40 sqm extension

ruskin

Hello,
I'm involved in a project where we are seeking to constuct an extension to a house without planning (i.e. exempt, less that 40 sq.m etc). The exisiting house already has a crappy small boiler house extension onto the back, but we are intending to demolish this. The proposed new extension (which in part would occupy the area previously occupied by the boilerhouse) comes to 55 sq.m. Since the new extension 'overlaps' the existing boilerhouse area and the real amount of 'new' extending in terms of total floor area is 40 sq.m, would this be exempt? (i.e. if you are demolishing an existing extension and building a new extension that 'envelopes' the existing extension area, how do you assess your 40 sq.m exempt area)

Officer Giggles

ruskin wrote: »

Hello,
I'm involved in a project where we are seeking to constuct an extension to a house without planning (i.e. exempt, less that 40 sq.m etc). The exisiting house already has a crappy small boiler house extension onto the back, but we are intending to demolish this. The proposed new extension (which in part would occupy the area previously occupied by the boilerhouse) comes to 55 sq.m. Since the new extension 'overlaps' the existing boilerhouse area and the real amount of 'new' extending in terms of total floor area is 40 sq.m, would this be exempt? (i.e. if you are demolishing an existing extension and building a new extension that 'envelopes' the existing extension area, how do you assess your 40 sq.m exempt area)

As far as I know it's the total extension cannot be more than 40m2 onto the original house, you don't get credit for knocking and rebuilding, you are looking to build a 55m2 extension onto the original house so you will need planning

BryanF

• not exempted development

• new building control regs apply

ruskin

Thanks for the clarification. We will have to modify our sizings to be well under the 40 sq. m so. Our friend bought the neighboring house and wishes to extend to the back of his house too in a similar way- he suggested that our separate exempt extensions share a party wall- makes sense in my opinion, the project could all be done at once, and since we are both entitled to our 40 sqm exempt it shouldnt matter that both extensions share a party wall and flat roof.

4Sticks

ruskin wrote: »

it shouldnt matter that both extensions share a party wall and flat roof.

Except it will matter if you build a route for fire to transfer over. Do not omit an architect or architectural technician from this project just because the less than 40m2 rule of law does not force you to include one.

sydthebeat

As far as im aware the boiler house would be included as habitable area therefore even if it exists pre63 you can't exclude it for the extension floor area.