Building above a front porchway

[SilverShadow]

Hey guys - move this to this forum, as my question seems trickier than i first realised 🤔

 

I'm just here to gather a few thoughts and opinions from anyone with some prior knowledge in these kinda things.....

 

We're looking to purchase a house, and with a front porch extension (which is approx 5m2 and had PP granted). The house itself is a 1960's detached 2 story building, with 'pyramid' shaped pitched roof, set back 8m from front boundary, with 2 story houses either side and ample space between each property

 

A few basics:

• Existing porch is 2 x 2.5m (looks to have been built in last 20 years)
• Porch has a concrete floor from what i can see
• Porch materials are brick, with sloping tiled roof
• Porch exterior is mostly glass (door and 4 x windows), with brick corners (1ft by 1ft) and a brick wall over 0.5m high for walls under windows

 

Due to the house layout, we were wondering if it'd be feasible for us to build a 2nd 2 x 2.5m floor above the porch (in the same style of brick/roof, etc)? We realise front elevation changes need planning permission, so any thoughts from you guys as to advice is most welcome

 

My 1st mistake: assuming build above a porch to same height/style as rest of the house would be relatively straightforward PP, if it has been granted in the past & no change to footprint 🙃

 

Huge thanks for your time

Shadow

[FuerteStu]

To me this seems like a lot of work for very little gain. 

 

More than likely you will have to dig up the original footings for the porch and put better ones in, you'll need to spend a significant amount on planning and building control, demolition and redecorating for a relatively small amount of floorspace.. For the cost and effort you could gain a single story extension at the rear which would be five times bigger. 

[Conor]

+1

 

No way this will be cost effective. You'll likely have to demolish the porch as it would not have been built to the right spec. 

[SilverShadow]

Thanks Stu & Conor 👍

 

A little more context might help explain my thought process....

 

• The existing porch had concrete foundations >1m deep, so we'd assumed good enough to build on
• Our biggest desire: to make the upstairs room a little larger (ground floor generally ok)
• So we thought rather than pay for 2 floor extension to just build above the existing porch
• Seller (worked in the building trade) mentioned about a huge 'u shaped' concrete piece of the structure, to hold it rigid with the house (if that makes any sense)

 

 

For the record, it's quite probable we'd do a rear extension. But wondered whether the porch would be an option (if cheaper than 2 floor extension and wasn't going to be a total nightmare for PP, etc)

 

Sounds like the small front extension is a no-goer

Edited April 29 by SilverShadow

[Mr Punter]

Unless you are doing this for aesthetic reasons as part of a facade remodel you are wasting your money.  You can do a 2 storey rear extension without full PP.

[FuerteStu]

16 minutes ago, SilverShadow said:

 👍

 

• The existing porch had concrete foundations >1m deep, so we'd assumed good enough to build 

It doesn't matter about the size and the make up of the foundations. They were designed to take a small load (shallow wall and windows). 

 

It's unlikely they will be tied into the original foundations, which building control will insist upon checking all round. 

 

If your digging to expose them, may as well put new ones in. 

[SilverShadow]

thanks guys - plenty for us to consider

[SilverShadow]

Sorry guys, thought of 1 last thing to ask, please.....

 

On the property (towards the back of the rear garden), there is a standalone breezeblock workshop, about 10 meters from the house (afaik, it passes all building regs as regards size/height/proximity to boundary, but that is a separate matter). About 6m long x 3m wide x 2m high

 

If we decide to build an extension at the side or rear of the property, then does this outhouse floorspace limit the size of floorspace we can extend without planning permission? I seem to recall something about permitted floor area, and wasn't sure if this outhouse counted towards this in any way.....

 

 

Many thanks again for all your sound advice

Mark

Edited April 29 by SilverShadow

[kandgmitchell]

To use Class A.1 Permitted Development to extend your property, one of the constraints is that the total area of buildings within the curtilage excluding the original house should not exceed 50% of the ground within that curtilage excluding the original house. So it's plot minus original house = X, you can then have up 1/2X to use for buildings (obviously subject to other constraints depending on size, height etc etc). So the workshop uses 18m2 up and the porch another 5m2 leaving you (1/2X - 23m2)m2

[SilverShadow]

Many thanks for that. Wow, this is a whole new area to understand!

 

From what I can tell: detached outhouse + porch extension is circa 50% of the house floor plan (curtilage). There is an adjoining 7m× 3m garage to the house, built at the same time. 

 

From what I gather garages do not class as part of the floorplan curtilage allowance, so we couldn't assume another 10.5m2 from that

 

I guess future extensions would still be possible, but would need full PP. Not unless we reduced the size of the outhouse, or demolished completely 

 

 

 

Sounds like our conveyancer will know the score 

Edited May 1 by SilverShadow

[kandgmitchell]

No, curtilage is the area of the land the house stands on (there can be subtle interpretations of that for farm houses etc) and runs with it that forms the "planning unit".

[SilverShadow]

Got it! Thanks buddy 😁

 

So allowable extension = (land plot size - house footprint) / 2

 

Presumably that's single story, & anything exceeding it or double story would go thru PP

[SilverShadow]

Ps, does the adjoining brick garage count in house footprint calcs?

[kandgmitchell]

If it was part of the original house footprint.

 

However, before you rush off and build there are other more significant restrictions on what constitutes permitted development - heights, depths and positions relative to the dwelling. The footprint one is probably the least restrictive as few owners build quite that much. Single storey extensions are not all PD.

 

So, you need to look at https://assets.publishing.service.gov.uk/media/5d77afc8e5274a27cdb2c9e9/190910_Tech_Guide_for_publishing.pdf  that gives more detailed guidance.

[SilverShadow]

brilliant stuff - very grateful for all the advice 😁

 

Certainly won't be rushing into doing much - we'll be skint for a while after buying the property! 😂

 

However, this sort of advice is still amazing to have. Even at this early stage, so we can appreciate what factors might affects us if we go ahead later down the line

 

Many thanks