Single storey extension or conservatory

[ferdinand2000]

I need to decide between a single storey extension and a conservatory, and I'd welcome any comments.

It is a 2 bed old cottage which is rented out, which I plan to sell at some point in the future, but need to keep for some years.

In the long term (10 years) I will build a big (25-30 sqm x 2) two storey extension, because it is a small house on a large plot, and it would easily pay back double the cost on sale. That will cost £50k+ to do.

In the short term, I need a small extension or conservatory for the use of the the current long-term tenant to give a more useable kitchen - say 3x3m to 4x3m extra space. This would face South-West, but won't receive sun until the late afternoon, due to a large gable next door.

I'm torn between

1) a small conservatory - which would be professionally installed, to be removed or resited when I do the large extension.
2) a basic single storey extension designed to be demolished as and when I do the big one in the future.
3) a larger single storey extension which would be larger but turn eventually into the ground floor of the big one.

I don't want to get into £1-£2k for planning etc now, and permitted development allows me to go up to 4m back from the back wall, which is *just* enough (but would need excellent detailed layout design) for the floor area of a future two-storey extension. I will be fully complying with building regs etc, of course.

I'm estimating the conservatory as 4k->8k depending on how I do it, the small single storey extension as 8-12k, and the larger one as perhaps 15-20k to internal finishes before services and heating.

I'd value any comments on the pros and cons. Especially I'm not sure about the liveabilty of the conservatory route, though I'd expect cooling in winter to be a bigger problem than overheating in summer.

Thanks

Ferdinand

 

[freddiemercurystwin]

If you want to stay on the good side of Building Regs you need to retain an external door between the inside and the conservatory. making its use as an extension to the kitchen impracticable.

 

[IJWS15]

Your tennant won't be happy with a conservatory if they need to use it all year . .

Too hot in summer and too cold (even with heating which will cost a fortune) in winter.

Ours gets the sun in teh afternoon, and is not used in winter.

 

[RedHerring2]

I realise that you said that you didn't want to incurr planning costs now, but if you did start the planning/building consents now for the full extension, you could just start the ground floor part, and leave it like that until you're ready to continue.

With judicous choice and use, the roofing materials could be, by and large, re-used.

Once the build has started, the planning permission does not run out, so could be continued at some future date.
Also the Building regs would be at today's standards, not at some future point.

It would mean that you would not have a completion certificate for the ground floor until the rest was completed but I don't think that could prevent you from using it.

 

[ferdinand2000]

I realise that you said that you didn't want to incurr planning costs now, but if you did start the planning/building consents now for the full extension, you could just start the ground floor part, and leave it like that until you're ready to continue.

With judicous choice and use, the roofing materials could be, by and large, re-used.

Once the build has started, the planning permission does not run out, so could be continued at some future date.
Also the Building regs would be at today's standards, not at some future point.

It would mean that you would not have a completion certificate for the ground floor until the rest was completed but I don't think that could prevent you from using it.

That's an interesting idea, though as I read it councils kick up a fuss about completion certificates 10 years on, though they can't deny one in the end.

What happens to building regs approval on the bottom half of a 2 storey extension in use before the second storey is built? Perhaps it would be one to have an informal conversation about with Building Control - after obtaining the planning.

I like the sound of freezing the building regs.

One of the other interesting issues is that the property is *tiny*. 2 bed detached house in under 650 sqft, and the gutter height is perhaps 15ft, so the full thing does need careful design to make it fit visually- perhaps along the lines of a wide valley for visual separation/maintenance access and a separate 2-sided pitched roof on the big extension.

F

 

[RedHerring2]

I can't answer the latter part of your response and I doubt anyone else could on here without far more detail. One for your architect, perhaps.

On the PP/BCO query, my own PP/BR approval was about 4 years ago. I explained to the BCO on the first visit that I would be doing it in phases, first the garage, then the extension, then the conservatory. He not only accepted but agreed it was a logical process.

I may finish this winter, it may be next winter. At the end of each winter, on the last visit by BCO, I explain that I'm taking the summer off and will continue at the onset of winter and he's fine with that.

As far as 'freezing' regs are concerned , that's not quite how it happens 'cos a stage is approved as it is reached, e.g. the dpm/insulation is approved, noted, and you move on to the next stage, e.g. laying the floor slab.

The whole application is approved on the submitted details before you start. (Unless you submit a Building Notice.) I don't think that BCOs can then withdraw their approval of those details part way through the construction, even if there are changes to the requirements.

The BCO makes visits on your invitation for each stage, They don't, in my limited experience, make uninvited visits, althought they may have the power to do so, and may even do so on large commercial jobs or illegal jobs. But on a domestic job I would have thought it is unlikely unless they suspect something sinister is happening.

There was a recent thread, can't remember where, that suggested that some were still going after seven years, and still not completed.

So I would have thought that a little converstaion with your BCO will secure some understanding.

I don't know if BCO are more amenable to pre-application discussions than planning officers. Perhaps others might know.

 

[ferdinand2000]

Thanks.

I'm trying a thought experiment as to what happens at the BC office when I build stage 1 (1 storey), put a temporary but very insulating and reasonable looking roof on it that isn't strictly in the design, fit out the inside with heating and wiring, get the electrics certified, create the entrance into the rest of the house, let the T start using it, and they hear nothing for the next 7-8 years .

I think the official position might be to say "2 separate projects, 2 sets of permissions" (and 2 sets of fees).

Definitely one for conversation with the architect !

Ferdinand

 

[freddiemercurystwin]

A project built today under a full plans application that is approved can be commenced now and finished in twenty years time or so under the regs for which it was approved (at least until they change this rule).

 

[RedHerring2]

So, in your thought experiment, the BCO has inspected the drains and is invited to inspect the floor insulation/slab/dpm/dpc.
The next inspection would be the roof carcass, I think.
The electrics would be covered by the sparky, who is directly employed by you or your builder and should cooperate in your thought experiment.

The BCO might want to see the internal drains at some point, but just as likely won't.

So, in your thought experiment, there may be quite a few years between the floor insulation/slab/dpm/dpc inspection and you inviting him back to inspect the roof carcass.