wouldn’t have been allowed anyway because of the loft and side extension joining?

The planning officer responded the other day to say the following:

The principle issue pertains to the scale of the proposed rear dormer. The dormer proposed subsumes the resultant rear roof slope and fails to appear as a subordinate addition to the host roof slope.

Whilst there are some examples of dormers in the locality these are not of comparable scale and in any event each site is assessed on its own merits.

I am offering one opportunity to address this concern by inviting revised plans amending the width of the dormer. Preferably it should also be reduced in height but if this is not possible then an even more meaningful reduction in width should be made. I cannot give exact figures however I would suggest the reduction in width needs to be at least 3m.

I’ve asked the architect to revise the plans(attached) but it seems that the the resulting dormer is now significantly smaller and not adding as much space as I would have liked.

The question I have ultimately is what are people’s thoughts on this new design and is it realistically the best I can achieve in the circumstances?

Thanks in advance

 

[freddiemercurystwin]

Can you post the plans - ground & first floors from before any extensions were added, as they are now and the new proposed plans?

 

[Pdp16]

Unfortunately the original plans aren’t available on the councils website from when the first extension was done in 1995. But I’ve attached the current and proposed extension ground and first floor plans. I’ve highlighted the areas in yellow that were extended from the original house, hope that helps.

 

[stevie888]

In general planners don't like loft conversions.

As soon as you put one on a planning permission drawing they can refuse it even if it is PD. I have had a planner tell me this directly and then refuse the application when my client said chuck it in as is.

Way round it is to do a planning for the extension if you can't work it as an LRE. The thinking now is to look at the proposed addition and lump it in with any existing additions that it abuts and assess the combined structure against the cited criteria.

Then do a stand alone LDC for the loft, or just do it if you're brave enough: you don't actually have to get permission for PD though I always advocate doing so,

 

[Pdp16]

Thanks for your help.

Sorry this is all a bit new to me. What does LRE stand for?

The architect is suggesting as some of the permitted development rights would have been taken up by the side extension to proceed with the planning application with a reduced dormer and hip to gable in line with the planning officers suggested reduction.

And then later on the provision it is accepted revise the design and reapply for either planning or a lawful development certificate once we have more time to calculate it.

Does that sound achievable?

Thanks

 

[stevie888]

LRE is large rear extension the process whereby rear extensions under an LDC previously limted to 3 or 4m can go to 6 or 8 (with the consent of the neighbours).

Your architect is partly right for the` wrong reason in mentioning the existing extension. It used to be the case that PD involved the total volume but this was changed many years ago to the independant assessment of each element against the appropriate criteria, What they do do however is look at all the additions lumped together so in effect on the ground floor you have an L shaped addition so it is a side extension and cannot exceed 50% of the original width under PD rules which it does already. So the rear is definitely a Planning Permission job.

For the loft you can add 50cum to the ORIGINAL (or pre 1946) roof so you need to establish that which is easy enough as you just look around at matching properties that are unmolested. Worst case you had a hip and that has moved over: this would have added max volume.

There are several tricks to get the dormer volume down to match what volume is available but my gut feeling is to forget the hip to gable and maximise volime in the dormer,

 

[^woody^]

Are you sure the dormer can't be built under PD?

 

[Pdp16]

Looking at the adjoining neighbours house (which hasn’t been extended) to do it under permitted development it looks like the original roof width is just under 5m. And the max height I could get away with from my understanding would be 2.35m (ridge height). Based on the original plans, a depth of 4.32m would give a volume of 25m3

I’ve decided to keep the planning application with the hip to gable at 14.04m3 and a reduced dormer size (4.47m length, 3.68m depth, 2.02m height) at 16.61m3 giving a total volume of 30.65m3. This gives me the option of a better layout if approved.

Is there any other way of increasing the dormer volume if going down the PD route?

Thanks

 

[wessex101]

The planning officer responded the other day to say the following:

The principle issue pertains to the scale of the proposed rear dormer. The dormer proposed subsumes the resultant rear roof slope and fails to appear as a subordinate addition to the host roof slope.

I do not think the Planning Officer is saying that you cannot have a rear dormer, just that it needs to be a bit smaller. I would take the available size under permitted development as a starting point and see how much you can increase the dimensions before it appears too bulky. Chances are you could get something somewhere between permitted development and the original design.
I would keep the hip to gable and have a rear dormer central to rear elevation slightly larger than the smaller amended design. It has worked for me on numerous planning applications.

 

[stevie888]

Once you have a target maximum volume for the dormer you look at the 3 dimensions you can vary and play arouind to get the optimum layout.

Going for least height you can get away with is the most effective. Cold decks overall are thinner than warm and my favourite dodge is to take my roof joist suitably sized and cut middle to outside edge to 1:60 and turn the offcut over to provide the fall on the other bit. More work than just plopping a firring piece on top but gains another inch or so. It does however need to be considered in conjunction with insulation requirements as it can be that you need as much extra depth in the insulaltion so you need a designer who knows his stuff and is diligent enough to look for thebest solution rather than the first one that works. Another option is to use the shallowest floor joists you can get away with even if it uses more timber.

Back to post 5: the idea of having thinking time and then submitting a new application after you vhave approval doesn't impress. You're paying the guy to know what he's doing. The good news is that they have not refused the application but given you the option to amend. This amended version will count as your application and if that is refused then you get a second go at no cost apart from another 8 week wait. So go big as you can reduce again second time around.

Your architect shouldn't really be charging you extra as he is the expert. (I never do but if the client wants something that I don't think will work then my fee is set accordingly)